I may have missed what year your engine is. Wondering which opti you are using. 92-94 have the small spline drive that is VERY easy to get installed out of time. It has a blind spline that you would think makes it only go in one way...not so. I found a similar drivability concern as you describe after doing head gaskets on my sons 93 Z, and found I had missed the mark by a tooth or two. It slid right on in any position, the blind spline used is weak at best.

The later vented type opti has a better design of drive, but I have read of these not being installed correctly..something to check before an unecessary tear down.

I run the hot cam, and probably a ton of others as well. It is not a large cam at all, and designed for everyday driving. NO special engine prep necessary.

As with most performance cams, it likes gears and headers. I ran mine at first with stock manifolds for a while. I liked it alot. Then put on a set of long tubes...wow upper rpm pulled much better!

In my car it pulls better than stock starting around 2,200 and at 4,500 or so pulls harder to redline.

You should be able to do a compression test and see if your cam timing is out.
Sure sounds like opticrap concerns to me though.

HTH
Keith

 

I'd start looking for a part number stamped into that cam somewhere to be sure.

Degreeing a cam at .006 is tough to do so don't even try. The 050 numbers are a little whacked but you'd be surprised how hard it is to get an accurate reading just doing a quick check in your garage. The maximum lobe lifts and centerlines are dead-on, however. I'm going to say that you have the cam in there that you think you do and, almost unfortunately, you're going to have to look elsewhere for the cause of your problems.

 

i still insist that you check the timing chain! before you can put blame on components you must check your own work! go back check the timing chain. it is on wrong. there are ten bazillion hot cams, i doubt you got a manufacturing defect. check your own work first before you blame the cam, so far you have not reported if you have checked it yet.

 

OK To clear some things up. First of all I seem to leave out a lot of info on these boards some times and it bites me in the butt... At this moment I have the motor completly out of the car, the heads are off and the timing cover as well. The first thing I checked was that the cam was corect and I installed it dot to dot. (I did install it right after all) Secondly I bought a cam lifter tool so I can degree the cam properly. Although I just found out that all my reading were bogus. The gage I bought has a bigger radius on the tip than a regular lifter roller, thus lifting early by about 5 deg. So then I decided to verify the gage by using an indicator and a lifter. So doing it this way gave me a 218/228 dur @ .050.

Int @ .050
Open: 0 TDC
Closed: 38 ABDC
ICL 109

So I was wrong and the cam was 100% correct. It is worth mentioning that by degreeing the cam, I found that nothing was wrong with the setup and that the cam was installed at 109 deg just as the cam card says. Also I have a 95 and am running a brand new opti unit as well. I also checked this unit when I took it off, and the dowel pin was in the right location.

So I'm back to square one at this point. I have sent a couple of e-mails to KB-silvolite and Andvance-Induction, to see if they see anything that sticks out. Right now I have a feeling that my dynamic compression ratio is too high @ 8.5 and that I have too high a quenched distance @ .055. Other than this I am baffeled.

So what's the next step? Do I change the pistons, change the cam, and lower the quenched distance? What would you guys do? (BTW the LT headers are going in before that motor ever starts again!!!!)

Thanks

 

If ya cut the quench down to .035-.040 ya can run a 9.0DCR no problem on 92. Ya have to have the valve seals working correct on the intake valve,the A/F ratio has to be dead nuts and that is done on the dyno by experiment(no opinions),your timing has to be dead nuts on the dyno(same as above)You can have NO vacuum leaks and the intake has to be on properly. The black is oil in the ports and that raises compression.Ya need to eliminate the source of that.If its the PCV breather that hooks to the TB get rid of it.If its the PCV valve fix it.If the rings haven't seated replace them with something that will and re hone.If ya got molly rings and poured oil over them when installing them, they will most likely NEVER seat.They slick out and can't seat.The way C/A does it works-- a wrung out oil soaked rag and wipe cyls after proper hone and clean,a little oil on the skirt and pin and install,they will seat before 100 miles--know from experience.
All I can think of. Oooo get headers.

 

Check the timing chain bro, it's off.
I had the same problem, on a different setup but it sounds exactlly the same.

 

well, if the chain is on right, the cam is correct, then the answer to this answer is beyond what i know or would like to take a poke in the dark at. good luck

 

please tell me that you checked fuel pressure
I might have overlooked that in the numerous posts

since you are checking for knock retard with the scanner I assume that you can pull the fuel trim data stream up. Is it way too positive?(and adding fuel) or have you not driven the car enough for them to adjust.

This sounds like a Z I worked on a couple monthes ago and it had 18 psi I was suprized it ran as well as it did

good luck

 

The fuel trim data I looked at was lean in some operating conditions and rich in other. I did not actually check the fuel pressure, but I don't believe it was running lean.

 

check the fuel pressure, maybe the motor isn't getting what it thinks, did you buy new injectors? check the size in the program?!

 

Bringing this back. What happened?