Onan twin genset engine on WH tractor

[Greentored 3,220]

Onans are not cheap, we are all well aware of that.  Im seeing a lot of old RV gensets with the big Onan twins, running, going for a couple hundred or less. Most of these things didnt get run much either.

Are these the same bolt pattern, tins, etc... as our WH twins?  Only thing I can think may be different would be a tapered/shorter crank PTO, and if thats the case, betting somebody could come up with an adapter.

Just more thinking out loud. Sure would be a cheap repower option for the budget crowd. Anyone attempted it?

[Macgyver 92]

The question I have is are those engines horizontal or vertical shaft? I thought they were vertical. Still might be able to use some parts.

[ebinmaine 70,742]

19 minutes ago, Macgyver said:

The question I have is are those engines horizontal or vertical shaft? I thought they were vertical. Still might be able to use some parts.

Could be either

 

Most of the big generators I've seen are horizontal like our tractors are.

 

26 minutes ago, Greentored said:

tapered/shorter crank PTO

 

I am by no means an expert there but I can tell you a couple different things.

a tapered crankshaft can be made up for with an adapter. I've seen it on this site a time or two.

@Achto or @WHX24 maybe one of you boys?

 

The engine for Colossus is a counter engine.

Meaning, it wasn't built into a home. It was literally bought as an engine without being in a different kind of machine.

 

Where you have to use some caution in this situation is that some of these engines may not have a crankshaft  thrust bearing and you would be forced to use an electric PTO.

 

Absolutely doable. Just a couple things to keep in mind.

[pfrederi 18,333]

[lynnmor 7,560]

Some generators run at 1800 RPM, so a governor modification or replacement may be needed.

[Achto 28,779]

Looks like the two biggest hurdles have been covered. Tapper crank shaft & 1800 RPMs. Most Onan RV gen sets will be 1800 RPM, this was done to keep the noise level down. The RPMs can be changed though. @pfrederi showed the tapper to 1" adaptor, the same supplier also offers a tapper to 1 1/8" adaptor. I used the 1 1/8" adaptor when I install a Hatz engine in one of my tractors.

[peter lena 9,088]

greentored, think that was a good question to ask, as said rv gen sets are available for much better money , major detail as macgyver asked is about horizontal set up. feed back is already coming in , it would be great to have this idea and availability  to solve tired onan,s on horses. hope this evolves into the go to  for keeping horses alive, pete  

[bc.gold 3,403]

usually you'll find that the gen head is the starter, oil pan different configuration, some engines not equipped with an oil filter, governor has ten fly-balls to maintain 1800 rpm, just removed five to reach 3600 rpm.

 

The gen engine for tractor use would need oil pan to accept starter, install ring gear on flywheel use electric fuel pump or replace the camshaft with one that has the lobe to operate a manual pump. Remove 5 of the 10 fly balls from the governor for 3600 rpm.

 

Would not worry about not having an oil filter the Onan's use a large capacity oil pan and regular oil changes will keep your engine happy.

 

Most gen engines have less than 100 hrs or less.

 

Th gen armature is held onto the engine taper with a long bolt the goes the fill length of the armature. You can press the shaft from the armature, machine it to suite your needs, use a shorter bolt to secure the new stub to the tapered crank end.

 

I love my Onan engines they always start regardless how cold it gets here in Central Canada.

Edited March 6, 2020 by bcgold

[WHX?? 50,731]

All I know about Onan/Cummins is they are pricey... the new ones anyway. I looked at them for about two seconds after I bought my toy hauler and only because the hauler was prewired with their remotes. Bout fell off my barstool when I saw what they get for even a small one! Promptly marched down to HF for a Predator cheapy and to heck with the remotes! 

 

That said I would guess the older stuff might be adaptable to a horse. If I remember right they made gennys for the military using a PPG based motor? Wonder if a guy could find them at surplus Uncle Sam places?? 

Edited March 6, 2020 by WHX24
speeling

[Greentored 3,220]

Great discussion fellas! I love my big Onan, and if these things can be adapted into our horses relatively simple, dont put it past me to pick one up and hotrod the snot out of it 

Edited March 6, 2020 by Greentored

[bc.gold 3,403]

The older Onan CCK engines use forged steel connecting rods with replaceable bearing shells, std, 0.010, 0.20 and 0.030 and have a full pressurized oil system.

 

The engine blocks I've disassembled show absolutely no cylinder wear, thinking that Onan added nickle to their casting alloy did an acid test to see if there would be a color change to indicate the presence of nickle but  the test showed negative.

 

Was not overly keen to discover the type of main bearings used, a replaceable shell rather than Timkin, none of the shells have shown excessive wear.

 

Just to satisfy my curiosity, I at one at one time thought of sending a sample of an old Onan engine casting in for an XRF to determine the make up of the casting alloy. The $20.00 fro the XRF is a non issue but has reasoned to leave the casting formula as Onan  had intended - secret.

 

Both my Onan engines are from the mid 1970.s and both have years of life left in them, perhaps even more that i.

[bc.gold 3,403]

5 hours ago, bcgold said:

usually you'll find that the gen head is the starter, oil pan different configuration, some engines not equipped with an oil filter, governor has ten fly-balls to maintain 1800 rpm, just removed five to reach 3600 rpm.

 

The gen engine for tractor use would need oil pan to accept starter, install ring gear on flywheel use electric fuel pump or replace the camshaft with one that has the lobe to operate a manual pump. Remove 5 of the 10 fly balls from the governor for 3600 rpm.

 

Would not worry about not having an oil filter the Onan's use a large capacity oil pan and regular oil changes will keep your engine happy.

 

Most gen engines have less than 100 hrs or less.

 

Th gen armature is held onto the engine taper with a long bolt the goes the fill length of the armature. You can press the shaft from the armature, machine it to suite your needs, use a shorter bolt to secure the new stub to the tapered crank end.

 

I love my Onan engines they always start regardless how cold it gets here in Central Canada.

 

Onan and Kohler both use the same alternator stater.

 

I made a plate to cover the hole where the mechanical fuel pump sat, before installing the cover drilled and tapped a ole to accept a threaded barb for a  hose connection to operate a pulse fuel pump.

 

I've had pulse pumps freeze up from engine moisture during our cold winters and I;m not fond of having to drag a machine into the shop to thaw. Opted for electric pump.