Early S Cams in 2.7 with Std S Pistons?

[sketchers356]

I thought that I heard somewhere that you cannot run the early S cams in a CIS 2.7S because of valve impact with the piston. Instead one would have to switch to RS pistons. Is this true?

I have been thinking about switching to EFI and this would be the next mod after doing such. If I could just pop a new cam it would give me extra incentive.

[911pcars]

Yes, this is true. Aftermarket pistons are another option. Some will say the Mahles provide the longest service life.

Sherwood

[Wayne 962]

Running an 'S' cam with some higher compression pistons with pockets will give you a screaming engine, similar to the original RS engine.

-Wayne

[sketchers356]

Assuming that my pistons are in good condition can I simply swap out my pistons/piston rings?
Sounds pretty good otherwise!!

Also, I am interested in switching the cams because I like driving higher in the RPM band when I am in a sporty mood. Is there a cam that is streetable but even more 'hot' than the early S?

Thanks for the help.

[Wayne 962]

Originally posted by sketchers356
Assuming that my pistons are in good condition can I simply swap out my pistons/piston rings?

I'll assume that you meant:

Assuming that my *cylinders* are in good condition can I simply swap out my pistons/piston rings?[/QUOTE]

Yes, you can, but most of the 2.7 used cylinders turn out to be junk...

-Wayne

[KobaltBlau]

But you can have them bored and replated and get JE pistons to match. This ain't free, but it's usually cheaper then a Mahle set. Alternatively you can find somebody else's used Nikasils if yours aren't Nikasil or aren't in good condition.

[camgrinder]

If your switching to EFI the S cam's 98 degree lobe centers will be too tight. I would try a wider lobe center cam with less duration and similar, or more valve lift.
It really depends on how much valve overlap the EFI will take.

[dweymer]

would a 996 cam work? benifits? thought I remember reading that it would somewhere.

[svandamme]

a 996 cam has 4 bearings
early cams use 3

so the cam housing will be a problem ( and beeing a watercooled engine , it's not simply a bolt on swap for the housing either )

besides that, 996 = variocam...

[camgrinder]

I thought the 996 was a 4 cam engine?

[CliffBrown]

Alexander

I have a pair of freshly ground 2.7 CIS cams with a 3.0SC CIS grind.

These cams are in excellent condition, still in the sealed box from the shop and ready to install.

These cams have the nut style front snout and fit early Porsche 911 2.7 litre CIS type engines. These cams should provide an easy 15 to 25 additional horsepower to a stock engine and still allow your car to pass emission testing.

The Intake duration @ 1mm is 236 degrees valve lift is .450".

The Exhaust duration @ 1mm is 224 degrees valve lift is .395"

Set up at 1.4-1.7 mm

A very popular upgrade for the 911 2.7 S engine with CIS injection.

The casting numbers are 911 105 143 0R left side and 911 105 144 0R right side.

Price is $290 but all offers and trades are considered.

[dweymer]

sorry all not 996; 964 cam, too many numbers to remember.

[svandamme]

Originally posted by camgrinder
I thought the 996 was a 4 cam engine?

just checked PET, your're right ...
so there's another reason why not

[svandamme]

Originally posted by dweymer
sorry all not 996; 964 cam, too many numbers to remember.

964 is also a 4 bearing cam ... so you would also need the cam housing ( i think it should be just a bolt on replacement , but not speaking from experience , maybe somebody else can comment on that)

[dweymer]

I thought it was in Waynes book, no details on it though; I was hoping he would confirm what was needed.