# Time for a new Horizontal Hit and Miss engine



## Brian Rupnow (Oct 6, 2022)

I'm a bit bored today. Not a lot, but winter's coming. I've played with my v-twin engine until I've reached a point where it will run like crazy at mid range speeds, but doesn't respond well to slowing down, not for that matter to speeding up. I think I am going to put it away for a while, and come back to it later. I have enough stock "in house" to build a pair of 4 1/2" flywheels. I would like to run a 1" bore, not because it would have more power, but because at 1" bore I can use a 3/8" thread sparkplug which I can purchase from a local automotive store. If I use a 3/4" bore, then I can only fit in a 1/4" sparkplug. I have my own complete set of 24 DP gear cutters, and may opt to use a 25 tooth and a 50 tooth set of timing gears. Probably go for a 1 1/4" stroke, maybe 1 3/8". I would build my own mixer (carburetor). Air cooled is the easiest route for me to go, but I would design it to also use a water jacket, because since I sell these drawings I am sure people would like to have a choice. I don't think I would put a fan on this one, because if the hit and miss cycles are working properly, the engine will pump enough air through during the miss cycles that it will run pretty cool anyways. Brass, in any size, has become so terribly expensive that other than some trim pieces the engine would primarily be made from steel and aluminum. Cast iron cylinder sleeve and cast iron piston. Paint is still cheap as dirt, and if done properly can really give some eye appeal to an engine. I won't be cutting metal for a while yet, but I get excited thinking about the design stage.


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## Brian Rupnow (Oct 7, 2022)

After having a good look at the cam gear mounted governor, I prefer the Breisch Olds style to the Chinese style of governor. The Breisch style has ample movement at 0.148" and looks simpler to me.


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## Brian Rupnow (Oct 7, 2022)

The cam gear will be a bit complex. It will have the mounting points for the governor pivot shaft, a section of hub, and a cam machined onto the face of the hub. With an oilite bushing pressed into the center, it can be supported on the side of the engine frame by a shoulder bolt. There will be no camshaft, as the intake valve will be atmospheric and not depend on a cam to open it.


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## Brian Rupnow (Oct 7, 2022)

By going through the past 13 years of models, I can find enough ready made models of parts to get a very good start on a new engine. The newest part on here is the governor lever and it's associated gear, and the crazy looking air cooled cylinder.


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## Ghosty (Oct 7, 2022)

Will be following along, again, Keep up the great work, love the problem solving.
Cheers
Andrew


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## Vietti (Oct 7, 2022)

How about a vertical?


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## Brian Rupnow (Oct 7, 2022)

Well, at the end of the day, I have everything except exhaust, carburetor, and the actual components that make it hit and miss. The exhaust and carb will be mainly copy and paste operations. Vietti--It's  horizontal mainly because I like the look of a horizontal more than a vertical. I've managed to kill a whole day here. Good wife is away to a funeral today and won't be home until later this evening. Time to go find a good book to read and grab some supper now.


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## Brian Rupnow (Oct 8, 2022)

Got a start on the hit and miss mechanism. Have to go and get some breakfast now and see what chores my wife has set up for me pre-thanksgiving.


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## Brian Rupnow (Oct 8, 2022)

So, that's enough playing for one day.


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## Brian Rupnow (Oct 9, 2022)

I had to do a bit of rearranging. I had the large cam gear above the centerline of the crankshaft so it would line up with the top valve on the cylinder head, which is the exhaust. I didn't like the look of it though, because too much gear was showing. Allright--I'll move the big gear to a point below the crankshaft, and line it up with the bottom intake valve---and then I'll be tricky and put the rocker arm and mounts on the cylinder head at an angle so that it will still operate the exhaust valve. That pretty well does it for the major design. A ton of bolt clearance holes and threaded holes to be added, but that is fairly simple stuff.  I haven't thought much about a gas tank location yet, but will probably do that next.


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## Brian Rupnow (Oct 9, 2022)

I've decided to make the 60 tooth gear and the cam as two separate pieces and then pin and solder them together. This is the absolute fastest way to make a cam. When there is no need to make a machined flank on the cam (because the cam follower is a bearing) I can rattle one of these off using first the lathe, then the rotary table on my milling machine in less than an hour.


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## packrat (Oct 10, 2022)

Just looked at my old Stover 1 1/2 HP engine, set up is like your drawing, but exhaust is on the side and of course has a magneto trip lever
and is water cooled...


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## Brian Rupnow (Oct 10, 2022)

After doing a lot of research, I have found a governor which gives a much stronger reaction and takes up no space on the outside of the engine frame, allowing the flywheels to set in closer to the center of the engine. This governor is very similar to a flyball governor and sets inside the engine frame and just clears the connecting rod.


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## Ghosty (Oct 10, 2022)

Brian,
Would there be enough clearance with the conrod, looks very close.
Cheers
Andrew


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## Brian Rupnow (Oct 10, 2022)

Ghosty--if I did my math right, there should be 0.100" clearance.---Brian


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## Brian Rupnow (Oct 11, 2022)

This morning, after searching around a great deal, I found the engine which uses this type of governor. It is a Hercules engine from the early 1900's. Attached is a rather crummy video of the engine, and you don't see the actual governor until very near the end of the video at 6:11.


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## Jasonb (Oct 11, 2022)

There are several that use similar, these from a Ruston Hornsby I started making one of these a few years ago but on the back burner at the moment. These like the one in your video link are geared from the larger cam gear so they run faster which should be easier to get working than scaling down a slower rotating one on a cam gear.


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## Brian Rupnow (Oct 11, 2022)

And just because I can---This is the Kerzel engine and my new engine together. Admittedly, the fact that my new engine is air cooled and the Kerzel is water cooled, makes quite a dramatic size difference in the cylinder diameters. Also, the Kerzel is 3/4" bore, while my new engine is 1" diameter bore. The Kerzel has 3 1/2" diameter flywheels, my new engine has 4 1/2" diameter flywheels.


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## stevehuckss396 (Oct 12, 2022)

Just can't sit still can you? LOL!


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## Brian Rupnow (Oct 12, 2022)

Steve--You're absolutely right. It drives me a bit crazy, and I've always been this way.---Brian


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## Brian Rupnow (Oct 12, 2022)

WOWZA!!! Ya never know your luck in the big city. I remembered having a 30 tooth gear in my shelf of "things recovered from old projects" and I did. But---amaze me--I had a 60 tooth gear in there that I had forgotten all about. Both gears will require a bit of creative hub rework, but not near as much work as setting up and cutting new gears.


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## GreenTwin (Oct 12, 2022)

Brian Rupnow said:


> Steve--You're absolutely right. It drives me a bit crazy, and I've always been this way.---Brian



Welcome to the club.

.


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## Richard Hed (Oct 12, 2022)

Me too--it's called ADHD--really.


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## mikehinz (Oct 13, 2022)

Brian Rupnow said:


> WOWZA!!! Ya never know your luck in the big city. I remembered having a 30 tooth gear in my shelf of "things recovered from old projects" and I did. But---amaze me--I had a 60 tooth gear in there that I had forgotten all about. Both gears will require a bit of creative hub rework, but not near as much work as setting up and cutting new gears.


Brian, I'm carefully watching this thread.  Will you offer plans for sale for this engine whenever appropriate?

Interesting design!  

Mike


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## Brian Rupnow (Oct 13, 2022)

Good News!!!--My gears (actually old gears with new hubs) mesh perfectly when set up on a couple of dummy shafts for tryout. Yes Mike, I will be offering plans for sale once the engine is finished and performing properly.---Brian


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## Sparky_SC (Oct 14, 2022)

Anxiously following this build !


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## Brian Rupnow (Oct 14, 2022)

These pictures aren't going to mean a lot, unless you are following my hit and miss engine thread. The pictures show two sides of the same thing. The aluminum plate is destined to become one of my engine sideplates. I have shown the governor, which does seem to work quite well, but I haven't done a dynamic test of it yet. There has been a major screw up with the people who I buy my bandsaw blades from. The new blade which was supposed to be here yesterday is still setting in Texas waiting to be shipped, so I'm kind of stuck with machining things that don't need to be bandsawed for now. I've had a chunk of 3 1/2" diameter aluminum about 3" long that has been acting as a door stop for the last year but is now destined to become my outer cylinder, so I'm not entirely stuck for something to do. The cylinder will have a cast iron inner sleeve.


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## Brian Rupnow (Oct 15, 2022)

Much of today was spent converting my aluminum door-stop into a cylinder. I haven't put the bore in yet, that will be for tomorrow. Some very butt-puckering machining here, as the cuts between the "fins" were 0.425" deep with a 3/32" cut-off tool. None of them cut absolutely clean--they all jammed up and stalled my lathe at least once for each cut. It's amazing how quickly you can back the tool up and hit the e-stop button all at the same time and not crap yourself while doing it. The bore will be 1 1/8" and will be sized for a shrink fit onto a cast iron inner sleeve.


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## Richard Hed (Oct 15, 2022)

Brian Rupnow said:


> Much of today was spent converting my aluminum door-stop into a cylinder. I haven't put the bore in yet, that will be for tomorrow. Some very butt-puckering machining here, as the cuts between the "fins" were 0.425" deep with a 3/32" cut-off tool. None of them cut absolutely clean--they all jammed up and stalled my lathe at least once for each cut. It's amazing how quickly you can back the tool up and hit the e-stop button all at the same time and not crap yourself while doing it. The bore will be 1 1/8" and will be sized for a shrink fit onto a cast iron inner sleeve.


I have thin 'piano wire' thick springs to make.  The slowest my lathe will turn is 70rpms.  It gives me the willies just thimking about not being able to turn off the machine if somehow my fingers should get caught, wrapped up in the wire somehow.


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## Charles Lamont (Oct 16, 2022)

Richard Hed said:


> I have thin 'piano wire' thick springs to make.  The slowest my lathe will turn is 70rpms.  It gives me the willies just thimking about not being able to turn off the machine if somehow my fingers should get caught, wrapped up in the wire somehow.


You could make a hand crank to fit in the back of the spindle. I find mine very useful. I use it when I want to tap a thread in the lathe, except for very small ones, and sometimes for single point thread cutting too. Myford even offers one as an accessory.


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## Richard Hed (Oct 16, 2022)

Charles Lamont said:


> You could make a hand crank to fit in the back of the spindle. I find mine very useful. I use it when I want to tap a thread in the lathe, except for very small ones, and sometimes for single point thread cutting too. Myford even offers one as an accessory.


I have a hand crank for my small lathe--never thot of that.  thanx


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## pileskis (Oct 16, 2022)

Brian Rupnow said:


> Much of today was spent converting my aluminum door-stop into a cylinder. I haven't put the bore in yet, that will be for tomorrow. Some very butt-puckering machining here, as the cuts between the "fins" were 0.425" deep with a 3/32" cut-off tool. None of them cut absolutely clean--they all jammed up and stalled my lathe at least once for each cut. It's amazing how quickly you can back the tool up and hit the e-stop button all at the same time and not crap yourself while doing it. The bore will be 1 1/8" and will be sized for a shrink fit onto a cast iron inner sleeve.


Did you use any lube??
Is the tool good an sharp?


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## Brian Rupnow (Oct 16, 2022)

Yes, tool was newly sharpened and lots of wd40 for lube.  My 3/32"cut of tool was only HSS. I have never plunge cut to this depth before. Most air cooled cylinders I have made were of cast iron, and the maximum plunge cut depth was 3/8". I found the aluminum to be much "grabbier" than cast iron. I do have a carbide cut off tool that would probably have worked better, but it is 0.125" wide, which wouldn't have looked right.


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## Brian Rupnow (Oct 16, 2022)

And, just like that, my doorstop has turned into a cylinder!! It looks HUGE. Those are the deepest cut fins I have ever made at 0.425" deep. There will be a cast iron liner fitted inside the aluminum cylinder.


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## Brian Rupnow (Oct 17, 2022)

Due to supply chain screw ups, I've been setting here figuring out what I could make without using my bandsaw.--Turns out that there is a lot of stuff!!---Handle for ignition advance, 2-valves,-2-valve cages,-2-valve spring retainers,-a piston,-2 outer flywheel rims (cut from a section of heavy wall pipe)-an exhaust stack, and a muffler. That should be enough stuff to last me until my saw blade gets here from Texas.


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## Brian Rupnow (Oct 17, 2022)

About 13 years ago, when I built the Kerzel, I made up a couple of oilers for the bearings. For one reason or another, one of them was never used so, I will add it to this engine for a cylinder oiler. This engine won't need oilers for the bearings--the bearings will be ball bearings with the seals removed to give maximum free spin.


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## Brian Rupnow (Oct 17, 2022)

Today I built an exhaust pipe and spark arrestor. Nothing real exotic here, but a few "scratch my head" set ups.  Good wife has had me running around town today doing banking chores.


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## Jasonb (Oct 18, 2022)

Is that thing going to allow the engine to breath enough?

I thought it looked a bit small on the general assembly but now I see those few tiny holes I can't help thinking it will restrict exhaust flow. All the pancack type mufflers I have made just have 3 or 4 small spacers between the two halves and the open area is at least as large as the pipes cross section if not more

Even the ID of the pipe looks a bit small now I can see you have a reduced dia for the thread what is the bore at the threaded end? The various 24mm bore engines that I make tend to have at least 6mm (1/4") clear


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## trlvn (Oct 18, 2022)

Brian Rupnow said:


> until my saw blade gets here from Texas.


There is still the option of R&D Bandsaws in Brampton:









						Home - R&D Bandsaws
					

Home - R&D Bandsaws | Bandsaw blades




					tufftooth.com
				




Brampton is about an hours drive, right?  You could be doing curb side pick-up tomorrow morning!  

Craig


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## Brian Rupnow (Oct 18, 2022)

The exhaust pipe has a 0.150" hole thru it. the small holes are 0.050" diameter. Cross section of a 0.150" hole is .0177 square inches. Cross section of a 0.050" hole is 0.0019 sq. inches times 16 holes =.031 sq. inches. Craig--My son used to work for Fastenal, and I can get my blades from them at cost price, which is a considerable savings to me.


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## Brian Rupnow (Oct 18, 2022)

I've worked for a couple of large companies that had casting foundries. The dies were made of h7 steel, and each die section had a thermocouple in it. These thermocouples were always covered in a copper based heat transfer paste before being fitted into the die sections, to ensure that they get a true temperature reading from the die section they were inserted into. I have never made a cast iron liner with an aluminum outer cover, but I'm wondering if I should use a similar heat transfer paste, and where I could get it in Canada..


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## Jasonb (Oct 18, 2022)

Kind of confirms what I thought the engine won't breath that well. From your hot rod days you would have ported and polished things to keep a smooth flow. Even more important on a hit & miss engine as it will suck and blow cooling air through the held open exhaust when the engine is missing.

Easiest fix would be to counter bore the head so you can put a fine 3/8 or 5/16 thread in and then you can run 1/4" bore tube and open up the muffler a lot more.

This is my midget, 7mm around the valves, 6mm passages in head and 6.5mm ID exhaust so that's 31mm2 area around the valve stem and only a slight drop to 28mm2 passages that's 0.044sq inch on a slightly smaller engine bore.




This is the similar 24mm bore Thompson which has fine M8 thread for the same size exhaust pipe as the midget


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## Brian Rupnow (Oct 18, 2022)

Yes Jason, you're right. I will see what I can do to open that exhaust passage.---Brian


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## Brian Rupnow (Oct 18, 2022)

Bad case of lazy-butt today, but some parts were made. Two push-rod guides and a handle for the adjustable ignition points bracket. I'm using up some of the material that I bought for $100 a few weeks ago. A ton of material, but just what material is "Best guess". Lots of mystery steel as well as brass, bronze, aluminum and copper.


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## Ghosty (Oct 18, 2022)

Brian,
You won't need heat transfer paste between the cylinder liner and cylinder outer, just a light press fit is all that is needed, The reason that it is used with the  thermocouple setup is to get accurate and consistent readings, I use a copper paste when fitting temp sensors on my aircraft engines for the same reason.
Cheers
Andrew


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## Brian Rupnow (Oct 18, 2022)

Thank you Andrew.


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## Nikhil Bhale (Oct 19, 2022)

Brian Rupnow said:


> I've worked for a couple of large companies that had casting foundries. The dies were made of h7 steel, and each die section had a thermocouple in it. These thermocouples were always covered in a copper based heat transfer paste before being fitted into the die sections, to ensure that they get a true temperature reading from the die section they were inserted into. I have never made a cast iron liner with an aluminum outer cover, but I'm wondering if I should use a similar heat transfer paste, and where I could get it in Canada..


How about the thermal paste used on CPU? 

regards
Nikhil


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## Brian Rupnow (Oct 19, 2022)

Yesterday evening I felt that I should do one more thing to round out the day, so I set up a piece of 4 1/2" o.d. heavy wall pipe in my lathe, turned the o.d. to 4.375", and then parted off two rings which will become flywheels. The walls on this pipe are .450" thick, so I made my cuts only 0.350" deep and will finish cutting them free from the pipe if my bandsaw blades ever get here. Nasty work indeed--lots of squealing, smoking (from the cutting oil) and lots of vibration.  Jason--I took your advice and opened all the passages in my cylinder heads and exhaust to have a minimum of 0.25"  (6.35mm).----Brian


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## Brian Rupnow (Oct 19, 2022)

Jason--I have opened up my intake and exhaust ports and the inside of the exhaust pipe to  1/4" (6.35mm). I have opened the twelve holes around the spark arrestor to 0.075" diameter . Not sure what carburetor I will use yet.---Brian


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## Jasonb (Oct 19, 2022)

That should do the trick

Don't go too big on the inlet as you want a reasonable velocity through the carb to get it sucking up the fuel and atomise it, 5mm or 3/16" would be about right for the tube you mount it to particularly with the Traxxas carb when you think how fast those engines rev compared to a slow hit and miss.


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## Brian Rupnow (Oct 19, 2022)

Jason--Just so I get this right--Are you telling me I should have a smaller throat size on the carburetor than the exhaust system? At this time, it is great to find out, as I can design the carburetor to whatever works best. I am thinking of using Malcolm Strides carburetor without a working throttle for this engine.---Brian


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## Charles Lamont (Oct 19, 2022)

That looks about right to me, but I would suggest a taper draught tube on the outlet side of the carb, back up to your 1/4" port diameter. As I understand it, that is, If anything, more beneficial than a taper or bell-mouth at the inlet. The outlet taper wants to be no more than about 10° included.


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## Brian Rupnow (Oct 19, 2022)

Okay Charles--I have reworked the carburetor body somewhat, to make it fit where it has to go. I have put a 9 degree included angle taper in the discharge side of the carburetor, opening up to the 1/4" dimension.


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## GreenTwin (Oct 19, 2022)

Richard Hed said:


> I have thin 'piano wire' thick springs to make.  The slowest my lathe will turn is 70rpms.  It gives me the willies just thimking about not being able to turn off the machine if somehow my fingers should get caught, wrapped up in the wire somehow.


Just turn the lathe chuck by hand.

.


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## Jasonb (Oct 20, 2022)

On both the flat twin based on malcom's Bobcat and the midget shown above I went with tapered inlet and then straight through with 5mm much the same as your 0.195 like your first drawing I'm sure you have seen the videos of them running. Thompson is the same. Could probably have done  the inlet in the head at 5mm too but did it 6mm


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## Charles Lamont (Oct 20, 2022)

Jason - the thing to avoid, from a theoretical point of view at least, is a sudden increase in diameter. Because it is 'lossy' it decreases the velocity and vacuum achieved in the throat. A slow taper, the most efficient is about 6° included, allows Bernoulli to do his stuff. Counterintuitive though it may seem, a sudden contraction is less significant, and a short taper or bell-mouth entry is best. 

A while ago, to check a new taper D-bit reamer was cutting OK, I cut a taper in a short offcut of 1/2" aluminium bar, going from 5/32" to 1/4". Out of interest I put a bell-mouth at the other end. When they try it, people are surprised, as I was, to discover how much easier it is to blow through it from the bell-mouth end than from the taper end.


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## Richard Hed (Oct 20, 2022)

Charles Lamont said:


> Jason - the thing to avoid, from a theoretical point of view at least, is a sudden increase in diameter. Because it is 'lossy' it decreases the velocity and vacuum achieved in the throat. A slow taper, the most efficient is about 6° included, allows Bernoulli to do his stuff. Counterintuitive though it may seem, a sudden contraction is less significant, and a short taper or bell-mouth entry is best.
> 
> A while ago, to check a new taper D-bit reamer was cutting OK, I cut a taper in a short offcut of 1/2" aluminium bar, going from 5/32" to 1/4". Out of interest I put a bell-mouth at the other end. When they try it, people are surprised, as I was, to discover how much easier it is to blow through it from the bell-mouth end than from the taper end.


THAT seems very interesting.  However, to make sure I understand, can you show a diagram?


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## Charles Lamont (Oct 20, 2022)

Your wish is my command. Apologies, Brian, if this digression is getting out of hand.


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## Brian Rupnow (Oct 20, 2022)

Today I have to go across town and buy the 1144 stress-proof steel to make the crankshaft, the cast iron for the cylinder liner, and the aluminum to make the cylinder head. In the meantime, I have to design a gas tank for this critter. The only real restriction is that the top of the gas tank has to be below the centerline of the carburetor. From what I've seen on the internet, the gas tanks were very shallow and tucked in underneath the cylinder, or they were very shallow and stuck out at the other end of the engine, or were mounted on the side of the engine. Mounted on the side of the engine works, but doesn't look good (I like symmetry). Directly below the cylinder is rather appealing, but a lot of heat comes of the air cooled cylinder so I'm a bit ginchy about putting a fuel tank there. I am going to design something right now, and I will post a picture when I finish.---Brian


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## Brian Rupnow (Oct 20, 2022)

I do like this. If I tuck a gas tank in here, I can use a piece of 1 1//2" sq. x   1/8" wall rectangular tubing for the gas tank body, with one side cut down to 3/4" high, which is below the carb centerline. The base is 3.9" long, the cylinder is only 2.9" diameter, so I could put a filler cap at one end of the tank. This is my favourite, because it doesn't change the "footprint" of the engine.


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## Brian Rupnow (Oct 20, 2022)

Okay---I like this. far end of gas tank is flush with far side of base, near side extends far enough beyond cylinder and base to allow room for the filler spout and cap. It also leaves the far end of the base clear so I can mount my ignition condenser there.


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## Jasonb (Oct 20, 2022)

I generally only use a double taper on the glow and diesel aero engines where the revs are much higher. Don't feel it makes a lot of difference on the hit and miss engine and lets face it you don't get any tapers on a Lunk just plumbed in with pipe which a lot of full size and models use. I think the only H&M that had a venturi was the ball hopper monitor


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## Brian Rupnow (Oct 20, 2022)

Okay--What to do, what to do.--I'm still waiting for that damned bandsaw blade to show up here. I did go across town to my metal supplier this morning and bought enough 3 1/2" aluminum to make two flywheel centers, enough 1 1/2" diameter 1144 stressproof to make a crankshaft, enough cast iron to make a cylinder liner, enough 3" diameter aluminum to make a cylinder head, and some 1 1/2" square tube to make a gas tank. I want something easy peasy to do this afternoon that doesn't require a bandsaw, so I'll make a couple of flywheel centers


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## Brian Rupnow (Oct 20, 2022)

First I machined the starter hub, which bolts to the face of one flywheel. (Setting on top of the flywheel material). Then I proceeded to cut the flywheel. Flywheels used to be easy, when I could just plunge in and cut the center relief and leave sharp edge corners. Now I cut that center relief with a 1/4" round nosed tool which leaves a beautiful 1/8" radius in the corners of the cut. It seems like a lot more work, but I'll get quicker as I do more flywheels. While I was cutting this flywheel, I realized that although I can cut half a flywheel into each end of the stock, I still have to use the bandsaw to separate the two flywheels from the main material. Ain't no way I'm going to try and cut 3 1/2" diameter aluminum with a parting off tool.


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## Brian Rupnow (Oct 21, 2022)

HURRAY!!!! My bandsaw blade finally arrived, and it is the right one. Work can begin now on all the bandsaw related parts.---Brian


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## Brian Rupnow (Oct 21, 2022)

I spent the rest of today finishing off the flywheel centers, finishing off the flywheel outer rims, and joining them together.  The bandsaw played a big part in this, and my, but it's nice to have a new blade on it. The old blade was getting pretty dull, and then two weeks ago I finished it off by cutting a piece of 1" diameter bronze bar with it. Now there are two things I know not to cut on the bandsaw. #1---Don't cut drill rod, and #2 Don't cut bronze stock.  The saw is quite happy cutting mild steel, both hot rolled and cold rolled, aluminum, and brass.


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## Gordon (Oct 22, 2022)

So how do you cut drill rod and bronze? Mostly I slow down the feed rate so that there is less load on the teeth. I have actually pulled back on the bandsaw frame to make less pressure. I have put new seals in my feed cylinder a couple of times. Also lube if possible.


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## Harglo (Oct 22, 2022)

Brian
There is a wax style lube that little machines shops in CA sells its comes in a round tube you just push out the product a tiny bitt an apply the moving blade its melts as it heat is formed from the friction you can feel difference. It doesn't leave quit a mess as other oil types.
Harvey


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## Sparky_SC (Oct 22, 2022)

I also have a DoAll bandsaw and use it to cut all sorts of things.   I have cut drill rod, shortened small grade 8 bolts, brass, bronze you name it and don't have any problems with blade life.     One thing that comes to mind is what pitch blade Brian is using?     In a home shop blade pitch is a real problem because we cut all sorts of things all different thickness.     Something small like drill rod will dull a blade quick and even break teeth off if the blade is anything but a fine pitch (say 18-30 TPI).   You can cut small stuff with the coarser pitch BUT its a real delicate balancing act, you have to feed it extremely gentle.     It comes down to the old rule of at least 3 teeth engaged in the work thickness.

Bronze on the other hand is quite slippery and the blade does not like to "dig in" and cut, it likes to slip over the surface unless you put a lot of feed pressure.    That slipping can generate a LOT of heat which is hard on a blade.

I don't know what Pitch blade Brian is using,  I use something around  6-10 vari pitch for most everything and its always a compromise.    Nobody wants to change a blade for cutting various pieces in a home shop so we just make one blade do it all which is hard on the blade.     For steels I run the speed at around 200-225 feet per minute.  (got that number talking with tech support from the blade company)    I usually get a year or two out of a blade.

I will say that bi-metal vari-pitch blades last the longest by a huge margin.     I never use any lube but should on larger pieces especially.


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## Brian Rupnow (Oct 22, 2022)

I use a bi-metal blade 0.025" x 1/2". It has a variable pitch, 6-10, and it costs me $62 including tax..  I do have the proper solid wax in the tubes to keep the blade slippery. Everyone has their own method of prolonging bandsaw blades--I use very little bronze or drill rod, and they cut okay on the lathe using a carbide cutting tool. I hope to get a lot of work out of that new blade today!!


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## Sparky_SC (Oct 22, 2022)

Brian Rupnow said:


> I use a bi-metal blade 0.025" x 1/2". It has a variable pitch, 6-10, and it costs me $62 including tax..  I do have the proper solid wax in the tubes to keep the blade slippery. Everyone has their own method of prolonging bandsaw blades--I use very little brass or drill rod, and they cut okay on the lathe using a carbide cutting tool. I hope to get a lot of work out of that new blade today!!


Can't find any fault with the blade you use or how you use it.     Its the same blade I use.


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## Brian Rupnow (Oct 22, 2022)

Oh my, I love my bandsaw!!!


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## Gordon (Oct 22, 2022)

Are you using your horizontal bandsaw or the vertical band saw?


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## Brian Rupnow (Oct 22, 2022)

Last year I bought a great big vertical industrial Do-All bandsaw from a used machinery dealer in Toronto. I sold my old converted wood bandsaw to somebody who had a small hobby shop. I love my new/used bandsaw, but when the blade is dull you really know it.


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## Brian Rupnow (Oct 23, 2022)

Holy Cats, Batman!!! A few hours with a new bandsaw blade yields some nifty things. Everything is built "as per drawing".--Maybe that should be "As per Modell"  I am very happy with the results. The bearings you see in the pictures will have their seals removed and all of the grease washed out of them. Oct -23-2022


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## Brian Rupnow (Oct 23, 2022)

The gears do mesh properly, and the governor fits where I wanted it to. The governor weights are shown in their "engaged" condition---They won't extend any farther into the con rod space. They miss the crankshaft and the con rod, but it's tight---very tight. So far everything is going as planned, but I may consider changing the bronze bushing that the camshaft runs in for a roller bearing. I will call Canadian Bearings tomorrow and see what sizes are available.


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## SteamChEng (Oct 24, 2022)

Holy smokes!  Brian, I am always amazed at how fast your models go from drawing board to workbench.  This one is really cracking along!  I'd still be fiddle-farting around with the cylinder, but you have this thing halfway finished already!


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## Richard Hed (Oct 24, 2022)

Brian Rupnow said:


> The gears do mesh properly, and the governor fits where I wanted it to. The governor weights are shown in their "engaged" condition---They won't extend any farther into the con rod space. They miss the crankshaft and the con rod, but it's tight---very tight. So far everything is going as planned, but I may consider changing the bronze bushing that the camshaft runs in for a roller bearing. I will call Canadian Bearings tomorrow and see what sizes are available.


How is that governor put together--it looks like it would work well and far simpler than other governors.


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## Oldiron (Oct 24, 2022)

Brian Rupnow said:


> The bearings you see in the pictures will have their seals removed and all of the grease washed out of them.


Why remove the seals and grease? Bob.


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## Brian Rupnow (Oct 24, 2022)

Bob--to get these small hit and miss engines to "free-wheel" between firings, as the full size engines do, it is necessary to remove as much possible friction as you can. Removing the shields and the grease and lubricating the bearings with light lubricating oil is one of the steps towards very low friction.---Brian


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## Gordon (Oct 24, 2022)

Brian Rupnow said:


> Bob--to get these small hit and miss engines to "free-wheel" between firings, as the full size engines do, it is necessary to remove as much possible friction as you can. Removing the shields and the grease and lubricating the bearings with light lubricating oil is one of the steps towards very low friction.---Brian


Most ball bearings are available without seals or with seals only on one side.


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## Brian Rupnow (Oct 24, 2022)

Gordon--I know that, but it costs more to buy the bearings without seals than it does to buy them with seals. Their default is to build the bearings with seals. They charge you extra money if they have to take the seals out.--I worked like mad this morning making a cylinder head and finishing the second flywheel. Then at 1:30 a customer called with changes to a design I did for him last week, and that eat up my afternoon.


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## Brian Rupnow (Oct 24, 2022)

Currently, I have my camshaft riding in a bronze bushing that I made and pressed into the engine sideplate. It works, but isn't as friction free as I would like. I called Canadian Bearings today, and I can buy a roller bearing with no inner race that fits my 7/8" camshaft and is 1/2" wide, same as my engine sideplate for $9.00. The camshaft is very short, and although it is not good practice to run a roller bearing with no inner race on a cold rolled steel shaft, I can make remake my camshaft from a piece of 01 material and flame harden it.


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## Brian Rupnow (Oct 25, 2022)

Today I finished off the flywheels with keyways and set screws, and finished the cylinder head. I sweat blood every time I make one of these cylinder heads. It's not bad when you first start machining them, but the more you do, the more fear you have of screwing something up and having to scrap the part. This one turned out fine, and I'm happy to be finished with it. The engine looks more proportional once that head gets bolted on.


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## Brian Rupnow (Oct 26, 2022)

This morning I machined and assembled five little pieces that are associated with the "hit and miss" action of the engine. My new roller bearing for the camshaft has came in to Canadian Bearings, and this afternoon I will go over and pick it up.


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## Brian Rupnow (Oct 27, 2022)

Today I replaced the camshaft bushing with a Koyo roller bearing and made a new camshaft out of 01 steel that I can harden. It has made a remarkable difference to how freely the crankshaft and camshaft rotate. It doesn't sound like much, but I managed to use up the entire day doing it. Tomorrow I will flame harden and quench the camshaft, then reassemble things and move on with some new parts.


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## Brian Rupnow (Oct 28, 2022)

I didn't feel like a real ball of energy this morning, so decided to build something relatively simple. I decided that a mounting block for my adjustable ignition points was something that didn't require a lot of thought, so that's what I made. This doesn't mount directly to the engine sideplate. There is an intermediate plate that I haven't made yet. I will make it this afternoon. the points shown are a damaged set that I keep around for "fitment". I haven't bought the points I will actually use yet.


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## Brian Rupnow (Oct 28, 2022)

This afternoon I machined the "intermediate points mounting block" which bolts to the engine sideplate  and installed it. It is painted black and you won't realy see much of it in this picture. I also took the seals off of the crankshaft bearings and washed them out with paint thinners, then blew them dry with compressed air. I can't believe how freely everything rotates now.


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## pileskis (Oct 29, 2022)

Brian Rupnow said:


> This afternoon I machined the "intermediate points mounting block" which bolts to the engine sideplate  and installed it. It is painted black and you won't realy see much of it in this picture. I also took the seals off of the crankshaft bearings and washed them out with paint thinners, then blew them dry with compressed air. I can't believe how freely everything rotates now.


Why don’t you just buy shielded bearings instead of sealed? 
Should have something there to keep the contaminates out.


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## Vietti (Oct 29, 2022)

Nice engine!  How do you remove the bearings once the crank is in for disassembly?


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## Brian Rupnow (Oct 29, 2022)

You don't. Not without a lot of grief anyways. These bearings are not self aligning. To get away without any binding, the counterbore holes in the engine sideplates are bored about .002" to 0.005" larger than the outer diameter of the bearings. The o.d. of the bearings are then coated lightly with J.B. Weld, pushed fully into their recesses in the engine sideplates, then a 1/2" length of cold rolled steel is passed thru both bearings, all of the bolts holding the sideplates in place are torqued down, and the J.B.weld is allowed to set up for 24 hours. This guarantees perfect alignment of the bearings. The counterbored holes that the bearings fit into have a 9/16" clearance hole where the shaft passes thru. If you want to remove a bearing, the shaft and sideplates are removed, the sideplate is heated with a torch until the J.B.Weld lets go, then  the bearing is tapped out with a 9/16" drift punch.  Today I heat treated (hardened) the cam shaft and reinstalled it, made a new ignition cam and installed it, and had to do a bit more machining on the underside of the sideplates because they weren't perfectly square to the frontplate that holds the cylinder.


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## Brian Rupnow (Oct 30, 2022)

Todays task is turning a piece of round 1144 stress proof steel into a crankshaft. First a slab is cut from both sides, then what is left gets machined on both sides and one edge, then the crankshaft is layed out on the remaining flat piece. Every time I make a "machined from solid" crankshaft, I spend more time planning what I'm going to do next than I do actual machining. These are one of those things where if you cut away something you shouldn't, then you have to buy a new piece of 1144 and start over again.


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## Brian Rupnow (Oct 30, 2022)

And yes, that crankshaft turned into a full days work, but I expected it to. Lots of cheek clenching and many, many passes with 180 grit paper to reach final exact size, but I'm happy with the results.


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## Ghosty (Oct 30, 2022)

Brian,
The way you are going, it will be finished next week  
Still looking.
Cheers
Andrew


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## Brian Rupnow (Oct 31, 2022)

This morning I came down to the bat cave and machined a cast iron cylinder liner. It was intended to be a medium press fit into the aluminum cylinder.---The machining gods laughed, and it ended up being a smooth sliding fit into the cylinder.---Not good!!! I am now involved in a series of talks with a Loctite representative, trying to find a two part epoxy with really good thermal conductivity. Apparently Loctite does have exactly the thing I need, Loctite #PE3142, but it is only sold in one gallon cans and costs a zillion dollars. I am waiting for a call back from a Loctite rep, hoping like Hell that he has something very similar in small tubes.


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## CFLBob (Oct 31, 2022)

Brian Rupnow said:


> I am waiting for a call back from a Loctite rep, hoping like Hell that he has something very similar in small tubes.


... or there might be a sample size for engineering evaluation.


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## Brian Rupnow (Oct 31, 2022)

I just ordered a small tube of two part heat transfer epoxy. The cost is just about equal to the price of another piece of cast iron and a couple of my hours to machine it.


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## Big Daddy (Oct 31, 2022)

Oh boy Brian, I really am liking this one too.  I can't wait!!!  I have a soft spot for hit n miss engines.


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## trlvn (Nov 1, 2022)

Brian Rupnow said:


> I just ordered a small tube of two part heat transfer epoxy. The cost is just about equal to the price of another piece of cast iron and a couple of my hours to machine it.



Not something that I know anything about but...is differential expansion any concern?  What kind of running temperature do you expect for the engine?  Are the thermal expansion rates of aluminum and cast iron different enough to make create an issue?  Is the epoxy bond elastic enough to cope?

Craig


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## Brian Rupnow (Nov 1, 2022)

Craig---Best answer--I don't really know. These engines do not run hot unless they are under protracted heavy load. They pump cool air thru the cylinder during the "miss" cycles, which bleeds away a lot of the internal cylinder heat. I haven't used a heat transfer epoxy before, so it is definitely a "try it and see" kind of thing.----Brian


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## Brian Rupnow (Nov 1, 2022)

Today's nifty trick was to build and install a connecting rod and cap. It fits, fits very well. Yes, there is room between the governor and the connecting rod, as I thought there would be, but there is not a lot.  Ah well, a miss is as good as a mile.


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## Steamchick (Nov 2, 2022)

re: #99 - Craig:
ON Differential expansion... This is very complicated for a cast-iron liner in an aluminium block. - Fit and temperature and yield strength all play an "active" part.
I was involved in trying to predict the fit of a steel tube pressed into an aluminium block. The calculations were proven by the real engines on test - and failed exactly as predicted - except for one factor. The steel and aluminium both deformed permanently, so the result was 2 parts that didn't fit at times and leaked. But the result was that fitted "as originally designed" and "glued" with Loctite thread-lock (the adhesive already in use on the production line in that area) produced a sealed fit that never leaked. 
The calculations of differential expansion showed less dimensional change than the "interference" value. But what was actually happening was that the steel tube (a relatively low-grade steel) was swaging when press fitted into the aluminium block (at room temperature) so if removed immediately it was smaller than before fitting. And after reducing the temperature of an assembly to -30C (minimum service temperature at which the engine was expected to be started) the aluminium was found to have yielded slightly such that the hole was measurably larger than the original. The conclusion at +120C (max "design service" temperature at that position) was that the steel tube would be loose in the aluminium... - and thus would leak oil - but the Loctite prevented this. It seemed to form a seal at the edges of the metal-to-metal fit - which was wiped "dry" along the contact surface during assembly (So didn't assist the fitting/disassembly force). - The original "fit" dimensions had been based on the steel tube pressed into an iron block. We never actually changed the dimensional fit, just added the Loctite as that made the assembly "work properly".
On Richard's engine I expect the Loctite adhesive to secure the components and being so thin a film (actually just filling the machining grooves, so just a few microns thick!) it won't materially affect the heat flow from cast iron liner to aluminium block.
BRIAN, I would have guessed a regular "Thread-lock" anaerobic adhesive should be adequate for securing the "sliding-fit of liner to block. - But follow Loctite's recommendation as they are the experts. - I would (if it were my engine) fit a tiny pin to ensure the liner does not become free to rotate in the aluminium. - It looks (from photos) as if there is a top flange (held between block and head gasket?) to prevent linear movement of the liner. - Good design.
K2


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## lathe nut (Nov 2, 2022)

Brian, super nice work and love those drawings, that does take the guess work out, great to be able to follow along and thanks for sharing with us, Joe


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## Brian Rupnow (Nov 2, 2022)

Good morning guys. It is nice to hear from you. I see that a lot of people are following this thread, and that pleases me. I am having fun building it.---Brian


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## LorenOtto (Nov 2, 2022)

Brian Rupnow said:


> Good morning guys. It is nice to hear from you. I see that a lot of people are following this thread, and that pleases me. I am having fun building it.---Brian


I always enjoy your unique solutions to problems I didn't even know I had.


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## Brian Rupnow (Nov 2, 2022)

Today was valve train day. We have the valves, turned to a smooth sliding fit into the valve cages, and into the valve spring retainers. The rusty "handles" are still attached to the valves so I will have something to hold onto when I lap the valves into the "seat area" in the valve cages. They will be cut off after the lapping is finished. The springs in the picture will be cut to the correct length and will serve as valve springs. The valve cages will be Loctited into the cylinder head.


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## Brian Rupnow (Nov 2, 2022)

And this is the "fix" for all who may at sometime be "Machining Challenged". My cast iron liner which was supposed to be a medium press fit into the aluminum outer cylinder, ended up being a "smooth sliding fit" into the aluminum outer cylinder.  This is not a good thing, because without a press fit, there will be very poor heat transfer from the inner cast iron sleeve to the outer aluminum cylinder which has the cooling fins on it, to radiate heat away. This is a thermal, heat conductive two part epoxy. It's main purpose in life is to transfer heat from one metal surface to another. It cost me $41 Canadian, but it is going to save $15 worth of cast iron and about two hours of my time. I will mix it up, coat my iron inner cylinder liner with it, then slide it into my aluminum outer cylinder and let it set up for 24 hours. I will let you know how it works, I have never used it before.


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## xander janssen (Nov 3, 2022)

Brian Rupnow said:


> The rusty "handles"


I always thought that the valves had to be some sort of stainless steel to avoid corrosion and hence leaking valves over time. What is your experience? Would save me buying and machining stainless next time.


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## Brian Rupnow (Nov 3, 2022)

I have never used stainless steel for valves, and I've never had a valve "burn" on me. I just use cold rolled steel for valves and never have a problem.----Brian


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## Brian Rupnow (Nov 3, 2022)

Today I had a bad case of "lazy arse". I used my thermal epoxy to attach the cast iron cylinder liner into the outer finned aluminum cylinder housing, and while I was doing that I decided to use the same epoxy to fasten my valve cages into the cylinder head.  I wasn't going to do anything else today except have a nap, but decided that I had to machine at least one thing to keep the project moving forward. I searched around in my brass bin until I found a piece of 3/16" brass large enough to make the bottom part of my rocker arm pivot from, and that's all I made today.


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## Steamchick (Nov 4, 2022)

Top job Brian. I like the way you consider all the various things that affect the design of parts - such as heat flow, fits, material selection mentioned recently. This reinforces  my knowledge and adds where I am less experienced. Keep up the good work. And your patience combined with the ability to resolve odd problems is an example to s all .
Thanks for posting your work - warts n all!
K2


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## Brian Rupnow (Nov 4, 2022)

Hello Steamchick--Thanks for stopping by and saying Hi. Today I machined a piston from cast iron. First thing I did was to lap the inner cylinder sleeve with a brass lap and 600 grit paste to bring everything to a uniform finish inside the cylinder. Then I turned the piston in the lathe until it was about 0.002" oversize. I then use 220 grit garnet paper to bring the o.d. down just enough to start the piston into the cylinder, then stopped working on the o.d. and completed the rest of the features on the piston. Once I reinstall the cylinder, you won't see anything of this piston, so here's a picture of what it ended up like.


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## Big Daddy (Nov 4, 2022)

Hello Brian.  I'm guessing you are partial to cast iron rings, which is great, over the Viton O-rings.
I just have been noticing more and more folks utilizing the Viton option.  I'm guessing because it is a lot less fuss.
Thank you and keep up the great work.

Greg Knipp


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## Brian Rupnow (Nov 4, 2022)

Greg--People use Viton rings because they always work and they are really easy. I have bought a lot of fairly specialized equipment and made quite a number of cast iron rings, and I'm still not good at it. I try, because that's what we all do--try and improve the way we do things. I wish I was more sure of myself when it comes to cast iron rings.


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## Brian Rupnow (Nov 5, 2022)

This morning I cross drilled the 0.039" cross hole thru the valve stems for the cross pin that holds the valve springs in place, then lapped the valves into the seats and cut the "handles" off of them. The valve springs were cut to length and installed on the valves. The cylinder head was installed, with the exhaust stack loctited and threaded into it. I found a piece of 3/16" square keystock and mounted it in the guides, as it will be used to ensure that the rocker arm support gets installed in the correct place. Probably the next thing I will make is that rocker arm support tower and the rocker arm itself. The only thing outstanding now are the gas tank, the carburetor (which I will make), and finishing up the hit and miss mechanism.


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## Brian Rupnow (Nov 6, 2022)

Today I'm working on the rocker arm and support pedestal, but decided to make a couple of design changes on other things. There is simply no good way to mount the gas tank below the cylinder as I had it before. Firstly, it interfered with air circulation around the cooling fins on the cylinder, and secondly, even more important, there was really no good way to hook up the carburetor to the gas tank---they were too close together. My plan now is to mount the tank at the other end of the engine frame, and drill all the way through the engine baseplate to allow a discharge pipe to come out at the carburetor end, making for an easier gas line hook up. I have also taken the radial slots out of the flywheels. They do nothing except provide an interesting visual as they rotate, but add nothing in terms of performance to the engine.


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## Brian Rupnow (Nov 6, 2022)

The rocker arm and rocker arm support tower are finished. A couple of minor things yet to be done, but not today. I think I will build the gas tank tomorrow, just to get it finished and off my list.


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## Steamchick (Nov 7, 2022)

Aha! Do I spy an automatic inlet valve? - Looks like only the one push-rod and rocker to exhaust valve?
Will the main bearings run oiled or greased?
K2


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## Brian Rupnow (Nov 7, 2022)

As far as I know, all hit and miss engines used atmospheric intake valves. The main bearings will be lubricated with light oil.


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## Brian Rupnow (Nov 7, 2022)

Today I am going to build this long peckerd gas tank. I have a piece of 1 1/2" sq. tube with 1/16" wall, and hopefully can come up with enough scraps of 1/8" plate to build it without buying anything.---An interesting side note---The last time I used my relatively new tig welder, it was just horrible. Kept arcing like crazy, burning off the electrode, terrible results. I switched over to the mig welder and accomplished what I had set out to do. Last night, as I was laying in bed, going over my days work, I had a sudden thought. --The last time I used that tig set up was to weld aluminum, and I never changed to a proper steel welding electrode afterwards. I'm hoping that today, with the correct electrode in the tig, I get better results.---Brian


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## Sparky_SC (Nov 7, 2022)

2% lanthanated electrodes work extremely well for both aluminum and steels,  3/32 size for general purpose.   It is the go-to electrode for most TIG welding.

The other thing is to be sure and remember to switch to AC for aluminum and DC for steel.    I have forgot on more than one occasion and it reminds you real quick.
​


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## Steamchick (Nov 7, 2022)

Hi Brian: "As far as I know, all hit and miss engines used atmospheric intake valves." - I didn't know that. I thought the hit and miss option worked on the inlet valve push rod linkage: engaging the inlet valve when required, but disengaging when the governor said "Slow down boys!". That way you always need two push rods for the 2 valves. But yours is more economical with friction I guess?
Must look closer at other engines... I haven't paid this much attention to these engines before. Thanks for the help,
K2


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## Brian Rupnow (Nov 7, 2022)

All hit and miss engines that I am aware of, used atmospheric intake valves. The governor would lock the exhaust valve open during the miss cycles so that the engine could not build compression and fire. Once the rpm's slowed down, the governor would unlock the exhaust valve, the exhaust valve would close and let the engine fire, thus increasing the rpm and reactivating the governor.


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## Steamchick (Nov 7, 2022)

Thanks Brian, My understanding was wrong then. I thought the inlet valve being held from operating, when over-speed for the governor, meant no charge taken in for combustion. In your description/method, the charge is not taken into the engine because the cylinder with open exhaust valve does not develop the vacuum to draw fuel-air mix past the automatic inlet valve. Just a development of engines that I had not realised existed.

Here is the earliest infernal combustion engine design I have found: Otto's original!








						Otto-Langen Atmospheric Engine
					

In 1867, Nicolaus Otto and Eugen Langen debuted an efficient, free-piston, atmospheric engine. Although the Otto-Langen engine was outclassed in 10 years, it led the way to the four-stroke internal…




					oldmachinepress.com
				




Thanks for the help,
K2


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## Steamchick (Nov 7, 2022)

I found this Crossley engine hit and miss arrangement... but have not yet worked out what is happening! - Just clickety clack repeated 7 to 10 times then Wheeze-Chuff! 

- Lovely!
The attached description says, "Instead of holding the exhaust valve open, the governor lifts up the latch and prevents the gas intake valve from opening. " - So today's lesson for me was that both systems existed and worked.
K2


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## awake (Nov 7, 2022)

Brian, the problems you are describing with the TIG sound like either bad ground or no gas. Or at least, those are the causes I have when I have had those symptoms ... I can't comment on the effect of the "wrong" electrode, because as Sparky mentions above, I use 2% lanthanated electrodes for all TIG welding, steel or aluminum.


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## Sparky_SC (Nov 7, 2022)

awake said:


> Brian, the problems you are describing with the TIG sound like either bad ground or no gas. Or at least, those are the causes I have when I have had those symptoms ... I can't comment on the effect of the "wrong" electrode, because as Sparky mentions above, I use 2% lanthanated electrodes for all TIG welding, steel or aluminum.


Probably not in this case, but I will mention it anyways.    Another pretty common problem is the wrong gas, welding suppliers have been known to occasionally mislabel a tank.     75/25 blend intended of MIG really raises hell if used on a TIG for some reason.       Brian stated he was burning up the electrode so that means he had a decent ground at least.         He will figure it out.     I was just surprised when he mentioned using different electrodes for steel and aluminum.


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## Brian Rupnow (Nov 7, 2022)

Today was spent making a gas tank. I found that with the correct electrode, the welder worked much better. I do have the correct gas. I'm not very good with the tig--it is a new welder that I just bought last year. I'm going to have to check and see if the local community college is running any tig welding classes. I am a good welder with my old AC buzz box and my mig, but the tig is still mostly a mystery to me. At any rate, the gas tank is built, except for the long outflow pipe, which I will add tomorrow. You will see that I silver soldered the filler spout.  Tomorrow I will leak test the gas tank, reweld any leaky spots, add the outflow pipe, and then do some cosmetic work on the tank before priming and painting it.


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## lathe nut (Nov 7, 2022)

Brian, you are a master at anything, you will get it, I don't have on yet and that sometimes holds me back, I like the Miller Mig and Hyperthern Plasma cutter but still a stick man, been looking at Tig's but will hold out a little while, your engine looks great, thanks for sharing your knowledge, Joe


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## Richard Hed (Nov 7, 2022)

Brian Rupnow said:


> Today I am going to build this long peckerd gas tank. I have a piece of 1 1/2" sq. tube with 1/16" wall, and hopefully can come up with enough scraps of 1/8" plate to build it without buying anything.---An interesting side note---The last time I used my relatively new tig welder, it was just horrible. Kept arcing like crazy, burning off the electrode, terrible results. I switched over to the mig welder and accomplished what I had set out to do. Last night, as I was laying in bed, going over my days work, I had a sudden thought. --The last time I used that tig set up was to weld aluminum, and I never changed to a proper steel welding electrode afterwards. I'm hoping that today, with the correct electrode in the tig, I get better results.---Brian


Since you have  a closed vessel, you should let it fill with argon--makes a better weld inside.  make sure you practice on something before just jumping into the weld of your box.  It would be good to put some backing if possible to keep the stainless from warping.  It is stainless, didn't you say?  also, lots of little tacks.

What kind of TIG machine did you get?


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## Steamchick (Nov 8, 2022)

Brian, In service, how will the tank be vented to prevent low pressure developing in use? I don't know... but guess the seal under the filler screw cap can have  small slit - not in line with a tiny hole in the cap - that can relieve internal low pressure? ( internal pressure will push the seal against the cap to prevernt fuel leakage).
Keep up the good work.
K2


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## Brian Rupnow (Nov 8, 2022)

Venting is achieved by a 1 mm hole in the center of the screw on cap. My tig machine is a  Solidweld.


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## Steamchick (Nov 8, 2022)

Thanks Brian. I like the location of this tank.... away from hot engine and exhaust.
K2


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## Brian Rupnow (Nov 8, 2022)

Time to back away and take a fresh look.--I have so many pin holes in this gas tank that I have decided to start over again. This time around I will use a piece of rectangular tubing with the ends J.B.Welded in place. Only the filler neck and the discharge pipe will be silver soldered into place. This is a formula I have always used in the past, and it has proven to work well and look good. I hate to do this, but until I have a better grasp of using my tig welder I think this is for the best.


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## packrat (Nov 8, 2022)

Hit and Miss engine intake valve....https://www.youtube.com/watch?v=ajvd0YO8vqI


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## Gordon (Nov 8, 2022)

Brian. I have soldered the end caps on. I usually use round tube and turn a shoulder on the end caps so the solder flows into the joint. I also have the outlet at the top with a ball check in the dip tube.


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## Richard Hed (Nov 8, 2022)

You should continue to try to get it right with TIG.  TIG will work well, just practice a bit before trying the box.. also tack it lots.  If you need to turn down the amps, do that too.  Cooler is slower so it gives you plenty of time to weld and not be in a hurry.  What are you using for filler?


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## Brian Rupnow (Nov 8, 2022)

Richard--I am using the filler rod recommended by the manufacturers of the welding machine. I have been welding for over fifty years---just not with a tig. I really need to learn more of the basics of tig welding.


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## Richard Hed (Nov 8, 2022)

Brian Rupnow said:


> Richard--I am using the filler rod recommended by the manufacturers of the welding machine. I have been welding for over fifty years---just not with a tig. I really need to learn more of the basics of tig welding.


Exactly.  I have been welding for about the same time.  I learned first, in my teens to weld with acetylene but I did not like doing it.  Then I learned stick, using that for many years.  then I learned Wire feed which was like spreading hot butter on hot toast and lots of fun.  About 1980, I bought a TIG attachment for my Lincoln -- This is not like the TIG welders on the market today--it was a "strike" like a match type TIG.  It was too much trouble to use for aNYthing I did in those days.  Last year, I managed to get a TIG machine that I did not get set up till last month.  it is SO much easier to use than the old TIG which you set by the transformer settings, and that was about the onl7y way you could adjust it.  

But now, one can turn down the amps, or up, and do all those other manipulat5ions to make TIG welding so much easier just by the flip of a switch or turn of a knob.  TIG is without a doubt, the most difficult of all welding techniques and takes practice practice practice.  I struggled with the adding of the filler metal till I saw on a utub vid that the welder used his fingers differently to move the filler wire in.  I was using my thumb and forefinger to try to move it in but it didn't work well.  The utub welder held the wire betwee his forefing and middle finger and moved it ahead with that.  He wasn't constantly struggling to get a new grip on the filler to move it ahed.


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## pileskis (Nov 9, 2022)

Brian- it sounds like, as others have pointed out too, that your settings are off and maybe even your filler rod. It’s best that you do the research yourself, rather than blindly accepting the guy behind the counter. That maybe a good start, but need to know for yourself. Good TIG welding is an art that does need practice. Even if you’ve been doing it for a while and go away from it for any period of time, you loose a little muscle memory. 
It’s a whole different set of feelings compared to stick or Mig.


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## Richard Hed (Nov 9, 2022)

pileskis said:


> Brian- it sounds like, as others have pointed out too, that your settings are off and maybe even your filler rod. It’s best that you do the research yourself, rather than blindly accepting the guy behind the counter. That maybe a good start, but need to know for yourself. Good TIG welding is an art that does need practice. Even if you’ve been doing it for a while and go away from it for any period of time, you loose a little muscle memory.
> It’s a whole different set of feelings compared to stick or Mig.


That's right.  I am not a pro TIG welder but I have done it enough to like it, I just don't get to use it as often as I would like.  So every time I want to use it, I essentially have to re-learn it.  However, since I have gotten a new and modern machine, I'm sure to use it more often--still, I needs practice practice practice.  I managed to get some stainless sheet and I have a small project using stainless sheet, so I will get to it soon, but even before that, I will bone up on stainless TIGging.


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## Brian Rupnow (Nov 9, 2022)

Today I machined and installed the starter hub on the near side flywheel, machined and installed the push-rod mechanism, and almost finished the second most expensive gas tank in the world. It still needs a little cosmetic finishing and then paint and primer, which I will probably get to tomorrow. I was going to take a video of the push-rod mechanism working, but decided that the only person excited about it was probably me.----Brian


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## lathe nut (Nov 10, 2022)

Brian I would like to see the push-rod mechanism, hope that you did take some pictures of it, I like the expression about the fuel tank, think we have all been there and done that, Engine really looks great, Joe


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## Brian Rupnow (Nov 10, 2022)

Thank you Joe.--I will make a video of it today.---Brian


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## Brian Rupnow (Nov 10, 2022)

Today will be the day to make the lockout lever. There is more to this lever than meets the eye. Not only does it have to pivot about a fixed point, it has to hold a compression spring to hold it away from the valve lifter rod. When the governors reach a certain speed, the governor slider forces the lockout lever to pivot, compressing the spring, and making the end of the lockout lever latch under the pushrod to keep it from releasing the exhaust valve.


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## Brian Rupnow (Nov 10, 2022)

And, here we have a video of the lock-out arm working.


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## Brian Rupnow (Nov 11, 2022)

Today I finished the million dollar gas tank, painted it, and drilled and tapped the frame base for two #8 shcs to hold it in place. A 3/8" hole was drilled full length of the baseplate to accept the long line running from the gas tank so no gas line will be visible.


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## raveney (Nov 12, 2022)

Brian Rupnow said:


> Time to back away and take a fresh look.--I have so many pin holes in this gas tank that I have decided to start over again. This time around I will use a piece of rectangular tubing with the ends J.B.Welded in place. Only the filler neck and the discharge pipe will be silver soldered into place. This is a formula I have always used in the past, and it has proven to work well and look good. I hate to do this, but until I have a better grasp of using my tig welder I think this is for the best.


Hello Brian,
Sometimes one will chase their tail following good advice. I too struggled with attempting to use TIG building an small scale fuel cell. Watched many dozen videos and learned a great deal. 

As an engineer, you may appreciate the scientific approach of listing the variables and only changing one at a time to determine the best solution. Please know that I have full confidence that you can accomplish this, as we have witnessed you overcoming numerous challenges. I have a list of variables that you may chose to review. For me I needed to use a higher argon flow on my setup. I think that outside corners are the reason why. For the thin walled tank, autogenous welding and lapping the corners may give you a better result. I experimented/practiced on many coupons before getting any reasonable parts.

Welding Machine Settings

DC Electrode Negative
Amperage (1 amp per 0.001”)
Pulse off
Gas flow 20 CFH Pure Argon
Pedal control
Turn fan away from work
Grounding to part or table
Material Preparation

Use dedicated flap disc
Remove all mill scale inside and out
Use dedicated wire brush
File saw cut edges
Wipe with acetone
Fit up
Filler

Type
diameter
Fresh end
Wiped clean with acetone
autogenous
Torch

Cup size
Gas lens
Tungsten type
Tip angle and grinding technique
Stick-out distance (same as cup ID size)
Electrode diameter
Cut off contaminants if dipped
Technique

Electrode to material distance
Angle of torch to weld
Backing
Travel speed
Hand support
Tig Finger
The part circled is a good use of coupons to practice edge, fillet, lap and outside corner. Please note there were lots of other scrap parts. On carbon steel tube the mill scale can be very difficult to TIG weld and achieve a leak tight result. The pipe fitters at work often discard the flap discs and use new ones as they break through to shiny metal. You may consider using cold rolled 1/8 sheet instead. The thicker material will allow tapping the feed tube into the side as I did with the tank below.


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## lathe nut (Nov 12, 2022)

Brian Rupnow said:


> Brian, that is impressive, I really like that one, your hours of work got paid when you see it rung so good but cannot get paid for the tank, that cost too much, been there with projects one small thing can eat you up, thanks for sharing, Joe


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## Brian Rupnow (Nov 12, 2022)

Today, the gas tank has been painted and installed.  I think I'm down to the carburetor and the governor. I have had a few more thoughts on the governor, and today I hope to get them designed. The governor works fine as it is, but I think I can rearrange things a little bit to cut down on the headroom to keep it farther away from the connecting rod.


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## Brian Rupnow (Nov 12, 2022)

Raveney--Those welds are beautiful. I hope someday to be able to do the same.---Brian


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## SteamChEng (Nov 12, 2022)

Brian, I am watching with great anticipation as things continue to come together.  It is a beautiful machine and shows your skill and care!  I'm looking forward to the running video!


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## Brian Rupnow (Nov 12, 2022)

The small change to the governor works really well. With the governor in action, the governor weights clear the con rod, and that is all they really have to do. This is one of those small changes that I can't really even show you. I am putting up a drawing with a couple of cross sections thru the camshaft, showing the governor "engaged" and "not engaged".--You will see that in either condition, the governor weights don't extend beyond the collar which they are attached to.


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## Charles Lamont (Nov 13, 2022)

The following is a small detail in Brian's design, but may help to elucidate the general principle.

Briefly, the new clearance bevel on the weights has removed some mass that was counterproductive anyway.

Consider the right hand weight in the right hand diagram. The centrifugal force on that weight is acting to the right.* So the force acting on any-part-of-the-weight-that-in-the-diagram-is-below-the-pivot-point is tending to rotate the weight anticlockwise. However, those parts of the weight above the centre of the pivot are also subject to the same rightward centrifugal force, and the moment of force on them is tending to rotate the weight clockwise. So for optimal design one would remove as much as reasonably possible of the mass above the pin.  

*(I know this is not strictly correct.)


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## Brian Rupnow (Nov 13, 2022)

Today I will have a go at the carburetor. This design is very close to the design that Malcolm Stride used for his Lynx and Jaguar engine, but the throttle has been removed, as the rpm of a hit and miss engine depends on the hit and miss mechanism to provide the speed control. The throttle bore is always in a "wide open" condition.


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## Brian Rupnow (Nov 13, 2022)

Very little accomplished today. I did machine the main body of the carburetor, which is actually made from two pieces silver soldered together. I will make the rest of it tomorrow.--In other news---We had our first snowfall of the winter today. Not a lot of accumulation, but enough to cover the grass in our yard. I would have been just as happy if it never snowed---ever!!


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## Brian Rupnow (Nov 14, 2022)

It has not been an auspicious morning!! I machined the rest of the parts for my carburetor, but broke off an 0.031" diameter drill in that very small (0.079") protrusion on the part on the left hand side. I can't get it out.  My machines are not "precision" enough to try and carbide the broken drill out. I now have to decide just what I'm going to do next. The local hobby store doesn't have any brass tube in a size that would help me out, and I don't have any more 0.031" drills.


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## Brian Rupnow (Nov 14, 2022)

If at first you don't succeed--design a different carburetor that still uses the same main body as the previous design.


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## Steamchick (Nov 15, 2022)

Hi Brian, at first I liked the simplicity of this... then looked closer. So maybe you have resolved the issues I shall mention... or will resolve them if necessary.
#1: It looks like the needle is entering a metering hole that has been drilled through the wall of a circular passage. The sealing seat of the hole that the needle enters will not be a perfect circle to seal - if that is ever needed - and will it close off the fuel adequately to stop the engine - if ever required?
#2: The venturi if formed suitably by the taper of the inlet tract (bottom of the drawing). So I wonder "why?" you have what appears to be a smaller hole at the choke of the carb instead of the ore being parallel? - If you think you need a further venturi at the carb itself (Based on your experience of many small carbs - I have no experience worthy of comment!) - then I would have made a smoothly tapered inlet into this light blue cross piece, instead of a turbulent "step" from the tract diameter of the green part into the choke shown in the blue part?
#3: On the only carb I have made of this design I used a ground long tapered point from my drawing compass set (dates back to the 1960s). It worked fine without a reduction of diameter at the choke of the carb itself, but I did arrange a rotating bar with semi-circular notch to act as an air throttle, just on the "outside" of the fuel mixing point. (The engine only ran for a minute before it lost compression (cracked cylinder!), so cannot say it was a good carb design or not!).
Anyhow, I wish you success with this one!
K2


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## Brian Rupnow (Nov 15, 2022)

These carburetors work on a venturi principle. Any reduction of the passage which the air rushes through, will create a pressure drop in that area. The blue fuel rail tube has a hole through it slightly smaller than the main carburetor air passage at that point, so creates a low pressure area at that point. The fuel rail is drilled so that all of the internal holes are perfectly round. Raw gasoline is sucked into the right hand side of the blue tube because of the low pressure. the round red needle can be screwed into the discharge hole in the blue tube to meter the amount of fuel which rushes into the carburetor main air passage. as soon as any gasoline enters the main air passage, it is picked up by the moving air stream and atomized, then sucked into the cylinder to be burned. There is no choke at all on this carburetor.


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## Steamchick (Nov 15, 2022)

Sory Brian, I am using "Engineering English" again. I don't mean to confuse. 
In my "Engineering English" the "Choke" is not a device used for cold starting - as named on cars, but any reduction of cross-sectional area in the passage through which the gas (Air, then air plus fuel) is passing. The Chioke of a carburettor is the reduced diameter zone at or near the fuel jet. As you start with a tapered inlet, the inlet tube itself is "choked" and accelerates the air with consequential pressure drop. Usually this is a simple parallel passage, all-be-it on some race carburettors they add a Bell-mouth which adds to the intake velocity a little, but the main reason is producing laminar flow through the carburettor to maximise gas flow and also velocity. Your carb looks like there is a small step between the passage in the light green part and the blue cross part. This "step" change of diameter will cause a turbulence, which will significantly reduce flow of air (maybe by 10%?) and consequently, slow the air so there is a reduced pressure drop compared with what you could achieve if this was either straight at the same diameter or blended with a further taper in the blue part between the outside and the point where the jet is positioned.  Then you will have a better venturi. I am ot saying you won't make your design work as it is, buit simply suggesting an engineering reason for adding a taper in the blue part.
Regards,
K2


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## Brian Rupnow (Nov 15, 2022)

And here we have it, carburetor finished. The soldered joints look a bit lumpy, but when this thing is in place under the cylinder, nobody is going to see it anyways. Steamchick---Most hit and miss carburetors don't have a tapered throat at all---they are just a plain bore, straight thru, and depend on the tip of the fuel rail sticking up into the air stream to create enough restriction to cause a venturi effect. If the cone in the intake side of my carburetor causes any problem (and I don't think it will) I'll turn a cone shaped piece of brass with a bore same as the main carburetor body and Loctite it in place. The carburetor was the last major piece required to finish the engine. Now comes the time for all the farting around required to get the engine running. I have to go down to my local automotive shop tomorrow and pick up a set of ignition points, a condenser, and a sparkplug.---Wish me luck!!---Brian


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## Steamchick (Nov 16, 2022)

Thanks Brian. Good luck with getting it running when you have added the ignition bits. I think your design of hit-and-miss governor is simple and interesting. Looking forward to seeing it work!
K2


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## Brian Rupnow (Nov 17, 2022)

Tomorrow I am going to cut keyways in the crankshaft. But--This requires a bit of thought. On a normal 4 cycle engine, I would cut a keyway in the small gear to lock it in position on the crankshaft. I could then loosen off the grub screws on the cam gear and turn the gear until it reached the correct position to operate my valve train in proper sequence with the position of the piston. I would loosen off the grub screw in the ignition cam and turn it to a position where the spark came at the right time in relationship to piston position. However, on this engine, the cam gear is "fixed" in position on the shaft, and since the cam is part of the shaft, it too is "fixed" in relationship to the camshaft. This means that I don't want to put a keyway in the small gear on the crankshaft, or I won't be able to set my valve timing. Basically, I want to be able to loosen off the grub screws in the small gear and turn it until the cam gear which it meshes with is in the correct position to set my valve timing. My ignition cam is mounted on the crankshaft and has no keyway in it, so I can still turn the ignition cam freely until it reaches a position where my ignition timing is correct, then tighten the grub screws which lock it to the crankshaft.  (This is a waste spark set-up, so the sparkplug fires every time the piston approaches top dead center).


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## xander janssen (Nov 18, 2022)

I had some doubts on the gripping of a grubscrew for the small gear on the crankshaft without the shaft having a flat area. Never build an engine before, I wanted to maximize the chance of it to run without parts coming loose. So came up with the following:

- Cam fixed to large gear
- Small gear fixed to 1st flywheel
- 1st flywheel adjustable but firmly fixed to crankshaft by tapered bushing.

So valve timing is set by rotating the 1st flywheel over the crankshaft.

- Ignition cam adjustable to crankshaft by grubscrew as this does not take any force.
- 2nd flywheel adjustable but firmly fixed to crankshaft by tapered bushing to set the spokes in the same orientation as the 1st flywheel


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## Jasonb (Nov 18, 2022)

Can't you just unmesh the gears and move the gear one tooth, should give you increments of a a few degrees which should be good enough. Thats how I usually do it where the cam is integral to the large gear and small gear keyed to crankshaft.


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## Brian Rupnow (Nov 18, 2022)

Jason--Yes, I probably could.--Didn't think of it. So--what have I been doing? Main ball bearings have been Loctited into cavities in side-plates. New sparkplug has been installed. New ignition points have been installed and timed. Condenser has been bolted to side of baseplate and wired up to ignition points, along with the "feed wire" that takes 12 volts to the ignition points. Head gasket has been made and installed. A bit of clearance machining done to the governor side of the con-rod to make sure it clears the governors under all conditions. A bit of clearance machining to both con-rod and con-rod cap, to allow the con-rod assembly to fit thru the 1" cylinder bore. Valve lash has been adjusted. Keyways have been cut in both ends of crankshaft and keys made to fit. Xander--I don't use the separate tapered hub with my flywheels, just two grub screws at 90 degrees apart, one over the key. The separate tapered hub is a good design, but I find that I don't need it, and it does add quite a bit of machining. I think that all I have to do now is make a set of compression rings for my piston, and machine an oiler for the cylinder. I have an oiler left over from another build, but it looks to small and puny on this engine.


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## Brian Rupnow (Nov 18, 2022)

The last time I made piston rings for a 1" piston, I made six extra rings. I have had these rings in a small bottle for the last year or so, and now is the time to bring them out and see what I have. I can see by the gap that these rings have been heat treated, but not "finish sanded".  My piston is made, and has ring grooves 0.046" wide. These rings measure 0.045" wide. With a little bit of luck and some very light sanding, two of these rings should do. I have the correct material to make more rings if I have to, but I'm really hoping that two of these rings will do.


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## Brian Rupnow (Nov 19, 2022)

Today, for something simple to machine, I'm making the starter spud that lets me use my variable speed drill to start the engine. (That is the green thing floating in space just outside of the flywheel).


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## Brian Rupnow (Nov 20, 2022)

Today, the six piston rings were sanded flat, against a piece of 600 grit carborundum paper, backed up by a sheet of glass to ensure absolute flatness. I have a tapered flap sander that fits in my mill that is 7/8" diameter on the narrow end and 1 1/8" diameter on the large end. Each side of each ring was held in my fingers and forced up onto the revolving mandrel to remove any burrs from the inside. Each ring was pushed squarely into a 1" bore spare cylinder that I have, and the end gap was checked with a 0.004" feeler gauge. One ring didn't survive. When I tried to file a bit more end gap into it, it went all egg shaped so I threw it out. Two of the rings were installed in the ring grooves in my piston, and the piston was reinserted into the cylinder with the help of a tapered sleeve that I have which is 1" bore on one end and 1 1/8" bore on the other end. Before I put the cylinder head back on the cylinder, I held the flat of my hand against the cylinder bore and turned the engine over with my other hand, and it did seem to have good suction against the palm of my hand. Everything is finished now, except for the cylinder oiler.--I don't need the cylinder oiler to start and run the engine. If the engine runs well, and if I sell enough plan sets, I may indulge myself and buy an oiler from one of the companies which sell them. Wish me luck people!!---Brian


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## Brian Rupnow (Nov 21, 2022)

Time for some modifications---I'm not getting a lot of compression, and I should be. I unscrewed the sparkplug and went searching for my air jack that screws into the M10 x 1 pitch threads in the sparkplug hole, so I can put some air pressure into the cylinder and see exactly what is leaking compression.--Ha!!!---Can't find one. Maybe I never had one. So--I ordered an M10 x 1 threading die from Amazon and it is supposed to be here tomorrow. As soon as it arrives, I will make up an air jack to match the sparkplug threads.  Secondly, even though the carburetor should be positioned high enough from the fuel tank to prevent fuel syphoning down and dripping out the carb throat, it isn't. Poop!!!  Can't have that, don't want to burn the place down. So--shave a flat on the bottom of the cylinder and cylinder head cooling fins and modify the carb body a little bit, and this allows me to lift the carb up 1/4". No way that fuel is going to gravity drain uphill.


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## Sparky_SC (Nov 21, 2022)

Why a M10 die?    Do you not thread at all on your lathe?


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## Brian Rupnow (Nov 21, 2022)

Sparky--Best answer is no, I don't. My lathe requires you to change  a bunch of gears to cut different threads. I did set up one piece of 3/4" round aluminum, followed all the directions and did cut a quite acceptable thread which accepted a 3/4" off the shelf nut. Having proved that I actually could do that if I really, really had to, I've never tried to cut a thread since.


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## Gordon (Nov 21, 2022)

Most lathes also require a special gear in order to cut metric threads. Also cutting a thread on something that small is a lot of work. That is approximately 3/8 dia x 3/8 long.


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## Brian Rupnow (Nov 21, 2022)

That thread is the thread on an M6 sparkplug from NGK. I wanted a die, so I called my usual tool supplier in Barrie. They could have a die here tomorrow for $37. I said that was too much. He said he would check his other suppliers and find me something cheaper. He called back in 15 minutes and said he could get one for $17.50 but it would take two weeks. I said no, and went to Ebay---they had one for $10 but I couldn't get the damned site to work. Then I went to Amazon, and they had one for $13 and would deliver it here tomorrow. This is for a die that I might use twice a year.


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## johwen (Nov 22, 2022)

Hi Brian, don;t know if you have seen this video but "Blondi Hacks" makes it relative easy. We can't let the fairer sex better us but she is very good and has many sites.
John.


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## Brian Rupnow (Nov 22, 2022)

Johwen--I have watched some of her videos, and I agree, she is quite good.---Brian


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## Brian Rupnow (Nov 22, 2022)

I spent this morning preparing a fixture which screws into my engines combustion chamber so that I can pressurize it with air to see where it is leaking compression. My M10 x 1 threading die came this afternoon and I quickly threaded the end of the new fixture and screwed it into the sparkplug hole. I found a thread yesterday on Youtube where a man done this, only he incorporated a Shraeder valve from a car inner tube into the fixture, and then after pressurizing the cylinder he disconnected the air pressure and said that the combustion chamber should remain pressurized for 15 to 20 seconds after the air line is taken away. This sounds like a very good idea to me.


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## Brian Rupnow (Nov 22, 2022)

Attaching a piece of tubing to the fixture and blowing on it by mouth quickly shows that my exhaust valve is not leaking, but my intake valve is. There doesn't seem to be anything leaking past the piston and rings. This stands to reason, as the mechanical exhaust valve has a much stronger spring than the automatic intake valve. I will now pull the cylinder head off and relap the intake valve.


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## Brian Rupnow (Nov 22, 2022)

Improvement---engine is firing randomly. This is definitely an improvement over not firing at all. Relapping the intake valve has helped a lot with the intake valve, it is sealing much better now. I think the spring on my intake valve is too stiff---Have to root around thru my box of springs and find a lighter one. Moving the carburetor up 1/4" higher has fixed the fuel dripping from the carburetor.


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## Richard Hed (Nov 22, 2022)

Brian Rupnow said:


> Johwen--I have watched some of her videos, and I agree, she is quite good.---Brian


yes, yes. and she edits her stuff VERY well--no long winded speaches and all that.


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## JohnBDownunder (Nov 23, 2022)

I am a fan of Blondie Hacks and she is not afraid to show us her mistakes etc. Plus no long winded explanations as a rule.


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## Steamchick (Nov 23, 2022)

Hi Brian, rather than buy a die to make a compression tester adapter to do just the same job as you, but on my motorcycle engines, I simply took the threaded end of a used spark plug and silver soldered it onto the adapter, which had a schrader valve stem (from an old inner tube) brazed onto the other end for air supply and gauge from my tyre pump.
Keep on keeping on.
K2


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## Brian Rupnow (Nov 23, 2022)

Steamchick--I have done that in the past, but in this case a $13 die was cheaper than a $20 sparkplug.


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## CFLBob (Nov 23, 2022)

It seems like a useful thing to make up one of these adapters for any sparkplug size we're likely to be using.  Before trying to turn the engine over for the first time, stick the pressure tester into the cylinder and test how well it seals.  I can almost talk myself into saying every cylinder could have a test port for a pressure tester in addition to the spark plug.  A shrader valve is - what? - 1/4" OD?  Bicyclists use a skinnier valve, a Presta valve that's closer to 1/8", but they require a different size fitting on the pump side.  Adapters are like $1.35-ish each on eBay.  (Not my listing)

Either make an adapter for every engine, or if we end up building engines always using the same sized plug, it's only one adapter.


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## Brian Rupnow (Nov 23, 2022)

Bob--You're right, and since we only use a couple of sparkplug sizes with these small engines, a proper test set up could have interchangeable ends to suit either size of sparkplug threads. I think it would be extra unnecessary work to build an engine with a second port for this testing, but the sparkplug hole is always there. I mentioned a Shraeder valve because that is what I always thought that all tire tubes had. I don't think that the size of valve matters too much, because it doesn't have to flow a high volume. The beauty of a test rig made like this is that it actually measures the leak-down time after outside pressure is removed, and a "finite" measure of seconds is a very good indication of whether the valves are sealing properly. I have always just blew into the end of a tube connected to one of these sparkplug adapters with my mouth, and you can hear which port the air is leaking from.---Brian


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## Steamchick (Nov 24, 2022)

Canny lad Brian! (Means I respect your intelligent decision).
K2


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## Brian Rupnow (Nov 24, 2022)

I would like to find a sparkplug which reaches deeper into my combustion chamber. The plug I am currently using in an NGK CM-6. it has a M10 x 1 pitch thread on it, and the threaded portion is 8.6MM (that is 0.338" imperial) long. I would like to find a plug available in Canada with a longer threaded portion about 16mm [5/8"] long but with the same M10 x 1 pitch thread. I have used up my google-foo and can't find what I am looking for. It doesn't have to be NGK. Can anyone help me out here please.---Brian


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## Jasonb (Nov 24, 2022)

Brian although not a Canadian site I use this one which allows you to enter diameter and various reaches though not 16mm. You could use that to get the make and model of some suitable plugs and then see what's available to you






						10mm Diameter - The Green Spark Plug Company
					

Buy 10mm Diameter from The Green Spark Plug Company Online Today for Next Day Delivery.




					www.gsparkplug.com


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## Brian Rupnow (Nov 24, 2022)

Okay---Got it sorted. The boys down at Partsource helped me out. The plug is an NGK-R and has an M10 x 1 thread and is 0.730" long in the threaded portion. I actually made a 0.125" thick bronze washer to go between the sparkplug and the cylinder head to give me the correct amount of sparkplug protruding into the combustion chamber. Thank you Jason for your help.---Brian


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## Brian Rupnow (Nov 24, 2022)

The longer sparkplug did the trick. The engine is firing regularly on every other revolution of the crankshaft. It hasn't taken off with a roar and made me grin like a Chessy cat yet, but I'm a lot closer.


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## woodenbird (Nov 24, 2022)

Brian Rupnow said:


> The longer sparkplug did the trick. The engine is firing regularly on every other revolution of the crankshaft. It hasn't taken off with a roar and made me grin like a Chessy cat yet, but I'm a lot closer.


Great job, Brian. Always a pleasure watching your builds and troubleshooting techniques.
Glenn


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## Vietti (Nov 24, 2022)

Jason,

Thanks for the link to Greenspark.  They have a great selection of ignition parts.  Bought a coil!
John


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## Brian Rupnow (Nov 24, 2022)

No joy today. Ignition is working fine, big fat spark at the correct time. I have a second home built carburetor that I know works because I have used it on many of my engines while setting them up, so I put it on the engine today. Still, not running. More testing shows that the intake valve is still leaking, enough that the engine won't "bounce back" when spun by flywheel. (It will "bounce back" if I put my finger over the carburetor intake). Tomorrow I will see what is going on with that leaking intake valve. I needed something to cheer me up, so I went to Youtube and typed in "brian rupnow engine"---many videos of my past engines are on there, so I watched them for half an hour. I'm happy now. Going to shut things down and go read a book.


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## Brian Rupnow (Nov 25, 2022)

So, what are we looking at here? This morning I came down to the bat cave, dismantled the cylinder head, reseated the valve cage with my George Britnel tool, and reground the valve with 600 grit paste, then reassembled the cylinder head. The cavity inside the cylinder head is filled with Naptha gas, and I'm waiting to see if remains in there, (which means the valve and seat are air tight) or runs out around the valve.


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## Gordon (Nov 25, 2022)

I would not think that the fact that it holds liquid would necessarily mean that it holds under pressure. 

What do you use for valve material? In the past I have used steel, 1018 or 12L14. Recently I have been using 303 stainless. I have also found that the problem can be the stem not sliding freely in the guide. It seats but too late.


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## Brian Rupnow (Nov 25, 2022)

Gordon--I find it to be a fairly good method of checking for how good a seal the valve has with the seat. This time it did anyways. My engine has good compression now, and has a very obvious "bounce back" when you try to spin it with the flywheels. It has been a frustrating day. Good spark, good compression, good fuel---but no protracted runs.  Many "almosts", but nothing longer than about 20 seconds. Although the engine fires and tries to run on it's own, it is running very slowly and I don't know why. Adjusting the spark timing doesn't seem to have any great effect. Most of these hit and miss engines will take off and rev so high they scare you half to death if the miss mechanism is disabled.  I spent the afternoon with a different gas tank, trying it at different heights in relation to the carb, but didn't get anywhere with that.  Tomorrow I will try it with a purchased carburetor, because I'm running out of things to try.---I always use cold rolled steel for my valves, and have never had a problem with it.


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## Big Daddy (Nov 26, 2022)

Brian, what do you think about larger, heavier flywheels? I'm thinking maybe more inertia would help.


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## dsage (Nov 26, 2022)

How well does it run on starting fluid? That will eliminate (reduce) the suspicions of your carb being the issue (and all the work to try another one). If everything else if fine then it should take off on starting fluid.


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## Brian Rupnow (Nov 26, 2022)

Time for an admission of stupidity. Taking a fresh look at this thing this morning, I see that the discharge side of the carburetor was up tight against the back wall of the adapter. There was no possible way for the air-fuel mixture from the carburetor to make its way thru to the cylinder. I take full blame for that one. Now I know why playing with the spark timing and the fuel mixer needle didn't seem to be having any effect. big HEAD SLAP for me. I am currently making a new adapter.---Brian


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## Brian Rupnow (Nov 26, 2022)

And, we're away to the races. Engine seems to run fine, but I haven't hooked up the hit and miss mechanism yet. I'm happy that the engine seems to run very well. The carb I have on the engine right now is a throttled style carb, and if the throttle is wide open, the engine tries to levitate off my desk and nearly scares me to death. It is running at about 1/3 throttle in this video. Next step will be to get the hit and miss mechanism hooked up.---Brian


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## Brian Rupnow (Nov 26, 2022)

I just tried out the hit and miss mechanism, and it works. It engages just fine, but I need a stronger compression spring to disengage it, otherwise the engine just runs down and stops before the current compression spring (out of a ball point pen) returns the lockout lever into the 'run' position.


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## Ghosty (Nov 26, 2022)

Brian,
Congrats on another one running, can't wait to see it on hit and miss.
Cheers
Andrew


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## Steamchick (Nov 27, 2022)

Brian, 
I always enjoy your write-ups and videos. 
You deserve that "hoorah!".
K2


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## Brian Rupnow (Nov 27, 2022)

I found a stronger spring in my collection, and replaced the ball point pen spring which I previously had as part of my hit and miss mechanism. Now the spring is too strong, and won't allow the engine to go into "hit and miss" mode. The seat which the spring sets in is adjustable, so today I will play with a variety of springs until I find one that is "just right". I was going to make a proper size cylinder oiler and mount it on the engine, but found that I don't have any glass or plastic tube stock on hand, so this morning I ordered a new one from Ebay.


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## CFLBob (Nov 27, 2022)

The search for the Goldilocks spring?  "This one is just right!"  

There should be a way to measure the spring constant and bound the problem, figuring how many grams/cm are too much and how many are not enough, but I honestly don't know how to go about doing that analytically.


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## Brian Rupnow (Nov 27, 2022)

Bob--the engine runs just awesome!!! The spring which counteracts the action of the counterweights sets inside that red square piece  with the 1/4" orange capscrew in it. By tightening the capscrew, I can force the spring to put more pressure against the aluminum mounting plate, so I can adjust that capscrew to vary the pressure the spring exerts. That sounds great, but right now I'm having little success with it.  I'm going to have to study the mechanism on some full size Hercules engines and see what they did to make the governor disengage.


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## Brian Rupnow (Nov 27, 2022)

I'm about to pack it in for the day, but here's a thought. The governors work exactly as they are supposed to, and when the engine speeds up, the governor causes an arm to pivot and "catch" under the end of the grey plate which is sandwiched between the red funky shaped plate and the yellow push-rod. In a perfect world, as the engine slowed down, the compression spring buried in the pivoting hit and miss bar would force the end of the hit and miss bar out from under that grey plate, and the engine would fire again.  I have tried a few different strength springs, and that doesn't seem to be doing it. The OTHER factor here is how deep that "notch" is that the pivoting hit and miss bar is catching under. I've tried 0.062", and that doesn't work.---it won't disengage. I've tried 0.031" and that doesn't work--it still won't disengage. What next?--Well, the easiest thing for me is to make a new grey bar with an 0.015" step. That is a fairly simple part to make, and I will probably do that later today.


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## Mike1 (Nov 27, 2022)

Brian Rupnow said:


> Bob--the engine runs just awesome!!! The spring which counteracts the action of the counterweights sets inside that red square piece  with the 1/4" orange capscrew in it. By tightening the capscrew, I can force the spring to put more pressure against the aluminum mounting plate, so I can adjust that capscrew to vary the pressure the spring exerts. That sounds great, but right now I'm having little success with it.  I'm going to have to study the mechanism on some full size Hercules engines and see what they did to make the governor disengage.


Brian, your latch will work better if you file a small bevel on the toe of the latch so that it clears the latch stop when the spring pulls it open, similar to the shoot on a lock latch.
Mike1


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## Brian Rupnow (Nov 27, 2022)

There is a third factor in play here. If the hit and miss lever fits under the notch when the pushrod is at its extreme extent of travel, then the hit and miss lever is always under pressure, making it difficult to release, and consequently letting the engine run down and die. However, if the hit and miss lever can engage with the pushrod before it reaches the extreme extent of its travel then the exhaust valve will still be held open and the engine will miss, but every time the cam comes around it will bump the pushrod and momentarily remove the pressure from the hit and miss lever, allowing the compression spring to pivot the hit and miss lever and return the governors to the "run" position. I think that may be the answer, and again, I will try that later today.


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## danallen (Nov 27, 2022)

That is how my Farm Boy works. When the engine is coasting in "miss" mode the push rod moves ever so slightly every time the cam goes around. When the governor retracts the hold open lever there is no resistance.


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## Big Daddy (Nov 27, 2022)

Brian, did you settle on that Taxxas 15 carburetor for this one too?  Have you had any luck with Chuck's carburetor on this or other engines?

Thanks.
Greg


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## Brian Rupnow (Nov 27, 2022)

Big Daddy--I used a carburetor that I made for this one. Yes, I have had excellent results using Chucks carburetor.


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## Brian Rupnow (Nov 27, 2022)

I have the engine hitting and missing now. Its doing it in a very fast and frightening way, but it is hitting and missing. If I can just tame it down a little now, then we're good.


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## Big Daddy (Nov 27, 2022)

Thank you Brian.


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## Brian Rupnow (Nov 27, 2022)

Here's a little something you will find interesting. When I designed this engine, I mounted the gas tank as low as possible. I did this because these carburetors which I use don't have a needle and float, so if the gas tank sets higher than the carburetor, they will continually flood themselves. I've been trying to get consistent runs out of the engine today, but the runs were not consistent. In fact, they were all over the place, and I couldn't figure out why.--On a whim, I fully unscrewed the carburetor needle valve and guess what!!!--A steady stream of fuel was peeing out of the carburetor. The gas tank wasn't located low enough in relationship to the carburetor, even though it looked like it was. So--I took a trip out to my main garage, and sawed up a long wedge from a 2 x 6 and mounted the engine and attached gas tank on an angle. Now I know for sure that the gas tank is lower than the carburetor. I will do more trial runs tomorrow.


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## JohnBDownunder (Nov 28, 2022)

That idea sure beats fiddling around and actually changing the tank position just to see if it helps. At least then you know and can vary the wedge to find the so-called sweet-spot. Love reading your build logs.
Regards,
John B


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## Jasonb (Nov 28, 2022)

Brian Rupnow said:


> There is a third factor in play here. If the hit and miss lever fits under the notch when the pushrod is at its extreme extent of travel, then the hit and miss lever is always under pressure, making it difficult to release, and consequently letting the engine run down and die. However, if the hit and miss lever can engage with the pushrod before it reaches the extreme extent of its travel then the exhaust valve will still be held open and the engine will miss, but every time the cam comes around it will bump the pushrod and momentarily remove the pressure from the hit and miss lever, allowing the compression spring to pivot the hit and miss lever and return the governors to the "run" position. I think that may be the answer, and again, I will try that later today.


Brian on all the ones I have done the latch does not engage at full travel, it will engage as the valve starts to close so every time the cam comes round it will give the pushrod a slight nudge which releases the latch and then if the weights are still out they will stop the valve closing but if the weights have moved in the latch will get realeased and have time to disengage before the rod comes back off the nudge.

Your best bet will be to put slots in your grey plate so that you can loosen the fixings and slide it into different positions to find the sweet spot. It is also usual to angle the latch and latch plate so they lock into place

If you look at my model of the Gade you can see that the pushrod moves every time so the latch disengages lengthways but the governor keeps it pushed in sideways until it is time for the next hit. The longer of the two plates that latch together is slotted for adjustment.


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## Brian Rupnow (Nov 28, 2022)

No really great news to report today. I didn't like the engine setting up on an angle, so I machined three 1/2" square aluminum pieces to fit between the base plate and the three vertical plates, and changed my model and drawings to reflect the change. This took care of the gasoline tank being higher than the carburetor. I have had the engine running off and on many times today but I'm still not happy with the consistency of my runs.  What I am after here is an engine that runs reasonably slow without the hit and miss lever hooked up. Then I will try lighter springs in the lever return mechanism until I reach a balance point between the rpm of the engine and the rpm at which the lockout lever works. I had it doing that yesterday afternoon, but the engine was doing about 2000 rpm while it was happening.---Very scary--kind of like working on a bomb.--And just for the record, the governor weights don't touch the con rod when the governor engages. I don't think you could get a cats whisker between them, but there are no marks on the con rod nor on the governor weights.


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## Sparky_SC (Nov 28, 2022)

Considering the carb has no throttle plate to adjust rpm's it sounds like you need to make a reducer bushing for it to accomplish the same function.

Pretty easy to try.


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## Brian Rupnow (Nov 28, 2022)

Okay---I'm happy. After a full day of trying to get good runs and failing, as a last resort I stole a flywheel off another engine and added it onto the crankshaft.--Engine immediately started up and ran until it was out of gas. Big Daddy who suggested heavier flywheels---You were absolutely right.


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## CFLBob (Nov 28, 2022)

Is the hit and miss operation working as you want?  I can't discern any hit and miss action listening to and watching it.


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## Sparky_SC (Nov 28, 2022)

In the video it appears you are now using the commercial carb and have a throttle lever.    Will the engine slow down at all?     Its running well but awful fast for a hit miss engine.


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## Brian Rupnow (Nov 28, 2022)

As per the written comments part of the video, no, the hit and miss lever is not hooked up. You have to have these engines tuned almost perfectly before you even think about having them hit and miss. Sparky--you're right---That is a commercial, throttled carb currently on the engine.  I have been on a three day quest to get this engine to make consistent runs. The commercial carb is probably temporary--it just removes one more engine component that might be suspect.  (Although hit and miss engines will work perfectly fine with a throttled carburetor that is set to "wide open throttle"). Now that I have finally reached a point where I know that the engine needs heavier flywheels, I will modify the flywheels to be heavier, then see about having the engine slow down. There are more than a dozen things that will keep an engine from running consistently, and they are not all readily apparent. All I can do is work my way thru each thing and see if it makes a difference on how well the engine works. Honestly, I was running out of things to check when I tried adding the extra flywheel.


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## Brian Rupnow (Nov 29, 2022)

Today, I'm adding to the outside diameter of my flywheels. Unfortunately, no one in town had 5" double extra strong pipe which would only have required a bit of machining. So, for the princely sum of $17 I bought two 3/4" lengths of 5" diameter solid. My largest drill is 1" diameter, so I've just spent two hours machining one of them for a precision fit over the o.d. of a flywheel. one down, one to go. The deepest depth of cut I can take is 0.025", so I'm taking out 0.050" of material with each cut. I have to remove about 3/12" of steel after I have used my 1" drill. I think that adds up to about four billion passes with the boring tool--at least my wrist says so. I'd like to get them both finished today and coat the insides with J.B. Weld and mount the rings on the flywheels so they can set up overnight.


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## Gordon (Nov 29, 2022)

Why not just make new flywheels from the blanks even if you had to bolt on the hubs?


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## GRAYHIL (Nov 29, 2022)

Brian.
Could you not trepan the middle out?
Graham


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## Brian Rupnow (Nov 29, 2022)

I'm done!!! Started at 12:00 worked till 7:20, had a half hour off to grab some lunch. There are three or four ways this job could have been done. I chose the way that I thought might be less work. Any of the other ways suggested would have worked just as good, and probably would have worked out the same time-wise. I wanted to finish today so the J.B. Weld could set up overnight. Now I'm off to watch Jeopardy with my good wife.


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## Brian Rupnow (Nov 30, 2022)

Nobody knows but you and me---and we're not going to say a word--are we!!!


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## Brian Rupnow (Nov 30, 2022)

Not a great deal accomplished today, but my flywheels are modified and painted and ready to go back onto the engine tomorrow. I've spent a goodly portion of my afternoon watching videos posted by Andrew Whale of the United Kingdom, as he builds the Jerry Howell Farm Boy engine. If, in a worst case situation my engine doesn't work as expected with the style of governor I am using, it would be a relatively easy thing to change it to the same style of governor as the Farm boy uses. I don't want to do that--I have already built the Kerzel engine, the Philip Duclos "Odds and Ends" engine and the Duclos "Whatzit" engine using the sliding sleeve on the crankshaft, and I want to do something different.


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## Brian Rupnow (Dec 1, 2022)

After adding a bit of weight to my flywheels, the engine is running fine. I swapped out a couple of different springs in the hit and miss mechanism, then found the right one. The engine is running and going in and out of hit and miss mode on its own now. I will slow things down a bit and do a bit of "finessing", but overall I am very pleased. This engine is built entirely of bar stock, no castings. I sell a complete set of engineering drawings for $25 Canadian. If you wish to buy a plan set (about 50 drawings) please contact me at [email protected]  The desk which I have the engine clamped to right now is very noisy, and all of the other things on it are bouncing around adding to the noise. On a solid base, the engine is much quieter than you are hearing on the video.---Brian Rupnow


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## Brian Rupnow (Dec 1, 2022)

I must say, I'm "Over the moon" right now. It always puts me on a big high whenever a new engine runs satisfactorily. When it is a new engine with a new, untried hit and miss mechanism, then the effect is doubled. The engineer part of me says "Of course it will work!!"--It's all logic. The other part of me that has built over 40 engines says "Yes, in theory it should run, but I've built things in the past that worked great in theory, but I was never able to get them running in the "real world". I've ordered an oiler from Ebay, and I still may do a bit more painting. Now I have to go back over the engineering drawings, make any changes that didn't get recorded, and save the drawings as .pdf files so that people without specialized Software programs are able to open them ---Brian


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## Sparky_SC (Dec 1, 2022)

Still going to try and get it running slower like the typical hit/miss engines ?


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## Brian Rupnow (Dec 1, 2022)

Sparky---Read the text in post #231


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## Brian Rupnow (Dec 1, 2022)

I just added up the number of detail and assembly drawings, and there are 46 drawings, and some of them are multiple sheet drawings so probably about 55 sheets overall. At this time, all of the machining is finished. The next trick will be to find a spring for the hit and miss lever that is weak enough to let the engine go into "miss" cycle at a lower rpm., but strong enough to move the hit and miss lever back into the "run" position before the engine quits at the end of the miss cycle. This is a rather delicate balance. A "normal" 4 cycle single cylinder gas engine will idle at about 1000 rpm. A hit and miss engine when working properly, will average about 600 rpm. because the engine rpm is slowing down during each rotation of the crankshaft during the "miss" part of the cycle.


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## JohnBDownunder (Dec 2, 2022)

Thank you Brian for a great read-along post. I find it always worth following your posts and really like the current running video. I do agree that the speed could be slower, glad the extra flywheel weight helped.
Congrats,
John B


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## Jasonb (Dec 2, 2022)

You will also need to look at how it is firing as well as sorting out the latch spring. At the moment it is stuttering and not firing strongly enough when the latch disengages and fires(hits) multiple times before the governor latches in again. I would be looking to get it to fire once and strongly before trying to get the speed down.

Without looking back do you have one or two springs in the system, you want one to control the governor weights and another to disengage the latch.


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## Brian Rupnow (Dec 2, 2022)

I have two springs in the system. One is a tension spring, hooked to the pushrod to keep it in contact with the cam (actually the compression spring on the exhaust valve does most of that). I have a compression spring in the hit and miss lever that keeps the lever away from the push-rod and keeps the governors in the "run" position until centrifugal force overcomes the spring and swings the hit and miss lever into "miss" mode. I do plan on having the engine running slower. Yesterday was a "first run" where the engine was actually hitting and missing. As I said earlier, the machining work is finished. Now it's purely a matter of getting the right compression spring in there to slow down the engine some more.----I woke up this morning and remembered that I had promised a water cooled cylinder with the drawing package, so I am working on that today. Jason---do you have two springs acting on your hit and miss lever? I only have the one, I don't know if there is a second spring inside the actual governor or not.--It doesn't seem that I need one there.---Brian.


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## Jasonb (Dec 2, 2022)

That's a single spring then, you really want to keep the weight springing and the latch springing separate.

To get the engine to run slower you want a softer spring for the weights so they throw out at lower reves

But you probably don't want to go softer on the latch spring as that will stop it unlatching.

This is a section of the same sort of governor from a full size open crank engine, part 22 is the spring that ONLY affects rate at which the weights fly out.

Cam following spring is not really needed as the valve spring takes care of that


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## Brian Rupnow (Dec 2, 2022)

For those of you who prefer a water cooled hit and miss engine, I have designed a water jacket and lid, and changed a couple of parts to work with them. They will be marked "For water cooled engine only" and included with the drawing set.


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## Brian Rupnow (Dec 2, 2022)

Thank you for that information Jason. I have carbided a counterbore to hold a spring where the blue dashed lines are. it wasn't that hard a job. The big trick now will be to choose a spring of the right size and strength.---Brian


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## Brian Rupnow (Dec 2, 2022)

Quick question--I want to do some rework on my camshaft which is made from 01 material, and is flame hardened and oil quenched. I think I can return it to a softer state by flame heating it to cherry red, then letting it air cool. I have to tap a couple of #4-40 holes in it, then harden it again. I think I can just reheat it to cherry red and oil quench it again to reharden it, but I haven't done that before.---Brian


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## Nerd1000 (Dec 2, 2022)

Brian Rupnow said:


> Quick question--I want to do some rework on my camshaft which is made from 01 material, and is flame hardened and oil quenched. I think I can return it to a softer state by flame heating it to cherry red, then letting it air cool. I have to tap a couple of #4-40 holes in it, then harden it again. I think I can just reheat it to cherry red and oil quench it again to reharden it, but I haven't done that before.---Brian


That should work, but you'll need to temper it again as well.

It's best to avoid repeated heat-quench cycles because they tend to remove the carbon from the upper layers of the steel, reducing the surface hardness.


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## Sparky_SC (Dec 2, 2022)

a quick search found this recipe on a steel manufacturers site for annealing O1 steel.     Sounds like the proposed torch method may still leave it quite hard.


Annealing​
Annealing must be performed after hot working and before re-hardening.


Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1425 -1450°F (802-816°C), and hold at temperature for 1 hour per inch (25.4mm) of maximum thickness; 2 hours minimum. Then cool slowly with the furnace at a rate not exceeding 50°F per hour (28°C per hour) to 1000°F (538°C). Continue cooling to ambient temperature in the furnace or in air. The resultant hardness should be a maximum of 212 HBW.


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## Charles Lamont (Dec 3, 2022)

If you have some vermiculite in your potting shed you could bury the red hot part in that, so that it cools more slowly.


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## Gordon (Dec 3, 2022)

Brian Rupnow said:


> Quick question--I want to do some rework on my camshaft which is made from 01 material, and is flame hardened and oil quenched. I think I can return it to a softer state by flame heating it to cherry red, then letting it air cool. I have to tap a couple of #4-40 holes in it, then harden it again. I think I can just reheat it to cherry red and oil quench it again to reharden it, but I haven't done that before.---Brian


Put it in your kiln and let it cool in the kiln. That will make uniform heating.


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## Brian Rupnow (Dec 3, 2022)

I just put the cam shaft in my vice and heated it to cherry red, and I'm leaving it to air cool. I don't have any vermiculite. ---I do have another unhardened piece of 01 steel, so if I need to I can make another camshaft. After this one cools, I will let you know how much success I had threading very small holes in it.


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## Brian Rupnow (Dec 3, 2022)

And the story is---No, it didn't work for me. The part is still very hard. I could turn a bit off the o.d. with a carbide cutting tool, but no way was I going to be able to drill and tap it for #4-40 threads. That's okay. I have lots of unhardened 01 to make a new cam shaft, and I've learned something today.---Brian


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## L98fiero (Dec 3, 2022)

Brian Rupnow said:


> I just put the cam shaft in my vice and heated it to cherry red, and I'm leaving it to air cool. I don't have any vermiculite. ---I do have another unhardened piece of 01 steel, so if I need to I can make another camshaft. After this one cools, I will let you know how much success I had threading very small holes in it.


_DRY_ kitty litter/Floor Dry works for larger pieces pretty well, too, or put it in with another, larger piece beside the one you want annealed.


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## Brian Rupnow (Dec 4, 2022)

No cat, so no kitty litter. I will remake the camshaft and cam, they are not complex shapes. If this had been a really complex part with a lot of hours in it, I would have taken it to one of the local machine shops and had the threads edm'd in. As it is, it will only take a couple of hours to remake the part.


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## trlvn (Dec 4, 2022)

Brian Rupnow said:


> I just put the cam shaft in my vice and heated it to cherry red, and I'm leaving it to air cool. I don't have any vermiculite. ---I do have another unhardened piece of 01 steel, so if I need to I can make another camshaft. After this one cools, I will let you know how much success I had threading very small holes in it.


Annealing a hardened piece of O1 shouldn't be difficult.  It needs to get slightly above critical temperature (non-magnetic) and stay there for a little while (minutes with a small piece like this).  It probably cooled too rapidly in the air.  Another old timers solution is to bury the hot piece in fireplace ashes while cooling.  Even dry sand will work.  Not wet sand--red hot metal plus moisture equals "A Bad Thing".  

Craig


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## Brian Rupnow (Dec 4, 2022)

Today is a "no work day". Both of our boys have a birthday in December, so today is family feast day with all of our kids, spouses, and grandchildren coming at noon for birthday celebrations. I am currently doing a bit of rework on the camshaft to get a better "hit and miss" situation going, on advice from Jason. This view with the camshaft removed shows the roller bearing that fits into a hole in the near sideplate to support the new camshaft.


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## Brian Rupnow (Dec 4, 2022)

This is a cross section thru the governor shown in its "engaged" condition. A hit and miss governor should engage at about 500 rpm. engine speed. The strength of the governor spring should hold the governor in its "not engaged" position until the engine rpm reaches about 500 rpm, at which point the governor should engage and start the engine into its "miss" cycles. Since my governor is driven off the camshaft, then my governor should begin to engage at 1/2 that speed, so my governor should engage when it reaches 250 rpm. It is a lot of work to get at that governor spring to change it, so I will do a mock up on my milling machine which has an rpm readout on the quill, and drive the governor at 250 rpm. and use that as a basis for the governor return spring that I use.


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## awake (Dec 5, 2022)

Asking out of ignorance ... would increasing the weights of the governers also slow down a hit-n-miss engine?


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## Brian Rupnow (Dec 5, 2022)

So----It did take more than a "couple of hours", but I have a new camshaft and a new big collar where the swinging counterweights pivot from. All seems to be well, and I will be making my test tomorrow driving it with my milling machine to determine what strength of compression spring it needs . Andy--Increasing the weight of the governors make them swing out sooner due to centrifugal force, so yes, it would slow the engine down. The more you play with governors, the more you begin to see the interdependencies between governor weights, governor rpm, engine stall speed, engine recovery speed and governor return springs.  I see that on the original Hercules engines that used this type of governor, the governor was driven from a small gear and spun much faster than it would if it had been ran directly of the cam gear like mine is. Tomorrow I will get to see if I can achieve the same results running of the cam gear but with a much lighter governor return spring.


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## awake (Dec 6, 2022)

Ah, it just now clicked for me that you are running the governor on the cam shaft, not the main shaft. That surely makes it much more challenging to get the weights and springs and such set just right, since you're turning half-speed.


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## Brian Rupnow (Dec 6, 2022)

Today we are going to build a test rig to test the optimum spring strength for my governor. The grey part will be made from aluminum with a 0.875" hole in it to match my camshaft diameter and the bottom of it will be held in my milling machine vice. The green part will be turned from a piece of aluminum and bolted to the face of the 60 tooth gear. A second pulley of the same diameter will be held in my milling chuck and a 0.1" neoprene drive belt will connect the two pulleys with a 1:1 ratio. Whatever rpm my spindle is turning, the governor will turn at the same rpm. I want to find a spring that lets the governor actuate at 250 rpm.


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## Brian Rupnow (Dec 6, 2022)

This test was one of those things that worked good in theory.---In practice, not so much. The rubber o-ring drive belt kept stretching and slipping, and the camshaft kept finding tight spots, then loose spots in the aluminum bar which is supporting it. No good conclusion could be reached from this test, but I THINK that the spring I have in the governor right now is way too stiff. I had the mill rpm turned up to 500 rpm, but couldn't see any visible movement of the center pin in the governor, which is supposed to move at 250 rpm. Tomorrow I will repeat this test, but will couple the camshaft to my mill spindle with a short driveshaft with two universal joints that I built a few years ago, and a set of 90 degree bevel gears mounted in a carrier that I built a few years ago. Hopefully that will work better, as there is nothing to slip.


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## Jasonb (Dec 7, 2022)

Why don't you pull the crankshaft gear off the engine and mount that on a stub held in the lathe. alter the height of your bracket so you can mount the governor on the cross slide as you have a read out on the lathe too.


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## Brian Rupnow (Dec 7, 2022)

I thought of that Jason, but the rpm readout on my lathe doesn't work.


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## Brian Rupnow (Dec 7, 2022)

This video shows a set up whereby I can set the rpm of the governors to what it would be on the actual hit and miss engine, and see if the lockout pin in the center of my 60 tooth gear operates. This test was a definite fail----at 250 rpm, the governor weights and lockout pin didn't move at all. My conclusion is that I need a lighter governor return spring. The spring that I have in there now is one that I just picked up out of my tray full of springs and installed because it fit. Next step will be to replace it with a much lighter spring and try this test again.--Edit--Should have said 'When centrifugal force activates my governor"--Brian


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## CFLBob (Dec 7, 2022)

Brian Rupnow said:


> This video shows a set up whereby I can set the rpm of the governors to what it would be on the actual hit and miss engine, and see if the lockout pin in the center of my 60 tooth gear operates. This test was a definite fail----at 250 rpm, the governor weights and lockout pin didn't move at all. My conclusion is that I need a lighter governor return spring. The spring that I have in there now is one that I just picked up out of my tray full of springs and installed because it fit. Next step will be to replace it with a much lighter spring and try this test again.----Brian




One of the reasons I find this design process interesting is it's so far out of "my world."  All I know about springs is some Physics 101 or Statics stuff on spring constants.  And I've wound a few to different designs, stuff like "wind .010" music wire 1" long, close wound."  These things don't really tie together easily.  

Did you test how fast it has to spin before the spring pushes enough?  Is it engaging marginally too high, like 300 RPM, or closer to 500?  It might help you know how much weaker the spring needs to be.


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## Brian Rupnow (Dec 7, 2022)

CFLBob--95% of what I am doing is "Try it and see what happens" stuff. I know a fair bit from experience and from watching ten thousand videos, but it is mostly "Seat of the pants" engineering. My test today shows that the spring I am using is way to stiff---I needed to jack the rpm up to 800 before the governor would engage. So next thing was to try a few weaker springs from my spring collection. I came to the conclusion that not everything is "scaleable". Now I know why the full size Hercules engines  ran the governor off a smaller diameter gear and it revolved much faster than my governor which is ran off the cam gear, which only rotates at 1/2 the crankshaft speed. It is much easier to get consistent, repeatable results from a faster turning governor and a much stronger spring than from a low speed governor and a weaker spring. Eventually I used the lightest spring I had and started reassembling things on my engine. I have two compression springs to deal with here---one inside the governor which I tested today and is difficult to access, and one which fits inside the lockout lever and is easy to access. Ergo, my best hit and miss action will be tuned by monkeying with the spring in the lockout lever. I don't think I have ever seen a model engine using this style of governor, and perhaps today I found out why. I'm not terribly concerned-if I absolutely have to, I will change the governor to the Farm Boy sliding sleeve on the crankshaft style. This is the style that all my other hit and miss engines use. If I do change the style of governor, 90% of the engine remains unchanged. I've only sold one set of plans, and if I change the governor style I will send the guy new updated prints of anything that changes.---Brian


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## bruedney (Dec 8, 2022)

Could you add some holes filled with lead to the weights?


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## Steamchick (Dec 8, 2022)

Hi Brian, I heard depleted uranium is a bit more dense than lead... but mentioning that on an open website possible means I'll have a visit from the CIA now... I just don't know where to get that stuff. Tungsten is a reasonable alternative.

But maybe to get from 800rpm to 250rpm you simply need to add a lot more coils, or decrease the pre-load on the spring you have to make it 31% of the load as applied now.
K2


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## Vietti (Dec 8, 2022)

I puttered with an under performing governor years ago.  The first idea was to increase the weight of the fly balls by adding lead.  No effect.  I then read a little booklet on governors by Tee publishing (?) and the jist was the weight of the fly balls make no difference in a governor, IIRC, is this true?  Seems counter intuitive. I think a more effective fix for governor performance might be to lengthen the arms.


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## Steamchick (Dec 8, 2022)

The whole idea of a governor is a balance between mass of Bob weights, lever arm, spring pre-load and speed of rotation. From those 4 factors, altering any one will have an effect. But the degree to which any one affects the "set-speed" is really determined by the design. A bit of relatively simple maths can make a numerical model of a design, then that can be tweaked to a "working" condition without cutting metal.
Brian, if you want to send me a drawing of the governor I can do a mathematical model and suggest the optimum change(s). 
But I know you have a "natural feel" for these mechanical things, and are happy to manually tweak each variable as suits your design and boxes of bits (springs in this case?). 
K2


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## Brian Rupnow (Dec 8, 2022)

I just finished reassembling everything. Very little was changed. I did end up putting a very light spring inside the governor spindle, and I added a "wear ring" between the 60 tooth gear and the side frame of the engine. I will do more engine testing later today and give an opinion.


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## Brian Rupnow (Dec 8, 2022)

An honest opinion--Adding a spring inside the governor didn't do much for me. In fact, if anything, the engine is less inclined to hit and miss now than it was before I added the spring to the governor. The problem seems to be that the camshaft simply isn't turning fast enough to operate the governors properly.  Okay, I've learned something. I'm disappointed, but this is the way we learn. I've only sold one set of plans, but I will refund the guys money and give him the option of a refund or waiting for a new set of plans.  My next amazing stunt will be to see what's involved in putting a different governor and a sliding sleeve on the crankshaft, similar to that used on the Farm boy.


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## Steamchick (Dec 9, 2022)

Hi Brian, did you try without a spring, just to see at what speed the bob-weights actually fly out? If this is below the speed you want when the engine is idling in hit and miss mode, then there is hope for the design. The spring can only raise the speed of operation from the "no-spring" condition. - I think?
Of course, the "traditionalists" would note that for simplicity, the governors were usually geared-up from crank speed, on "slow" engines. But mathematically, all things are possible, but some things are unreasonable. 
Never stopped you from trying though!
Keep up this interesting project.
Regards,
K2


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## johwen (Dec 9, 2022)

Hi Brian I would have tried heavier weights  on the governor which would cause them to activate at a lower speed. Worth a try before a re design. Drill a hole in them and fill with lead John


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## raveney (Dec 9, 2022)

Brian Rupnow said:


> An honest opinion--Adding a spring inside the governor didn't do much for me. In fact, if anything, the engine is less inclined to hit and miss now than it was before I added the spring to the governor. The problem seems to be that the camshaft simply isn't turning fast enough to operate the governors properly.  Okay, I've learned something. I'm disappointed, but this is the way we learn. I've only sold one set of plans, but I will refund the guys money and give him the option of a refund or waiting for a new set of plans.  My next amazing stunt will be to see what's involved in putting a different governor and a sliding sleeve on the crankshaft, similar to that used on the Farm boy.


Brian,
Admiring your tenacity, and sharing your frustration. 
Would you consider modifying the weights so the mass center of gravity is moved farther out the moment arm? 
Perhaps the red area could be ground, filed, milled away as a last ditch effort before scrapping?


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## dsage (Dec 9, 2022)

IF the above diagram is correct for Brian's design then I have to agree with Raveney.
It appears to me most of the mass is inboard (and even a bit below) the pivot point. In my mind there would be little to no centrifugal force acting on the mass to fly out in a direction along the plane of the page.
 In fact, if there is any force it will be against the pivot pin NOT in a direction vertical on the drawing which would be necessary for the weight to move. And possibly even some in a downward direction.
I agree that the predominance of the mass should be out where Raveney has drawn the big black dot. Leaving only a thin section to act on the pin. Almost like you should flip the weights over on the pins.

Brian I think you can solve this problem with a little bit of rework on the weights. I wouldn't abandon it yet.


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## Brian Rupnow (Dec 9, 2022)

There isn't enough room to add anything to the existing governor weights. They can't be taller or they hit the connecting rod. They can't be longer on the opposite end because they hit the engine sideplate. They could be drilled and filled with lead, but there is such an insignificant difference in the weight of lead and the weight of steel that I doubt that would help. Today I'm off on a quest to use a different style of governor and try and save all the existing parts of the engine that are already made. Thank you for your interest and your comments. This rodeo isn't over yet.---Brian


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## Sparky_SC (Dec 9, 2022)

Brian Rupnow said:


> There isn't enough room to add anything to the existing governor weights. They can't be taller or they hit the connecting rod. They can't be longer on the opposite end because they hit the engine sideplate. They could be drilled and filled with lead, but there is such an insignificant difference in the weight of lead and the weight of steel that I doubt that would help. Today I'm off on a quest to use a different style of governor and try and save all the existing parts of the engine that are already made. Thank you for your interest and your comments. This rodeo isn't over yet.---Brian


The excellent suggestions given suggest removing material inboard of the pivot pin, not necessarily adding, making taller etc.     It could be a simple fix that would only take a few minutes to machine away some material and try.


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## Brian Rupnow (Dec 9, 2022)

So, this is the Farm Boy style governor. It will fit on one end of the crankshaft, and the butterfly shaped part will bolt to the side of the flywheel, the sliding sleeve slides back and forth on the crankshaft, The lockout arm end (which is not shown) will fit in the unoccupied ring and pivot over the camshaft centerline. note that I do not have drawings of the Farm Boy engine here, but there are enough videos of other peoples builds on the internet that 98% of the information is there, if you hunt for it.


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## Steamchick (Dec 9, 2022)

Hi Brian,
Just found 10 mins to review your design per post #241, and agree with the idea from post # 272 etc by Raveney and Dsage, but you know what is possible in the available space. But doubling the "acting" mass only reduces the effect of the governor from 800rpm to 800/(sq.root. 2) =571rpm. (v= sq.root of (F x r / m) ). Doubling the speed of the governor (if fitted on the crankshaft) gives you the 800 rpm operating speed at 800 rpm of the crankshaft, not 800 rpm of the camshaft, so you need more leverage, and or mass using this (equivalent) design on the crankshaft instead of the camshaft to resolve the issue.  Just a bit more work than simple tweaking.
Regards,
Ken


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## Brian Rupnow (Dec 9, 2022)

Thank you Steamchick--I have spent today redesigning the engine for a Farm Boy style governor. Surprisingly, very little of the existing engine has changed. The crankshaft gets swapped end for end, the engine sideplate on the governor side gets replaced (or repaired) , and the 60 tooth gear gets recut. One flywheel gets some clearance holes added for the governor weights, and the starter hub gets moved to the flywheel on the other side of the engine. One of the pushrod guides gets moved over a bit, and the lockout lever gets replaced. Since I have the capability to weld aluminum, I may plug the hole in the side of the engine sideplate which originally held a 7/8" roller bearing and simply add a threaded hole to the plug to accept a shoulder bolt. The new shoulder bolt will be custom machined with a slot to hold the new lockout arm.


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## Charles Lamont (Dec 9, 2022)

Although it is moot, as Brian has done a complete redesign, I cannot see any significant advantage in removing the hatched red bit from the narrow actuating fingers as proposed by Raveney and supported by several others.

The radius of gyration of the weight is one consideration, but what also matters is the the moment of the mass about the pivot pin, in the plane of the paper. Now, in the extended position, the mass of said red area is more or less equally disposed, half above (outboard of) and half below (inboard of) the pin. Net result - nada.


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## Harglo (Dec 10, 2022)

Brain
Any thoughts on changing the pivot points of the gov arms?
Harvey


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## Brian Rupnow (Dec 10, 2022)

For those of you who thought I could change the pivot points or remove material from the top of the governor weights----there simply is no room to do this. The top side of the governor weights where the pivot pin goes thru is simply a narrow band of material which can not be made any smaller. There is nowhere to move the pivots to. The space for this governor is very restricted. This is the kind of thing that either works the way I have it, or doesn't work at all.  It does work, but only at higher rpm than the cam shaft never reaches. That is why I'm changing my design to the crankshaft which spins twice as fast as the camshaft, and has more available room.---Brian


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## Brian Rupnow (Dec 10, 2022)

Bits and pieces, pieces and bits. I decided at the last minutes to use some hex stock I had instead of round brass governor balls.  I will probably finish this governor tomorrow.


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## Brian Rupnow (Dec 11, 2022)

As my dear old dad used to say, "No rest for the wicked!!" And I must have been pretty damned wicked because I sure didn't get much set-around time today. But--I have a new governor. There is an amazing amount of work in such a small, uncomplicated thing!!


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## Brian Rupnow (Dec 12, 2022)

Today I modified one flywheel where the new governor weights stick thru the face of the flywheel, and I'm just about to make a test run to select a proper spring. I will post a video of the governor "working". I also spent some of the Rupnow fortune and bought a beautiful little oiler off Ebay. The oiler is very nice, cost about $25 Canadian.


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## Brian Rupnow (Dec 12, 2022)

Engine has been torn down---(This only takes about 15 minutes). Crankshaft has been reversed so the starter hub and flywheel goes on the other side where the ignition points are and the long end of the crank now sticks out to receive the modified flywheel and new governor. The roller bearing will be pressed out of the sideplate and a plug welded in to fill the hole. My tig can weld aluminum, and luckily for me the weld will all be hidden behind the flywheel.---if I totally screw up the weld, I have lots of material to make a new sideplate if I have to. I did make a video of the new governor working, but the quality was poor so I'm not going to post it.  (The new governor seems to work fine.)


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## Brian Rupnow (Dec 13, 2022)

Today I turned the plug which will be welded into the engine sideplate where the roller bearing used to be, and tapped a 5/16"-18 hole through the center of it. I made up a "special" shoulder bolt which acts as a stationary camshaft, and I was able to build a jig which let me turn the end off the original camshaft and and save the actual cam portion and the gear. The gear/cam got rebored to fit the special shoulder bolt. Now all I have to do is weld that plug in place, and then I can begin reassembling things.


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## Brian Rupnow (Dec 13, 2022)

Well Sir!!! That wasn't just a fail. It was an absolutely horrible fail. By the time I had things hot enough to form a puddle and add some aluminum filler rod, the whole damned thing turned into a slush puppy and  poured itself down the table. Fortunately, it didn't run off the table and down the top of my boot. (That did actually happen about 55 years ago when I was learning to braze patches onto a 1953 Ford pickup.) No more tig welding for me until I can take a course in basic tig welding. POOP!!!---Tomorrow I will machine a new sideplate to replace the one I melted.


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## Sparky_SC (Dec 13, 2022)

Rough rule of thumb is 1 amp for each thousandth of material thickness without preheating.    With a TIG like you have preheating a piece like that is  mandatory.    If you don't preheat the aluminum will just absorb the heat applied and not puddle until the entire piece is near melting point.     Preheating to 350-400 degrees makes a world of difference, you can quickly get a puddle going on thicker pieces.        Too late now, the boat has sailed but preheating is standard practice on thicker aluminum pieces.    Steel does not conduct the heat away from the arc nearly as fast so the problem does not happen like with aluminum.


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## Brian Rupnow (Dec 13, 2022)

In retrospect--I think part of my mistake was putting in that big 45 degree chamfer on the "plug" as seen in post #286. That would be normal with stick or mig welding. The filler rod would fill up the prepared v-groove and get good penetration into both pieces. I would probably put a lot less heat into the part while welding if I hadn't put that v-groove in there.


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## Sparky_SC (Dec 13, 2022)

Brian Rupnow said:


> In retrospect--I think part of my mistake was putting in that big 45 degree chamfer on the "plug" as seen in post #286. That would be normal with stick or mig welding. The filler rod would fill up the prepared v-groove and get good penetration into both pieces. I would probably put a lot less heat into the part while welding if I hadn't put that v-groove in there.


Deep V grooves with a gap are standard practice TIG welding pipe.    Even the best pro tig welder couldn't have done that piece without preheating using a welder limited to 200 amps max.


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## Sparky_SC (Dec 13, 2022)

Here is a hinge knuckle I made for my skid steer.    Its 5 pieces total.   The largest section is 1-1/2 inches thick.    With preheat I did it at about 150amps.   Without preheat not a prayer.


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## pileskis (Dec 13, 2022)

Brian Rupnow said:


> Well Sir!!! That wasn't just a fail. It was an absolutely horrible fail. By the time I had things hot enough to form a puddle and add some aluminum filler rod, the whole damned thing turned into a slush puppy and  poured itself down the table. Fortunately, it didn't run off the table and down the top of my boot. (That did actually happen about 55 years ago when I was learning to braze patches onto a 1953 Ford pickup.) No more tig welding for me until I can take a course in basic tig welding. POOP!!!---Tomorrow I will machine a new sideplate to replace the one I melted.


Did you have the gas turned on??
Better start making the new piece.......


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## Brian Rupnow (Dec 14, 2022)

Okay, we're back in business. Made a new sideplate this morning. No trauma, everything fits. I have to go out now and pick up some supplies and shuttle a teenage granddaughter from one school to another school. She is taking pictures of sports events at about 5 different local highschools for a yearbook.


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## Brian Rupnow (Dec 14, 2022)

And a very expensive afternoon it turned out to be. I stopped at about 5 different places, picking up taps, bearings, steel rod, etcetera, and the last place I stopped before picking up my granddaughter, my truck wouldn't start. Tried boosting the battery---made no difference. Not even a click click when I tried to engage the starter. Had to get a flatbed tow-tuck to come and load up my truck and take it to the Ford garage. That cost $100.00  Got a ride home, and about an hour later Ford called, truck needs a new starter----$650.00. Bah Humbug!!! My Christmas present to myself!!!


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## Ghosty (Dec 14, 2022)

Brian,
It is always when you need the truck, I have several trips in the next week that i will need my phone for when traveling, it died two days ago, had to buy a new one at $1600, hurts this time of the year.
Cheers
Andrew


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## Brian Rupnow (Dec 14, 2022)

Andrew--I've driven a half ton truck almost all my life, and for the first 50 or 60 years I used it as a truck. The last five years I've driven a truck, but truthfully, the last five years I've hardly carried anything in it. Yes, it's a big ouch to have to pay out $750 unexpected dollars just before Christmas.


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## Steamchick (Dec 15, 2022)

I feel for you Brian. Just when you are on top of things, sometimes "Fate" hits you between the thighs... (Or the wallet). But in this case, no-one got hurt or anything, so "stiff upper lip and Carry on". (As you did with the model).
I'm off to a funeral today... another big C victim. An Engineer who was 12 years chairman of the local Model Engineers...
His models and memory lives on.
Cheers my friend.
K2


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## Brian Rupnow (Dec 15, 2022)

Great progress was made today---Flywheels are remounted, new governor is in place, and new pushrod guide is finished and installed, and half of the new lockout arm has been machined. Tomorrow I hope to make a new pushrod and machine the other half of the new lockout arm. We are having a full grown blizzard outside today---all day. It's a good day to be inside.


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## Brian Rupnow (Dec 17, 2022)

Today I am all finished with the governor changes. Luckily, I didn't have to make any changes to the crankshaft nor any of the other engine frame parts. I did machine and add the Farm Boy style governor with sliding sleeve on the crankshaft, a new push rod, and a new push rod guide. The lockout lever also changed. I had to relocate the condenser form the side of the engine to the back of the engine to get some additional flywheel clearance. Since the flywheel with the starter hub switched to the other side of the engine, I had to retime the ignition and the valve timing, but that was a 5 minute job. The engine will now rotate in the opposite direction to what it did before. Now I have to dick about to find the proper spring strong enough to hold the governor  counterweights in their "not engaged" condition at low rpm  but weak enough to let the governor engage at about 500 rpm. That is always a guessing game until you find the right spring. I hope to start some trial runs this afternoon.---Brian


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## Brian Rupnow (Dec 17, 2022)

Getting some awesome results here. New governor is working fine. Still tuning to find a happy speed, but looks very promising.


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## Brian Rupnow (Dec 17, 2022)

I have completed the Farm Boy style governor  on my hit and miss engine, and it does everything that I had hoped it would do. I'm getting a good differentiation between hit and miss cycles, the governor is operating and the engine is running good. When I first built this engine, I used a different governor, similar to that used on the old Hercules hit and miss engines, but I didn't have any way of adjusting it, and due to lack of room it was a failure. I'm very pleased with the way this has worked out.---Brian


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## Brian Rupnow (Dec 17, 2022)

Well Sir!! That new oiler is a pretty thing. So far I have been running the engine on 2-cycle gas, which has some oil mixed with it. Makes a Hell of a mess all over everything. That oil doesn't really burn---it lubricates the piston and then spews out the exhaust and covers everything on the engine. I'm hoping that the new oiler will serve to lubricate the piston but not to the point where it is spewing out my exhaust. Now that the engine is running, I will switch back to the home made carburetor. The purchased carburetor was only a temporary thing, to ensure that I wasn't going to have carburetor problems which are rather horrible to diagnose.


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## Nerd1000 (Dec 17, 2022)

You might try using TC-W3 oil for outboard motors, it burns at lower temperatures than regular 2 cycle oil.

It's also worth noting that regular 2 cycle premix is set up for the engine running full power, at light load and idle there is far more oil than needed.


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## Jasonb (Dec 18, 2022)

You are better off using the drip feed oiler than adding much if any to the fuel as it is a hit and miss engine the drip feed will still keep lubricating when the engine is freewheeling, mixed oil will only get drawn in on the hit cycles.

Most engines of this layout also have a hole in the top side of the piston above the wrist pin so some oil can drop down and lubricate that which oil in the fuel won't do either.

You can still put the 2-stroke oil into the drip feed so any that does get up past the ring will burn off.


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## Brian Rupnow (Dec 18, 2022)

Wife is out Christmas shopping. I am down in the shop playing. I've been changing governor springs this morning. I had a weak spring on the governor arms, and the engine would idle very, very slowly. Only thing is, at that slow an rpm, the engine only has to burp once and it stalls. Then I tried a stronger spring, but the engine revved to high, even though the hit and miss was working. Then I put my original weak spring back in, but cut two coils from it. That seems to have done the trick. My idle speed is a bit faster than it was, but it's fast enough that if the engine does "burp" the momentum of the flywheels carry it on thru the cycle to the next firing stroke. That purchased oiler works really well---no mess all over my engine from unburned oil. I've got a grandson coming over this afternoon to watch the original Avatar movie with me, then next week we'll go and see the second Avatar movie at the theatre.


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## Brian Rupnow (Dec 18, 2022)

Okay, I'm happy with the engine now, and next week I will put the home made carburetor back on it. I feel confident now that if someone builds this engine from my plans, they will end up with a working hit and miss engine. I have revised and updated the drawings, and will be sending a new drawing package to anyone who has purchased the plan set.  If you are really bold and are looking for a project in the new year, I sell the complete plan set for $25 Canadian funds. This gives assembly drawings, sub assembly drawings, parts lists and detail drawings. If you want to buy a plan set, contact me thru the forum.---Brian rupnow


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## Sparky_SC (Dec 18, 2022)

How many RPM's is that in the latest video?


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## Brian Rupnow (Dec 18, 2022)

Don't know Sparky. I'll check it tomorrow. I may design something that lets me alter the spring tension without having to change springs.--Brian


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## Brian Rupnow (Dec 19, 2022)




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## Brian Rupnow (Dec 20, 2022)

I am being asked about the tension and compression springs used on this engine. Here is a run down of the 4 springs which are used.  The intake valve spring is a compression spring  0.013" diameter wire  x 0.75" free length x 0.215" outside diameter. The exhaust valve spring is a compression spring 0.025" wire x 0.75" free length. x 0.300" outside diameter,  The pushrod return spring is a tension spring 0.022" wire diameter x 0.190" outside diameter with a loop at both ends x 1 1/4" center to center of loops. The spring between the ends of the governor is a tension spring 0.019" wire  x 0.213" outside diameter with a loop at both ends, the center to center of loops is 0.9" free length.


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## Brian Rupnow (Dec 20, 2022)

This video shows my hit and miss engine running with the home made carburetor on it. My first few runs with this engine were made with a purchased Traxxas carburetor on it until I got everything tweaked and adjusted properly. Then I removed the Traxxas carburetor and installed the home built carburetor, which actually works better than the Traxxas for this application. Plans for this home made carburetor are included in the drawing package.---Brian


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## mnay (Dec 20, 2022)

Brian,
Just something to try.
The late Bob Shores suggested Coleman Fuel with 10% WD-40 mixed in.  Burns very clean and also keeps the cylinder lubricated.
I have run my Hit and Miss on it and have not had to use any other lubrication.


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## Brian Rupnow (Dec 20, 2022)

Mnay--Thanks---With the drip oiler on the engine I don't have to mix any oil with the fuel now. Just straight Coleman fuel.


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## Brian Rupnow (Dec 22, 2022)

So, my friends, this is the end. It has been a good build, mostly everything only got machined once, and it hits and misses like it is supposed to. I'm ready for Christmas, and there's a bottle of Baileys upstairs with my name on it. Merry Christmas to you all, and may we all have a great New Year.----Brian


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## lathe nut (Dec 23, 2022)

Brian, thanks again for your time to share your knowledge and skills with us, that truly is a fine-looking machine and runs as good as it  looks,  you have a way of not making it difficult when it really is, again thanks for sharing with us, after you get the Holidays behind you makes one wonder what is next. Joe


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## ShopShoe (Dec 23, 2022)

Thanks again for a nice project and a nice series of posts following its build. As always, I enjoy the saga of each one and your posting of your experiences "warts and all."

Merry Christmas and Happy New Year and enjoy that Bailey's.

--ShopShoe


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## karlw144 (Dec 23, 2022)

Brian, I sure enjoy your designs and builds. Amazed at how quickly you go from “I’m bored“ to having a running engine.  Schmuck ups and redirects are just the way it goes sometimes. Was in Barrie once about 20 years ago and traded an Amco shaper for a tuba (long story here). Spent 3-4 weeks every winter in Kapuskasing doing tests for GM. Don’t miss that at all.
karl


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## Brian Rupnow (Dec 24, 2022)

Karlw---I worked in Kapuskasing about 50 years ago at Spruce Falls paper company. They had an opening there for a young engineer, as an older guy was retiring. One thing for damn sure, you didn't leave your brass monkey outside at night in the wintertime!!!---Brian


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## Brian Rupnow (Dec 27, 2022)

Just a foot-note. When I first assembled this engine, it had amazing compression, and would "bounce back" if you spun the flywheels by hand. I have about 3 hours total run time on it, and each time it ran, it seemed to have a little less compression. Finally, yesterday, it didn't even have any "bounce back" when you flipped the flywheels by hand. It would still start and run just fine, but that lack of compression bothered me.  I've never had an exhaust valve or a intake valve burn on me, so that only left one thing, the Viton compression ring. This morning I dismantled things and removed the ring. When set side by side with a brand new Viton ring, the old ring was visibly smaller in cross section than the new ring. I put a new Viton ring in, reassembled everything, and my compression is back in a huge way. The engine starts right up and runs good. I haven't seen this happen before on any of my other engines. All I can conclude is that the first ring gave up most of it's life bringing the inside of the cylinder to a very fine finish. I don't expect this to happen again, but thought that I would mention it here.


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## Gordon (Dec 27, 2022)

Brian Rupnow said:


> Just a foot-note. When I first assembled this engine, it had amazing compression, and would "bounce back" if you spun the flywheels by hand. I have about 3 hours total run time on it, and each time it ran, it seemed to have a little less compression. Finally, yesterday, it didn't even have any "bounce back" when you flipped the flywheels by hand. It would still start and run just fine, but that lack of compression bothered me.  I've never had an exhaust valve or a intake valve burn on me, so that only left one thing, the Viton compression ring. This morning I dismantled things and removed the ring. When set side by side with a brand new Viton ring, the old ring was visibly smaller in cross section than the new ring. I put a new Viton ring in, reassembled everything, and my compression is back in a huge way. The engine starts right up and runs good. I haven't seen this happen before on any of my other engines. All I can conclude is that the first ring gave up most of it's life bringing the inside of the cylinder to a very fine finish. I don't expect this to happen again, but thought that I would mention it here.


Is it perhaps due to the fact that you were adding oil to the gas and when you put on the drip oiler you no longer added oil to the gas? Has this happened since you stopped using oil in the gas?


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## Brian Rupnow (Dec 27, 2022)

You could be right Gordon. That is about the only thing that is different. The oiler does let drips of oil directly into the cylinder, where it is picked up by the piston skirt and spread over the entire inside of the cylinder as a lubricant. If it is the fault of the oiler, then I expect to have it happen again. Really good suggestion.---Brian


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## JohnBDownunder (Dec 28, 2022)

For what its worth Brian, a friend's Farm Boy Hit & Miss needed a new Viton ring after a few, (8hr or so) hour running. He was sure it was mostly the ring polishing the bore during those first hours of running.
It has since clocked up 300 - 400 hours as he runs it for the 4 days of our local agricultural show. I am unsure how many rings have been replaced in total but think a couple as a routine service after each show.


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## Brian Rupnow (Dec 28, 2022)

Thanks John--if it continues a problem, I will make a cast iron piston with heat treated cast iron rings.---Brian


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## Brian Rupnow (Dec 29, 2022)

This is a video of my newest hit and miss engine doing some real work. I'm running low on wood for my kitchen stove and my fireplace, so I hitched up my two field mice Sally and Dobbin and skidded up a few logs from out of the woods. Going to cut them into lengths for the woodstove and get the wife to split them and carry them up to the stove when she gets home from buying groceries.


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## Brian Rupnow (Dec 29, 2022)

Wife said her back was tired from grocery shopping, so I said "Don't worry Honey, I'll do it with my woodsplitter."


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## Gordon (Dec 29, 2022)

Brian Rupnow said:


> This is a video of my newest hit and miss engine doing some real work. I'm running low on wood for my kitchen stove and my fireplace, so I hitched up my two field mice Sally and Dobbin and skidded up a few logs from out of the woods. Going to cut them into lengths for the woodstove and get the wife to split them and carry them up to the stove when she gets home from buying groceries.



Why are you sending your wife out to the grocery store? Why not just go kill a bear for her?


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## Brian Rupnow (Dec 29, 2022)

Bears are all denned up for the winter. Maybe I'll get one when spring comes.----


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## awake (Dec 30, 2022)

They're skinny in the spring, after hibernating; best to bag them in the fall.


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## Brian Rupnow (Jan 1, 2023)

Well, all good things must come to an end. I'm happy with this engine. It hits, it misses, and it keeps running. If you don't know---there are a myriad of things to "tweak" on these engines to make them hit more often---miss more often---switch from hitting and missing to hitting every other stroke while running under load. Counterweight size can be changed. Counterweight spring can be changed. Spark timing can be tweaked. Valve timing may be tweaked. Diameter and weight of flywheels can be tweaked. Carb needle setting can be tweaked. All of these things can be infinitely be tweaked until you get the results you wanted. This engine is finished and it's time to put it up on a shelf with my other fourty engines. Hope you all enjoyed it, it's been fun from my end.----Brian


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## CFLBob (Jan 1, 2023)

Brian Rupnow said:


> Well, all good things must come to an end. I'm happy with this engine. It hits, it misses, and it keeps running. If you don't know---there are a myriad of things to "tweak" on these engines to make them hit more often---miss more often---switch from hitting and missing to hitting every other stroke while running under load. Counterweight size can be changed. Counterweight spring can be changed. Spark timing can be tweaked. Valve timing may be tweaked. Diameter and weight of flywheels can be tweaked. Carb needle setting can be tweaked. All of these things can be infinitely be tweaked until you get the results you wanted. This engine is finished and it's time to put it up on a shelf with my other fourty engines. Hope you all enjoyed it, it's been fun from my end.----Brian



It _has _been interesting to watch.  What's next?  Do you have another design, another kind, or another thread going I haven't bumbled and stumbled across?


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## Brian Rupnow (Jan 1, 2023)

No Bob---Nothing new. I am not very happy about the way things were left on the V-twin engine. It ran, but not in a controlled fashion. It is not enough for me that an engine runs. It has to run and respond to the throttle in a controlled manner.  I will be jumping back to that thread in the coming week, to see why it ran but not in the fashion that suits me.---Brian


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## JohnBDownunder (Jan 2, 2023)

Thanks again for posting Brian. Your posts are always an interesting read that I look forward to.
John B


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## Oldiron (Jan 2, 2023)

Did you ever post a build of that wood splitter. Looks cool. Bob


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## Brian Rupnow (Jan 2, 2023)

Model Woodsplitter
					

As far as  I am able to determine, no one has built a model wood splitter. A google search on wood splitters show two main types, either hydraulic (which are not suitable for a model, in my opinion), and electric screw type which might hold some promise.  Then of course there is the cone shaped...




					www.homemodelenginemachinist.com


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## Brian Rupnow (Jan 2, 2023)

Model Woodsplitter
					

As far as  I am able to determine, no one has built a model wood splitter. A google search on wood splitters show two main types, either hydraulic (which are not suitable for a model, in my opinion), and electric screw type which might hold some promise.  Then of course there is the cone shaped...




					www.homemodelenginemachinist.com


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## Brian Rupnow (Jan 4, 2023)

I LIED!!! I wanted to see what effect heavier flywheels would have, but didn't want to make new flywheels. I got digging around in that $100 worth of material I bought a few weeks ago from a guy who was leaving the hobby, and found a big piece of 1/8" brass plate. So---I made a "bolt on" piece which bolts to the outside of each flywheel. The danger of making a flywheel too heavy, is that the engine has to fire two or three times before the flywheels can gain enough speed to make the governors work. The danger of making them too light is basically that you won't have a good long "coast" time between firings.


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## JohnBDownunder (Jan 5, 2023)

Yeah, Well now we all want to see it running OR not. Pretty Please.
Well at least I do, probably shouldn't speak for all who are following.
My uneducated guess = a few firing strokes and prolonged miss cycle?
John B


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## Brian Rupnow (Jan 5, 2023)

And now you know how I spent my morning, and a good part of my afternoon. The brass rings added to the flywheels definitely make the engine a bit prettier, but I don't really see a big difference in the hit and miss action.


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## JohnBDownunder (Jan 6, 2023)

Oh Well, looks good. My only suggestion would be that perhaps swapping to countersunk bolts in the brass rings would improve the look?
I really like it, 
congrats,
John B


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