/6 guys - need piston help Options

[ahdoman]

I've got a 2.4T (73 1/2) that I have torn down. This is what the pistons look like that are in the engine...


What's the difference between these and these that are typically on eBay...


Also, These are both 84mm. Since they list these pistons as for a 2.2 / 2.4 is it just a different stroke between the 2 engines? If that's the case are the cylinders interchangeable?

[ahdoman]

Hey everybody thanks for the great info. Maybe I didn't make my question clear though; I am happy with the 2.4T CIS as it stands except that I'd like to ditch the old iron cylinders and use something like the birels to get better heat dissapation. Other than the 84mm ID, are the jugs the same dimensions for both the 2.2 and 2.4 engines?

[ArtechnikA]

Hey everybody thanks for the great info. Maybe I didn't make my question clear though; I am happy with the 2.4T CIS as it stands except that I'd like to ditch the old iron cylinders and use something like the birals to get better heat dissapation. Other than the 84mm ID, are the jugs the same dimensions for both the 2.2 and 2.4 engines?

2,2 911E and S used the Biral cylinders. Largely unobtanium since they've been out of production for more than 30 years and racer-types needing stock cylinders buy them up when they can find them.

So this is where you really need to ask yourself what it's worth to you...

If you -really- want cooler cylinders, you can get a set of Nickies, and Charles will precision-hone them to whatever piston clearance is required.

Long way to go for not much, IMO.

2,2 911E and S used forged pistons, which have expansion characteristics that match the Biral cylinders. Similarly the cast T pistons and the iron cylinders.

I don't think a 2,4T, especially a CIS one, makes enough heat for it to be an issue (another reason the 73,5 T engines are prized by racers - they have seen very little stress in life...)