View Single Post
Flieger Flieger is offline
Max Sluiter
 
Flieger's Avatar
 
Join Date: Mar 2006
Location: So Cal
Posts: 19,644
Garage
Quote:
Originally Posted by loosecats View Post
CORRECTION

Bruce -

I meant I wasn't confusing MFI with EFI (not CIS... I guess I had CIS on my brain)

But anyway, maybe I am?

What did the 2.7 RS run? MFI ?
The 2.7 RS used MFI and had 8.5:1 static compression ratio, S cam profiles, single ignition, and could run regular fuel. 8.5:1 compression is quite low, especially with high-overlap cams. I think 9.5:1 with 90mm bore is about the sweet spot for street fuel. It should run alright with single ignition and twin spark would be added insurance and allow more favorable ignition timing for a touch more power/efficiency. The high-overlap cams allow a little more static compression due to the dynamic compression effects with valve timing and engine speed. Many people up the compression to 9.5 when doing "RS spec" builds.

9.5:1 compression, 90mm bore, single ignition, MFI would provide an RS+ spec engine with a little more bite than the 210 hpower and 188 lb-ft of torque. Makes for a nice, zippy driver.
__________________
1971 911S, 2.7RS spec MFI engine, suspension mods, lightened
Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance
Old 12-13-2009, 01:30 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)