John Deere Engine

[Bogstandard]

Chuck,

That is really looking remarkably good.

If I was you, I wouldn't worry about the thin skin that the cylinders are going to mount to. If you have room, just put a tapped backing plate on the inside of the crankcase, to sandwich the case between the cylinder block and backplate. The strength will then come from the joints and curvatures in the crankcase itself. You might have to open up the access hole a little to let you get the backplate inside. Or maybe two tapped strips if you can't get the hole big enough. Just a suggestion by the way. Don't want you ruining all your great work with a slip of a blowtorch, trying to get the plate a bit thicker.

John

 

[cfellows]

Thanks, John! Since space inside the crankcase is going to be kind of tight, I'm thinking I'll just use nuts on the inside. The skin, which is .045" thick, should be thick enough since this will be powered by compressed air and will be a slow runner.

Chuck

 

[cfellows]

A little more progress. I got the pistons turned down to size... still have to hollow them out and drill holes for the wrist pins. Also finished making the connecting rods tonight.

Chuck

 

[cfellows]

I finished the design of the head and started cutting metal again today. This engine will have an overhead valve, similar to the JD engine which is my avatar. However, since the valving is quite different, the internals of the head will also be different.

Normally I drill the exhaust port which contains the sliding piston valve dead center on the poppet valve assembly. However, since this will be an overhead valve, the valve push rod would interfere with the exhaust manifold and pipe. Therefore, I moved the exhaust port in toward the center, out of the way of the push rod. The exhaust port hole, which is 3/16" diameter, enters the valve assembly hole tangentially, overlapping enough to create an opening into the valve assembly hole. You can kind of see the half moon shaped hole where in the accompanying pictures.

In this picture you can see the two exhaust ports which will come out the top of the head in the assembled engine.

And finally, this shows the two holes on the opposite face which will let air into and out of the cylinder.

I will be using 3/16 hardened stainless steel balls for the sliding valves instead of my usual piston shape. My thought is that as the ball passes over the hole into the cylinder, some of the air will pass around the ball and out through the exhaust, adding a little extra pop when it "fires".

Chuck

 

[chuck foster]

looking good chuck 8) ;D

can't wait to see some video of it running.

chuck

 

[cfellows]

looking good chuck 8) ;D

can't wait to see some video of it running.

Thanks, Chuck. What's the story on the v-twin engine you have as an avatar?

Chuck

 

[cfellows]

I'm going to try something different on the cam gears to avoid a big cam gear. I'm going to use a double reduction gear set, the first being 3:4 ratio and the second being 2:3 for an overall ratio of 1:2.

By the way, I figured out a way to have a cam concentric with the crankshaft, but running at one half the speed, without planetary gears. Use a double reduction gear set, primary driving gear of 14 teeth on the crank, primary driven gear of 21 teeth, secondary driving gear of 15 teeth, and final driven gear, free spinning on the crankshaft, of 20 teeth. I figured this out for a radial engine design.

Only problem is, in a 3 cylinder radial, the cam has to rotate in the opposite direction of crank and with this set up, both cam and crank rotate in the same direction.

Chuck

 

[Brass_Machine]

Chuck... That is looking great. You gots skillz!

Thanks, Chuck. What's the story on the v-twin engine you have as an avatar?

Chuck

Yeah... I wanna know too!

Eric

 

[chuck foster]

gee whizz i thought i could sneak in a new avatar and it would go unnoticed for a day or two :big:

will i finished the standby engine that was mentioned on here and i have been watching the build progress of mr fellows
john deere engine and the drawings for his hit and miss style engine. so with that in mind i thought i just have to try
building one! ;D

i have always wanted a vee twin of some kind so that is what i started on saturday morning.
it has 3/4" bores and the stroke will be 1 1/8" and the crank rotates on ball bearings.

to be honest at this point i'm not sure if it will be a compressed air engine or a gas engine ???
it will most likely be a compressed air engine but one never knows.

if it works ok on air i might just try turning the v8 block i have into an air engine as well.

i think i will use a small pin on the top of the piston to lift the check ball in the cylinder head (to allow the compressed air in to the cylinder).

well thats the story on the avatar pic.

thanks for the intrest, i will start another post to show the progress if anyone would like to see the build .

chuck

 

[Brass_Machine]

gee whizz i thought i could sneak in a new avatar and it would go unnoticed for a day or two :big:

....

well thats the story on the avatar pic.

thanks for the intrest, i will start another post to show the progress if anyone would like to see the build .

chuck

Hey Chuck... Nothing gets by us ;D

Please start a new thread on this engine. I for one would be very interested in seeing it.

Thanks
Eric

 

[cfellows]

Hey Chuck... Nothing gets by us ;D

Please start a new thread on this engine. I for one would be very interested in seeing it.

Thanks
Eric

I second that! A V-twin running on compressed air is also on my list of to-build engines!

Chuck

 

[cfellows]

Some more progress this evening. I got started on the overhead valve assemblies. Although this engine uses the same basic principle as the horizontal single, it has the overhead valve which complicates things some. Here is what they look like in the head (sans screws).

Here they are outside the head. You can see the 1/8" hole that ports the high pressure air into the passage in the head when the valve is open. The valve will be made from 1/4" drill rod and the valve stem will be 3/32" in diameter. The groove is for an o-ring, or more specifically, buna quad-rings, to keep the high pressure air contained when the valve is closed.

The valve assemblies are held in the head by 2-56 socket head cap screws.

Chuck

 

[cfellows]

Thought I'd post a few more picture so folks wouldn't think I've been slack all weekend! ;D

I pretty much finished up the head and the valve assemblies. Next I expect to tackle the camshaft, timing gears, and rocker arm assemblies.

I think it needs a larger flywheel. This one, at 3", seems a bit small. I'm thinking 3.25" or even 3.5" diameter.

Chuck

 

[bretk]

Chuck,

Lookin' good! I think 3.25 might do'er juust fine! :big: That overhead valve is really nice, what a great piece of imagineering Walt Disney would have been proud. ;D

-Bret

 

[cfellows]

I love it when a plan comes together! To make a bigger flywheel, I cut a 5/8" long piece of steel tube that was about 3.5" in diameter and about .050" smaller than the flywheel I had made. I bored out the inside of the tube to about .010" smaller than my flywheel, to a depth about the thickness of the flywheel. I then heated it until it turned blue, then dropped the existing flywheel into the ring. Very close fit, so when it cools, it should be nice and tight.

Here's a pic taken just a few minutes after I dropped they flywheel into the ring. I used an expanding mandrel for a handle.

When I face it off, it will look like all one piece.

 

[bretk]

Chuck,

That looks great, That is exactly what we did when we renewed the steel tires on our steam locomotive.

-Bret

 

[cfellows]

Got a little more work done on the JD engine. Installed the Camshaft bearings and the valve lifter guides (Brass). I also finished the primary timing gear. I made it from 9 tooth, 24 pitch pinion wire from Stock Drive Products. I made a hub for it, turned down part of the gear and pressed it into the hub. Pinion wire is basically a pinion gear that can be ordered in 12", 24" or longer lengths. You simply cut of the amount you need for your gear, bore a hole through it, and figure out how you are going to attach it to the shaft. I will use a set screw in the collar.

Chuck

 

[Brass_Machine]

Looking good Chuck. I am really digging this JD engine. Keep it coming!

Eric

 

[lathe nut]

Chuck, been doing copy and past in a Word Document, got all the picture and the write up when you are doing I am going to do one, thanks for sharing how about even more pictures while you are milling on or on the lathe, thanks so much, Lathe Nut

 

[chiliviking]

This is an amazing piece of work. I am in awe of the genius of the folks on this board. Keep the photo's coming.