Re: Engine Rebuild?????(long)
Posted By: Barry
Date: Sunday, 25/6/2000, 11:34 a.m.

In Response To: Engine Rebuild?????(long) (Brian)

Have a valve job done, new guides, etc. As for the bottom end, if you feel you truly need the bottom end rebuilt due to oil consumption, consider getting overbore Mahle pistons. The rings will already be installed on the pistons. When you bore out a block, you're enlargening the cylinder bore, so when you use the same 83.xx mm piston with the larger bore, this means the rings will have to compensate for the extra gap between the cylinder wall and the piston. Evidently Pete McHenry has encountered problems with bored out M20's with stock pistons. Mahle makes high compression pistons and upto 3rd oversized 84.55mm pistons...that's almost a 1/2 mm increase in bore = increase in displacement. Bore sizes above 85mm require custom made pistons...JE, Arias, etc. and rings...Total Seal, Deves, etc. The crank should be fine, have the machine shop check the journals to make sure everything is okay. Ever thought about going 2.7 or 2.8?

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It sounds like a real good plan. I'd have to agree with you . . . have the head done by a machinist, he'll reseat your valves, clean everything up, and install everything. Oddly, that was one of the cheapest parts of my engine rebuild.

I don't have a CLUE about why this is, but I was told by Pete McHenry (who has tons of first hand experience with e30 engines) that these engines don't take well to honing and re-ringing, and suggested I go for the bore, new rings, and new pistons. . .

. . . Like I said, I really don't know why . . . anyone?

It takes a lot of patience and just remember to keep EVERYTHING organized and marked that you take off.

Best of luck to you...it's fun!

-Richard Klein