View Single Post
ChrisBennet ChrisBennet is offline
Irrationally exuberant
 
ChrisBennet's Avatar
 
Join Date: Aug 2001
Location: Nashua, NH USA
Posts: 8,164
Garage
Quote:
Originally posted by Scott Clarke
Chris-
I don't have any data available to compare against your numbers, but it is surprising that your information suggests that the common notion that:

1) All other things being equal, change in stroke from 66mm to 70.4 mm will change the compression by one point.

2) Mahle/Porsche CR claims are optimistic, and that measured results will reveal lower numbers.

are both false. I'm completely open to the idea that the common conceptions are incorrect. I't wouldn't be the first time!

Is it certain that the pistons in question are RS, or are they the more recently designed "sport" pistons?
I'm leaning towards some sort of error in my process. I just got another set of "9.5:1" JE's that measure out to be 10.5:1 and I'm really concerned that I'm doing something wrong.

The piston was ID'd by YTNUKLR in this thread: Piston Identification
"Looks like a 2.7 RS factory Mahle to me."

-Chris
__________________
'80 911 Nogaro blue Phoenix!
'07 BMW 328i 245K miles!
http://members.rennlist.org/messinwith911s/
Old 04-13-2005, 01:23 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)