the impression I have got from reading for more than an hour in a search is that you can only use basically a stock chain for a replacement to the timing set on a pre vented opti set up. would this be right? I can't even use and ED timing set on a non vented opti design?

 

I also have a 94 and went with the Cloyes True Roller chain set with a larger bottom gear. I had to get mine thru a local engine builder but you should be able to order it thru a local speed shop

 

Maybe this might be of some help for you non-vented people. Couldn't find any info on it from Summit (their website is messed up) or Lunati.
Lunati

 

Lunati set is good and only 108 bucks.

 

i like my cloyes. but u need to go w/ an electric H20 pump if u go with this one.

 

ditto

 

Curious if that Lunati posted above really fits a 94[unvented opti]
The pic sure doesn't look like an early LT1 timing set?

 

I have the lunati on my 94 Z. I didn't install it. I had it put on when i had the engine assembled. The installer didn't say anything about it not fitting. Everthing works fine and i have no problem with it.

Thanks
Shawn

 

so the cloyes will work with the non vented opti? I was under the impression you had to change to a vented opti and change to the electric water pump

 

Shawn W thanks.. I just don't think that pic posted is the actual timing set[ no 'opti drive' provision..]

nov194.. no you can't use the CLOYES with a unvented opti, no..
We are talking about the LUNATI timing set that you can use the unvented early opti..[it's relatively new product..]
Charlie

 

I was also thinking of getting the Lunati, I figure it must be better than stock because it is made of billet steel, instead of powdered metal, and I don't want the risk of electric waterpump failure.

 

well thanks for the clearing up of this guys, I appreciate it.

 

You might want to look into the LT4 xtreme timing chain. It is a very nice upgrade, I don't have it yet but its definatly the one I'm going to go with!! you can search for it at GMPartsdirect.com

 

LT4 timing sets fit only 95 and later LT1s.

 

If you have the cash ($550), here's another alternative for the pre-95 LT1’s: http://www.dougrippie.com/drm/engine_components.htm

It appears to be yet another linkbelt chain, but hopefully much stronger than the puny factory set. [EDIT] -- I take that back, it looks like a roller...

The question is whether it is worth purchasing a $550 timing set for your current setup, or spending $470 to upgrade the optispark and use a 95+ compatible timing set (+ ~200 = $670). –That’s assuming you’re already performing a cam swap, as most aftermarket LT1 cams are set up for 1995+ vehicles (the cam is also required for the swap). Of course, you’d have to add more money for an electric waterpump if your timing set demands it. You can weigh the pros and cons and see what's best for your needs...


------------------


To belabor Bud’s point, the LT4/ED and Cloyes aftermarket timing sets WILL NOT WORK on a pre-95 vehicle without upgrading to a vented optispark and corresponding parts!!! You won’t have a functional ignition system!!! An electric waterpump is the least of your worries if the engine is entirely inoperable in the first place.

Since our waterpumps are internally gear-driven instead of externally-driven by a belt and pulley, all factory LT1 cam gears have additional teeth integrated on the back to accommodate the waterpump gear/driveshaft – a rather unique setup.

The 93-94 cam gears are one step worse: not only does it have the unique waterpump teeth, but it also has a ~2" optispark driveshaft fixed to the center of the gear (which protrudes thru the timing cover to drive the unvented-style opti). Since aftermarket cam gears cannot incorporate this splined shaft, our options are severely limited. At least the 95+ LT1’s can get away with using an electric waterpump to resolve the issue, since they are driven directly by the cam dowel.


I’m sure that’s been explained numerous times, but if it helps someone understand, I’ll say it once more…

HTH