1974 911S CIS to Carbs Setup HELP!!

[D85James]

So I am wanting to switch to carburetors on my 911S and need some help getting the recommended set up or opinions on the best set up for my car which will soon be a dedicated track/street car, more track though.

I've scanned other Pelican's threads and have seen a variety of suggestions. My questions are with it being a 911S from 74':
-does it have the larger cams? I've been told both no and yes.
-If it does have the better overlap with larger cams, what all other parts am I needing
for intall?
-size of carbs and Webers vs. PMO's (positives vs. negatives, Italy made vs. US made)
-low pressure fuel pump brand, placement, etc
-What HP gain will I see running headers to race pipes?
-Do I need higher compression Pistons, ie J&E pistons?

Any info will help and thanks in advance for advice!

James

[timmy2]

Lot's of information in the engine rebuilding forum.
Here's one:
CIS to Carbs?

[Steve@Rennsport]

Originally Posted by D85James

So I am wanting to switch to carburetors on my 911S and need some help getting the recommended set up or opinions on the best set up for my car which will soon be a dedicated track/street car, more track though.

I've scanned other Pelican's threads and have seen a variety of suggestions. My questions are with it being a 911S from 74':
-does it have the larger cams? I've been told both no and yes.
-If it does have the better overlap with larger cams, what all other parts am I needing
for intall?
-size of carbs and Webers vs. PMO's (positives vs. negatives, Italy made vs. US made)
-low pressure fuel pump brand, placement, etc
-What HP gain will I see running headers to race pipes?
-Do I need higher compression Pistons, ie J&E pistons?

Any info will help and thanks in advance for advice!

James

James,

If I can,.....

You have CIS S cams which are quite mild. There are some other mild cams which are better than what you currently have, but you'll need new ones to upgrade. SC & 964 ones will not fit your 3-bearing cam housings.

Personally, I would use either Italian-made 40mm Webers that have been rebuilt by Paul Abbott or new PMO's.

The PMO fuel pressure regulator works fine if your pump is OK.

Use either SSI's or 1.5" headers and a good dual-inlet Sport Muffler like Dansk. Everything else makes less power & torque.

Aftermarket pistons such as CP or JE allows much more flexibility in cam profile selection, not to mention a nice bump in compression ratio. With the right pistons, you can run Solex cams with 9.5:1 CR for a VERY good running engine.

[James Brown]

nothing to add to steve's post except the wow factor will improve 1000%

[speedo]

PM sent....

[jm993rs]

when I finished my 914 6 upgrades I would mount too in my 911 2.7 S '75, the same uogerade with carburetors !!!!!