keeven1320

ok so i have a non vented opti on my car now and i have a brand new accel vented opti also, what im trying to find out is what all i need to get the vented opti to work on my car? or would it just be cheaper to buy another non vented opti?

shbox

A lot of work to do.

If you want to change to a vented from non-vented, you have to do many things. It may not be cost effective unless you are doing a cam swap at the same time.

Besides the optispark itself (GM p/n 1104032), you need:

• 95 or later timing cover [1995 front cover (includes round seals) GM p/n 12552426]
• late model or aftermarket cam (or have your cam modified by drilling the hole in the front to the proper size [.500"dia. X 1.0625" deep] and a longer dowel pin added
• 95 and later optispark electrical harness GM p/n 12130319
• optispark vacuum harness GM p/n 12555323
• vacuum fitting [GM p/n 14082470] or "tee" to provide vacuum for the opti
• 95 or later timing set components (or at least the cam gear) cam gear (GM p/n 10206039), crank gear (GM p/n 10128346), chain (GM p/n 10128485)
• timing cover gasket GM p/n 10128293
• water pump gaskets [2] GM p/n 10128343
• intake manifold gaskets if you are pulling the cam GM p/n 12524653

Or you can put an MSD cap/rotor kit on it and essentially have a vented opti. They come with their own and similar venting system.

1993 z28 f1

iTrader: (6)

^^ SHBOX, beat me to it, teach me to watch TV while posting an answer. His was more in depth anyway but same outcome....

Hey:

They have advantages, the vented over the non, but unless you are doing a cam, EWP and timing cover upgrade, it may be cheaper to buy a real GM OPTI and a MSD cap and rotor as the MSD caps come with a vent kit. Also the reason you can find the Accel one so cheap is they are, and not highly thought of by many. @1 time they had a unique failure rate or complications that could not be explained away, except when you changed out that Accel OPTI the probs went away. The caps themselves are not bad but in no way would I go through an OPTI change to put on one of them. It's not worth it, to take the chance of complications later on. Other than the GM OPTI the only really proven reliable OPTI is the DYNASPARK. but they are not dirt cheap. You gets whacha pays fur, as they say around these parts. MSDs can be hit or miss, I keep one as a spare for my daily as I bought it and then went to the DYNASPARK and LTCC on my other car. My 270,000 Miles daily has a real GM OPTI with a MSD cap kit on it. Good Luck with whatever you choose.

Dub

keeven1320

well i have the motor out of the car right now, the cam thats in it is for a 95 so it has a dowl pin in it, i would just have to get a longer one right? my harness plugs in to the vented opti i have ( im guessing someone modified my non vented one?) an couldn't i just drill the cam gear out to fit? and then i would need to find a timing cover

btw thanks for the reply's very helpful

edit: could i just cap the vents on the opti? this car only get driven about 1,000 miles a year an never in the rain

94Z28rag

iTrader: (10)

95's had vented optis, so that cam will work fine.

shbox

The harness may plug in, but the connectors are different lengths. You must have the correct harness for the opti type or it won't work.

I would not totally cap a vented opti. Even the non-vented one actually has some vents on the bottom. It just does not use vacuum for a positive venting system.

fresh one

Just made this decision myself. Got a Delco opti with mitsubishi sensor & ordered msd cap & rotor to convert to a vented unit. I have a 93 Z28 with 27k original miles & was horrified when I opened up my original opti....the car was NEVER driven in the rain & engine never got wet. The ozone effect alone destroyed it!