I've got a 93 LT1 (with a '94 pcm/opti upgrade) I'm looking at picking up a top end combo of a fellow CZ28 member, but it's out of a '97. I understand there are some differences with the dowel pins on the cams over the years? My question is will a '97 Cam work w/a '94/'93 setup or not?

Thanks
-Brahm

 

Not an "Advanced Tech" topic. I'll move it to LT1 Based Engine Tech, where numerous people can answer the question.

The 97 cam will work with the 93-94 unvented Opti. You just have to shorten the dowel pin, since it is not required to drive the Opti. You have to keep your 94 timing set, since it has the splined hole in the cam sprocket that connects to the splined shaft that drives the 93-94 unvented Opti.

Personally, I'd use it as an opportunity to truly '"upgrade" the Opti by going to a 95-97 vented Opti. The 94 Opti is not an "upgrade" over the 93, its the same part.

 

What's involved in upgrading the opti, and is it needed as I plan on doing a delteq setup shortly as well? Well the newer opti work with my 94-95 harness, and 94 PCM, and it was my understanding that the 93, and 94 opti have a different plug which is why with the newer PCM (94) we couldn't use the 93 opti

 

No it's not needed.

Delteq has been effectively defunct for years now.

There is often confusion about optis because the B-body got the upgraded opti in 94 while the other cars got it in 95. Maybe that's what you've got going on.

Doesn't matter anyway - use the new cam, leave the opti alone.

 

How far do you have to shorten the dowel pin, to work in a 94 setup? I also have an electric water pump so it's not driven off the cam.

 

Not sure what the water pump has to do with it, since its not driven by the dowel pin in any case. The pin has to be short enough not to hit the back of the Opti. It can be flush with the cam sprocket, since its only there to index the sprocket correctly to the cam.

When you take your 93 cam out, swap the dowel pin to the 97 cam, or measure the 93 pin length and cut the 97 to match.

 

I thought and I could be wrong, stock water pumps were cam driven? My motor already had a miezer pump when I traded for it. If I can just swap dowel pins that would work. The cam i'm looking at is the LE2.2 I'm looking to pick up a complete LE3 setup from another CZ28 member and he has the LE2.2 cam but for a '97.

Unfortunately I have no idea, what the current cam is in my car, so I'm hoping to swap to something that will match my setup...motors just seem to run so much better when all the parts are made to operate at the same rpm range.

 

Thanks again for your prompt responses Fred, one last thing. Do you know what I should degree the LE2.2 cam to?

 

The water pump is driven by gear teeth on the back of the cam sprocket (gear), and the cam sprocket is driven by the crank sprocket, via the timing chain.