911S cis cams

James Renfroe · 08-06-2005, 03:34 AM

Would 911S cis cams work in am earlier 2.4 911T with carbs?

johnsjmc · 08-06-2005, 04:08 AM

When you say 911S cis cams I expect you are talking about the very mild (little or no overlap) cams in the 2.7 engines about 1976/77? The cams everybody refer to as "S" cams are definitly not those .If so your T grind is better .I would have "Camgrinder" recommend a regind to a modern cam if what you have is worn or unsuitable.

camgrinder · 08-06-2005, 07:50 AM

The 911 S with cis have casting numbers ending with 143 and 144.
These cams would work in place of the original carb T cams but the improvement would be small. Definetly not worth the effort unless your engine was out and you needed to replace the cams.
A better choice would be grinding your T cams to E specs.

Rex Walter · 08-06-2005, 11:21 AM

I don't mean to hijack this thread - but I need to replace my 2.7L "S" CIS cams. I was just going to replace them with the same cams - is there any other cam profiles that I should be looking at for a stock rebuild?

Rex

camgrinder · 08-06-2005, 11:49 AM

The 2.7 cis S cams can be ground to SC specs. A nice upgrade.

tab tanner · 08-07-2005, 07:47 PM

What will be gained by using SC cams in a 2.7

safe · safe's Garage

Can you use SC cams or, must you regrind the original?

Rex Walter · 08-08-2005, 04:17 AM

I have an article written about the 1975 911 and the author liked driving the standard 911 better than the 911S because the torque of the standard came on at a lower, and more useful, RPM - even tough the "S" was ultimately faster. What can we expect when going from an "s" cam to an "SC"? Does the torque peak at a higher RPM? At the expense of lower RPM torque?

camgrinder · 08-08-2005, 08:00 AM

The increase is in the 2000 to 6000 rpm range.
The original SC cams have 49mm, 4 bearings camshafts. The 2.7 has 47 mm, 3 main cams. To use an original SC cam in the 2.7 would require the 3.0 camshaft carriers.