OMC/CD Power heads

[labrador-guy]

We were talking about CD power heads in the Oily Flywheel tread. I decided to start a new thread. Mister Mumbles showed us his Johnyrudegaleseaking special! I am in the process of building one of those baby’s. I have three power heads a ’59 a ’56 and a ’55. The leg I am using is from the 55 motor. I think my 56 will work with the 55 head and 55 carburetor mounting housing. The original 55 power head has had mutiple rod problems venting the lower half of the crankcase. The 59 has real nice pistons and crankshaft. Mumbles mentioned that he had to do something special to attach his ’58 motor to his earlier leg. I am attaching some pictures. You guys see any problems shoot me a comment.

dale

• This topic was modified 5 years, 2 months ago by Mumbles.

[labrador-guy]

Try it again!

• This reply was modified 5 years, 2 months ago by Mumbles.

[adam1961]

Just be carful with matching up the water inlet from the LU to the PH. When I put one together last fall, I noticed that there are a few subtle variations of the PH base gasket. The likely all have different part numbers, but the dealer that my parts stock from had them all on the same hook. As long as the water goes in and out where it should, I think you will be fine.

[fleetwin]

Don’t think the 56 crankcase assembly will mate up to the 55 midsection properly, water passages are a bit different along with the base gasket…. That being said, perhaps Mumbles does have some trick for mating up these dissimilar assemblies…

[Mumbles]

In your last photo, you can see the small drain hole and passageway which have to be filled in to mount this style block on the early mid sections. I’m not positive but I think the tiny hole and passage started with the thermostat motors, ’59 and later, It’s probably a combination drain and an aid to help the water circulation to the cylinders. The six horse have it for sure.

You can double check to make sure there won’t be any leaks by placing your new 303467 gasket on the block to visually see that everything is water tight.

[labrador-guy]

Thanks mumbles, I was pretty sure that was the problem you mentioned in the other thread. Gotta find or make the right gasket and I think the old girl will live again! Using the 56 PH.

dale

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