2.0 S difference

[thor]

Hello ,

are there big differences between carbu 2.0S piston 68 and MFI 69 2.0S pistons?
I would like to use theses pistons in my 2.0 E engine .
thanks a lot

[69 911s]

69S pistons had larger pockets cut into them to accomodate the larger valves.

[thor]

Do you have photos ?

[Wayne 962]

69S stuff = pretty uncommon. If you're concerned about clearance - do the install and then measure the piston to valve clearance, and then have the pistons machined...

-Wayne

[thor]

thanks
I'm concerned today to compare the two models because I would like to upgrade my 2.0 E with S pistons and I own a 2.0 S MFI pump 69 . Then If I use 2.0S piston '68 carbu is it quiet the same result (9.8 instead 9.9 CR ? )
If I use a S carbu pistons , is it possible to put heads of 69 S due to larger valve ?
I know it s a bit complicated but ....

[jluetjen]

Thor;
I've got 2.0S pistons in my engine, but I don't know if they are '69 or <'69. The engine runs great with the stock '69E pump and an MSD. I doubt that the difference of 0.1 in the CR will make a difference.

As far as the 2.0S MFI pump, I don't think that it will work as well on your engine as your current E pump as long as you are keeping the E cams. If you are going to switch to S cams then I'd suggest that you use your S pump. If you have or can get 2.0S heads, that would be great. But I suspect that your 2.0E heads will work fine until about 6500-7000 RPM after which I suspect that the S heads will work slightly better.