I have decided that i am missing while under heavy acceleration so much because my opti is still the originial one. I have to replace it. I read it on all data under a technical service bulitin for my car. Any one know which one i should buy and how is the installation tough...time consuming . thanks a lot guys

 

I have brand new GM vented opti if you're interested. It's part # 1104032 and it's the vented one for the 95-97 LT1. The install will take a bit of time because you have to drain your coolant to remove the water pump, remove the air pump and remove the balancer to get to the opti. If you haven't replaced your plug wires, then it's a good time to do that as well. Oh yeah, $180 plus shipping if you're interested in the new opti I have. Shoot me an email.

 

You have to tell us what year your car is.

The job is not that bad as long as you prepare well. Have fluids and gaskets so you don't have to stop (except for a cold one or four).

I agree that it will be an optimum time to change wires and plugs, but that will add significant time to the job. For me, about 2-3 hours more.

Tips:

Care must be taken when installing the opti so that the "notch" in the opti drive shaft lines up with the "key" in the opti.

Many recommend replacing the opti drive shaft seal and water pump drive seal due to the frequency of oil leaks immediately following an opti swap. I agree.

Search these forums for instructions on removing the balancer. Some slip off, others need various levels of assistance

If you replace the H2O pump and decide to put your old or a new 160 thermo in, do not use the 94 GM service manual torque specs for the thermo housing bolts.

Haven't polled here yet, but I think it is pretty much a split when it comes to the coolant system sealant tablets. Above service manual also says to puts a pair of these in the radiator after a major cooling system service (pump, rad, core replace). I'm on the fence on this one.

Good luck,
Sean

BTW, if you have a 93-94 (non-vented) opti, it will cost about 100 bucks more.

 

What would be the difference between a 1994 and a newer optispark????

 

94's were of the non-vented line, and a little more expensive. 95+ were vented and cheaper.

 

The differences are numerous enough that the conversion is pretty costly and time consuming.

Do a search and you can find the details.

Sean

 

As noted above, 93/94 is "non-vented", 95-97 has two vent connections to remove moisture and the ozone generated by the high voltage discharge. And the drive mechanism is different. 93/94 is driven by a splined shaft that goes into the cam sprocket, and the 95-97 Opti is driven by a dowel pin that goes into a hole in the nose of the cam.

The timing covers are different because of the different drive method.

See this article for good info on the various versions of the LT1/LT4

 

Is a conversion possible, what are some gains?

 

If you don't watch your Opti very well and you still got the stock water pump id suggest why your replacing your opti you replace your water pump cause usually when ur water pump goes it takes out your opti to, and I'd hate to see you replace opti then your water pump went and ruined your new opti

Just my advice i replaced Opti and Waterpump 2 months ago at same time.

 

The benefits as I see them are this:

Longer opti life (not sure by how much, i only get about 40k from the non-vent version). I have never had water contamination failure though. Mine first two were in the cap and rotor section and looked like normal cap and rotor wear. My third was a victim of a blown opti drive shaft seal that allowed oil into the cap and rotor section.

95+ opti required for hot cam or LT4 conversion.

I am sure there are more.

Sean

 

Vented Opti Conversion parts list

 

I have a 1994 z28. I am going to change the wires while i do this also. I just need to get coolant and a h20 gasket am i correct. and i have to worry about the splines linning up in the optin coreect. i should eb able to do this in my shop thank you guys