Stationery engine design

[up2oneghz]

Perhaps you all can help me, and I want to thank you for your time up front.

I wanting to build a stationary engine for co-gen. I have a 300 straight six that I want to modify.

From what I can tell old stationary engines seem to be low hp, huge displacement, and very low RPM engines. I'm assuming that the reason many of these engines ran for decades in factory settings is the low RPM aspect. After all kinetic force is mass x velocity squared, and the low rpm allowed for better heat dissipation. My goal is 500rpm and to achieve 5-15hp


Where I'm lost is spark timing, and cam design?

Any advice would be well appreciated

Thanks again

 

[GreenTwin]

Part of the secret to long life of old equipment is the massive babbitt bearing surfaces, and the shape of the front of the bearing which was designed to push a layer of oil between the wear surfaces.
I have seen a book somewhere (I forget the source) detailing exactly how the old large babbitt bearings were shaped.
Lots of X cuts in the bearing too to spread the oil.

I have to guess that the old bearing designs also keep the maximum forces on the bearings at a level that problably lower than many modern engines.
The tradeoff is that the old machines were very large, and so had a low amount of power produced for a given mass.

I have deliberately rebuilt large pumping equipment that was over 100 years old (in my line of work), rather than replace it, because once rebuilt, there is basically no maintenance for a very long time.
Modern pumping solutions are very compact and sophisticated, but they may only last 5 years or less.

I am not sure exactly what you are trying to do with your engine.
Is is an existing gasoline engine ? If so, then can you find its original ignition and timing system drawings ?

.

 

[ajoeiam]

Perhaps you all can help me, and I want to thank you for your time up front.

I wanting to build a stationary engine for co-gen. I have a 300 straight six that I want to modify.

From what I can tell old stationary engines seem to be low hp, huge displacement, and very low RPM engines. I'm assuming that the reason many of these engines ran for decades in factory settings is the low RPM aspect. After all kinetic force is mass x velocity squared, and the low rpm allowed for better heat dissipation. My goal is 500rpm and to achieve 5-15hp


Where I'm lost is spark timing, and cam design?

Any advice would be well appreciated

Thanks again

Hmm - - - or - - you may want to build yourself something like a Lister (listeroid being the more modern) diesel - - - that would be interesting - - - anyone on here with one to help get dimensions etc?

 

[tractor162003]

A 300 straight six sound like a Ford engine.

 

[up2oneghz]

A 300 straight six sound like a Ford engine.

Yes, with a propane carburetor for a 16hp motor and a grossly oversized oil pan. Any recommendations on a cam and timing to get peak power at 500 rpm?

 

[up2oneghz]

Hmm - - - or - - you may want to build yourself something like a Lister (listeroid being the more modern) diesel - - - that would be interesting - - - anyone on here with one to help get dimensions etc?

Part of the secret to long life of old equipment is the massive babbitt bearing surfaces, and the shape of the front of the bearing which was designed to push a layer of oil between the wear surfaces.
I have seen a book somewhere (I forget the source) detailing exactly how the old large babbitt bearings were shaped.
Lots of X cuts in the bearing too to spread the oil.

I have to guess that the old bearing designs also keep the maximum forces on the bearings at a level that problably lower than many modern engines.
The tradeoff is that the old machines were very large, and so had a low amount of power produced for a given mass.

I have deliberately rebuilt large pumping equipment that was over 100 years old (in my line of work), rather than replace it, because once rebuilt, there is basically no maintenance for a very long time.
Modern pumping solutions are very compact and sophisticated, but they may only last 5 years or less.

I am not sure exactly what you are trying to do with your engine.
Is is an existing gasoline engine ? If so, then can you find its original ignition and timing system drawings ?

Just a run of the mill gas engine. The main journals, wrist pins, rings, etc are extremely oversized if I derate the engine to 15hp. The problem is it is designed for peak hp at high rpm. The engine runs with a carb swap to a small propane one. It doesn't generate much hp though, as it was designed to reach max hp at 4000rpm and I'm planning on running it at 500rpm. I plan on Swapping the ignition for an electronic one to use as a govener set for 500rpm. My question it what cam profile you would recommend. The stock cam appears to be "249 lift with 252 duration"