Exchanging a HG-42 to a OC-3 engine

[Joe Clayton]

I have located a rebuilt OC-3 engine and would like to put it in my vintage1945 HG-42 crawler. Would like to know if this has been done and what problems would be experienced on doing so. I would like to keep the existing bell housing, flywheel, and pressure plate. Any information would be must appreciated.    Old Joe

[1956oc3]

I think the only issue will be the lower rad hose and water pump, and all the extra power!

[Lowspeedlife]

The clutch, flywheel & bell housing should be interchangeable. The only reason I could think of to chenge them to the originals would be if I wanted to keep it a crank start, assuming the OC3 has a starter. As Scottie said, there might be a difference in the lower radiator hose if the OC3 has a water pump, other than that it should be a bolt in change.

Scott R.

[oliverchris]

Shouldn't be a problem at all. While you have the one engine out, you might consider strengthening up that mainframe with a longer steel fillet on the inside but extending either way from the bell housing, if you are that way inclined - especially if you plan to work that IXB hard with some equipment (see first pic). Many an HG mainframe has cracked in that bell housing area. The later OC-3 mainframe were much stronger there and flanged up a bit around the bell housing for extra strength. If you can can locate an OC-3 mainframe complete - even better, as it's also stronger and stiffer at the rear end too (see second pic)

[oliverchris]

Second pic. OC-3 Mainframe

[Joe Clayton]

Thanks for the replies. Will be working on the engine overhaul this winter in the old "crawler cave" may need a new manifold? Know a good source I think mr.Z has them at a health price? Thanks for tip on frame reenforcement and have been working on that as well.  Oliver dude at the Canandaigua steam show also mentioned frame problem. That show will feature Cletrac Oliver next year to celebrate 100 years.
Sourdough Joe  

[oliverchris]

Gimme a shout when you need a manifold. I usually have one or two on the shelves, and they are not made of gold. I can throw one up on eBay or my Facebook for you to look at.
Chris - OliverCrawlers.com