1970 911t AA pistons and cylinders

[Andrehasaposse]

Hi guys. Been gleaning all I can off this message board as I am working on rebuilding a 1970 911t. Was seized hard after sitting for god knows how long. Motor sat uncovered and got water in 2 cylinders.


Was planning on going with new piston and cylinder set as the old cast iron ones are pretty rough.

Budget is a concern so looking at the aa p&c sets. Going to keep the motor with “t” crank and cams and webbers. Just looking for a driver not a race car.

Looks like the 84mm low compression set would be a stock replacement.

My question is would it be a better idea to use the 84mm high compression set?

What about the 86mm sets either low or high compression with the je pistons?is this an even better idea?

Hoping to get some feedback as searching came up empty.

[Richey]

Do not use the high compression set , the actual compression ratio will be too high . Do some more research .

[targa72e]

Since your have a T with cast iron cylinders its pretty easy to have them bores larger and then you just need pistons. If the cooling fins are not broken you could bore them to oversize 84MM or go to 85MM or 86MM for more displacement and use JE Pistons and pick thr compression you want. Might check with EBS Racing as they may have these sets ready to go with exchange of your old cylinders.

John

[doswald]

On my ‘71T in a similar condition, I bored the cylinders to 85, (was advised not to bore to 86); used JE pistons for a measured 9.5:1 compression; and reground the cams to a Solex grind. Very pleased with the results.

dho