Camshaft choice?

3k5g6 · 01-08-2007, 09:56 AM

Hi folks and happy new year from France,

I try to find the best camshaft for my engine! It's a 2.4 with cr at 8.5 and pmo carbs (40 mm). I want best power and good idle. It's not for a race car, it's just for pleasure on small french roads!

I'm not sure that S cams are ok for that (pmo + standard cr) and I'm waiting your opinion! What do you think about solex cams or E cams?

Thanks

jluetjen · jluetjen's Garage

That CR sounds awfully low to be running an S camshaft. Chances are an E or maybe a T. Here's the result of earlier research that I did on this sort of subject. It also depends on what sort of ports you have in your heads. You didn't say enough other information about you car -- such as the model, specifically T/E/S? Also, is your car a 73.5 T which originally came with CIS, or a 72 or a 73 which came with MFI?

3k5g6 · 01-08-2007, 01:18 PM

John,

Thanks for your help! my engine use S heads and 8.5 is standard cr for one 2.4 engine. It's the first 911 engine that can runs with low octane level petrol.

I know that I can modify my cr up to 9.5 or 10.5 but it's not my idea( I want preserve one old magnesium engine case).

And I know that Porsche had some trouble with this engine at low rpm (during the development). For this reason they have modified ignition system and lenght of intake manifold.

I try to find one camshaft less "peaky" than a S!

I hope that somebody, on this forum, haves one engine like mine and can tell me how it's running.

P.S.: excuse me for my not so good english!

Steve@Rennsport · 01-08-2007, 02:15 PM

Hi:

I think "E" cams work very well in engines such as yours.

Your English is very good and FAR better than my French,...

Lukesportsman · 01-08-2007, 03:31 PM

Not like I have any knowledge next to Steve. I do like my E cams on my 2.4 (2.7 RS Cans). The RS pistons are only 8.8 and I lack your S heads though have MFI. I would think that E cams would be nice if you don't wish to go aftermarket. They are torquey yet still rev 7000 though not pulling like big duration cam. I find them quite flexible and with the better heads, you may have better luck yet and didn't Porsche rate the E faster 0-60 than the S? Just a fun fact if a buddy shorts you for not having a full S spec.

kenikh · 01-09-2007, 08:53 AM

I believe that you would be happier with a Solex grind or one of John Dougherty's hybrid cams like his "Mod-E" or "Mod-Solex" cam. Even his "Mod-S" cam would be good. PM camgrinder on this board for details. His cams are amazing.