930 "sc" CAMS?

lendaddy · 11:32 AM

As the motor is coming out soon and I would like more bottom end these seem like a good way to go. The Turbo could certainly use more bottom! But, my question is what are SC cams? Are they actually a cam from the '78-'83 NA 911's or is it one of those interesting internal codes we love so much? Any thought or different recommendations would also be welcome.

Oh yea, the car is a '77 930

cds72911 · 12-13-2001, 11:33 AM

lendaddy,

It is my understanding that they are the cams from a 911 SC, not a special internal designation.

Cheers.

John Rogers · 12-13-2001, 11:43 AM

When we had our 1987 930 overhauled a few years ago we used "SC" cams and the low end response is much better. They give a slightly rougher idle but they still pass smog in CA. We also use a long neck intercooler to eliminate the popoff valve and HKS boost controller which has made the car much more fun to drive since boost comes on at 1500 RPMs now! Good luck.

lukeh · lukeh's Garage

If you go to www.911turbo.com and do a search under "cams" you will find info on the options. It was well worth my time.

88 Turbo cab

Early_S_Man · 12-13-2001, 01:45 PM

'SC' cams are actually the cams from the 1976 Carrera 3.0 engine!

Bill Verburg · Bill Verburg's Garage

The SC cams did first appear on the '76 Carrera 3.0 and continued to be used thru the '89 Carrera 3.2, thougn with different tining specs.

GIBSON · GIBSON's Garage

One of the reasons SC cams work well is that they too were designed for the CIS system. CIS systems don't tolerate valve overlap. Other cam grinds would be desirable for the Turbo except for the fact that they allow too much valve overlap, i.e. the intake and exhaust valves are open at the same time.

Bruce Herrmann

GIBSON · GIBSON's Garage

Of course, the other issue with valve overlap and turbo cams is you loose boost if there is overlap so that's another reason to stay with CIS-based cam grinds. I noticed a nice change in low-end torque with SC grinds on a grey-market turbo some years back. With the right exhaust it really has a nice idle sound, smooth but throaty. Nice cams for a Turbo.

RarlyL8 · RarlyL8's Garage

I would think that the biggest performance gain to be made on an early 930 to be the addition of an intercooler and a free flowing exhaust.

Once those two items are in place you can add on all sorts of go-fast parts.
On the other hand, without the addition of at least a free flowing exhaust NONE of the other bolt-ons will work properly.

JEB · 12-14-2001, 09:54 AM

My car has the SC cams. While I don't have a point of reference to compare them to, the PO who had the work done (at Stoddard Porsche) said it made a lot of difference in the low end and the boost came on faster - less lag.

My car runs great and has a nice burble/rumble at idle. As I remember from posts on the Rennelist Turbo board, the SC cam sacrifices some breathing on the upper end to get the low end. Per the previous post check the archive over there (www.911turbo.com)

Jeb
79 930