Will 993 P/C's fit for 964 engine?

[ischmitz]

Hi,

can I use 993 P/C's in a '91 964 engine with stock rods given the heads get machined to the later style 964 version with the head gasket?

My concerns are piston shape differences if any, piston to valve clearance issues, and differences in the wrist pin area if any. I noticed the circlip for the 993 pistons are 23x1,6 as opposed to 23x1,8 for the 964 pistons. Would the lower weight of about 50 gramms per 993 piston have any negative effect or to the contrary lessen the stress placed onto the rod bolts if I replace all 6 of them? Has anyone ever done that?

Ingo

[Bill Verburg]

No, I know at least one person that tried. The 964 rods are thicker. There may have been other issues as well.