2.4 911S piston and 2.2 911S head compatability

[Neil '67 911S]

I have a set of 2.2 911S heads and the opportunity to buy a set of 2.4 911S pistons and cylinders. Are they compatible? The pieces would be going on a 901/05 block.

While both the 2.2 and 2.4 911S use biral cylinders, are the pistons the same? I don't know if there is any difference in the piston dome volume/valve pockets. If someone could post some pictures of each that would be most helpful.

Thanks!

- Neil
'67 911S (Ol' Ivory and the Rust Bucket)

[kenikh]

All are compatible, but have different dome volumes. Just realize, depending on the throw of your crank, your CR will be affected. Putting 2.2S pistons on a 70.4mm crank bumps CR to almost 10:1, which is a popular performance upgrade. Putting 2.4S pistons on a 66mm crank would have the opposite effect of dropping CR to about 9:1.

[Neil '67 911S]

Thanks. It occurred to me after my post that I could have simply gone to the Stoddard website and seen that the part numbers differed. For someone else who stumbles onto this thread and is curious, here they are:

911-103-918-01-SET 2.2 liter, piston/cylinder set. Compression ratio 9.8:1. Fits 1970-1971 911S.

911-103-944-01-SET 2.4 liter, piston/cylinder set. Compression ratio 8.5:1. Fits 1972-1973 911S.

- Neil
'67 911S (Ol' Ivory & the Rust Bucket)