background: i'm installing an LT1 into an s10. LE1 heads/cam.

right now i have an avon 4145 timing set that i got from brett. i plan to run a CSR EWP. the gear doesn't have a provision for the opti though; is there something i'm doing wrong? why do i have to use this gear when using an EWP?

http://www.progearweb.com/4000/4145.htm

 

Well if you read the description, it says "With hydraulic roller cam except motors with reverse flow cooling system." Just so you know, the LT1 motor has reverse flow cooling. You're going to need an LT1 timing setup, whether you use the EWP or not. In the case of the EWP, all you do is plug the hole in the WP where the drive gear was, and plug the hole in the timing cover.

 

If you are using the early non-vented opti, that timing set won't work? But, should work on the Gen II vented opti.

 

ok, i've been doing some numbers matching, and i've found that my LT1 is a 94, and not a 95 as i was told when i bought it . i'm going to do some reading/searching, but since it is the holidays, if anybody is feeling generous could you let me know what is involved in switching from 93-94 non vented to 95-up vented?

 

To convert to a Gen II opti you'll need a 95 timing cover, longer dowel pin in the camshaft, 95/96 opti wire and vacuume harnesses.

FYI: Search around for the opti wire harness, it can be very expensive from a GM Dealership.

 

ahhh sweet. thanks for your help Stl94LT1!

http://para.noid.org/~muttvette/opti.html

 

No, thats wrong. If you are running an electric water pump, you can run any timing set made for a factory hydraulic roller cam. I'm using a Comp Cams double roller with my 95. It has a hole that accepts the dowel pin that drives the opti; all factory hydraulic rollers have this pin, its just longer on LT1s.

 

...Just as long as it is not a 93-94 non-vented opti LT1...

 

I just recently did the conversion, my original 94 cam did not have the large hole in the center of the cam for the shaft with the two o-rings, if your not changing cams this will be a big problem. I dont know if all pre 95 cams were like this.

 

Correct.... you have to have a cam from a 95-97, with the larger hole in the nose for the vented Opti pilot shaft. Or an aftermarket cam.

Its all explained in the para.noid link that is posted above, with detailed photos showing the differences.

 

Right. Stock pre-95 cams do not have the large hole in the front. So, that is a consideration just as the para.noid.org link above indicates.