differences between 964 & 993 longblocks???

[fastbacker]

Just wondering what the differences between the early and late model air cooled 3.6 longblocks are?

Thanks-
Craig Backer

[Bill Verburg]

Obviously the crank rods and pistons are different, the 993 has the block mounted oil filter which can be adapted w/ some difficulty to the 964 block, the heads are a different alloy, ports and valves are smaller on 964.

[fastbacker]

Originally posted by Bill Verburg
Obviously the crank rods and pistons are different

Not trying to be a smartass, but why's that obvious?

Thanks-
CB

[randywebb]

take a look at Aichele's engine book & at Frere -- at some point they used CAE to redesign the valve train and reduce recip. masses

[Bill Verburg]

Originally posted by fastbacker
Not trying to be a smartass, but why's that obvious?

Thanks-
CB

Maybe it's just obvious to me. The 964 has a harmonic balancer on the snout and 993 doesn't