GM LE2 engine conversion

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mm4440

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Great Forum! I've learned a great deal from reading through this thread. I too want to be able to use a production automotive engine with these capabilities. I'm a proponent of keeping things as stock as possible and had run across the LH7 turbo diesel and after looking at the hp/torque/rpm chart wondered if this could be used driving a prop directly off of the flange end of the crank through a BMW drive shaft vibration damper. The prop hub would require its own bearing, of course. I'm new to this means of communicating so wondered if we could start a thread specifically for that engine to avoid cluttering this discussion?
The prop shaft needs two bearings to carry radial and moment loads. The rubber joint will not do it for long. A four cylinder four stroke DD Diesel is very tough on props. Stick with wood with a beefier than normal hub and blade shanks.
 

Yellowhammer

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If I had such an airplane I would definitely be interested. But the "extra" airplane I have is going to be used for a test bed on a 58HP engine that's a lot lighter.

What you should do is contact the people on the Zenith Aircraft internet forum, and find someone with a CH-750 who is interested in auto conversions. That would be a perfect airframe for testing what you are doing.
VB,

Is that 58 hp, lighter engine, the one I have been so excited about??
Thanks,
Yellowhammer
 

wsimpso1

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I'm new to this means of communicating so wondered if we could start a thread specifically for that engine to avoid cluttering this discussion?
Go ahead. Up by the top of the forum there is a button for "Post Thread", and you get going there. Make the Title represent what you want to talk about. The Original Post sets the tone so edit it carefully and let people know what the thread is about. Have fun.
 

ivanhoyt

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The prop shaft needs two bearings to carry radial and moment loads. The rubber joint will not do it for long. A four cylinder four stroke DD Diesel is very tough on props. Stick with wood with a beefier than normal hub and blade shanks.
Thank you for the help. Good info on prop suggestions. The more I think about driving the prop in line with the crankshaft, the more I realize that it would create a ground clearance problem. I'll attempt to start my first thread ever.
 

Chris Matheny

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This particular engine has the thrust washer in the 3-4 cylinder webbing so you'd still need a support bearing setup on the prop end and the feed and return for the turbo would post an issue then. Easier to keep it right side up and and run a PSRU.
 

rv7charlie

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You need a bearing, but it has nothing to do with thrust. Ex: Conts & Lycs work fine in both tractor & pusher designs. Thrust is one of the smallest loads on the crank.
 

PMD

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Ever run a diesel in high altitude, freezing conditions? They don't make heat.
Uhhh...yeah. They do just fine, thanks. Have run diesels in the arctic winter. At IDLE, yes, of course, but under load even the most efficient possible current tech diesel is still rejecting more energy into the cooling system than it is putting to the flywheel.
 

Chris Matheny

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Concerning the thrust bearing I was just pointing out that the flywheel side is not supported by a larger more robust bearing in that area. By the time you machine a support bearing you're halfway to a PSRU as far as weight but adding way more complexity trying to invert the engine.
 

WonderousMountain

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Used to work with a guy who did BioDiesel
conversions back in the day when grease was FREE!
The craftsmanship was poor & components cheap,
but once the heater coil got warm it ran just fine in,
little less than arctic conditions Minnesota winter.

High Carbon Count Paraffins gel at low temperature.
 

RVC

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Chris,

Just read through this thread. I am very impressed with your ideas and demonstrated capabilities. Some questions:

1 - What gave you the idea for this engine and what do you consider to be safe operating limits for the LE2? I'm uncertain if the LE2 can meet my needs but I have to follow this because of the creativity involved in the project.

2 - Your own redrive design? Billski appears to be an excellent adviser. Do you have this described in a separate thread?

From one weight weenie - with less fabricating capability that you possess - to another.

Rick
 

Chris Matheny

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The project is still active, just slow at the moment due to work. I chose this engine based on size, weight, availability and reliability. The only reliability issues it seems to have are related to systems that won't be in place in my application. I would not be afraid to run this in a 120-130hp range for extended periods with a better turbo than stock for this application. These have a nice forged crank and fractured cap forged powered metal rods from the factory that are robust. Weight wise is should come in around or under a Corvair engine. The re-drive is under revision for some changes I wanted to make for my application in particular. I'm now learning the coding for my ECM for it and it's a learning curve.
 
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