# I may design an I.C. engine---



## Brian Rupnow (Jun 14, 2013)

After having built 4 i.c. engines and 12 different styles of air/steam engines, plus numerous "things" to run with these engines I may design an engine of my own. One of the most popular first time builders i.c. engines has been the Webster. It is a good running, 4 cycle, single cylinder air cooled engine, and has been built by many people around the world. The plans are free on the internet. The Kerzel hit and miss is another great i.c. engine, and is a single cylinder water cooled engine, with free plans on the internet. Both are simple engines to build from bar stock. I won't be designing a multi cylinder engine, nor a radial. My preference is leaning towards a single cylinder hit and miss engine, which uses a fly-ball governor rather than a flywheel mounted governor. If I do proceed with this, I will post free plans and "in process" pictures and technical write ups as the engine develops. My preference for the hit and miss water cooled engines stems from the fact that these engines can be run all day without overheating issues. Air cooled engines can only be ran for relatively short periods of time, (which is fine for presentation pieces) but they do have a tendency to overheat and seize if ran too long. I would like to hear input from other model engine builders to see which directions my design should take. I would like it to be an engine which is easy to build for first timers, uses only "bar stock" with no castings, and requires only a small lathe and mill and (possibly) a rotary table.----Brian


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## Cogsy (Jun 14, 2013)

Sounds like a brilliant idea Brian. I'd be very interested in building just such a beast from your plans.


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## prophub (Jun 14, 2013)

Hi Brian,

The things you create are always cool.  I'd be interested in seeing what you come up with!  

Shawn (prophub)


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## /// (Jun 14, 2013)

Yep, sounds good to me.
I've always liked fly-ball governors too, looking forward to seeing what you come up with.


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## motmaluk (Jun 14, 2013)

I too will be looking for a project engine in a few months,please persevere with your design,I will watch your progress with interest. The only point that I would like to make,and it's purely personal,I do prefer a pure IC engine,the hit and miss part I find a little fussy,let the thing run I say,but that's just my 2 cents worth.Good luck with your design!


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## Brian Rupnow (Jun 14, 2013)

Even a hit and miss engine will run like a standard 4 stroke engine if you don't build the governor part. All that is required in that case is a throttled style carburetor.


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## cfellows (Jun 14, 2013)

Brian, if it's going to be a hit n miss, I don't think the water cooling is really necessary.  My inverted hit n miss which has only a few, widely spaced fins, never gets above about 120 degrees F, even after 30 minutes or more.  Being air cooled would certainly make it a lot simpler to build.

Also, running it with a vapor fuel tank would simplify things.

[ame]http://www.youtube.com/watch?v=cNm4idhYJZA[/ame]

This video was done before I cut the fins in the cylinder and painted it.

Chuck


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## Paulsv (Jun 14, 2013)

If you are going to do that, you might want to read Malcom Stride's book "Miniature Internal Combustion Engines."  He kind of walks you through the design process.  A lot of it is pretty self-evident, but some of it, I think, would be really helpful.  Having built so many things, you might not need it, but if I were going to design one, I'd find it very helpful.  I'd be glad to lend you my copy by mail, if you are interested.


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## cfellows (Jun 14, 2013)

Sorry, here's a later video...

[ame]http://www.youtube.com/watch?v=JjaAdQSyFnU[/ame]

Chuck


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## Brian Rupnow (Jun 14, 2013)

Thanks chuck.--Actually, I would like the engine I design to be somewhat generic.---That is to say, it could be built with the governor to give a hit and miss action, or without the governor but with a different carburetor to act as a simple 4 cycle engine. Cooling reservoirs are always somewhat of a pain, but I am thinking in terms of a plain o.d. cylinder, with a separate reservoir made from aluminum and mounted with o-ring seals.----Brian


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## Brian Rupnow (Jun 14, 2013)

The other reason for using a flyball governor, is that I would like to be able to adjust the spring tension on the governors while the engine is running, to dial in the "perfect" engine speed. On conventionally governed hit and miss engines, this can only be achieved by trying many different spring combinations until you find the engines "sweet spot". I would much prefer a system where that could be adjusted by means of a counter-spring mechanism while the engine was actually running.


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## Goldflash (Jun 14, 2013)

I like the Idea of a simple bar stock engine whether it be of open or enclosed crankshaft design. Something along the lines of a single cylinder hoglet appeals to me. and being of a reasonable size so that the valves etc are not to fiddly.


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## cfellows (Jun 14, 2013)

Brian, I'm sure what ever you come with will be a winner.  It would be nice to have an alternative to the Webster, especially for first timers.  You may already be familiar with this site, but if you go to the Gallery, there are lots of single cylinder engines that others have built.  There is a vertical gallery and a horizontal gallery.

http://www.floridaame.org/

Chuck


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## Cogsy (Jun 15, 2013)

If I can make a suggestion it would be to use 2 smaller flywheels rather than 1 big one. I've just made 2 of them at 3.5 inches OD and that was stretching my nerve and abilities on my small lathe. I'd hesitate to attempt something with a 5 or 6 inch flywheel as a newbie.

I agree with Chuck - whatever you design will be brilliant.


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## roxwellmax (Jun 15, 2013)

Hello Brian,

I think your intension to design an engine along the lines mentioned is a great idea, I'll love to build it.

I have just completed a air cooled hit & miss engine, sort of my own design but based on the economy engine. I built this using material i had around the workshop so not the most beautiful but starts first time and runs perfectly using a flyball governor, trembler coil and vapor carburetor. I"m quite new to model engineering and completely self taught so much of the machining process is completed according to how I think it might be done which may not be the correct way but it's a great feeling to turn a pile of metal into something that resembles an engine and then fires up and runs, very satisfying.


Regards,

Max


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## Brian Rupnow (Jun 15, 2013)

Cogsy--I agree with you. Although my machines can handle fairly large stock (biggest being 6" o.d. as in the "Atkinson" flywheel, I think I will keep the flywheels to 4" maximum diameter for guys with smaller machines. By the same token, the bore will be kept to 7/8", and the stroke will be 1 1/2". This allows for a cylinder of 1 1/8" o.d. and a water jacket of 1 1/2" o.d. I may even go to 1 5/8" o.d. for the water jacket. I don't want to make the water jacket part of the supporting frame, because this engine will be designed in a somewhat "modular" style, allowing people to run either a water jacketed cylinder or a cylinder with cooling fins. I think the cylinder head will also be the main support for the cylinder, similar to the Webster. Will your machine handle that size of stock?---Brian


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## Brian Rupnow (Jun 15, 2013)

This is just some preliminary sketches, sorting out what I want to do in my own mind. The length of the cylinder is not to scale, as I haven't figured that out yet, but the rest of the drawing is to scale as far as regards the bore of the cylinder and a cross section thru the water jacket (which will be dependent on finished cylinder length.) The backing on the cylinder head is just a guess, and I know I haven't shown a sparkplug hole nor provision for valving, etc.--That will come as things develop.---Brian


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## kuhncw (Jun 15, 2013)

Hi Brian,

Nice to see a new design coming along. 

Have you considered eliminating the complication of actually surrounding the cylinder liner with coolant?  The cylinder block and bore could be one solid piece with a fake hopper added for looks.  My three hit & miss engines run almost continuously at the shows with no coolant at all.  Granted, they idle and are not driving a load.

You could also design the cylinder block to look like the screen cooled engines which have no hopper.  Again, no need to cool the liner.

Good luck with your project.

Regards,

Chuck Kuhn


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## Brian Rupnow (Jun 15, 2013)

kuhncw said:


> Hi Brian,
> 
> Nice to see a new design coming along.
> 
> ...


 

In this case, the liner is the cylinder. In keeping with the "modular" concept, one could use a finned cylinder without any water reservoir at all.----Brian


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## kuhncw (Jun 15, 2013)

Right, I see that the liner is the cylinder, but what I was getting at was eliminating the need for the O-ring seals.  The cylinder and hopper could all be one piece of metal with no water passage surrounding the cylinder.  Just a thought.  Maybe I didn't say it clearly.

Regards,

Chuck


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## Brian Rupnow (Jun 15, 2013)

Chuck--I'm trying to keep this simple to machine. I understand what you are saying, however I do think the water needs to go completely around the cylinder----at least that is the way the full grown hit and miss engines were, and its the way this one will be.---Brian.


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## Brian Rupnow (Jun 15, 2013)

Okay--This is it for today. Still has miles to go on that cyl. head/end stand, but its beginning to come together.


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## Brian Rupnow (Jun 16, 2013)

This just keeps on evolving. Last night while laying in bed thinking about it, I decided I didn't want to have to turn so much material off the outside diameter of the cylinder to leave the large ring that the bolts pass thru. Then I realized that the bolts don't actually have to pass thru that ring on the cylinder. They can go thru the cylinder head and be tapped into the water jacket, clamping a much smaller "ring" of material on the outside of the cylinder between the cylinder head and the water jacket, with the o-ring on one side, and the head gasket (not shown) on the other side.--Very similar to the Kerzel set up.


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## Brian Rupnow (Jun 16, 2013)

And just to be really weird and different---A crankshaft which incorporates the flywheels as part of it.----And it comes apart in the center to slip the con rod big end into place. This of course means that the con rod doesn't require a bolted on end cap.


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## Cogsy (Jun 16, 2013)

Brian Rupnow said:


> Will your machine handle that size of stock?---Brian


 
Sorry for the late reply - I missed your question.

I have a 7X, so in theory I guess it can swing a 7 inch diameter, but with the 3.5 inch wheels I had to locate the tool in the toolpost parallel with the OD of the stock to turn the OD. I'm assuming 4 inch would still be possible though. I'll measure it tomorrow and let you know for sure.

Luckily, I'm getting a larger lathe in the next few weeks, so it won't be a problem for me any more. 

The plans are looking very intriguing so far, I plan on building one very soon.


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## Brian Rupnow (Jun 16, 2013)

Careful, Cogsy---I don't want to lead you down the garden path!!! I will be building this as soon as all the design is finished. I find that when I do that, I discover my own screw-ups and can correct the drawings if required (And its generally always required, in the wonderful world of prototypes). I REALLY hope some other folks will build this, but wait until I have discovered any potential mistakes/oversights/disasters before you get into it.---Brian


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## jwcnc1911 (Jun 16, 2013)

Have you gentlemen seen the attached?  It's another option, a Frenchie similar to the Webster.

I'm looking forward to seeing what you come up with Brian.  Your design and build skill brings my attention to everything you post. 

View attachment ar bihan.pdf


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## Brian Rupnow (Jun 16, 2013)

Dang---I'm liking this!!!


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## Paulsv (Jun 16, 2013)

Brian-  If I understand how that cylinder to head connection works, the cylinder is bolted to the head through the compression of an o-ring.  I wonder if that is going to be solid enough.  I wonder if the o-ring is necessary-  would a copper gasket provide sealing, as it does in automotive engines?  Also, I wonder if you need 12 bolts to hold the cylinder to the head.  I don't know anything about these water cooled farm engines, but on the Webster and others like it, there are 4 bolts.


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## cfellows (Jun 16, 2013)

I like what you're doing here, Brian.  I've been noodling around with a non-compression engine design, similar to Rudy Kouhoupt's Pioneer and I like your overall design.

One thing I don't like about the Webster engine (and the Odds n Ends) is having the intake and exhaust share the same port.  The exhaust tends to make the intake assembly get really hot which makes urethane or rubber fuel line impractical.   I think the heat may also play funny games with intake fuel mixture.  

Chuck


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## /// (Jun 16, 2013)

Hi Brian,
Your '_Reservoir Seal Ring_' at the crank end of the cylinder may not be needed. If you can find an o-ring that is a nice sealing fit on the outside diameter of the cylinder, you may only need to machine a groove in the reservior for the o-ring to sit in which is slightly smaller than the outside diameter of the o-ring.
When it comes to assembly, place the o-ring in the groove and slide the cylinder thru the o-ring which will be compressed between the cylinder and reservoir. 

This method is used on both ends of water cooling jackets used on model boat motors, I have never had one of these leak.

First pic shows o-ring in groove, second shows similar sleeve (your reservoir) with motor pushed thru(your cylinder)


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## Brian Rupnow (Jun 16, 2013)

Paulsv said:


> Brian-  If I understand how that cylinder to head connection works, the cylinder is bolted to the head through the compression of an o-ring.  I wonder if that is going to be solid enough.  I wonder if the o-ring is necessary-  would a copper gasket provide sealing, as it does in automotive engines?  Also, I wonder if you need 12 bolts to hold the cylinder to the head.  I don't know anything about these water cooled farm engines, but on the Webster and others like it, there are 4 bolts.


Paul--It doesn't show up really well, but what happens is that the o-ring compresses a certain amount, then the cylinder bottoms out on a register turned in the water jacket and the cyl head is separated from the end of the cylinder by a gasket. (see detail B on post #23) As far as the bolts are concerned, you are right, 12 is too many. In the initial stages of my design, 6 bolts at 60 degrees connected the cylinder to the water jacket and 6 different bolts also at 60 degrees connected the cylinder head to the cylinder, thus a total of 12 bolts. The design morphed into something else, but the bolt count stayed the same. Only 4 bolts are needed on the Webster, but they aren't doing double duty of sealing compression and also sealing the water jacket joint to prevent water leaks. Also, due to the stacked sizes to incorporate a water jacket, I have had to use smaller bolts, specifically #4-40, so they can't be torqued quite as tightly. As soon as I have posted this, I am going to change things to 8 bolts per end.


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## Brian Rupnow (Jun 16, 2013)

cfellows said:


> I like what you're doing here, Brian.  I've been noodling around with a non-compression engine design, similar to Rudy Kouhoupt's Pioneer and I like your overall design.
> 
> One thing I don't like about the Webster engine (and the Odds n Ends) is having the intake and exhaust share the same port.  The exhaust tends to make the intake assembly get really hot which makes urethane or rubber fuel line impractical.   I think the heat may also play funny games with intake fuel mixture.
> 
> Chuck


Chuck--Although I did get both the Webster and the Odds and Ends engines to run well, I am not a real fan of having both exhaust and intake ported thru the same hole into the cylinder. You will see in this design that the sparkplug hole is offset towards the top of the cylinder. That is to allow sufficient for two valves thru the cylinder head, an atmospheric intake valve and a rocker arm activated exhaust valve. I will also be incorporating valve cages, because I seldom (if ever) get the valves to seal on the first "go-round" and its a lot less work to remake a valve cage than to remake a cylinder head.


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## Brian Rupnow (Jun 16, 2013)

Simon--Thank you for the information. I will probably still use the "reservoir seal ring", because although its a little more work I will feel better about it. I also wear a belt AND suspenders.---That's more a reflection on my own personal quirks than any good sound reasoning.---Brian


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## Jasonb (Jun 16, 2013)

I used a couple of O rings to seal either end of the liner on this engine, I'll see if I still have my drawings.


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## Brian Rupnow (Jun 16, 2013)

You know, what I really would like to do is arrange the stempost of the governor to set vertically, like the one on this steam engine I built a few years ago. It would be much easier to have the flyball governor run directly off the end of the crankshaft, using one end of the crankshaft as the stempost, I just think it looks a lot niftier with it vertical like the one in the picture. Due to the "impulses" of a hit and miss engine, I don't think it could be driven by a belt or o-ring drive. However, a set of bevel gears would get the job done. I don't have the faintest idea yet how I would arrange the exhaust valve lockout arm, but I will think on it. The governor would be a 3 ball unit instead of the two ball in the picture. I think one of Bob Shores "Angel" series engines had the governor set up the way I would like to do. I'll have to do some research------


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## Brian Rupnow (Jun 16, 2013)

Jasonb said:


> I used a couple of O rings to seal either end of the liner on this engine, I'll see if I still have my drawings.


Thanks Jason--


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## Brian Rupnow (Jun 16, 2013)

At this stage of development, I can see that it would be possible to run 3/8" ball bearings everywhere but at the wrist pin. I will price out some "open" single race bearings tomorrow. As someone pointed out "friction is not your friend" when it comes to hit and miss engines. If buying 3 ball bearings doesn't break the bank, now would be the time, before I go much farther with the design.


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## Brian Rupnow (Jun 16, 2013)

After some detective work, I found it was Bob Shores' "Silver Angel" that had the governor aligned somewhat as I wanted. I have watched a couple of youtube videos but there is too much happening too fast to zero in on his governor arrangement. Can anyone direct me to some good still pictures that show the governor area on the Silver Angel please. I know the pictures are somewhere on the web----I remember studying them a few years ago when I built my very first flyball governor.---Brian


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## Brian Rupnow (Jun 16, 2013)

Here is a link to all the poop about the Silver Angel governor. Its all from a post I started back in 2008.
http://www.homemodelenginemachinist.com/f26/flyball-governor-plans-2899/


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## Brian Rupnow (Jun 16, 2013)

I'm not exactly sure where I'm going with this, but its been an interesting way to spend fathers day!!!


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## Cogsy (Jun 17, 2013)

Looking great so far. No need to worry about me starting before you get the design tweaked - my idea of soon and yours are vastly different. I have to finish my 2 Upshurs first, and the way they're going it'll be another few months yet...

4 inch looks doable on my 7X lathe, in fact probably just as easy as 3.5, but I doubt 7 or even 6 inch would be possible.

Looks like I'll have to research cutting bevel gears next .

Keep up the good work!


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## Brian Rupnow (Jun 17, 2013)

Well, it looks like this is going to be an all ball bearing show. I called Canadian Bearings today, and a 3/8" i.d. ball bearing is only $4.98, so I ordered 3 of them, one for the big end of the con rod and two for the crankshaft bearings.. The only bushing will be in the small end of the con rod, and MAYBE (I'm not sure yet) in the governor stem-post.


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## cfellows (Jun 17, 2013)

Nice looking engine, Brian.  Have you given any thought to the cam gear and the valve assemblies?

Chuck


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## Brian Rupnow (Jun 17, 2013)

Yes, but not too much. As soon as I got back from my ill fated holiday I stepped in a big pile of engineering work for one of my current customers and haven't had much time today. The valves in the Webster and the Kerzel are both 1/4" heads with .093" stems. I find that size very difficult to work with. Those engines have 7/8" and 3/4" bores, respectively. The Atkinson and the Odds and Ends are both 1" bores, and both have 3/8" valves with 4MM and 1/8" stems which are a heck of a lot easier to work with. I don't really know if a 3/8" valve would be over-carbureting my engine or not. That may be a "Suck it and see" answer. I will be using valve cages with them, and the valves will exit thru the "cylinder head", similar to the Kerzel design, with the intake valve being atmospheric and the exhaust valve actuated by a rocker arm. My next real step is going to be exploring the arcane science of a vertically aligned governor and how to tie it into the valve train. One of the chaps who built my sawmill and posts regularly on the other forum I post on has sent me some pictures of a governor set up like this, but I haven't had time to study on it too much. The gears will be 24DP because that is the size of cutters I have, and they will be 1/4" wide because I have a bunch of 1/4" brass plate, but I haven't thought about diameters yet.--Of course it will be the conventional 2:1 ratio.--Brian


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## Brian Rupnow (Jun 17, 2013)

Someone on another forum has asked why I didn't use needle bearings, because they are much smaller than a ball bearing and would be easier to fit into a small engine. My answer is as follows: There's a little trick to needle bearings that a lot of people aren't aware of.--The friggin' things don't come with an inner race. You can't run them on a plain old cold rolled shaft, because they just chew it up, ruining both the needle bearing and the shaft. They are meant to run only on hardened shafts. You can buy the inner race as a separate part, but then the needle bearing has to be proportionally larger to account for the diameter of the inner race. I checked with the bearing folks yesterday before ordering the ball bearings. A needle bearing to fit a 3/8" shaft was 9/16" o.d. However, if you bought an inner race to fit a 3/8" shaft, then the needle bearing jumped to 3/4" o.d. and cost $17 for one inner race and needle bearing. A ball bearing is only 1/8" larger than that, at 7/8" o.d. and costs less than $5 per bearing. An additional factor is that size for size, needle bearings are considerably longer. For a 3/8" inner diameter, a ball bearing is only 5/16" wide. A 3/8" needle bearing without an inner race is .515" long, and with an inner race jumps to .569" long.---Not great when you are trying to fit them into 3/8" sideplates.


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## cfellows (Jun 17, 2013)

I've also read that needle bearings must be run on hardened shafts.  However, I've had 3/8" ID needle bearings running on my Hit n Miss engine for a number of  years now and there is no sign of any wear.  Of course, I only run my engine maybe an hour every couple of months.  I think the "chewing" problem is more likely to occur if your shafts are under moderate to heavy loads or only after many hours of running them.

Either way, the note of caution is worth heeding for anybody contemplating the use of needle bearings.  If someone chooses to take the risk, they can't say they weren't warned!  :fan: 

Chuck


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## RonGinger (Jun 17, 2013)

> Cooling reservoirs are always somewhat of a pain, but I am thinking in  terms of a plain o.d. cylinder, with a separate reservoir made from  aluminum and mounted with o-ring seals.



I do not believe that a hopper full of water on the cylinder of an engine does anything to help cooling. There are 3 methods of heat transfer, conduction, convection and radiation.

A hopper of water does neither of these- I does not conduct heat any better than a metal, it does not convect heat away, and it does notradiate better than a black metal. If the water was so hot it was evaporating away it would carry off some heat, but no model engine Ive ever seen runs this hot. 

Having a separate reservoir of water will also not carry away heat, unless the reservoir is finned, or has some air flow over it to carry the heat off by convection.

Of course, water run through a radiator with air flow over it can carry off heat. A friend of mine runs a Duclos odd and ends hit and miss engine at shows. He never puts water in it, and it runs all day without trouble.


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## jwcnc1911 (Jun 17, 2013)

I think a radiator brings a whole level of complication that would defeat the purpose of this engine.  It's directed towards beginners after all.

IMHO bearings are better for this application any way.  Needle bearings are for areas of higher radial load which just isn't seen in a model engine.  You can get thin section bearings for about the same cost as a "regular" bearings.

Also, shouldn't this thread be titled "I am designing an I.C. engine---"


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## GailInNM (Jun 17, 2013)

Brian,
3/8 ID bearings also come in a 5/8 OD flavor.  Standard base part number is R1038 with a suffix for plain, shielded or with seals.  Shielded work well for low friction as they do not add any friction to the bearing. The shield can be removed easily if necessary.  

Although a little bit late for you for this build, AVID has ball bearings for radio control cars at a very reasonable price.  Most are US$1 each.  Have always shipped to me within a day with a $2 per order handling charge plus their cost for the shipping. They do ship to Canada.

http://www.avidrc.com/product/9/standard-bearings/

Gail in NM


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## jwcnc1911 (Jun 17, 2013)

I don't know if you guys have a Fastenal in your area but they usually carry any bearings I ever need.  Usually in stock and less than I could order online any way.


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## Brian Rupnow (Jun 18, 2013)

Ron ginger--You are probably right. That being said, I remember as a boy seeing many of these engines in sawmill and agricultural use and they all had water reservoirs. They all were worked hard all day, and at noon lunch break they were always topped off with water to replace what had evaporated. Probably not needed for small model engines, as has been said, but I like them with a reservoir. I know that my Odds and Ends gets pretty hot, even with the water in the reservoir. I am going to design an alternate "bolt on" air cooled cylinder, so that people can build it either way.---Brian


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## Cogsy (Jun 18, 2013)

RonGinger said:


> I do not believe that a hopper full of water on the cylinder of an engine does anything to help cooling. There are 3 methods of heat transfer, conduction, convection and radiation.
> 
> A hopper of water does neither of these- I does not conduct heat any better than a metal, it does not convect heat away, and it does notradiate better than a black metal. If the water was so hot it was evaporating away it would carry off some heat, but no model engine Ive ever seen runs this hot.
> 
> ...


 
Water has a much higher Specific Heat Capacity than most metals  (over 4 times that of Aluminium for example), which means that it absorbs much more heat (energy) to raise it's temperature per degree than metals can (in general). So a lit match under a 1 gram piece of Aluminum will heat it to a much higher temperature than a lit match under 1 gram of water.

So the water acts as a big heat sponge and releases it into the surrounds through the normal means.


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## Brian Rupnow (Jun 18, 2013)

And for those among us who don't want to mess with cooling reservoirs, this is the air cooled version which will be offered as an option. It doesn't do much for me, but different strokes for different folks----


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## jwcnc1911 (Jun 18, 2013)

Cool Brian, are you going to put a belt driven fan on it for additional cooling?


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## Brian Rupnow (Jun 18, 2013)

jwcnc1911 said:


> Cool Brian, are you going to put a belt driven fan on it for additional cooling?


 Surely to God if someone has enough mechanical smarts to build an engine, they will have enough brains to know how to figure out a belt driven fan!!! I will offer up the air cooled cylinder as an alternate design. I don't intend to build it. People who build the engine with the air cooled cylinder are on their own, fan wise.


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## Brian Rupnow (Jun 18, 2013)

Well Poop!!! I can't remember where I bought the small brass bevel gears that I used on my 3 ball governor. I have checked with the McMaster Carr catalogue and the W. M. Berg catalogue, and it doesn't seem to be either of them. I have lost the computer files from the time that I built that 3 ball governor with the gears on it to use on the Webster engine, in one of various computer crashes. I have a fairly good idea of what I want to do for a governor on this engine, but I first have to either buy the gears and then model them, or find somewhere with cad models of small bevel gears which I can download. I really hate to buy them first, because if they won't work for what I want to do, then I'm stuck with them. Its a lot safer to create an accurate model to see if it can be made to work with my assembly and THEN buy the gears.


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## jwcnc1911 (Jun 18, 2013)

Brian Rupnow said:


> Surely to God if someone has enough mechanical smarts to build an engine, they will have enough brains to know how to figure out a belt driven fan!!! I will offer up the air cooled cylinder as an alternate design. I don't intend to build it. People who build the engine with the air cooled cylinder are on their own, fan wise.



I literally laughed out loud at that.  Was just wondering how far you were going to take it.


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## weez (Jun 18, 2013)

> first have to either buy the gears and then model them, or  find somewhere with cad models of small bevel gears which I can  download.


Try http://www.sdp-si.com/.  They have downloadable models of the gears in their catalog.  I have not bought anything from them but their prices seem reasonable.


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## Brian Rupnow (Jun 18, 2013)

Thanks Weez!!! Jwcnc1911--Yer going to make me crazy!!! ---And I did find a great site that lets you set up whatever your gear requirements are, and it will create a 3D model in whatever format you are using and let you download it.
http://www.rushgears.com/Tech_Tools/PartSearch8/partSearch.php?gearType=BEVEL


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## Brian Rupnow (Jun 18, 2013)

Okay---Now we're cooking!!! We got gears!!! The bevel gears are 24DP x24 teeth x 1" p.d. I have taken a good hard look at this thing, and at the size we are dealing with here, there is just no way to get the timing gears and the governor gears all on the same side of the engine. That's okay though. It makes the engine look more balanced with the governor on the opposite side. Of course this means I will have to run a pivot shaft across to the other side of the engine to latch the exhaust lifter rod, but I don't see that as a problem. The spur gears are 15 and 30 teeth 24DP x 1/4" wide, much the same as the Odds and Ends engine, just 1/16" wider.


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## Brian Rupnow (Jun 19, 2013)

Now this, my friends, is where it begins to get rather exciting for me!!! The governor balls are 5/8" diameter, and there will be 3 of them. I could get away with two, but I like the look of three better.


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## Brian Rupnow (Jun 19, 2013)

So here we have the three 3/8" ball bearings for the Rupnow Engine. I know they have seals in them right now, but if I find that they give too much friction, I can pop them out with a jackknife. The part that really rocked me though, was the price of the bevel gears. In the background behind the bearings you will see a governor I built a few years ago. The two new bevel gears I require for the new governor are the same size as the large gear on the existing governor, at 1" p.d. . First place I called (Stock Drive Products) wanted $35 each, in steel. The second place I called (Applied Industrial Technologies) wanted $75 each in steel. the place where I downloaded the solid models from (Rush Gears) has a minimum charge of $1300 and only produce and sell in batches. I can't buy from McMaster Carr --they have stopped selling/shipping to Canada as of about 5 or more years ago, unless you had a pre-established account with them. Fortunately one of my friends owns a company that does have an account with them, so he ordered me two steel gears at $21 each. I have seen posts where people on the forum have machined their own bevel gears successfully, but I think that is beyond my machining capabilities at this point. I will however, cut the spur gears for the cam timing myself.


.


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## Brian Rupnow (Jun 19, 2013)

And if you wondered about the governor---this explains about 50% of it. The other 50% is what happens between the end of that vertical pushrod and the exhaust valve lifter rod.


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## Brian Rupnow (Jun 19, 2013)

Its time to bite the bullet as far as valves are concerned. I have a 7/8" bore engine and a 3/4" bore engine both with 1/4" valves and .093" stems. They work well, but I find it very difficult  to work with that size of valve because they are so small. I have two 1" bore engines with 10mm and 3/8" valves with 4mm and 1/8" stems, which are great to work on but MIGHT be a bit too much valve for a 7/8" bore engine.. I think I'm going to jump right into the middle and design up a 5/16" diameter valve with a 1/8" stem. There is no real air flow science involved with this decision.--It is based more on having a stem big enough to work on more comfortably, and a head small enough to fit the confines of my cylinder bore.


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## Brian Rupnow (Jun 20, 2013)

This has lead me a merry dance trying to fit the sparkplug, valve cages, and valves all into a 7/8" diameter circle. I made it, but it took a lot of thinking. I have attached a 3d pdf file of it. If you have the latest free edition of acrobat reader you should be able to double left click the image and rotate it in 3D. 

View attachment ASSY OF HEAD CYL AND SPARKPLUG-RUPNOW.PDF


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## cfellows (Jun 20, 2013)

Clever idea on the spark plug placement.  Any concern about whether the fuel/air mixture will get pushed up into that small space to get ignited?

Chuck


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## Brian Rupnow (Jun 20, 2013)

No worries Chuck. I have seen many engines run well with a very short nosed sparkplug that actually looked like it was setting back in a cave, hiding. They always fired with no problem.


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## jwcnc1911 (Jun 20, 2013)

Brian,

I've never worked with flyball governors.  That video you post in another thread helped a LOT but post #64 just opened my eyes.  The design is not as complicated as I was making it in my head.  I have a question though, what holds the push rod up against the governor arm?  There's got to be a spring some where and I don't see where one will fit in.  Also, it seems as though the design possibilities of a flyball governor are limitless.  How does one calculate the weight of the balls for a predetermined speed?

Fantastic work by the way!  I'll probably have to build this engine out of pure respect and appreciation.


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## /// (Jun 20, 2013)

jwcnc1911 said:


> I have a question though, what holds the push rod up against the governor arm?  There's got to be a spring some where and I don't see where one will fit in.



The exhaust valve spring?


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## Brian Rupnow (Jun 20, 2013)

jwcnc1911 said:


> Brian,
> 
> I've never worked with flyball governors.  That video you post in another thread helped a LOT but post #64 just opened my eyes.  The design is not as complicated as I was making it in my head.  I have a question though, what holds the push rod up against the governor arm?  There's got to be a spring some where and I don't see where one will fit in.  Also, it seems as though the design possibilities of a flyball governor are limitless.  How does one calculate the weight of the balls for a predetermined speed?
> 
> Fantastic work by the way!  I'll probably have to build this engine out of pure respect and appreciation.


 Take a real GOOD LOOK at the line of printing across the bottom of the drawing.


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## Brian Rupnow (Jun 20, 2013)

Just about done!!! Now if I just had the exhaust latch and a carb on this thing, I could start making detail drawings.


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## Brian Rupnow (Jun 20, 2013)

I need ten good men!!! I want to try something different this time. I am going to detail and build this engine. Any of you on the board who have followed my posts over the years will know that what I build works. I want 10 experienced (or semi experienced) people to build this engine with me. The plans will all be free. I will detail an alternate air cooled cylinder instead of the water cooled version which is shown. You can build it with or without the governor (although I think that may well be the most interesting part of the entire engine.) You can build it either water cooled or air cooled.  I would like to get at least one builder from each of the major countries around the world. My plans will be in imperial, however, if you are an experienced enough builder to tackle something like this, doing a metric conversion shouldn't be a major stumbling block for you. If you choose to "Build along with Brian", I would like you to start a post on this forum and show us your work as it develops. I will give any advise asked for, and try to explain any weird or different "set-ups" that are required. I will be posting the drawings and pictures of my build here as I go along. If I find any errors (shudder) in the drawings as I build, I will quickly let everyone know and revise the drawing. I think this could be a load of fun. I know its summer (at least on this side of the globe) and the build may not go blazingly fast, but believe me, it will happen. Who's in????---Brian


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## jwcnc1911 (Jun 20, 2013)

I saw the note... I still don't see the spring or room for it.  Will it be under the .174 - .474 rod potrusion?


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## Brian Rupnow (Jun 20, 2013)

This is what it looks like with the adjustable governor spring in place, with the red threaded tension adjusting knob directly above the spring. I modeled the spring thicker than what it will really be, so it will show up well. This set-up will let me adjust the RPM at which the governor lets the engine run. The second view is of the latch lever which interacts with the pushrod via a 3/16" cross shaft that runs from the governor side across to the pushrod side of the engine.


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## jwcnc1911 (Jun 20, 2013)

Ahhh!  It's pushing right where I expected but I didn't envision the extra lever.  I guess part of that will be used for speed control?


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## Brian Rupnow (Jun 20, 2013)

Its been a very long and busy day designing, and at about 5:00 PM I called it quits and went out on the back deck with my good wife to drink some wine and relax. And it was while we sat there in the afternoon sunshine, and celebrated Bacchus that I suddenly thought $#@^&---I didn't put any ignition points or cam on the damn thing!!!


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## Brian Rupnow (Jun 20, 2013)

Ate some supper and then realized I had forgotten the ignition cam and points!!! This is where solid modelling really shines. I just went into my archived files of the Kerzel engine from a few years ago, resaved the parts to the Rupnow engine file and modified the points mounting bracket.---about 20 minutes work.


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## Brian Rupnow (Jun 20, 2013)

All farther posts about this engine will be in the "Work in Progress" section at this link.
http://www.homemodelenginemachinist.com/f31/rupnow-i-c-engine-governor-21176/#post223810


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