Early 911S cams in late 70's?

RIX 911RS · 03-30-2006, 09:19 PM

Are the early 911S 1969 to 1973 cams the same as the late 70's cams?
How can I tell witch cams I've got in my 77 911S engine?

randywebb · 03-30-2006, 09:46 PM

You have cams for the CIS fuel injection on your car (unless something is very odd) -- they are nothing like the true "S" cams.

RIX 911RS · 03-30-2006, 11:08 PM

So the early ture S cams, are they the same cams that came in the 1973 2.7L 911RS?

Early_S_Man · 03-31-2006, 12:17 AM

Yes, and the '74 RS 3.0 as well!b

svandamme · svandamme's Garage

but they won't work with CIS pistons since those pistons don't have the deep valve pockets required for high lift/long duration cams such as the early (r)S cams.

and then there's the thing about CIS not liking early S cams , cause they "burp" back in the intake, and make the metering plate vibrate or something (but that's a bit open for debate from what i gather)