Thread: Building a 2.8
View Single Post
Steve@Rennsport Steve@Rennsport is offline
Registered User
Join Date: Jul 2001
Location: Portland Oregon
Posts: 6,985

The final CR with Mahle 92mm RSR P/C's depends on head volumes. 2.8 RSR heads had a 72cc chamber that yielded around 10.2 to 10.4:1.

Since that varies according to whether one uses 2.4 heads or 2.7 heads and whether they have been resurfaced or not helps determine final CR. These heads range between 64cc and 67cc and since one will need them machined for the lower plugs, that helps reduce it a bit.

Final real world CR is usually between 10.5:1 and 11.2:1, depending on the heads and whether any creative work is done to lower it down a bit.

Without question, a custom set of JE's can be sourced to get whatever CR you wish, but one should be aware that these do NOT last anywhere near as long as Mahles.
Steve Weiner
Rennsport Systems
Portland Oregon
(503) 244-0990
Old 06-17-2005, 11:41 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)