John Deere Engine

[Metal Butcher]

The motor is taking shape and looking good! :bow:

Can you give specific details on the gear train, and will you add this information later to the plans uploaded in repository?

Thanks. -MB

 

[radfordc]

The gears were purchased from RC Hobbies Online http: //www.rchobbies.org/

They are Robinson Racing Products 48 pitch gears: http://www.robinsonracing.com/catalog/48pitchpinion.html

I used 17, 25, and 34 tooth gears. Part# RRP1034, RRP1025, RRP1017

Once I finished the engine I will update the plans "as built" and include the gear info.

Charlie

 

[Metal Butcher]

The gears were purchased from RC Hobbies Online http: //www.rchobbies.org/

They are Robinson Racing Products 48 pitch gears: http://www.robinsonracing.com/catalog/48pitchpinion.html

I used 17, 25, and 34 tooth gears. Part# RRP1034, RRP1025, RRP1017

Once I finished the engine I will update the plans "as built" and include the gear info.

Charlie

Thanks for the gear information Charlie. I will patiently wait for you final updates.

-MB

 

[putputman]

Nice looking engine Charlie. Looking forward to the video and hearing that familiar JD sound. :bow: :bow: :bow: :bow:

 

[Metal Butcher]

Yea! It's looking mighty fine Charlie!
:bow :bow: :bow: :bow: :bow:

As soon as you give the O.K. I'll start building mine.

-MB

 

[cfellows]

Very nice work, Charlie. If she runs as great as she looks, it ought to be a winner!

By they way, did you install o-rings on the valve assemblies?

Chuck

 

[radfordc]

Yes, I used the o-rings as you showed.

 

[radfordc]

I posted the updated plans in the "Plans" section.

Yea! It's looking mighty fine Charlie!
:bow :bow: :bow: :bow: :bow:

As soon as you give the O.K. I'll start building mine.

-MB

 

[radfordc]

She runs! I got the new engine running yesterday. I was having trouble getting the o-rings sealed. Turns out that I was cutting the o-ring when installing the valve in the head. I had to put a chamfer on the edge of the hole in the head so that the ring could get started properly.

Charlie

 

[Metal Butcher]

She runs! I got the new engine running yesterday. I was having trouble getting the o-rings sealed. Turns out that I was cutting the o-ring when installing the valve in the head. I had to put a chamfer on the edge of the hole in the head so that the ring could get started properly.

Charlie

Hip-hip-hooray! Hip-hip-hooray!

Congratulations on your success!

:bow: :bow: :bow: :bow:

-MB

 

[cfellows]

Glad to hear it Charlie... Congratulations.

By the way, are you running it with a pressure regulator or just limiting the amount of air with a ball valve or some such?

One problem I had with this engine was the fact that the two cylinders "fire" in quick succession, followed by a full revolution in between. When the first piston "fires", it uses up all the air in the line between the engine and the pressure regulating valve. There isn't much time for pressure to build back up before the second piston "fires". This results in uneven powere between the two cylinders, and also, uneven sound.

I overcame this on my engine by building a separate control valve for each cylinder so I could adjust the pressure to each cylinder independently. I just made simple needle valves with a slotted screw to adjust them. Once you get the pressure balanced between the two, you can then vary the engine speed with the main control valve without readjusting the balancing valves.

Chuck

 

[radfordc]

No, I took the "easy" way out and just made the air supply tubes as large as possible to provide adequate volumn of air to the cylinders. However, I do notice the difference in sound between the two cylinders.

Charlie

 

[Metal Butcher]

Would adjusting (restricting) the valve opening on the primary cylinder via the rocker adjusting screw do the trick?

I was thinking about tying that, or using a drilled plug (removable) on the primary side intake.

-MB

 

[cfellows]

You can adjust the inlet valves to balance the pressure, but it doesn't seem to work as well, in my opinion. Your idea of a restricter plug might work well. You'd have to experiment with different size openings in it.

Chuck

 

[radfordc]

Chuck, how much air pressure does your engine operate on? Mine just ticks over with 20 psi.

Charlie

 

[Metal Butcher]

Hi Charlie. I know your question is directed towards Chuck. Being the designer he is defiantly more qualified than I to give you the correct answer. Your posted question reminded me I had a similar situation that might be worth mentioning. They are somewhat different in design, and that may-or-may not be significant.


Quote from one of my posts in My modified built of "Chucks Single":
The 3/4" long .020" exhaust valve spring was too stiff and required 20 psi to run the motor. I switched it to a ½’’ long .020" spring and it ran on 5 psi. Still not satisfied I tried a 3/4" long .016’’ spring and it ran on 2 psi! A motor that runs on low pressure is my goal and to me indicates a successful build. After a 15 minute break-in period it now runs well on 1psi every time.

The difference between the .020 wire 3/4" spring and the .016 wire 3/4" spring was about 19 psi for the motor to run.
However, it could be something all together different

-MB

 

[cfellows]

Chuck, how much air pressure does your engine operate on? Mine just ticks over with 20 psi.

Charlie

Unfortunately, the engine is packed away since we are in the midst of selling our house.

I usually control the engine speed with a simple ball valve rather than a pressure regulator, so I don't really know the minimum PSI required to run it. I do know that the springs are ball point pen springs which are .016" wire and 3/4" long, same as MB's.

Chuck

 

[radfordc]

My engine uses a ball point pen spring cut in half. Each spring is approximately 1/2" long. Don't you need alot more than a couple of psi of air to get the "poppin' john" sound?

 

[Metal Butcher]

My engine uses a ball point pen spring cut in half. Each spring is approximately 1/2" long. Don't you need alot more than a couple of psi of air to get the "poppin' john" sound?

I think that the sound (popping) was the same just louder with the stiffer springs on my build of "Chuck's Single". I was more interested in smooth-and-slow running at a very low pressure. It would stand to reason that the "John Deere" "tone" would be the same regardless of spring pressure, and that lower pressure would only have an effect on "Volume".

I haven't looked over the valving arrangement on the"John Deere" to see how it differs from the "Single". I'm kind of at a loss as to how it works. I am considering the the valve design used on the "single" for the JD. There's that "Butcher" in me again, trying to run my build! ;D

-MB

 

[cfellows]

The valve assembly in the horizontal single and the JD engine are functionally the same. Adapting it to an overhead valve arrangment for the JD engine was actually a lot of extra work. I just did that to come as close to the original JD engine in appearance as I could. Plus, overhead valves and rocker arms add to the visual appeal of the engine running.

The L-head arrangment of the horizontal single is a lot simpler to build since it does away with rocker arm assemblies and the o-ring.

As far as sound goes, you'll get more sound if you use a volume limiting valve, like a ball valve. The pressure starts out high, then drops rapidly after the intake valve opens. My theory is that this more closely emulates the operation of an IC engine.