PanzerSD's M117 Rebuild Question thread.

[PanzerSD]

I've had this M117.983 sitting in my garage for a while, and I got to thinking..I bought this engine, for to get the tranny (dud) and was stuck with an engine, I've removed cams and alternator and now starter. The engine is a D-jet engine, but that's all trashed and seized. So I was thinking of rebuilding, slowly, the long block and heads to eventually become a M117.986 Replacement.

I got some questions.

If this engine happens to need to be bored, is it a sleeved engine? and are new pistons of oversized dimesions commonly available?

[Tomguy]

It isn't sleeved - you might be able to find some older threads talking about the ingenious way the block was cast for reinforcement... You could probably get o/s pistons but I doubt that you'd need to have it bored. At 145k, my cylinder walls still had hatching showing. You may need new (stock size) pistons and rings (The softer, OEM-style ones). Put in new timing gears and chain and tensioner. If it has aluminum-backed rails find replacement rubber if plastic, just relace them all.

[Benz Dr.]

I would agree with Tom Guy.
These engines have very strong bottom ends. I would replace the crank gear, oil pump, chain, rails, main and rod bearings, gaskets and water pump. The heads are more likely to show wear and you will need to replace the valve guides and seals. Check the valve rockers for wear or pitting and replace any that are damaged.
I also check the intake manifold to make sure it's straight - some are higher at the ends due to over heating. They have to be perfectly level or you will get leaks at the coolant ports which will also get into the manfold screws. You will know what I mean if that's already happened because they will be next to impossible to remove.