How modify a 2,0 S to 2,4 S HC ?
 

Hello,

I have an original 911 S 2,0 crankcase 901-02 and a complete 2,2 S 911-02

I planed to install 2,2 S parts (heads, pistons, ...) in the 2,0 S and increase power with a 2,4 / 2,7 crank shaft (70,4 mm), 2,4/2,7 rods and 2,2S Mahle pistons. The problem is that skirt of piston is too long and touch at the botttom.

Engine is for a 914-6 so Weber 40IDS will replace MFI, and the 914-01 gearbox will have A,GA,M,S,X ratios.

In Wayne's book (if I remerber), the solution is to install 2,2E piston with 70,4 crank shaft and 2,4 rods but the maxi RPM is 6700 because 2,2E pistons are not forged.


Last solution : keep the 2,2 S 66mm crank shaft, 2,2 S rods and buy larger pistons.

Thank you for your advices

Or you could modify the piston skirts.

andy

Yes but very well known shops did this modification on piston skirts and told me that engine will run hoter + 10°C and it will brake !!

The simplest way would be to buy 87.5mm JE pistons and Nickie cylinders. They fit the stock spigot bore on the case, allow you to use the better 2L crank and gets you 2,4L displacement.

To keep the temperature down:

- Air baffle mod,
- piston squirters,
- front oil cooler which you should have if you want 2.2/2.4S power.

These things the 2.0S never had to begin with should assist you.

andy

Thank you
I think I will take 87,5mm pistons diameter

Voila - De rien!

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