Can I use 2.2S P&C's on a 2.4E engine???
 

Guys,
I have a nice set of 2.2S P&C's. I was thinking about using them on a stock 2.4E engine. Would I have to have anything else changed or machined to use them? The 2.4E engine has the complete MFI set-up. Would I have to have the MFI rebuilt to deal with the extra compresion? Is there anyway to calculate the extra hp from using the 2.2S P&C's on the stock 2.4E engine?
Thanks

It's funny, I was just reading an old volume of "Up-Fixin Der Porsche" and somebody asked Bruce Anderson the opposite question, could he put 2,4 slugs in a 2,2 motor.

Anyway, the cylinders are the same, 84mm.

The crank is obviously different, if you use the 70.4 mm crank and rods, you will increase the compression if you use the 2,2 pistons. This is a pretty well-known modification. However, the compression bump may be too great for pump fuel.

http://forums.pelicanparts.com/showthread.php?s=&threadid=246457&highlight=2.2+pi stons+in+2.4

Hi John,
I was aware of the increase in compression from using 2.2S P&C's on a 2.4 motor, which is the main reason why I would do it.
I am wondering more if the cylinder heads would need to be opened up to 36mm intake/ 35mm exhaust by going with the 2.2S P&C's - or any early S P&C's? Perhaps dropping early S P&C's into an E engine with smaller intake and exhaust ports would not give the engine enough airflow to make the 2.2S P&C's effective? Anyone else have any thoughts on this?

This will work and work very well.

Cr is around 9.7.

There is no need to change anytrhing else..the pump will cope easily..the cams are the main variable for pumps..

I am running exactly this in my 914-6 just now..just about the nicest early road engine IMHO.



Kind regards
david