sc cams

[quattrorunner]

I realize this is a stupid question, but I don't want to screw this up and it's got to be done soon. I'm rebuilding my 3.0 turbo engine with the low compression pistons and such, but know the cams should be replaced with sc for better low end response. What about the drive gear? Does it just bolt to the sc cams like the originals? I don't have the sc cams yet thats why I don't know. Does anyone know and any info would be great. Plus I'll need some GOOD sc cams if anyone wants to sell them. Thanks

[RarlyL8]

The SC cams must must be machined for the drive gear.
I have a set if you are interested.

[911nut]

Originally Posted by quattrorunner

... but know the cams should be replaced with sc for better low end response...

SC cams will improve the mid-range response at the expense of low range response. This is because the overlap (both valves open during the compression stroke) allows charge to escape the cylinder, reducing efficiency at low engine speeds.

[quattrorunner]

So low end response is lessened? Opposite of what I thought.

[steven c]

I was told not but here are the profiles for the 2 most popular upgrades.


Turbo profiles Duraton at 1mm Duraton at .050" Valve lift Lobe seperation angle Lift@overlap setting Notes

SC on Turbo I/E 236/224 228/218 .450"/.395" 113 1.4-1.7mm
Most popular upgrade for street driven 930



964 I/E 246/232 238/226 .470"/.430" 113 1.26 mm
Supports up to 550 hp in modified 930

[911nut]

Originally Posted by steven c

I was told not ....

By who?

If the mixture is being forced out of the cylinder at the moment of overlap, how can it have no effect? Less mixture means less power until the time that the valves are open for decreases.

Look at the 3.6 turbo engine as delivered by the factory. The stock cam has some overlap but the compression ratio was bumped by a half point to get back some efficiency at low engine speeds.