Onan diesel swap?

[chriswinvb]

I found a listing on GL for a Onan 4 cylinder diesel engine

http://www.govliquidation.com/auctio...&convertTo=USD


Would this "fit" in my M715?

[EGH2474]

I believe it would physically fit under the hood of the M715 but everything I'm reading online suggest it is only a generator engine. Either for a stand alone generator or for use in a RV. I can't say for certain but I think it only has betwee 18 to 24 Hp anyway. From what I've read on the zone even a cummins 4bt 4 cyl isn't really big enough for these trucks. For a diesel you need either a cummins 6bt 6 cyl from a Dodge or the 6.2 from a GM.

Good luck, Eric

[Flingarrows]

It would probably fit, but would require a lot of fabrication to mate a trans to it.

Onans are generator engines, so there probably are not a lot of aftermarket automotive manufacturers supporting it.

They are also designed for constant rpms. I'm not sure if there are any issues with that, but maybe others here can talk to that.

[Flingarrows]

I believe it would physically fit under the hood of the M715 but everything I'm reading online suggest it is only a generator engine. Either for a stand alone generator or for use in a RV. I can't say for certain but I think it only has betwee 18 to 24 Hp anyway. From what I've read on the zone even a cummins 4bt 4 cyl isn't really big enough for these trucks. For a diesel you need either a cummins 6bt 6 cyl from a Dodge or the 6.2 from a GM.

Good luck, Eric

Doh, I was typing at the same time on this Eric

[Don Cavey]

...

They are also designed for constant rpms. I'm not sure if there are any issues with that, but maybe others here can talk to that.

That is what I was thinking also...

[jeeper]

They are also designed for constant rpms. I'm not sure if there are any issues with that, but maybe others here can talk to that.

The electrical generation part of the generator needs to turn at a constant speed to ensure the Hz of the sine wave doesn't vary too far from 60Hz. In the U.S. we use 60Hz in Europe they use 50Hz. This is the main reason a generator is designed to turn at a constant RPM.

[jeeper]

Also that engine is only 18hp. I think that is a little too small to motivate an M715.

[Mikel]

I believe it would physically fit under the hood of the M715 but everything I'm reading online suggest it is only a generator engine. Either for a stand alone generator or for use in a RV. I can't say for certain but I think it only has betwee 18 to 24 Hp anyway. From what I've read on the zone even a cummins 4bt 4 cyl isn't really big enough for these trucks. For a diesel you need either a cummins 6bt 6 cyl from a Dodge or the 6.2 from a GM.

Good luck, Eric

A 4BT is plenty for our trucks unless you are building a hot rod. And I would take one over a 6.2 any time.

[tndonor]

A 4BT is plenty for our trucks unless you are building a hot rod. And I would take one over a 6.2 any time.

Agreed. I had a J10 with a 6.2 and then had a 4BT in it. While not a 715, its the only full size Jeep I am aware of to have both motors. stock 4bt was waaaayyyy better IMO for power, response, fuel consumtion, etc.

Even if you had a Cummins genset motor, it would take more money and time to make it only half way work. Most gensets use a fuel system that keeps RPMs and is load controlled, not variable ie they dont use a throttle cable. Also the internal camshafts, timing, etc are set for a 1-200 RPM range. Get the motor outside of that 200 rpm powerband and effeciency and power go out the window.

A lot of time, money, and replacement parts to get a sub optimal result versus using a motor designed for the purpose to start with

[chriswinvb]

What is the value of a running original Tornado with 21,000 miles?