3.4SS without twin plug?
 

Hi guys

I'm planning on the classic Max Moritz conversion on my '89 3.2 by boring my cylinders to 98mm and have them replated, which is much cheaper than buying a cylinder/piston package.

I'll be running single plug with 964 cams and enlarged throttle body with a new chip tuned for 99 RON octane, like so many others. This is my daily driver and not a track car. I'll be doing the build my self.

I have been quoted 1000$ for bore and plate. Now, for the pistons....so many to chose from?!?!

Wössner makes a very nice forged 98mm set with polished dome heads which should improve cumbustion (?), CR 10.5:1.

JE makes the 98mm with 9.5 or 9.8:1 CR or 10.5:1 and Mahle something similar (think 9.8:1).

Should the piston design be "Max Moritz" wedge dome or will any piston design be compatible with the single plug? Especially the design of the Wössner could maybe be of interest?

If you use the "MM" pistons, you do NOT want twin-ignition.

Those have special wedge-shaped piston domes specifically designed for single-ignition at that CR.

RSR pistons OTOH, have the double-valve relief, more traditional design that requires twin-ignition. :)

And the whole point of the original Max Moritz conversion was to keep it single plug....it was a quick upgrade kind of like a modern powerkit.

Yes I know. Seems to me the only correct pistons are made by Mahle then? Or are there other vendors of similar pistons?

Others make a wedge-dome piston, however the ONLY one I'd use in a street engine are Mahle.