i have a 94 Z with 120,000 on it.... well ever since i bought the car with 99,000 onit it had a slight hesitation. with 20k more on it i think the stock opti it giving up on me. i was wondering how do i upgrade from a unvented opti to a vented opti? is it cheaper to go with this setup?

any extra info would be great.
Thanks

 

A search will bring up everything you will ever need to know about what is needed.

It is worth it if you are keeping the car for awhile. Optis are cheaper, and theyll last longer usually, plus a true double roller timing chain can be run with vented setup, but not with unvented.

 

Timing cover, longer dowel pin, cam, vac harness, vac fitting, vented opti, wiring harness. Think that's it.

 

Better yet, here's a link. I imagine it won't be cheap.
http://para.noid.org/~muttvette/opti.html

 

I know a lot of people knock the dynaspark, but when I do my next opti swap I am seriously considering ordering one simply because it allows the swap to a vented opti without doing all of the other modifications. $600 is steep, but for a 1994 model Z the dynaspark becomes much more reasonable when you consider that you get to convert to a vented style opti without doing the other mods that usually go along with the conversion.

 

Unless you have a DEAD opti I would just replace what you have or rebuild it.
I did the complete conversion on my car when I did the LT4 hot cam install.
New front cover. New cam with longer pin. Different timing set(I used the LT4 extreme duty GM kit), newer style opti (95+), new harness adapter for the 95+ opti....it was like 30 bucks new from GM.
You can most likely find all of these parts used for a LOT less than new. HTH

 

well.....i work at a GM dealer so i can basically get parts at cost.
but do you think this is worth the time to convert to a vented opti....
i kno the vented opti is cheaper than the unvented, but buying the other parts to do the install might add up to a installed unvented opti...still deciding


BTW: "my opti is not dead, its just been on there for 120K now, and with a annoying miss i just know its gonna go soon. suprised it hasnt gone yet.


Also, what are somethings that would throw a brake code. i replaced the master cylinder but the brake light still comes on. usually when i brake hard the brake pedal drops to the floor a little bit, and when i let off the brake and press the brake to the floor again the light will go off... already bleeded the system twice. just cant figure out the D*mn problem

 

IMO, it is no worth the time/effort/money to convert if you are not intending to change the cam anyway. There is a lot more to do when changing the cam and then it escalates to valve springs, lifters, rockers, etc.

 

And since you HAVE to change[or drill] the cam to go 'vented' style in a 94, I'd wait til you do....

 

Are you sure its your opti causing the miss? How old are your plug wires? Plug wires are a major pain in the *** on the LT1 but if they get old or if they weren't routed very carefully they can get close to the manifolds or headers and will cause all kinds of misfire problems. My car recently has run into a high load miss when its warm that I think may be plug wires and/or the opti but its such a pain to replace either I havent messed with it.
If your timing set is as old as your opti I would recommend changing it before you have a MASSIVE failure and then change over the opti while you are at it (my timing chain snapped in half while decelerating from a highway race and did ALL kinds of valvetrain damage and left nice little dents in the top of my pistons). I converted mine, installed a cam, and did a new water pump at that time. Just food for thought.

 

not the plugs or wires. got ac delco plugs 6$ a plug, and taylor 8mm wire s all with bout 2k on them. so i should replace the timing chain also, like a lt4 chain

 

But you're still stuck with the old spined pin drive though - right??? If you want to upgrade the timing chain later down the road, you're still going to have to do the full opti conversion, and you'll have a $600 opti that wont work on the new setup.

I dont know much about the dynaspark, but I assume that if you order one that will work on the 92-94 Lt1, then it's going to have the old style drive, and therefore wouldnt work on the 95-97s. If that's not the case, I'd like to hear more...

 

To clear this up a bit...........
The LT4 Extreme duty timing SET.........is a set of gears AND a chain to match them. You can't do one without the other.
They are a matched set. If you decide to go this route you will HAVE to do the complete changeover......opti, front cover, harness, etc. I know someone that went thru the trouble of making an OLD style (93-94) cam work with the newer setup but it is a LOT of work. If you tear the thing down to the point of changing the timing set then in my opinion a cam change is NOT that big a deal. You will still use all of the original cam hardware (lifters, pushrods, rockers, etc). Keep in mind that a cam CAN give you a good deal of HP and torque if you set it up right. It is NOT that big a deal to adjust the rocker arm lash (if you can read a Haynes or Clymer manual then you can do this). The intake is a one piece removal and you can reuse your intake gaskets. Its not that big of a project if you go in knowing what you are doing.

 

Yes, when you speak of set, it includes sprockets and chain, but the parts are available individually also.

I would not recommend only swapping a cam and resusing all valve train parts. Reusing intake gaskets sounds like an invitation for trouble. I can't imagine anyone not changing them.

 

I have taken my intake off numerous times for various reasons, none of which were leaks. I have NEVER changed my intake manifold gaskets. If you dont tear them up there is no reason to change them. No coolant flows thru them. Mine still does not leak to this day. If you feel like paying for a new intake gasket....then by all means go for it (nothing wrong with that), I just chose to re-use mine and was only explaining that it COULD be reused. As for pushrods and lifters.....WHY change them? These are factory roller lifters....unless you throw a rod or a rocker arm breaks and does damage to the lifter or pushrods then why on earth would you change them? They will last virtually the life of the car under normal use. I only upgraded my pushrods AFTER my timing chain broke and bent half of them. Even then I debated re-using all but the damaged lifters (only 2) but went ahead and replaced them. On most LT1's the stock pushrods are hardened anyway so why replace them with the exact same thing? 40 thousand miles later she's still running strong.