# Rockerblock I.C.--Something a little different-



## Brian Rupnow (Apr 6, 2017)

And I do mean different. I want to machine something---but--Something I haven't seen or done before. This is destined to become a water-jacketed engine, 1" bore x 1.125" stroke. I have been casting around for something new to build, and I thought this up last night while fighting off my insomnia. A couple of hours spent on the CAD system this evening just to see if it could be done, and yes, it can. There will probably be many redesigns and changes along the way, but basically this is the overall framework I will stick to.


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## Brian Rupnow (Apr 6, 2017)

And yes, I'm even toying with the idea of water-jet cut flywheels.


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## Ghosty (Apr 6, 2017)

Brian,
I will be watching this one.

Cheers
Andrew


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## Journeyman (Apr 7, 2017)

Brian, saw your drawing and imediately thought - Atkinson Cycle Engine! Shall be watching closely.
John


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## ShopShoe (Apr 7, 2017)

Brian,

I will be watching. This one looks to be very interesting.

--ShopShoe


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## Brian Rupnow (Apr 7, 2017)

Well Sir, This is getting exciting. I love it when a plan begins to come together.


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## Brian Rupnow (Apr 7, 2017)

Now my engine can breath in and breath out. Another hours work and it will have ignition.--And yes, it does even have pushrods.--Little short ones at that, with little swivels where they attach to the rockers to take out any binding.


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## Brian Rupnow (Apr 7, 2017)

I almost got caught. Look at the creative carving I had to do on the bottom of that water jacket to clear the revolving crankshaft.


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## Brian Rupnow (Apr 7, 2017)

Speaking of the water jacket, my plan for sealing the jacket to the o.d. of the cylinder is shown in this section view of the water jacket. An annular groove cut at each end, just slightly shallower than the cross sectional thickness of a .094 Viton o-ring. Hopefully an o-ring in each groove will seal any water leaks. I will be able to get two or three bolts thru from the flange on the cylinder  into one end of the water jacket to keep it from turning on the cylinder.


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## Brian Rupnow (Apr 7, 2017)

Well Hot-Dog!! I even managed to sneak an ignition cam and my old stand by Chrysler ignition points in behind the offside flywheel.


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## Brian Rupnow (Apr 7, 2017)

There. That's a solid 8 hours playing. I have to dwell a bit on whether or not I have the crankshaft counterbalances on the correct side of the crankshaft or not, but other than that and a gas tank, the engine design/modelling is finished. Now I have to go shovel out the end of the driveway. We got 5" of April Fools last night. Yuk!! I was hoping we were done with that white stuff!!


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## Brian Rupnow (Apr 7, 2017)

I always think it sucks to design a nicely proportioned engine, and then stick a gas tank on it. Gas tanks don't leave you with a whole lot of options. They have to be near the carburetor, they have to set below the carburetor throat (but not too far below), they shouldn't block any other equipment which needs frequent adjusting, and they shouldn't be directly in line with the exhaust. That being said, you just do the best you can and hope it doesn't ugly things up too much. This is not an improvement over the normally configured gas engine. It's just a different, artsy fartsy way of doing it.


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## Johno1958 (Apr 7, 2017)

Brian this is a very compact , tidy little engine.
I like the look.
Cheers
John


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## Brian Rupnow (Apr 7, 2017)

Thanks John--It's amazing, the things I get up to when it's snowing outside and I don't have any "real" work to keep me occupied.---Brian


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## Brian Rupnow (Apr 7, 2017)

I ended up having to angle both the exhaust and the carburetor out 12 degrees from centerline to clear the gas tank. I could have squeaked by with leaving them "in line" but it would have been severely crowded, and since I have to make the yellow "elbows" anyways, I might as well do this and buy a bit of room.


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## Cogsy (Apr 7, 2017)

I'm looking forward to seeing this one. Looks great!


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## Brian Rupnow (Apr 8, 2017)

Has anybody used this type of con-rod connection at the crankshaft? I'm pressed for room where my rod attaches to the one piece crankshaft, and this would get me out of trouble. I think the actual hole for the rod journal would be the last step in the fabricating operation so everything would run true. I haven't used this before, but there's a first time for everything.--Brian


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## Brian Rupnow (Apr 8, 2017)

Dang, this thing is like a big chocolate cake!! All the pieces look so good, I don't know where to start. The beauty is in the simplicity. I shouldn't get so excited about my own work. Every time I do this I swear to myself that I'm going to take it easy, there's no rush, I'll just work on it in my spare time. Then it takes over my life and making another part is all I can think about. Good wife is away at her job in the local library, and won't be home until 3:00, so I think I'll make gears today. Gears are always fun. A bit intimidating, but fun, nonetheless.


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## Brian Rupnow (Apr 8, 2017)

What good is a build thread without "in process" shots? This is my 50 tooth gear, emerging from another "chucking stub" left over  from making a cast iron cylinder. It was barely, barely long enough. I hate doing really short stubs, because if you get to close to those hardened chuck jaws with the gear cutter you can kiss $80 goodbye. The 25 tooth gear which I will do next is on a comfortably longer piece of 1045 steel that was left over from a customer job.


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## Niels Abildgaard (Apr 8, 2017)

Brian Rupnow said:


> Has anybody used this type of con-rod connection at the crankshaft? I'm pressed for room where my rod attaches to the one piece crankshaft, and this would get me out of trouble. I think the actual hole for the rod journal would be the last step in the fabricating operation so everything would run true. I haven't used this before, but there's a first time for everything.--Brian



Two long screws with nuts are better than four short ones.

The easiest way to get acceptable balance is to put weigths on flywheels like steam locomotive wheels.
Either trial and error or doing it up front on Your CAD system.
It will be  easier/better if piston mass starts as low as possible


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## bazmak (Apr 8, 2017)

I disagree Niels.If Brian needs to be compact then single tapped holes thru
with short csk screws from each side are more compact and more pleasing
If the engine was a Victorian copy then nuts and washers/studs etc would 
be more in keeping.If there is room then I would prefer button hex hd
rather than csk.Just me. Regards barry


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## Brian Rupnow (Apr 8, 2017)

So--Today we made a start. I like cutting gears. I especially like making gears from left over bits and pieces that I have laying about. I always drill a pair of holes the calculated distance apart in a piece of scrap and fit the gears to shafts which set in the reamed holes. It is much better to do it this way and correct any "tightness" in the mesh, rather than trying to do it in a partially assembled engine. These gears seem to be "just right", although that is never a certain thing.


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## Charles Lamont (Apr 8, 2017)

Countersunk screws in shear, especially in a dynamic situation, tend to work loose. Fitted bolts in reamed holes is the "proper" way to do it.

If you need more room, the height of the crankshaft could be dropped a little in relation to the main rocker pivot, making the engine désaxé.* Although that would lose some of the pleasing compactness of the design.

Can I also suggest a much smaller shoulder on the cylinder liner instead of the thick flange. This would allow the jacket to bolt directly to the head plate, very much improving the cooling, and allow the liner to be made from a considerably cheaper bit of iron bar.

(* Any reader getting wierd characters, they are supposed to be 'e-acute'.)


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## dnalot (Apr 9, 2017)

> Has anybody used this type of con-rod connection at the crankshaft?


 
I used that kind of rod end on my Minnie Traction Engine. To keep the strap tight and accurately located I used a tapered pin between the screws. 

Mark T


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## Brian Rupnow (Apr 9, 2017)

Flat head capscrews as I have shown, also are self centering. You don't need a locating dowel when using that type of screw, although I would probably put one locating dowel between them. I'm still thinking on this one. It seems pretty obvious that the bolted on section would have to be bolted on as a solid piece with no hole to a rod end with no hole. The joint would be right on the split line. The screws are all tightened and a dowel inserted first, then the hole is drilled and reamed after the fact.


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## Brian Rupnow (Apr 9, 2017)

I think that to make the con rod a two piece like I'm thinking of, two separate pieces would have to be machined and bolted (and possibly dowelled) together as shown in the first picture. Then after they are firmly bolted and possibly dowelled together, the hole gets put in as shown in the second picture. The sides would have to be match marked to make sure they went back together the same way they came apart. Then they could be separated and put back together around the rod journal.


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## Brian Rupnow (Apr 10, 2017)

Hey---I'm not just a pretty face!! Sometimes I do real work too. Saturday I made gears. Sunday a customer came by on his way up to the Blue Mountain ski area and left me the smallest arbor press in the world to make some modified tooling for it. It is used for a punching/staking operation which he was previously doing in his vice.


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## Brian Rupnow (Apr 12, 2017)

Okay--Back to business. Immediately after I had machined the gears my phone rang about 5 times in a row, each time with a customer I couldn't turn down, and each customer wanted to be looked after "right now". Being a slave to my bank balance, I said yes to all of them, and haven't had time to play "small engine" since. I have discovered one thing, and I'm not sure yet whether it is really a problem or not. When I make built up crankshafts from 3/8" diameter stock, I ream the holes which I am pressing shafts into with a 0.3735" reamer. I use 3/8" drill rod for the shafts, which always seems to come in at .0005" oversize. This gives a VERY hard press fit, with .002" interference, and I have never had one "slip" after the fact. I don't use 3/8" cold rolled steel because it comes in at about .0005 to .0001" undersize, and though it does give a press fit, it is quite a light press fit, and it WILL slip after the fact. Last year I purchased a 0.4985" diameter reamer in case I wanted to make a crankshaft using 1/2" nominal shafting. The problem is, that I just stopped at my metal supplier today  and micrometer measured all of their "01" drill rod, and it all comes in exactly at 0.500" diameter. So--I will only achieve a .0015" interference fit. I have to think on this a bit before I proceed. ---Brian


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## Ghosty (Apr 12, 2017)

Brian, 
Have you thought about an adjustable reamer?, Set it to the size that you need and done.

Cheers
Andrew


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## deverett (Apr 12, 2017)

Brian

If you are concerned about the press fit slipping, why not cross drill and pin after the press fit?  No chance of a slip that way.

Dave
The Emerald Isle


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## Brian Rupnow (Apr 12, 2017)

What to do--What to do??--Well, we'll make a little test. I drilled and reamed a 0.4985 hole in a piece of 3/8" mild steel, and I turned a very slight "lead" on the end of a piece of 1/2" drill rod, and I pressed it to see what happens. This type of pressing can not be done on a manual arbor press. It gets done in my vice. This was tight, but not "Oh my God, I've just given myself a hernia" tight. (That's the way it is with a .002" interference.) So, to farther quantify the results (We're getting really scientific here), I put the piece of plate in the vice, clamped my vice grips on the 1/2" round stock, and gave it the old "Reef your guts out" test.--And it slipped---Just like I thought might happen. The fit is tight enough to withstand moderate abuse, but not exceptional abuse such as backfire, pre-ignition, or nuclear Armageddon. I do however, think it would work fine if the components were cross drilled and pinned. Probably with .094" (3/32") dowel pins.


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## Charles Lamont (Apr 13, 2017)

You can use Loctite with a press fit. The belief that a gap is required is a misunderstanding.


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## Brian Rupnow (Apr 13, 2017)

Charles, I always use a bit of Loctite 638 when pressing crankshafts. It actually acts as a lubricant during the pressing operation before it begins to set-up.---Brian


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## Brian Rupnow (Apr 13, 2017)

I've been thinkin', Lincoln---if I do get the flywheels waterjet cut, why not do something fancy? so, I got my old Philip Duclos  book out and using the information in it, created curved spoke flywheels. I think it adds a lot of "pizazz" to the overall engine.


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## Brian Rupnow (Apr 14, 2017)

I just ordered Jerry Howells gas valve plans and components to run this engine on propane, and ditched the gas tank. There is just too much beautiful "monkey motion" in those long rocker arms to cover them up with a gas tank, in my opinion. Also, if I do get the water-jet cut flywheels, there will be a relief machined in both sides to accentuate the spoked area.


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## Brian Rupnow (Apr 15, 2017)

Running the engine on propane is not going to let me mix a little two cycle oil with the gas to keep the viton o-ring lubricated. The simple fix for this is to add a small oil cup with a very small "dribble hole" of about 0.030" diameter to the rear of the cylinder, tucked up tight against the back of the cooling water reservoir.  This will let enough oil onto the piston skirt with each revolution of the crankshaft to carry oil thru the rest of the piston stroke and spread it throughout the cylinder while the engine is running. This was very common on the old hit and miss engines.


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## Brian Rupnow (Apr 15, 2017)

I just got a price to waterjet cut 2 curved spoke flywheels.---$69.50 each. So----I called the guy up and whined at him. The price dropped to $49.50 each. That's 2 1/2 hours setting at my computer designing something for a customer. If I tried to machine them myself I might be 80 years old before I got them finished. I said "Go ahead and make them!!" This should be very interesting.


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## Brian Rupnow (Apr 15, 2017)

Don't ask!! This is about one of those "Having your cake and eating it too" things.


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## Barnbikes (Apr 15, 2017)

Would one flywheel be enough to run the engine? 
If you had one flywheel and a single throw crank one whole side of the engine would be open to see all the movement.

Just a thought.


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## Brian Rupnow (Apr 16, 2017)

Maybe--But I want two.


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## Brian Rupnow (Apr 16, 2017)

So, here we go again, making it up as I go along. What are you looking at?--Well, I don't have any 5/16" plate, but I do have some 2" x 3/8" steel flatbar. First job was to mill a length of it long enough to make 2 crankshaft webs down to 5/16" thick. Next step was to lay out the profile on one end of the milled down section. Then cut that end off, clamp it tightly to the remaining piece, and run a bead of weld on both sides about half an inch long. This ensures two things. Most importantly, that any holes thru part #1 are going to be dead nuts in line with any holes in part #2. A secondary benefit is that I only have to drill and ream any holes one time. I don't do this in my mill vice, because I don't trust it not to "cock up" a little bit when I tighten the vice. This results in very bad juju on crankshaft webs. I will put a sacrificial piece of plate between this bar and my milling machine bed, and clamp it to the bed for all the drilling and reaming. I will then saw and mill away everything that doesn't look like a crankshaft web, leaving the two welded areas until the very last step before I separate the two pieces. They will be match marked with a center punch so that I don't reverse one or the other when assembling the crankshaft. Crankshafts are one of the things where "Close really does count".


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## Brian Rupnow (Apr 19, 2017)

The crankshaft webs have been drilled and reamed, then trimmed from the parent stock with the bandsaw. They are still welded together in two places. Next step is back to the mill to square up any "straight-line" surfaces, then mount them on a stub mandrel and turn them to finished diameter in the lathe. I will probably put a bolt and nut through at least one of the "lightening" holes and cinch it up tight so that when the welds get machined away the two pieces of plate won't try and slip and get out of alignment. This wouldn't affect the geometry of the plates in any way, its just that generally bad things happen whenever something tries to "slip" from where you intended it to be when you are machining it.


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## Brian Rupnow (Apr 19, 2017)

My "Gas demand valve" plans from Jerry Howell came today, along with some very small Tecumseh engine carburetor needle and seats parts and a diaphragm. The detail drawing of the parts I have to make seem to be well done, but it's pretty damned sparse on assembly drawings. In fact, there are no "assembly drawings" as such, just printed instructions that eventually make sense after you have read them and taken all the tiny parts out of the bags and studied on them to see how this thing works. Apparently I now have to buy a propane regulator to use with this thing, and I have no idea what that will cost, but will try to find out tomorrow. I had an email today from the waterjet cutter saying I could pick up my curved spoke flywheels tomorrow, so I'm fair excited about that. I am going nuts right now with design work, to the point where I can't get time to do my own "hobby" stuff.


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## Brian Rupnow (Apr 20, 2017)

Here is a link someone sent me, with some very good information about the "demand gas valve" that I just purchased.---Brian
http://www.floridaame.org/HowTo2.htm


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## Brian Rupnow (Apr 20, 2017)

Today we are talking "beautiful things". I went this morning and picked up my waterjet cut flywheels. Man, are they ever nice. These are 3/4" thick mild steel, and the finish on the inside of the cutouts is very, very nice. The man who cut them said he can cut up to 6" mild steel. I will be machining the outside diameter, the 3/8" bore thru the center, and will take a 3/16" deep "face" cut on both sides in the spoke area. I may paint the parts of the flywheel I don't machine. These flywheels are 4 7/8" diameter and have about 1 1/8" diameter inside the cutouts in what will become the hub area. These are the first parts I have had waterjet cut, and although they are pretty, they are not for the faint of wallet. I paid $90 for these two. Fortunately, I got a $100 bonus last week for finishing a "panic" design job ahead of schedule.--that worked out well!!! Laying on my old blue steel handbook you can see my two finished crankshaft webs. If anybody wants the dxf file for these flywheels, email me at [email protected] and I will send it to you. I have to give credit to Philip Duclos for the pretty shape of the spokes/cut-out areas. I didn't copy his numbers, but his "How to" article in "The Shop Wisdom of Philip Duclos" was certainly a big help to get me started in the right direction.---Brian


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## Brian Rupnow (Apr 20, 2017)

I'm going to get bold here, and do something I haven't done before. Since my crankshaft is built up from individual components pressed, Loctited, and possibly pinned together, I'm going to make up a one piece con-rod and assemble it with the crankshaft. If it works, then great, I'm way ahead of the game. If it doesn't, all I've wasted is a bit of time. Since this is a "demonstration" engine and is not going to see long hard hours of use, I'm not going to run any bearings on the con rod. Aluminum rod running on steel crankshaft lasts a long time if it is kept well lubricated.


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## Brian Rupnow (Apr 20, 2017)

I'm not blazing thru this build like I have some others, but I did manage to get some machining time in today. The con-rod still has to have the center relieved, but at least I did something. I can't assemble the crankshaft until I have the con-rod finished so I thought this had better be a priority.


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## Johno1958 (Apr 20, 2017)

Brian a lot of my old model aircraft engines con rods were aluminum alloy of some type, plain no bearing and they ran for many hours at high rpm with no sign
of wear or failure.I guess caster oil in the fuel is hell of a good lubricant.
What alloy is best for to use without bushing ? I have a bit of 7075 I was thinking of using but not sure.
cheers
John


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## Brian Rupnow (Apr 21, 2017)

John--all the aluminum I use is 6061---brian


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## Brian Rupnow (Apr 21, 2017)

I got so tired of bodging up temporary fixtures to relieve the center portion of connecting rods that today I actually took an hour and built a dedicated fixture for it. I will post a clearer picture of it when I get the other side of the rod finished. It works like a charm.


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## Brian Rupnow (Apr 21, 2017)

This is the finished con-rod, along with a shot of the fixture I made for relieving the section of rod between the two end bosses. The round rod in the center is turned to 3/8" x about 0.290" long. The remainder of the round rod is 9/16" diameter and passes thru a 9/16" reamed hole in the flatbar, and is welded a coupe of places on the side which fits into the chuck. The other bolt passes thru the far end of the con-rod and holds it snug against the flatbar, with the help of a flatwasher. The piece of flatbar which sticks out on the other side of center gives the fixture balance and can be tapped anywhere to accept a different length con rod.


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## Brian Rupnow (Apr 21, 2017)

The first stage of crankshaft assembly is completed. There is a lot going on here!! The large shaft is an alignment shaft only, turned to be "size on size" with the largest holes in the web plates---not a press fit, but a damned close sliding fit. The small shaft is a piece of 3/8" drill rod, at about half a thou oversize. It is a hard press fit (with 638 Loctite) into and thru the first web plate (0.3735" hole), then wiped down with solvent, then oiled and fit thru the bore of the con-rod, then wiped down with solvent a second time and coated with Loctite 638, then pressed thru the second web plate.  You don't see it, but there is a "washer" made from cardboard cereal box at 0.018" thickness setting on one side of the con-rod, because the con-rod is squeezed in there very tightly. After an overnight dry, I will make both ends of the crankshaft in one long piece and press it thru all in one blast. After the Loctite on it sets up, I will mill the piece out from between the web plates. Then I will soak the entire thing in water for a couple of hours to dissolve the cardboard washer and give the con-rod some side clearance. One thing to note---When you ream a con-rod to 0.375" diameter, a 0.3755" diameter rod will not fit thru it without pressing. I had to open the bore in the con rod by about .0005" to get a proper fit over the .3755" drill rod. I don't have any oversize reamers, so had to do a lot of persuading to get the bore opened out. This type of "persuading" is accomplished by sanding a taper on a piece of the drill rod in the lathe, coating it with cutting oil, and then CAREFULLY working the rod up and down the taper until it slides over the main diameter.


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## Brian Rupnow (Apr 22, 2017)

I turned the ends of the main crankshaft down to match the 12 mm sealed ball bearings (that I already had) and left it full diameter in the center area that had to be press fitted to the webs. I coated the critical areas with Loctite 638, and since I have a limited throat opening on my vice, I did it in my two ton arbor press with a cheater bar about 3 foot long on the handle I had prepared a brass "cup" to fit over one end and had my 3 pound hammer ready in case I needed to do some constructive pounding to get things into home position, but they slid right into place on the arbor press, no "pounding" was needed. After pressing  things into place, I set it up in the three jaw and checked for runout. Right now it has .008" total indicated runout, which isn't that bad. I just need that figure for comparisons sake when I mill the center portion out tomorrow. If it moves enough to trouble me, I will give it a few good whacks with the dead blow hammer to bring it "true". The jury is still out on whether or not I'm going to pin this crank together or not. Photobucket is being oinky today, but I will put up a picture when it decides to work for me.


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## Barnbikes (Apr 22, 2017)

Tried cutting the throws and the flywheels on the laser at work yesterday. 

Wow those throws are tiny - had problems cutting them because the heat had no where to go and the holes just wanted to blow out.


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## Brian Rupnow (Apr 23, 2017)

My little pile of parts is growing. Today I will finish off the crankshaft, and build the engine sideplates. I made the rocker yesterday afternoon, and for a simple enough part, there are a world of set-ups in it. I used my new con-rod fixture to relieve the material around the bosses on each side of the rocker, and it worked great for that too.


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## Brian Rupnow (Apr 23, 2017)

Barnbikes--Are you planning to build the entire engine, or just taking practice runs?---Brian


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## Brian Rupnow (Apr 23, 2017)

And just for the fun of it---here is the crankshaft, luxuriating in it's custom made water filled bath-tub. (which may have been a juice bottle at one time.) I trimmed away all of the unwanted parts this morning. Right now the con-rod appears to be Loctited to everything else, but I'm hoping that with a four hour soak, the .016" cardboard washer on one side of the con-rod will dissolve, and I can break the con-rod free of everything else. I may have to apply a little heat to the center of the con-rod and let it work its way down until the con-rod lets go and decides to turn for me.


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## Barnbikes (Apr 23, 2017)

Brian Rupnow said:


> Barnbikes--Are you planning to build the entire engine, or just taking practice runs?---Brian



Right now I am seeing what I can get done as far as not turning on my lathe. might have to cut the throws with out the holes and do them later.


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## Brian Rupnow (Apr 23, 2017)

Well there!! I've had as much fun as I can stand for one day. Those sideplates aren't quite finished yet, but they are awfully close. I'm tuckered out.


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## Brian Rupnow (Apr 23, 2017)

After a nice break and a drive with good wife, I had to come down and check on the state of my crankshaft, which has been basking in its own private bathtub. The water didn't have as much effect on the cardboard "washer" as I had hoped for. The next trick was to put one end of the crankshaft in my shop vice with aluminum soft jaws and carefully apply some heat to the center of the con-rod, while applying fairly gentle pressure on the con-rod. Once the heat migrated down the con-rod and softened up the Loctite which was preventing it from moving, it began to move freely, and I immediately squirted everything with lubricating oil to keep the heat from affecting the crankshaft itself.  The rod now moves freely. I set the crankshaft up in my lathe and put an indicator on it to see if the runout had changed after I cut the center out between the web plates. I discovered that this crankshaft is quite a "flexible flyer". Initially it had about .015" total indicated runout. I grabbed the free end and gave it a tug in the direction it had to move and after doing that a couple of times I had it down to .004" total indicated runout.  I had read before about how flexible these single throw crankshafts are, and as I understand it some snowmobile crankshafts with integrated connecting rod are adjusted for runout in the same manner. At any rate, I'm happy, and I think the crankshaft will work fine. I'm not going to pin the pressed connections. Both the rod journal and the crankshaft itself are small enough that I don't want to weaken it by drilling for pins.----Brian


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## Brian Rupnow (Apr 24, 2017)

Those curved spoke flywheels are really, really nice.--But---Oh my God--What horrible little piggies to machine. The worst part is figuring out where to start. I opted to plunge at the major diameter of the recess in the side of the flywheel. Just because of the geometries involved, you can only plunge about 0.050" before the heel of the parting off tool starts to drag. Then you move in towards center the width of the parting off tool you are using to plunge with and plunge again. Moving back and forth between the two positions you keep plunging until you reach the depth you were aiming for. Then grind an HSS tool with the cutting face reversed to what you would normally see, and cut in towards the center in auto-feed mode, taking 0.010" depth of cut. This requires nerves of steel and eagle eyes on the digital readout. When you get about .050" from the minor diameter of the recess in the face, kick out the automatic feed and take the last .050" by hand feed. I have one side of one flywheel finished. I'm going upstairs now and have a strong drink now to calm my shattered nerves.


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## Brian Rupnow (Apr 26, 2017)

I'm at the half way point in machining the flywheels. I still have two sides to go. When I was a young apprentice draftsman, I used to walk out into the shop delivering blueprints to various departments. We had about 50 huge lathes and shapers, and I used to see all these old guys, just setting and watching the machines take a long cut in automatic feed mode. They couldn't read a book, they couldn't get up and leave their machine. All they could do was set there and watch. They couldn't even get up and go to the washroom without having someone else to watch their machine while they went. Leaving a running machine for any reason was a firing offence. After machining the insets in these flywheels, I have a great appreciation for how those old guys must have felt. Set it up, dial in depth of cut, set the automatic transverse feed, and then set there and watch the readout until it comes to within 0.050" of crashing, kick the lathe out of automatic feed, finish the last 0.050" by hand feed, back  up the tool, and repeat--again and again and again.


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## Brian Rupnow (Apr 26, 2017)

Nice try, but no cigar!! I thought that for the second side of the flywheels I might be able to put the reverse jaws in the chuck on my rotary table and do a pass all the way around at the maximum recess diameter with a 3/8" endmill in my milling machine to give the lathe tool a nice "cut out" to start making passes from on the lathe. Alas, it may have been a good idea, but I just put the reverse jaws in my rotary table chuck, and it doesn't open large enough to accept the 4 7/8" diameter flywheel. The second side of both flywheels will get done on the lathe, same as the first two sides.


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## Brian Rupnow (Apr 27, 2017)

Owning a pick-up truck and being a natural born scrounger, I picked up this tall shelving unit that someone had put out to the roadside. It might not be fine enough to put in your living room, but it fits right into my office. This gives me a chance to put most of my engines up on display. I was starting to run out of places to put them, but this frees up a lot of space for future endeavours.


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## Johno1958 (Apr 27, 2017)

That looks fantastic.


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## Brian Rupnow (Apr 28, 2017)

Boys and girls, I'm here to tell ya----There is a world of work in those flywheels. They look pretty, and I'm sure they will do their job just fine, but man, what a marathon bunch of machining there is to get them to this stage. The first one that I carved the recess in was scary. I think I held my breath the whole time it was in the lathe. The second side was a bit easier, and I was able to breath a bit. By the time I got to carving the third recess I was thinking "Well, this isn't so bad at all", and the fourth recess was a piece of cake---Nothing to it. Still, I have a lot more machining time in these two than in any other flywheel I have made, and 99% of the cuts were "interrupted" cuts in the spoke area. I'm glad to be finished these rascals and ready to move on to something else!!!


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## Brian Rupnow (Apr 28, 2017)

And for those of you who like to draw----Go nuts!!!


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## Ghosty (Apr 28, 2017)

Brian,
Looking very nice. Now on to the easy part

Cheers
Andrew


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## Brian Rupnow (Apr 29, 2017)

I can see some excitement with machining this cylinder head. It is too long to hold in my four jaw chuck, so I have determined that it will be a faceplate job. First set-up on the faceplate will be to machine the side which faces away from the cylinder, and has a raised boss on it. Then after that side is machined, I will machine an aluminum plug which is a "precision fit" into the center hole of the faceplate and has a hole in it for a "precision fit" of the raised boss. Then I will flip the part over, locate the raised boss in the hole in the aluminum plug, and machine the recess in the side which faces the cylinder.


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## Brian Rupnow (Apr 29, 2017)

This is the "starting point" on the cylinder head. Most of the unwanted metal has been bandsawed away from a piece of 1 1/4" thick aluminum bar. the portion with the blue layout dye on it will become the raised boss.


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## Brian Rupnow (Apr 29, 2017)

I was mistooken!!! Before I absolutely committed to a faceplate job, I had to try it in my four jaw. What do you know----it fit, barely. One jaw is out to the point where there are only two turns of the chuck key holding it, but it cleared the ways by about half an inch and tightened up just fine. After turning the spindle by hand, checking for clearances, I started the lathe on it's lowest speed (which is very slow indeed) and seeing that nothing was going to explode in my face, I ramped the speed up to 220 rpm and cut with an HSS tool. Everything seems to have went okay, and I'm finished with that set-up.


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## Charles Lamont (Apr 30, 2017)

An occasionally useful ploy is to put the job at 45 deg. Set-up is not as easy and the method is not strictly kosher as it puts a side load on the jaws and their guides, but with a bit of common sense it is OK (and no more alarming than your arrangement).


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## Niels Abildgaard (Apr 30, 2017)

Charles Lamont said:


> An occasionally useful ploy is to put the job at 45 deg. Set-up is not as easy and the method is not strictly kosher as it puts a side load on the jaws and their guides, but with a bit of common sense it is OK (and no more alarming than your arrangement).


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## Brian Rupnow (Apr 30, 2017)

The cylinder head isn't completely finished, but it's about at 95%. Everything fits and follows the plan, so far. It is a cool, rainy, nasty day here, good time to be inside. Good wife is out in my garage rooting around thru a ton of stuff she has collected for a Parkinsons benefit yard-sale. I've machined enough today. Time to wash up and go read a good book.


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## Brian Rupnow (Apr 30, 2017)

As you can see from the pictures, I haven't put the large hole in the cylinder head plate like I show in this solid model. My initial theory was that I needed a hole that big so I could reach thru to the set screws to set the cams in their proper location. I normally set the cams by turning the engine over to the correct point in the cycle with the cam gear locked to the shaft, then turn only the cam until I feel it contact the valve, then tighten the set screw. The only problem with this is that such a large hole will weaken the structural support necessary to keep the cylinder in the right location. The alternative to this is to set both cams in the correct rotational aspect to each other, leave the cam gear loose on the shaft, turn the shaft and cams to the correct position and then lock the gear to the shaft. I'm going to leave that one to "cook" for a while and in the meantime finish the cylinder, piston, and primary con-rod. By that time I will have decided what to do.


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## Brian Rupnow (May 1, 2017)

Todays project (If I don't get called away to work) is the cylinder. It's worth posting a drawing, simply because it looks so strange after all the finned cylinders I have built lately. I don't remember, but I think this stuff machines fairly good. I will let you know.---Brian


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## Brian Rupnow (May 1, 2017)

Okay--the 316 stainless machines very nice, nicer than 1018 or 1045 steel. I'm running at 400 rpm with a .015" doc. using a brazed carbide, no cutting oil. The only issue I'm seeing so far is the fact that my brazed carbide has no chip-breaker built into it, so I'm getting some incredible "birds nests" which I clear with a pair of pliers after each pass. I'm not going to turn anymore off the o.d. until I get the bore drilled and reamed to size, then I will finish up the o.d. to finished size. I hope my hss drills have as little trouble as my brazed carbide has seen.


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## grapegro (May 2, 2017)

Hello Brian,
                I had a lot of rust problems in the water tank and adjacent areas on my Roseberry hit and miss engine. I overcame that problem with ready mixed anti freeze coolant. Benn in the motor now for over 3 years with no sign of rust. Hope this helps. Norm


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## deverett (May 2, 2017)

grapegro said:


> Hello Brian,
> I had a lot of rust problems in the water tank and adjacent areas on my Roseberry hit and miss engine. I overcame that problem with ready mixed anti freeze coolant. Benn in the motor now for over 3 years with no sign of rust. Hope this helps. Norm



But see my experience from a few years ago:


deverett said:


> A sad story. This is a Scott vacuum engine and is  stored in a sealed wooden travelling box when not out for running.
> 
> Believing that ordinary tap water would cause corrosion of the cast iron  cylinder in the bronze cooling hopper, I decided to use car radiator  antifreeze as a coolant. After all, most rads are copper and many  cylinder blocks are cast iron. Bad idea as you see below.
> 
> ...



Dave
The Emerald Isle


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## IceFyre13th (May 2, 2017)

Waterless coolant is the solution.... http://www.evanscoolant.com/how-it-works/

"Water contains oxygen, which causes corrosion and also allows  electrolytic activity which further damages engine metals. Evans  waterless coolants eliminate corrosion and electrolytic activity,  significantly increasing the life of the engine."


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## Brian Rupnow (May 2, 2017)

I run straight tap water in my coolant tanks, but I empty the engines out before they go up on the shelf. My well water has some very high mineral content in it---great to drink, but does leave deposits on the kitchen fixtures and ceramics in the bathroom.


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## Brian Rupnow (May 3, 2017)

Well, if that isn't the prettiest cylinder I've ever seen, it runs a close second. No issues at all machining the 316 s.s. with carbide on the outer diameter and drilling/reaming the inner diameter with my HSS twist drills and reamer. I still have a bunch of threads and counterbores to put into the flange, but the cylinder is close to being finished. I just have it propped up in the current position to take the picture.---Brian


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## Brian Rupnow (May 4, 2017)

Ta-Da!! We have a finished cylinder. Today was the only time I have noticed any difference machining the 316 s.s. My #6-32 tap definitely did not like tapping the four holes that hold the cylinder to the cylinder head.--Then again, it could be that my tap is just dull and needs to be replaced. The cylinder fits where it is supposed to go and all the bolts line up the way I had hoped. I guess my next moves will be a piston and the primary connecting rod. Jeez, I was afraid that tap was going to break off in one of the holes and ruin the piece. Lots of cutting oil, breath holding and backing the tap off every half turn got me there, but I was worried.


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## Brian Rupnow (May 5, 2017)

Oh, woe is me.--My favourite (and only) tool shop in Barrie is closing it's doors. When I first came to Barrie in 1986, Barrie was one of the fastest growing, technically based cities in Canada. In the early 1990's, things started going the other direction and the bleeding has never really stopped. One by one, machine shops closed down, factories either closed or moved away, and the many tool shops started to shut their doors. We are now a city of 150,000 with 60% of the people who live here commuting to Toronto to work, 60 miles south of us. Varty Machinery has been in operation for over 30 years, and it employed the owner, a travelling sales guy, a counter sales guy, and two women. It was the "go to" place to buy one drill or one tap or one milling cutter at a time. They had prompt service (order one day, they had it the next), reasonable prices, and friendly staff. There is still one tool-shop in town, but they only deal in large quantities and specialized tooling. I can still order "on-line" from toolshops in Toronto and get speedy delivery, but now I will have to pay an $8 shipping charge on a $6 tap. I know this is a story being continuously repeated throughout Canada and the USA, but it's nasty.---Brian


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## Ghosty (May 6, 2017)

Brian,
It happens everywhere, I can't even buy a tap or die here, have not been able to for years, 99% of the stuff I need is ordered on line, only winner in all this is the post/freight companies with the extra deliveries.

Cheers
Andrew


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## Brian Rupnow (May 6, 2017)

Today was kind of a "milestone" day for the rockerblock engine. All of the major mechanical parts are completed, and everything goes round and round and up and down without any interferences. I have to decide now whether to move ahead with the valve train, or machine the waterjacket. (I think the waterjacket would be more fun.) I have posted a picture of the engine with all of the major components in place, and a link to a video of it being "ran' by hand so you can see the action of the mechanism. Hope you enjoy this.---Brian



https://www.youtube.com/edit?video_id=33qlNr7Tkvw&feature=em-upload_owner


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## Cogsy (May 6, 2017)

Looks great Brian. Really interesting build. Your link doesn't work though.

[ame]https://www.youtube.com/watch?v=33qlNr7Tkvw[/ame]


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## Brian Rupnow (May 7, 2017)

I have been having trouble with You-tube. I post a video, it loads, then I copy the link and post it. They always send me an email to preview the post and I do watch it in the link they send me, but I still have situations where I post the link and people tell me they can't see it. I really don't know what I am doing wrong. Here is the link again.---Brian
[ame]https://www.youtube.com/watch?v=33qlNr7Tkvw[/ame]


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## Brian Rupnow (May 7, 2017)

I'll probably go here next. A piece of 2" square brass x 2 1/2" should be enough to make it. I'm not sure about the o-ring gland yet--will have to do a bit of research on what Viton O-rings are available for this. The o-ring closest to the open end of the cylinder isn't going to see much heat, but the one near the cylinder head is going to get pretty toasty. I have to work out how to hold this for machining. Will probably hold it in the four jaw and do the through-hole in the lathe. Hold it in the mill vice to put the rectangular hole from the top that intersects the thru-hole. Then possibly mount it on an arbor to machine the bottom half round. The cylinder clearance will be boring bar work in the mill, I think.-Lots of complex set-ups for certain.


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## Brian Rupnow (May 7, 2017)

Today I'm lazy, and don't feel much like taking on a lot of machining. However----I did make a camshaft and drilled and reamed the "cylinder head" for oilite bushings, and installed the cam shaft and gears. Thankfully, the gears mesh well. I just got an email from a well intentioned fellow warning that my phone number and address appears on my drawings on the internet. What can I say?--I had a web page up for 15 years with my phone number and address on it. If you run a business from home, there aren't a lot of choices in the matter. I have had design jobs from as far away as Capetown South Africa because of having my phone number and address up on the internet. ---Brian


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## Cogsy (May 8, 2017)

Brian Rupnow said:


> I have been having trouble with You-tube. I post a video, it loads, then I copy the link and post it. They always send me an email to preview the post and I do watch it in the link they send me, but I still have situations where I post the link and people tell me they can't see it. I really don't know what I am doing wrong.


 
The link they are sending you is the problem. From the bit I can see of it on your last post it ends with "upload-owner" so this is your personal link as the uploader of the video. When someone who isn't you uses that link, they are directed to their own channel page instead.


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## Brian Rupnow (May 9, 2017)

I think I will do a "step by step" on this waterjacket, just because it is something out of the ordinary. The starting point is this horribly expensive ($70) piece of 2" square brass, x 3" long. If I've done this correctly, there should be enough material here to build both the waterjacket and the top for the waterjacket, which is a separate piece. This job will involve drilling, boring, facing, rotary table work, tapping, 4-jaw lathe turning, and milling work. First step for me is to lay out the lines to mark the overall shape. The bottom which will be ultimately rounded using the rotary table in the milling machine will get two cuts from the bandsaw to remove a lot of the corner material. A third bandsaw cut will separate the piece destined to become the "top" from the bottom. A fourth cut on the bandsaw will remove about .370" from one side of the remaining bottom piece to get it close to the finished dimensions on the drawing. Then I will move to the four jaw chuck on my lathe to bore the round hole which fits over the cylinder.


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## Brian Rupnow (May 10, 2017)

This morning I swung by Hercules O-rings in town, and picked up five 1 1/4" i.d.  x 1/16" cross section Viton O-rings. I have never machined an internal o-ring groove like I show in both ends of the waterjacket before. I think I will machine a piece of aluminum to the correct bore and what I anticipate to be the right groove (It will be a different size than is shown in the posted drawing), and see how difficult it is to do this and how water-tight the resulting "seal" is before I try it on the brass. I do have other options, but this way of doing it is the simplest, if it works. I will have to custom grind a cutter for the o-ring groove, but I don't think that will be too difficult.


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## Brian Rupnow (May 10, 2017)

This drawing shows the correct o-ring groove for a 1/16" cross section o-ring. A 1/16" o-ring has an actual cross section of .070". So---My slot width at .075" should accept the o-ring without crowding it. The .058" depth of the o-ring groove will give approximately .024" of "diametral crush" on the o-ring, forcing it against the outer diameter of the cylinder to form a water-tight seal.---At least that is my theory for the moment.


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## Brian Rupnow (May 10, 2017)

Listen my children, and I will tell----Of my experience with o-ring grooves. I found a scrap piece of round aluminum and bored it for a sliding fit over the stainless cylinder. I bored a "step" in the face of it to hold some water, and I ground a HSS tool to 0.080" wide. You can hardly see it in this picture, but I plunged 0.056" deep into the inside of the bore. This all went very well, but no matter how I tried, I had a loop of o-ring that just wasn't going to fit down into the slot.


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## Brian Rupnow (May 10, 2017)

My next step was to put the aluminum back into the lathe, and deepen my plunge cut to .063". The o-ring fit a bit better, but there was just no way it was going to fit all of it down into the groove. At that point, with nothing to lose, I put the aluminum back into the lathe one more time, and widened the groove by .025". That did the trick!! The rubber o-ring finally went down into the groove. I then stood the cylinder on end, coaxed the aluminum ring with the o-ring in it down over the cylinder, and filled the "moat" I had machined into it with water. The water is not running past the o-ring seal. I will leave it overnight, and report back in the morning as to whether any water leaked past the o-ring or not. I don't think you can see the water in the last picture, but trust me--it's there.


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## Brian Rupnow (May 11, 2017)

It's morning here at the center of the universe, and I just came downstairs to check on whether or not my o-ring seal held back the tide. It did!!! far as I can tell, it never leaked a drop. This is great news. This morning, armed with the knowledge I gained yesterday, I will turn one more piece of aluminum, sticking to a groove depth of 0.056" and a width of 0.100" and see if the o-ring will seat into the resulting groove. Aluminum scraps are free, and I want to figure this out 100% correctly before I start machining the brass. The part I made last night where I deepened the groove to 0.063" fits very easily over the cylinder, because there isn't much "crush" on the o-ring. Last nights test was a "static" test with the cylinder setting on my reference table. In reality, there will be a lot more dynamics happening as the engine runs and makes the cylinder move and quiver and react to overturning and reversing forces in the engine, so I want a bit tighter fit.---Brian


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## Brian Rupnow (May 11, 2017)

So--Here is the final scoop. On the second piece of aluminum (closest to the camera) I bored it for a sliding fit onto the cylinder, then I cut the o-ring groove .056" deep x 0.100" wide. The Viton rubber o-ring snuggled right down into the groove as if it wanted to go there all along. I then gave the end of the cylinder a squirt of #30 automotive oil, and with a push and a twist it slid into place over the cylinder, but with a much snugger fit than it had previously with the deeper 0.063" deep cut slot. I think that I'm satisfied at this point that this method of sealing the waterjacket is going to work, so I will now move ahead and start cutting brass.


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## Brian Rupnow (May 11, 2017)

To paraphrase one of my old rock and roll heroes, "I ain't fakin'--A whole lot of hoggin going on"!!! I trimmed my block of brass down to size with the bandsaw and mill, then set it up in my lathes 4 jaw and drilled thru with about 3 successively larger drills till I maxed out with my 1" drill, which is the biggest I have. Then I bored for a sliding fit over the cylinder. Then, using the o-ring groove information I had sussed out with my aluminum test pieces I put the o-ring groove in both ends. One end I could actually see what I was doing. at the far end I just trusted my DRO because I couldn't really see what was going on. After the o-ring grooves were in, I hogged out the center area where the water will actually be with a different home brewed hss tool, again working blind because I couldn't see what was going on.--I don't like that very much, but you do what you have to do. I then removed everything from the lathe, cleaned it up a little, and tested to see if the O-rings fit into the grooves---they do.


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## Brian Rupnow (May 11, 2017)

I freely admit to being pretty "twitchy" when I cut the hole in the top of this thing, worrying that I was going to machine away the o-ring grooves I had put in earlier this afternoon. In a situation like this, all you can do is machine everything as closely as possible to the drawing, and have faith in the designer. It went very well. When I took it out of the mill vice, and brushed away all of the chips, the o-ring grooves were still there, just like the drawing said they would be. Ahhhh---big sigh of relief!!!  Next thing up will be to design and build a fixture to hold the waterjacket while I use the rotary table in combination with the mill to round off the bottom. Man, it's great to be home for a day and play in my machine shop. I'm home tomorrow too, so will post something about the fixture and the process of rounding the bottom.---Brian


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## Brian Rupnow (May 12, 2017)

Yesterday evening I posted that I had one more fixture to build yet. This shows the simple fixture that I had to make, a piece of 1 1/4" shaft to fit thru the water-jacket, with a flange on one end to allow the four bolts to go thru the flange into the tapped holes in the end of the waterjacket. This let me set it up in my rotary table with chuck attached, and every 2 degrees of rotation I moved the mill table to pass the area I wanted to be rounded under the milling cutter. This of course was a lot of "back and forth", so I set the table stops on the front of the mill table to confine movement to the area I wanted milled.


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## Brian Rupnow (May 12, 2017)

So---we have a waterjacket. All the holes and clearances went in without breaking thru into the water compartment. I still have some fitting/polishing to complete, but all the heavy lifting is done. The big end of the con-rod squeaks by without touching. I'm happy with the results and I really do like the contrast provided by the brass.----Brian


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## ShopShoe (May 13, 2017)

Brian,

Congratulations on getting the water jacket done without breaking through to the other features: The shop gnomes, elves, and pixies must be with you and you must be holding your mouth right on this one.

I've been following along and I find this design pleasing. For some reason I like it more than the dual opposed engine you buillt earlier. Best wishes for the rest of the build.

Thanks for posting

--ShopShoe


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## Brian Rupnow (May 13, 2017)

Thank you Shopshoe. It is always nice when people stop by for a look and leave a comment. I like this engine too, just because it is so unconventional.---Brian


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## Brian Rupnow (May 13, 2017)

This mornings labours were limited to "Things I can make in the 3 jaw chuck." I wanted to make the muffler from brass, but decided to make it from aluminum, because of the weight savings. The weight wouldn't matter if it screwed straight into the cylinder head, but it doesn't. It screws into a 90 degree elbow which is screwed into the cylinder head, and I am afraid that the weight of a brass muffler would make the 90 degree elbow turn and hang down at some lop-sided angle. I chased down a very short stub of 660 bronze which was left over from something and made the top rocker pin and retainer, as well as the bottom rocker pin from the bronze. I am running out of things to build that will keep me away from the valve train. The ignition cam is made and installed, so all I have really left to do is make up the two 90 degree brass elbows and the oil cup.


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## Ghosty (May 13, 2017)

Brian,
Looking good, it wont be long now and you will have another runner.

Cheers
Andrew


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## Brian Rupnow (May 14, 2017)

Ghosty--Maybe by the end of May. it depends on whether I hit any problems along the way.---Brian


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## Brian Rupnow (May 14, 2017)

As often happens, when I first design something from scratch, if I don't have a  clear vision of what is involved in making a part, my imagination runs a bit wild. Then as I work my way thru the build, reality sets in. Such is the case with the cylinder oiler. It started life as a somewhat fanciful "add-on" oil reservoir. Although I could actually build it as "first designed", there is really no provision for keeping it in place on the cylinder. if I used any kind of Loctite to "glue" it in place, then I would never be able to remove the waterjacket if I had to, because of the small tube at the bottom of the oiler that fits into a hole on the top of the cylinder. So--Today I redesigned it as a "bolt on" It can be attached to the front of the waterjacket with two #4 s.s. bolts. I have a length of 1/16" o.d. x 1/32" i.d brass tubing that I bought a few years ago for a carburetor experiment. I will Loctite this tube into a hole in the redesigned oil cup. With this change, it both simplifies the machining of the oil cup, and it is also removeable by removing the two #4 bolts and lifting it straight up away from the cylinder.


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## Brian Rupnow (May 14, 2017)

So---I've got a running start on the two 90 degree elbows for the exhaust/induction. These elbows will be made up from two pieces silver soldered together. That's not a lot of machining, but its all I'm good for today.


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## Brian Rupnow (May 15, 2017)

Either I'm getting better at silver soldering, or I'm getting luckier--not sure which. The elbows are both finished and I'm very pleased with how they turned out.---Brian


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## Brian Rupnow (May 17, 2017)

Tonight we have an oil cup. Granted, it won't hold much more than a teaspoon full of oil, but I don't plan on doing any long haul trucking with this engine. The only reason I'm putting an oil cup on at all is that I hope to power this engine with propane. If I used my normal gas/oil mix, it wouldn't even need an oil cup. The oil-cup is just setting in place right now, without the 1/16" o.d. x 1/32" i.d. tube Loctited into it. I will wait until I have tapped the waterjacket and bolted it into place before I drill the oil hole in the top of the cylinder and Loctite the tube into the oil cup.


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## DickInOhio (May 17, 2017)

Love what your doing Brian. I'm following along. Dick


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## Brian Rupnow (May 18, 2017)

Thanks Dick.--I dearly love it when people drop by and say hello.---Brian


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## Brian Rupnow (May 18, 2017)

This next part is going to be--Ahhh--interesting. It is one of those multi purpose items that does 2 or 3 jobs. First and foremost, it provides a set of guides for the lifters to ride in. It also provides a place for the rocker arms to pivot. It acts as a "bolster" to lend some strength to the cylinder head plate which has a large "window" carved into it to access the cams which operate the valves. It could have been built from aluminum with bronze lifter guides pressed into place, but I opted for bronze because it adds some contrast to the mostly aluminum engine, and doesn't need any inserts in it for lifter guides.


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## Brian Rupnow (May 18, 2017)

I am constantly amazed by the amount of time required to make some of this stuff. I'm not slow at machining. Its just that there are so many steps and set-ups to make a simple part like this. I've just put in a complete 8 hour day making this lifter guide/bolster. It has turned out fine. I decided to make the rocker arm tower out of a separate piece, which will be bolted on. I will make it tomorrow.---Brian


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## Ghosty (May 18, 2017)

Brian, I know what you mean, 75% of the time is used when setting up or changing tooling
Keep up the great work.

Cheers
Andrew


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## Cogsy (May 18, 2017)

Looking great Brian. This is the first thread I've read since spending a week in hospital and the progress you've made is astounding. I think  I might have to buy a copy of these plans off you when they're done.


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## Brian Rupnow (May 19, 2017)

Cogsy--I'm glad you're out of the hospital. I do plan on selling the plans for $25.00 plus postage.---Brian


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## Brian Rupnow (May 19, 2017)

This picture shows the finished bolster/lifter guide/rocker arm pivot finished and in place on the engine. The two open holes directly below the rocker pivot tower are where the valve lifters set. The camshaft and (as yet unfinished) cams set directly behind those two holes. (See picture without bolster in place.) The open slots on both sides allow me to get a hex wrench in there to lock the cams to the camshaft in the correct rotational aspect. The two open holes in the "cylinder head" are where the valves will be.


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## Brian Rupnow (May 20, 2017)

This has been a somewhat  hither-thither morning. I made and installed two brass valve cages, dealt with a roofing contractor, and helped good wife sort out a ton of stuff in my garage as she prepares for a Parkinsons Charity yard-sale. The diameter of the valve cages are such that they can't be pressed into place with fingers alone, but slide in very smoothly when coated with #638 Loctite and pressed in with my 1 ton arbor press. I have sorted thru my box of springs and found the spring that will keep my valves in the closed position. The slight recess in the top of the valve cages contains the bottom 0.050" of spring so that it can't slide over and rub on the valves when they are installed. The picture showing the inside of the cylinder head shows up a lot of dirt that I didn't even know was there. The Macro setting on my camera sometimes does that. If I'm not interrupted in the next couple of hours, I may even have some valves made today.


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## Brian Rupnow (May 20, 2017)

One valve down, and one to go. Both intake and exhaust are the same. The stem on these valves are almost ridiculously long, at 1.537", but once they are set into place in the cylinder head they look about right. The actual guided part of the valve in the valve cage is quite long. I turn these valves down to about 0.128" in 3 stages to keep from having a lot of deflection to deal with. The hardest part of the entire valve is to keep from turning the stem undersize. The last 0.003" or so, I work down to size (0.125") using 220 grit carborundum paper.


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## Brian Rupnow (May 20, 2017)

And that's the second valve finished. I'd have been done sooner, but I had to run across town to my sons house and look after a sump-pump emergency. Tomorrow I'll machine a set of "keepers" and drill that tiny 0.040" cross hole in the valve stems that allows a cross pin to hold the keepers and springs in place.


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## Brian Rupnow (May 21, 2017)

The time has almost arrived to make my rocker arms. I wasn't totally happy with the original design, as there was no good way to lock the adjusting bolt which sets the valve lash in place. So--this morning a couple of hours were spent redesigning the rockers. I'm happy with what I've came up with. I have to attend a birthday party for youngest grandson at noon, so I may not get any actual machining done today.----Maybe---


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## Brian Rupnow (May 21, 2017)

Those rocker arms look like monsters. They aren't really, they are only a bit less than 2" overall length.  I will probably attach two 1/4" plates together and do the side profile, which is where most of the work is, then separate them and do the top profile, thinning them out to 3/16" in the center.


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## Brian Rupnow (May 22, 2017)

YOWZAHHH---we got rocker arms!!! I had forgotten that today was a holiday. I got ready to travel to my office across town this morning and good wife said "where are you going? It's a holiday today."---So, today I machined the rocker arms I redesigned yesterday. There is a lot of work in those rascals. I spent most of today making them.


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## Brian Rupnow (May 23, 2017)

Made a mistake--Kissed a snake--ah, POOP!!! I totally screwed up the design of those rocker arms. I can't even see a decent way to modify the existing ones and "save" them. As for some idea of what I did wrong, look at the drawing I posted. The actual part of the rocker arm or the adjusting screw that contacts the end of the valve stem should be almost dead-nuts in line vertically with the pivot hole in the rocker arm. Pulling it away off center like I show in the 3d cad model means that instead of an almost vertical up and down movement, which is what you want to have acting on the valve stem,  it "swipes" across the end of the valve stem as it pushes it down. This produces undue wear on the end of the valve stem and also tries to make the stem bend sideways as the rocker rocks up and down. I will have to make new rocker arms, and probably have to make an adjustment to the height of the rocker pivot tower. Fortunately this hasn't cost me any money.--Just the best part of a days work. One more thing to file away in my mind about what you can and can not do when designing these little engines.---Brian


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## Brian Rupnow (May 24, 2017)

To give you some idea of what I'm talking about, the dotted line indicates the optimum position for the rocker arm pivot, in relationship to the end of the valve stem. Arranging it this way gives the absolute minimum of "side movement" on the end of the valve stem when the rocker arm rocks.


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## Brian Rupnow (May 26, 2017)

So---I'm back to where I was a week ago. The new rocker arms are made, and although they look an awful lot like the old rocker arms, there is a big difference in the geometry of the area where the adjuster screw sets. I shortened up the height of the rocker arm support tower by about 1/4", as that played into the overall geometry as well. Now I have to quit playing machinist and go help goodwife get ready for a yard sale tomorrow.


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## Brian Rupnow (May 26, 2017)

Here's a little trick I have found. The adjusting bolt in the end of my rocker arms is a #5-40 thread, but a #5-40 hex nut is huge when it's up against something 1/4" wide, like my rocker arms. The trick is to get a #4-40 hex nut which has a considerably smaller outer profile, and drill/tap it out for a #5-40 thread. It looks  much better, proportion wise.


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## bazmak (May 26, 2017)

Hi Brian, watching this thread with interest as do all your threads
Drilling and tapping a larger size in a hex. nut is common practice
when making model steam locos,although small hex nuts can be
purchased with the hex a size smaller than the thread purely for 
looks.Good thinking


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## Brian Rupnow (May 26, 2017)

Thanks Baz--I'm glad to know you are following my thread.---Brian


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## Brian Rupnow (May 28, 2017)

No machining to report today. Goodwife has been collecting donations for about 6 weeks to have a "Parkinsons Charity Yardsale" in support of the Parkinsons foundation. Our 41 year old son developed Parkinsons Disease a year ago. My garage was stacked right to the ceiling with other peoples junk, so yesterday involved setting it out along both sides of my 100 foot driveway and doing the yardsale thing. After a furious two hours of setting everything out, with help from our son and two of his children, I spent most of the day setting in a big old (donated) chair and helping wife oversee the yard sale. The sale went very well. We made over $600 for the charity. About noon my son and his two young children were getting pretty worn out, so we sent them home. We had a couple of small passing rain showers, but not enough to wreck anything. At the end of the day, even though we had sold a ton of stuff, there were still 2 tons of "stuff" left in the driveway, which Kathy and I had to then pick up and cram back into my garage. The next 2 weeks will see her donating everything that was left to various organizations around Barrie. It was a fun day, and the first day in months that I haven't been designing for a customer or working in my own machine shop on the Rockerblock engine. I'm sore today from using a lot of muscles that don't get used very often. ----Brian


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## Brian Rupnow (May 28, 2017)

It's kind of hard to believe, but I only have 6 parts left to make on this engine. I need two cams, two lifters, and two pushrods. Since I am used to operating these small engines on Naptha and oil mix, I will probably set it up to run on Naptha and oil initially. Once I get it to run with a fuel I am familiar with, then I will build the gas-demand valve and see if I can get it to run on propane. I thought I might have things completed by the end of May, but life gets in your way sometimes, so now it will probably spill over into June. I have "bits and bobs" of minor tweaking to do, but other than the 6 components mentioned, all the major parts are finished. I will use the same method for making the cams as I did for the Rupnow Vertical engine and the Overhead cam engine, using the rotary table and milling machine. That method isn't as accurate as the method outlined by Malcolm Stride, but it doesn't seem to matter that much. The engines run well no matter which method is used.----Brian


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## Brian Rupnow (May 29, 2017)

Tonight we have finished valves. After the killer yard sale on the weekend, and working "away" today, I hadn't planned on doing anything tonight.--But you know how it is---Just had to do some little thing to keep the flame burning. My valves always look a little "ratty" on the ends after the parting off operation, but I don't try too hard to clean them up perfect. I grind away any "tit" left on the center on my belt sander, but I don't try to polish out all the concentric circles. The heads of the valves don't show after the engine is assembled, and I did actually ruin a perfectly good valve once, getting too enthusiastic about taking out any marks left after the parting off operation.


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## Brian Rupnow (May 31, 2017)

This morning I cut the first cam. It turned out well although I find that every time I cut a cam using the "end mill plunge" system, the results are always marginally different from the input math I used to set it up. The engine won't mind, as long as both cams are identical. I still have to file a slight radius on both sides of the tip. I won't change any settings when I put my next cam blank in to machine it. That should guarantee that both cams are the same.


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## Sleddog (May 31, 2017)

I've just read the entire thread. Being a complete noob to model engine building I'm amazed at the talent. I've worked as a machinist, since high school, repairing & fixing but, didn't know what I didn't know until getting interested in model building! Can't wait to see the finished project.

Jack


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## Brian Rupnow (May 31, 2017)

Thank you Sleddog. Stay tuned. It's soon going to get interesting.---Brian


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## Brian Rupnow (May 31, 2017)

Here we have two little cam birds setting in their nest. They are not hardened yet. I have just finished turning the lifters, and am working on the link between the lifters and the rear side of the rocker arms. Both cams and lifters are made from 01 drill rod, which I will flame harden.  If all goes well and I have no disasters, I will finish the valve train on Friday.


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## Brian Rupnow (May 31, 2017)

We have an operational valve train!!! The cams go round, the lifters lift, the rockers rock, and the valves open and close. I still have a bit of fettling and fondling to do, but it works. I haven't cut my valve springs to length yet, as everything has to be disassembled, the cams and lifters hardened, and intake/exhaust ports drilled into the cylinder head. I was supposed to work (real work) today, but at the last minute it got deferred to tomorrow, so I had all day to play in my machine shop.  I'm quite excited about this as the valve train is the last major sub assembly on the engine. The solid model shows what I did for a pushrod.


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## Brian Rupnow (Jun 1, 2017)

And a beautiful thing it is!! After a days work "away" I came home tonight and after some very careful set-up, drilled, tapped, and spot-faced the cylinder head for the intake and exhaust elbow fittings. The holes ended up where they were supposed to be, and the elbows fit the way I had hoped.


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## Brian Rupnow (Jun 3, 2017)

This video shows the valve train in fully finished and operational mode. The valve lash is set to .005", but the cams are not timed yet. At one point in the video, I point out a slot in the end of the camshaft. This slot will allow me to turn the shaft with a screwdriver so that when I do go to set the cam timing, I can loosen off the grub screws holding the timing gear to the camshaft and turn the camshaft by itself without changing the rotational position of the gears. Anyone who has ever built one of these small 4 cycle engines will know exactly what I am talking about here. It is easier to do it than it is to explain it. What comes next?---Well, I need to think about how I am going to retain the rocker shaft in position, and mill some clearances in the rocker tower so that the bottom con-rod can "swing thru" without catching on the sides of the slot.  After that, it's basically re-assembly, add the ignition points, and hope for the best. Somebody please let me know if the video is working--I have had some problems with that in the past.---Brian
[ame]https://www.youtube.com/watch?v=9Kug_t03_8g[/ame]


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## DavidLloyd2 (Jun 3, 2017)

Video is working for me,

DavidLloyd


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## Brian Rupnow (Jun 3, 2017)

Thank you David.---Brian


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## bazmak (Jun 3, 2017)

Engine looking good,video working great.Cant get any audio ???


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## Herbiev (Jun 3, 2017)

Working fine here Brian.


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## Brian Rupnow (Jun 3, 2017)

Okay guys--Thank you. Baz, there is no audio. My mouth is terribly sore today, and my teeth are setting in a cup in my bathroom. I sound a bit like an old flannel mouthed dog without my teeth in, so I didn't say anything.


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## Brian Rupnow (Jun 3, 2017)

With a bit of clearance in the bottom of the rocker tower slot, I can use the same shaft and keeper plate on the bottom con-rod as I did on the top. A pair of drilled and tapped #6-32 holes at the top of the tower let me use a couple of set screws to retain the pivot shaft.


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## Brian Rupnow (Jun 4, 2017)

We have ignition!!!---Oh--Wait--Let me rephrase that. We have ignition points---that's what I meant to say. We also have a 0.030" head gasket in place. I was a bit concerned that when I added the head gasket (which moves the cylinder and water-jacket back 0.030") that I might have trouble with interference between the rotating crankshaft and the clearance cavity I had to carve in the bottom of the water-jacket. It worked out fine though. There is still adequate clearance for full crankshaft rotation. I have also modified the rocker support tower by milling clearance for the lower connecting rod to swing thru, and made a second bronze shaft and keeper for it.  Sometime in the next hour I intend to drill and tap the water-jacket and cylinder for the oil reservoir, and then about all that is left is to cut keyways in the crankshaft where the flywheels set.


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## Brian Rupnow (Jun 5, 2017)

So--The rockerblock engine is fully assembled, as per the solid model. Everything goes round and round and up and down with no clearance issues. I still have to devise a starter hub to attach to one of the flywheels, but that is the only thing remaining to be built. I haven't set the valve nor the ignition timing yet, as I just finished adding keyways to the crankshaft and assembling the waterjacket and oil cup. I added a little clear silicone to the internal O-rings on the waterjacket before assembly, and put a bit of silicone on the threads of any bolts which broke thru into the waterjacket. I think I will try and start this on Naptha gas and 2 cycle oil mix, as that is what I am most familiar with. I will borrow a gas tank from one of my other engines to do this with. I have purchased a "gas demand valve" kit from Jerry Howwel, and the eventual plan is to run this engine on propane.


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## Ghosty (Jun 6, 2017)

Brian, Looking very good, will be running in no time.

Cheers
Andrew


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## Crisptrans (Jun 6, 2017)

She is a thing of beauty Brian! I'm curious as to the cadence she's going to have. I'm in the middle of a little bit and miss now, but I may just have a go a something similar. I'm not much for plans, kinda fly by the seat of my pants, but I'm always looking for interesting paths to wander down.


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## Brian Rupnow (Jun 6, 2017)

And the good news of the day is that I filled the water jacket right to the top this morning before I went to work--And when I came home tonight it was still full, with no puddle under the engine.-- Now I have to pull out one of the cams, set it up on a degree wheel in my lathe, and determine exactly how many degrees of "cam influence" these cams have, which will establish my cam timing. If the cams had turned out exactly as I had designed them, I wouldn't have had to do this step.--Brian


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## Brian Rupnow (Jun 6, 2017)

I used my lathe, dial indicator, a set of feeler gauges, and a gear to establish that the cams I cut have a true "cam influence angle" of 120 degrees.--which is very close to what I planned on. I set the dial indicator up so that it is 0.010" away from the cam when the low side of the cam is towards the dial indicator plunger. I rotate the chuck by hand until I just see the indicator needle begin to move. At that point I mark a line on the face of the gear. (I have the 123 blocks piled up so that the top of them comes level with the centerline of the lathe, and I can rest my pencil on it to make the mark.) Then I rotate the chuck in the opposite direction until I see the needle on the dial move again, and make a second mark on the face of the gear. Then I measure the angle between the two marks to establish how many degrees the cam is acting on the plunger. At 120 degrees of "cam influence", that translates to 240 degrees of effect on the valves because of the 1:2 ratio between the crankshaft gear and the camshaft gear. That means that I can set my valve timing so that the exhaust valve begins to open 40 degrees before the piston reaches bottom dead center on the power stroke, stays open during the 180 degrees of travel during the exhaust stroke, and closes completely 20 degrees into the intake stroke. The same lead angle will apply to the intake valve.


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## Brian Rupnow (Jun 6, 2017)

Okay guys, help me out---I'm having a hard time visualizing this. If both cams are exactly the same, and the intake valve is set for the same lead as the exhaust valve, the two cams should be set so the lobes are exactly 180 degrees apart.---Right??


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## Ghosty (Jun 6, 2017)

In a word no. You need the exhaust to be closing at TDC, and the inlet opening at TDC, or where you want them to close and open in regards to TDC, the valve overlap is where the two valves are open at the same time. The photos show a cam I cut with 15deg overlap.
The other way of looking at it is when you want the exhaust to open ,and the inlet to close in regard to BDC.
Attached is a cam layout drawn by George Britnell, it shows the crank timing, exhaust open at 40deg BBDC and close at 10deg ATDC, the inlet opens and closes 20deg at both BTDC and ABDC, giving a 30deg overlap.
Hope this helps.
Cheers
Andrew 












View attachment CAM LAYOUT DRAWING.pdf


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## gunna (Jun 7, 2017)

With your settings Brian, shouldn't the cams be at exactly 90 degrees, ie 180 crankshaft degrees. Even in Ghosty's picture they "eyeball" at 90 degrees.
Ian.


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## Ghosty (Jun 7, 2017)

Ian,
The cams are actually 105deg apart(see pic), which would give 210deg of crank rotation. There is a lot in the design of cams, with relation to cam lobe angles, lift and overlap.

Cheers
Andrew


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## Brian Rupnow (Jun 7, 2017)

Thank you gentlemen. I was having a severe brain fart on that. I came downstairs this morning and set the exhaust cam. That was fairly easy to do, as calculations show that when the piston skirt bottom is 1/4" away from the end of the cylinder on the exhaust stroke, that is 40 degrees of crankshaft rotation before the piston reaches bottom dead center. I tightened the grub screws in the exhaust cam and locked it to the camshaft. Then I loosened off the grub screws on the cam gear and turned the camshaft by using the screwdriver slot machined in the end of it until I just seen the exhaust valve begin to move, then locked up the cam gear grub screws. That took care of the exhaust cam. The cams are difficult to access in this engine, however it is easy to pull the entire sideplate off the engine on the side opposite to the gears so I could plainly see the cams. The crankshaft is still held in location by the bearing in the sideplate on the side where the gears are located. This allowed me to turn the crankshaft until the piston was approx. 3/16" before top dead center, so I manually turned the intake cam until it was just beginning to influence the intake valve, then I locked it in place on the camshaft, using the grubscrews in the collar attached to the cam.--and you are right--The two cams are at about 90 degrees rotational offset between the lobes.---Brian


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## Ghosty (Jun 7, 2017)

Brian, no problems, we all go through this, just a part of life.

Cheers
Andrew


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## gunna (Jun 8, 2017)

Andrew, I was only guessing about your diagram. The point was that the cams are at "about" 90 degrees not 180.

Ian.


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## Brian Rupnow (Jun 8, 2017)

And now we have a combination drive-pulley and starter hub. The starter spud which I use in my variable speed drill is also new, laying in the foreground. That should be the end of the machining on this engine. The new points and condenser have been installed. All I need now is lots and lots and lots of luck. If I have lived a good clean life, etcetera, etcetera, the next post you see may be a video of the engine running.---Brian


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## Brian Rupnow (Jun 8, 2017)

And, as promised, here is the first run video. The Rockerblock IS ALIVE!!!!~!
[ame]https://www.youtube.com/watch?v=Y7OjPxqylK4[/ame]


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## DavidLloyd2 (Jun 8, 2017)

Congratulations  Brian 
                                 On a Fine Looking  Engine,  That made my Day,

DavidLloyd


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## Brian Rupnow (Jun 8, 2017)

Thank you David. The engine started up with very little fuss. At first I couldn't get it to fire, and was wondering what I could have done wrong. I checked for spark with a spark tester I made a few years ago, and it had lots of spark. Then I pulled the sparkplug and found a gob of oily goo setting on the end of the plug. After the plug was cleaned and blown off with compressed air, it started right up and ran.


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## Ghosty (Jun 8, 2017)

Congratulations Brian, Another different runner. Running great for a first run, can't will wait to see how it runs on gas.

Cheers
Andrew


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## Johno1958 (Jun 8, 2017)

Nice one Brian.
Very compact and visually interesting.
Down the track I would like to build one.
Cheers
John


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## Cogsy (Jun 8, 2017)

That is a really interesting motion to watch, and it looks to be another great runner. Nice work as always :thumbup:


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## ShopShoe (Jun 9, 2017)

Congratulations Brian!

This is a most interesting design. There are lots of interesting motions going on and it sounds great now. I look forward to hearing it after tuning.

--ShopShoe


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## Brian Rupnow (Jun 10, 2017)

Sometimes the engines I build run with no further work required on them. Sometimes I discover a "Gotcha". On this particular engine, it was designed so that at bottom dead center, the bottom of the piston skirt was flush with the end of the cylinder. After it's maiden run yesterday which I showed in the video, I seen something really strange. The skirt actually was protruding a good 1/4" beyond the end of the cylinder. This called for some head scratching. After deciding that there was no way the connecting rods could have "stretched", I looked more closely at the rocker support tower. The holes in the sideplates for the bolts which hold the rocker tower in place all have a standard "clearance" around the bolts. There is enough torque being transmitted to the rocker tower that it is tipping to the full extent of the clearance on these bolts. There are 3 vertically aligned bolts on each side. It is pivoting on the center bolt, and moving to the extreme left on the top bolt clearance and to the extreme right on the bottom bolt. After determining what was really going on, I set the rocker tower in the correct position and then drilled and dowelled the rocker tower and sideplates  together with two 1/8" hardened dowels on each side. Then I went back and modified the drawings to show this alteration. The attached picture shows an "in process" shot of drilling and reaming the sideplates and rocker tower for dowels "in assembly".


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## Brian Rupnow (Jun 10, 2017)

Here are two more videos. In the first video, I try and speed the engine up and it quits. After it quit, I realized I was turning the throttle lever the wrong way, so there will be a second short video here in a few minutes. I will be selling a complete set of plans for this engine on a disc, as .pdf files which any computer can open, for $25 Canadian plus the cost of postage to wherever. If you are interested, email me at [email protected]
[ame]https://www.youtube.com/watch?v=evVJaytMsAA[/ame]
[ame]https://www.youtube.com/watch?v=19wanqj2ya8[/ame]


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## Foozer (Jun 10, 2017)

Watching you over the years, you just get better and better . .


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## Brian Rupnow (Jun 10, 2017)

Thank you Foozer. I'm getting to understand these little engines better, at any rate.


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## Brian Rupnow (Jun 10, 2017)

Now that I know the engine will run okay on liquid fuel, the next step will be to start "cooking with gas". I have a couple of valves and diaphragms from Jerry Howell, and the next part of this adventure will be seeing if I can get the engine to run on Propane.


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## Brian Rupnow (Jun 11, 2017)

Selling the plans for this engine is not a money making venture. I have designed, built and posted free plans for 13 or 14 of these small engines. Each small engine costs me between $100 and $300 to build for material, bearings, carburetors, waterjet cutting, etcetera. I know that people enjoy watching these builds, and I know that thousands of people have downloaded the free plans. (My hosting site has a counter and counts each download.) I build these engines for my own enjoyment, but it would be nice to recoup some of my own financial outlay. I have just gone through all of the drawings for this engine and updated them and saved them as .pdf files. There are over forty detail drawings, and at least two general assembly drawings in the package.


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## Cogsy (Jun 11, 2017)

I'll be buying a set for sure Brian, just have to wait a little for some funds to free up. At this stage I have far too many projects already but it's a really unusual design so I must have it, plus I want to show a little support for the efforts you put in as well. I'll drop you an email soon hopefully.


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## Brian Rupnow (Jun 12, 2017)

That's great Cogsy. I always like it when you build my engines. They always look better than mine do by the time you are done with them.---Brian


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## bruedney (Jun 15, 2017)

Time to start a new thread Dave?

What about your hoglet?

Bruce


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## Brian Rupnow (Jun 16, 2017)

Now comes the waiting time. In the "kit" I purchased from Jerry Howell to run this engine on propane, he mentions a specific regulator that should be used on it with a low pressure gauge. I found a Canadian rep for Coilhose Pneumatic in a city near here. I was able to order the regulator and valve, but it must be manufactured on Mars, because it is a three week delivery. At this stage of the game, I don't even know it this regulator screws onto a Propane bottle or how that connection is made. I am totally breaking new ground here, as I have never powered an engine on Propane. If anyone here has experience with this, please post a picture or give me a shout showing what you did.---Brian


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## Brian Rupnow (Jun 16, 2017)

I have chased down a number of semi-conflicting threads on this propane business, and it appears that if the regulator I have purchased will screw onto a Propane bottle, then all I need is the propane bottle with regulator attached, then a pressure gauge to monitor what pressure I am outputting, then a line to the "gas demand valve", then a line to the carburetor. However---Some of the threads I seen had a regulator on the propane bottle, which fed into the Coilhouse regulator, then the gauge, then the "gas demand valve". Some people have bought a regulator from Walmart which is used to run a Coleman stove on butane, some have used the gas demand valve, some have not. There is a lot of conflicting information out there, but as I make sense of it I will post what I did.


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## grapegro (Jun 16, 2017)

Hello Brian, LP gas is normally in liquid form. As it converts to gas, icing can occur at the most restricted area. If one uses the method for liquid to gas, such as auto use, the volume of liquid being converted to gas is quite high. In this case, a water heated regulator is used to stop the icing occurring where the reduction of pressure occurs. So the regulation of pressure occurs here. In small quantities such as your application, the volume of liquid being converted does not normally create an icing problem, so it is best to use a regulator at the bottle source, which allows low pressure tubes and connectors to convey the gas. Normal LP gas pressure is 11 inches of mercury, but I think one or two pounds pressure would be ample for your situation. I am in the slow process of running my engines on LP gas. I use hydraulic tube connectors and fairly solid plastic tubing for my connections. I think it is a good way to go. Best of luck, Norm


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## Brian Rupnow (Jun 16, 2017)

Thank you, Norm. Right now all knowledge is good knowledge.---Brian


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## Barnbikes (Jun 16, 2017)

Back when I was displaying hit and miss engines with my dad. There was a guy who would bring a throttle-governed engine and he ran it simply by putting a small brass tube connected to a 20lb tank in the carb opening and simply adjusted the valve on the tank till it ran the way he liked.


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## Brian Rupnow (Jun 17, 2017)

Barnbikes--I know that can be done, but if possible I want to do it the "right way". I'm not sure exactly what the "right way" is, but by the time I'm finished, I will.---Brian


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## deverett (Jun 18, 2017)

Brian, 
Have you looked at F.A.M.E. Tips and Links?  The third tip is by Richard Williams (the designer of the demand valve that you have).  He shows a picture of the regulator directly on the gas bottle, a short length of hose to the demand valve and then the hose to his engine.  No sign of a pressure gauge!
http://www.floridaame.org/

Dave
The Emerald Isle


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## Brian Rupnow (Jun 18, 2017)

Dave, I have seen that. I've almost worn the internet out looking for information about running small engines on propane. I won't be real clear about it until the regulator I ordered shows up here and I see if it can be mounted directly to a propane bottle.---Brian


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## Brian Rupnow (Jun 18, 2017)

After a lot of reading and research, I have found out the following. Normal outdoor gas barbeques run on approximately 11" of water column propane pressure. 14" of water column equals 1 psi. The instructions in the "kit" I purchased from Jerry Howell recommends 1 to 3 psi pressure. I just took a tour thru my local Walmart (shudder) and found that they have a regulator intended to run an outdoor barbeque. This regulator screws right onto a propane tank and has a 16" long flexible high pressure line that runs from the regulator to the barbeque. It does have a gauge on it but the gauge doesn't have any numbers on it, just "low" medium" and "high". This unit retails for $26 and would probably be good enough for what I am doing. I have seen posts where this is what was used in conjunction with a "gas demand valve" to run small model engines. I don't believe the regulator was pressure adjustable, but there was a valve on it which closed off flow from the tank, so it would be to some extent "flow regulated" which is not what I want. My instructions in the "kit" seem to recommend using 1/8" bore silicone tubing between the regulator and the demand valve, and between the demand valve and the engine. It also seems that the "demand valve" is of particular use on throttled engines. the engine vacuum is what pulls open the "demand valve" and lets propane flow to the engine. As you increase the throttled speed, this makes the engine vacuum increase, ( this is exactly opposite to what I know--if you ever drove a car with vacuum operated windshield wipers, you would know that when you stepped on the gas to speed up and pass another car in the rain, then the engine vacuum would drop and the damned wipers would quit just when you needed them the most.) which allows more propane to flow to the engine as it is revved higher. If the engine for some reason stalls out or quits, there is no vacuum, so no propane will flow.


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## Brian Rupnow (Jun 18, 2017)

I just found out that my "real work" schedule has been shifted this week and I don't have to go in tomorrow. so---without giving away anybody's "proprietary" drawings, I think I will work on the gas demand valve tomorrow. The block of aluminum is 1 3/4" square x 1" thick. The brass inlet and outlet tubes are 4 mm o.d. x 1/8" i.d. x 0.8" log, and are Loctited into place.


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## Brian Rupnow (Jun 18, 2017)

Okay--Let's see if I can get this right. Gas from the regulator flows to the left hand side marked "propane in from regulator". Propane can not get past the closed red needle valve which is firmly held against the "rubber inner seat" by the spring.  Then you try and start the engine, and the engine creates a vacuum that sucks on the port marked "Propane out to carburetor". This suction pulls the diaphragm down, which acts on the top end of the red "needle" and forces it down away from the "rubber inner seat" in the "brass Tecumseh carb seat". As soon as the "needle" is pushed away from the "rubber seat"  the Propane begins to flow thru this newly created path into chamber "A" and then out to the carburetor. As long as there is any suction from the engine, propane will flow to the carburetor. As soon as the engine piston is past the intake stroke and beginning to go up on the compression stroke, the vacuum from the engine stops and the "spring" closes the red "needle" into the "rubber inner seat" and the propane stops flowing until the cycle repeats itself.--THIS POST HAS BEEN EDITED--I HAD IT BACKWARDS THE FIRST TIME


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## grapegro (Jun 18, 2017)

Hello Brian, You have everything correct. With propane and its very high pressure in the container, it is imperative to control that pressure safely. So the reason for the regulator to be connected to the container. When that pressure has been safely controlled, it is a piece of cake to control the low pressure safely. Norm


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## Brian Rupnow (Jun 18, 2017)

Norm--I feel a bit like the magician did, the first time he sawed a woman in half.--Jeez, I hope this comes out right-----


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## Brian Rupnow (Jun 19, 2017)

The reason I am stumbling around a bit on this propane business is that A--I have never built one before, and B--the owner of the outfit that now sells Jerry Howells plans is a complete LaLa and knows absolutely nothing about the plans he is selling. I contacted him for technical advice about how everything goes together, as there is no assembly drawing with the "kit". His response was that he had no idea, he was not a technical person, and that although he now has the rights to Jerry Howells stuff, he doesn't have a clue how it works himself. He suggested that "Anybody who can build an engine can probably figure it out without much problem."


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## BaronJ (Jun 19, 2017)

Hi Brian,
I don't post much but follow your work with some awe.  Re the demand valve, it might be instructive to get hold of an old washing machine water valve and take it apart. 

HTH


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## ICEpeter (Jun 19, 2017)

Hello Brian,
If I am not mistaken, the person you talked to is the son of Jerry Howell who inherited / took over Jerry's business after Jerry's passing. I might be wrong but that was my understanding after the change in Jerry's website some time ago.

Peter J.


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## grapegro (Jun 19, 2017)

Brian, Have you tried looking at you tube for your answers. There is  a great number of hits on gas regulators there. Norm


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## Brian Rupnow (Jun 19, 2017)

Today I made the main body, the bolt on "top" and the inlet and outlet tubes. This picture shows the components I made, along with the purchased components. I have to assemble it and make sure it works the way I think it should. I will let you know tomorrow. The test I envision is crude but  should work. Good wife will be the propane tank and blow into the tube which will eventually be connected to the propane tank. I will be the engine, and suck on the other tube. Wife shouldn't be able to blow any air unless I provide some vacuum on the other tube. I just hope good wife doesn't find out I compared her to a propane tank on the internet.!!


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## Brian Rupnow (Jun 19, 2017)

Hah---I didn't have to enlist good wifes help after all. I can suck on the engine side, and get air. The only way the air can get to me is by coming thru the tube which will be attached to the propane bottle. I can not blow thru the tube which goes to the propane bottle which means that the needle valve is sealing unless there is some vacuum on the engine side. I did have to put the gasket on the other side of the diaphragm from where I show it in my drawing. When it is arranged as I show it in my diagram the diaphragm puts enough pre-load on the end of the needle valve to keep it from closing all the way and lets it bleed air. I am rather impressed with the way this valve works. Of course I won't know for certain until the regulator I have ordered gets here, but so far, so good.


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## Brian Rupnow (Jun 20, 2017)

A common theme that I am seeing in all of the research on running a small i.c. engine on propane is that the fuel discharge orifice in the carburetor must be enlarged by about 50% and that the air intake diameter should be reduced by gluing in a bushing. (This creates more "suction at the "gas demand valve"). Of course the trick seems to be in knowing just how much to reduce the air inlet. Best suggestion is to put a piece of tape over the air inlet opening and poke a hole in it, starting with a small hole and then enlarging it in stages, trying the engine to see how well it runs after each "hole size adjustment". The line which feeds propane to the carburetor hooks up to the same port on the carburetor that the gasoline line originally hooked up to. It also seems that the needle valve must be opened more than when running conventional gasoline. I still haven't totally bought into the fact that when the throttle is opened on the carburetor that it will create more vacuum and thus flow more propane into the carburetor. In my experience, opening the throttle on any gas engine makes the vacuum fall off rather than increasing. The "gas demand valve" which I built yesterday serves only to shut the flow of propane off if the engine should quit.


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## Brian Rupnow (Jun 24, 2017)

The piston moving towards bottom dead center creates a vacuum, which causes air to rush in thru the carburetor air intake. The air rushing in thru a restricted area in the air intake creates a low pressure area at the venturi. This resultant low pressure area is what sucks the liquid fuel up from the fuel tank. Okay, I knew that.  If you restrict the opening of the air intake, then the air has to flow faster thru the restricted area to fill the volume of the cylinder. The fact that the air has to move faster, probably increases the "venturi effect". This gets into theory that I'm not really sure about. If that theory is correct, then restricting the air intake probably does increase the vacuum due to "venturi effect" and give a stronger signal to the "gas demand valve", thus letting more propane flow. I got an email from the Canadian company that reps for "Coilhose" telling me that my regulator and gauge had arrived in Ontario. Originally I was going to drive to Toronto and pick it up, but my life has been so busy this past week that I didn't have a chance to. I have ask them to send it to Barrie by courier, so hopefully I will have it this coming week.---Brian


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## Brian Rupnow (Jun 28, 2017)

My regulator and gauge arrived, and as I suspected, they don't have any way to hook up to a propane bottle. This is the gauge and regulator recommended in the Jerry Howell "propane demand valve" kit.  However, I resorted to "do it myselfry" and worked with an empty propane torch and nozzle to make what I needed. The torch already has a shut off valve which I could use. The gauge screws into one port on the regulator. I hunted around in my box of fittings and found 3 other brass fittings that had the correct threads, and silver soldered the ends I needed onto them. I haven't leak tested anything yet, but it looks good.


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## Brian Rupnow (Jun 28, 2017)

That pressure gauge is 0 to 60 psi. Am I impressed? No, not really. I am flying semi blind on this entire Propane thing. The information in the "kit" from Jerry Howell is not up to my expectations. As I understand things so far, the engine should operate on about 1 psi. However--I suppose that Propane is a gas, the same basic nature as air, and the gauge and the regulator probably won't know the difference. If I don't blow myself up in the process, I am going to fight this thru to a running engine. So far, I'm out $81 for the regulator and gauge. If it all doesn't work as I had hoped, I can still buy a tank of Propane with a "fixed value" regulator to run campstoves at Walmart for $26.---Brian


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## Cogsy (Jun 28, 2017)

Random interjection -- I had that exact same phone/fax in my home office for years! I still have at least 2 whole boxes of ink 'rolls' for it under my desk...

And of course I'm still following with interest Brian. I'm sure you'll get it sorted.


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## Blogwitch (Jun 29, 2017)

For initial starting with the Jerry Howell demand valve it really requires an activation button making that sits fairly loosely in your 'vent' hole in the top plate. Just make it out a bit of nylon or plastic.

When you press that button, it allows gas through the unit to the carburetor so that combustion can take place. 
If you don't have an override button, you will have trouble starting the engine as it will not be able to produce enough vacuum at this lower speed to get the valve working correctly., once started, the valve will work all by itself.







You can see here the button, cross hatched for clarity.

John


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## Jasonb (Jun 29, 2017)

Finger over the intake and turn it over a few times, same method used to suck fuel up to the carb if you have a low tank position. As the engine can't suck in air it will suck a lot harder on the fuel line and purge the air out bringing the gas with it.


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## Brian Rupnow (Jun 29, 2017)

So, here we have it, set up and ready to try. Immediately above the blue propane tank is the shut off valve that was part of the original torch head. Above that is the adjustable regulator which has a gauge in one port, and a plug in the opposite port. Above the regulator is a fitting which I made up from a brass fitting with a 1/8" npt thread and a custom made brass extension silver soldered to it , which fits into my neoprene gas line. The neoprene gas line runs over to the "gas demand valve", and from the gas demand valve up to the fuel inlet on the carburetor. I have tested all of my connections with liquid dish soap, and have hopefully sealed them all, with the help of some Teflon plumbers tape on each threaded fitting. Before I get really crazy and start modifying carburetors, I will try it with the carburetor "as is" and see what happens. I am doing this with my door and window open down in my office to get a bit of cross draft going and disperse any build up of propane in my office.---Brian


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## Brian Rupnow (Jun 29, 2017)

So--No joy at the moment. I have opened the needle valve two additional turns from where the carb was running happily on liquid fuel, I have checked for spark, and I can see the propane pressure gauge registering anything up to 10 psi. ( I have tried numerous different psi settings, all less than 10 psi). Engine doesn't want to fire at all. I have choked it with my finger completely covering the air intake, but it makes no difference. I pulled the sparkplug and checked for spark, and it has lots of spark. I don't want to modify the purchased carburetor that is currently on the engine. I do have an extra home built carburetor around, and if I can't get my engine to fire at all on propane I may re-jet the carb I have (a matter of enlarging the fuel discharge nozzle) to see if that helps.


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## BaronJ (Jun 29, 2017)

Brian, it is difficult to ignite propane without having a lot of air mixed in with it.


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## Brian Rupnow (Jun 29, 2017)

Somebody on another forum who claims to have expertise in using Propane is suggesting a different carburetor. He is suggesting a carburetor with no needle valve to adjust mixture, just a simple pick up tube. The tube itself creates a restriction in the main airflow to create the venturi effect which will signal the gas demand valve for propane flow.The drawing shows a very simple carburetor with no needle valve. I don't show a throttle plate in this drawing, but a throttle plate is simple enough to add. (As per the solid model.) The existing carburetor is held into the brass elbow with some light Loctite. I would remove the existing carb and put this one in it's place.


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## blawson4283 (Jun 29, 2017)

Brian,  What a unique looking design.  I have looked at some of your other designs and would like to try to build one of them, however I am unable to locate drawings.  Could you let me know how to find a list of your engines and a source for drawings.
Thank you,
Bill Lawson
[email protected]


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## Brian Rupnow (Jun 29, 2017)

Best bet is to type in my name and "youtube" to see some of the many engines I have designed and built. I don't really have a comprehensive list. I have built about 12 "steam" engines and 14 i.c. engines. some of the plans are posted free, some you have to contact me by email and I will sell you a disc with all the drawings.---Brian Rupnow


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## Brian Rupnow (Jun 30, 2017)

After watching a YouTube video on converting a larger two cylinder engine  to run on Propane, I have decided to try this "conversion" instead of an entire new carburetor. This would be very simple to make and add to my existing Traxxas carburetor. There is only an hours work in this, and if it works as well as the engine in the video I would be very pleased.---Brian


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## corky (Jul 1, 2017)

Converted my standby generator to propane a couple of years ago, the propane 
regulator required a vacuum line to the back of the diaphragm to control the flow of propane, the propane was introduced into the top of the carb. above the butterfly.
The regulator had the same button on the rear of the diaphragm, to Prime at start.
I am running a 25 hp twin on 8 psi propane


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## Brian Rupnow (Jul 1, 2017)

So here we are, ready for round two of the propane game.  This set up is as per the video I watched, with a separate venturi tube extending out in front of the carburetor  air intake. The small metal pipe which the clear flexible tube is attached to, protrudes approximately half way into the "venturi tube. This will create a restriction in the inrushing air so it will create a low pressure area where the end of the tube is. The carburetor has not been changed in any way. The liquid fuel line which runs up to the bottom of the carburetor has been plugged with a piece of 1/8" steel dowel inserted into the original fuel feed line. The new brass "venturi tube" is a very light press fit over the carburetor air horn with a bit of green Loctite to help it stay in place. The original carburetor throttle should work to control engine speed, same as it always did. I will give the Loctite a few hours to set up, then try the engine again to see what happens.


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## grapegro (Jul 1, 2017)

Hello Brian,
                Due to computer problems I am unable to send attachments, but I feel you have the basis of a working unit. In principle, similar to a vehicle gas conversion. Will be very interested to see how you fare with this unit. Norm


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## Brian Rupnow (Jul 2, 2017)

Sadly, I must report that I had no luck at all with Propane. I have tried all of my bag of tricks, and the engine simply won't fire and run on Propane. This is not a really big deal, and like many other things, you don't know until you have tried. I do have a spare gas tank setting around, and by making a simple bracket I can add it to the existing Rockerblock assembly. With the coming of summer, I don't want to spend a lot of time in my machine shop, so I will end this thread now and say a big Thank You to all the people who have followed my build.---Brian


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## Crisptrans (Jul 2, 2017)

Brian, don't think of your demand valve so much as a regulator for pressure of your gas, think in terms of scuba diving. The air from your tank only flows when you draw on it. It's known as a demand regulator also. It will only flow gas when it's asked. Propane forklift is the same way. More people have problems with too rich a mixture of propane than they do with too lean. It takes a surprisingly little amount to make an engine run. If I recall correctly the explosive concentration of propane is somewhere in the neighborhood of 2-10 %. Any more or any less= no joy. With enough patience and persistence I'm certain your motor will run on propane, not throwing in the towel is key. Your ability to create these little gems is amazing. Keep at it and if I can be of assistance don't hesitate to message me, I'm not the sharpest knife in the drawer but I do have a little experience that I will gladly share.
To


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## Brian Rupnow (Jul 5, 2017)

After my failed attempt to even have the engine fire on Propane fuel, I was beginning to wonder if perhaps the ignition timing or valve timing had "slipped" from the original settings where it ran so well on naptha gas. I had a spare gas tank setting around, so I installed it on the engine, and without readjusting anything the engine fired right up and ran well. I decided to have a 40 minute "endurance run", and about half way thru the run I picked up my camera and shot a short video. That explains the nasty oil on everything.---I had given all of the bearing surfaces a good squirt of lubricating oil and filled the water reservoir before starting the run. The water stays in the reservoir with no problem, but the oil quickly turns black and splashes all over the place.---Brian
[ame]https://www.youtube.com/watch?v=dp0CgAwvBss[/ame]


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## ShopShoe (Jul 6, 2017)

Brian,

Thank you for posting the latest video. I would say the great sound and hit-and-miss kind of makes up for the oil splashes.

Anyway, I know you build your engines to work, not look good on the shelf (which they do, anyway).

--ShopShoe


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## Brian Rupnow (Sep 2, 2017)

I have a few people around the world building this engine now, and I am being asked about setting the valve timing. The set screws in the cams are difficult to access. I covered how I did this back on post #158, but here is a repeat of the way I did it. I was very lucky and the very first setting I used seems to work fine.
--There is a bit of trickery involved in setting the valve timing. You must have the cylinder head and lifters and rockers all in place, and have the valve lash set at about 0.010" when the lifters are not "up" on the cams. I sawcut a 0.030" slot in the end of the camshaft that is on the same side as the cam gear, so that I could turn the camshaft with a screwdriver. I removed the flywheel on the side where the timing gears are and turned the other flywheel in the direction I intended the engine to run (clockwise when viewed from the side with the gears on.) The set screws in the exhaust cam were tightened at any random spot by reaching up through the bottom of the engine. The intake cam was left loose on the shaft. The setscrews in the cam gear were left loose. The crankshaft gear was tightened on the crankshaft at any random position. I turned the flywheel until the piston was about 40 degrees or so before bottom dead center, then used a screwdriver to turn the camshaft in the opposite direction to the crankshaft until the cam lobe was just beginning to influence the exhaust valve. At that point, I tightened the camshaft gear setscrews. That "locked in" the exhaust valve timing. I then kept turning the flywheel until the piston was about 30 degrees before top dead center. At that point I reached up through the bottom of the engine (with great difficulty) and rotated the intake cam until it was just beginning to influence the intake valve, then I locked it in place. The cam set screws are "accessible" either through the underside of the engine or through the vertical slots in the "bolster" which stiffens the cylinder head plate. If you simply can not get at the screws for the intake side cam, you can remove the other flywheel, the ignition cam, and the entire sideplate to get to the intake cam set-screws to tighten them. I think I covered this in post #158 in the original build thread.---Brian


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## Brian Rupnow (Sep 12, 2017)

Gee Whiz--I'm going international in a big way. The second Rockerblock engine ever built was just finished by DavidLloyd2 in New Zealand. Cogsy in Australia has a set of the plans, and a fellow in the U.K. also has a set. I just sold a set of plans to a fellow in Spain. I'm pretty sure I sold a set to someone in USA but I'm not certain---can't remember. David Lloyd2 in New Zealand has posted a video of his Rockerblock running on HMEM, and I think his actually runs better than mine.---Brian


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## DavidLloyd2 (Sep 13, 2017)

Thank You  Brian.  for the Grate set of plans 
I enjoyed making it,

DavidLloyd


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## holmes_ca (Oct 16, 2017)

Hello Brian, 
    I was browsing today and came across your post on rocker block, it looked a very interesting engine, unfortunately, I already have too much on my plate to contemplate adding to all my unfinished symphonies, but what did get my attention was the lower line in the post, ie: Animal Testing, that is something I feel very strongly about and I support as well and as a project it is a quicky and easily finished in just a few strokes of the hand on 
the keyboard,

Edmund...........Alberta,


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## Brian Rupnow (Oct 17, 2017)

holmes_ca said:


> Hello Brian,
> I was browsing today and came across your post on rocker block, it looked a very interesting engine, unfortunately, I already have too much on my plate to contemplate adding to all my unfinished symphonies, but what did get my attention was the lower line in the post, ie: Animal Testing, that is something I feel very strongly about and I support as well and as a project it is a quicky and easily finished in just a few strokes of the hand on
> the keyboard,
> 
> Edmund...........Alberta,


I have absolutely no freakin idea what you are talking about.


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## Brian Rupnow (Oct 20, 2017)

Another Rockerblock engine has sprung to life, in merry England. A fellow who had purchased my plans just sent me a very nice video, but it's not a YouTube post, so I can't direct you to it. The engine seems to run very well. So---We now have three running Rockerblocks in the world. Canada, New Zealand, and England.


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## Johno1958 (Oct 20, 2017)

Well I'm not surprised Brian. Such an interesting and compact looking engine will be springing
up all over the place.It really is a credit to you.
cheers
John


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