View Single Post
Walt Fricke Walt Fricke is offline
Registered User
Walt Fricke's Avatar
Join Date: May 2004
Location: Boulder, Colorado
Posts: 5,051
Porsche Crest

This sort of thing received quite a bit of discussion on Rennlist last winter, mostly centering around how well (or poorly) matched the components made to service a 3.0 liter engine would work with a 2.7. On that side of the equation the concensus was that it would work, but was not apt to be optimal. The owner went ahead and did it (as an interim step before switching to carbs), and it does work and he is driving around New Orleans.

But I think maybe he was just swapping fuel distributors or something less drastic than the whole shebang. If you want to swap the entire system you are faced with a sizing issue: The ports on your heads are several millimeters smaller than those on the '79. You don't want a lip like that in the way of the airflow, though the car would run.

Ok, you say, then I'll keep my old runners. Well, the '79 airbox has larger holes/tubes where the runners attach to it. So what you probably are going to end up doing is replacing the fuel distributor and air flow sensor (which should be a bolt-on replacement), the WUR, the Aux air slide, and any other peripherals. Leave the the throttle body and everything downstream from that alone.

Sell the stuff you don't use. The later SCs had smaller ports than the '79, and sometimes guys bore those ports (during a rebuild) and use the early SC runners (and airbox). Not legal in some racing venues, but for the street who cares.

Better yet, swap what you have for some 2.7 stuff. I'd think what you have would fetch a better price because it was only used for two years. If you lived in Colorado I'd be trying to peddle the complete system from my '77 2.7 that's been in my basement since I switched to a 3.0 in 1989. All the guys who switched to carbs have to get rid of the CIS stuff, too.

Walt Fricke

Walt Fricke
Old 08-18-2005, 09:00 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)