Cams, 964 and 993 differences

[Flat6pac]

I guess to start, 1988 911 has 964 cam carriers casting numbers but the large studs for the covers so it was early pre production 964 parts.
The late 83 engines for SC have the casting for the flywheel sensor and TDC sensor..basically a Carrera engine with 83 SC stampings.
Now to the cams..
993 cams have no key way, are vertically slIced on the front end to set timing and locate with a fixture, has a notch in the first bearing for extra oil for the hydraulic rockers.
What I have also seen is 993 cast cams with a key way, with the first bearing cut for the oil and a notch to the front of the engine to set 993 timing.
So the question is, it the 993 cast cam with a key way actually a 964 late production.
I appreciate the thoughts and hope for resolution,
Bruce

[Bill Verburg]

Originally Posted by Flat6pac

I guess to start, 1988 911 has 964 cam carriers casting numbers but the large studs for the covers so it was early pre production 964 parts.
The late 83 engines for SC have the casting for the flywheel sensor and TDC sensor..basically a Carrera engine with 83 SC stampings.
Now to the cams..
993 cams have no key way, are vertically slIced on the front end to set timing and locate with a fixture, has a notch in the first bearing for extra oil for the hydraulic rockers.
What I have also seen is 993 cast cams with a key way, with the first bearing cut for the oil and a notch to the front of the engine to set 993 timing.
So the question is, it the 993 cast cam with a key way actually a 964 late production.
I appreciate the thoughts and hope for resolution,
Bruce

Yes, early 993 produced in '94 and partway through '95 used the keyed cam and drive gears used on 964, on these cam timing is set w/ a dial indicator, later ones are keyed to be set w/ the fixture and timing is a friction fit.

[Flat6pac]

Thank you
Bruce