fireball451

Having to do some internal work to my '91 Z28 with t-5.
I am trying to find some gremlins.
158k miles on it and I know the timing chain is very loose.
Got some internal noise that I'm betting is some bad lifters.
The thing is running very flat over 3k rpm.
Runs great at low rpm and no power in the upper rpm.

Anyway, I'm thinking of putting a LT1 cam in it since I'm already in there and it won't take too much more effort.
Will I be possibly creating another problem by putting this cam with a speed density system?
Or will the computer accept the cam without any problems.
Just trying to get by for a while until I do my motor complete motor rebuild.
Also need to finally find out just what in the world is going on with this car.

BigWhiteGTP

Going from an L98 cam to an Lt1 cam is like going from Pepsi to Coke. Not much change. With 158k, I would do a compression check to see what's going on. If everything is good, I would then put some money into a full tune up. New cap and rotor, plugs and wires, new o2 sensor. Stuff like that. If compression is bad, then it's time for a rebuilt motor or start looking for a lower mileage replacement.

Remember, all TPI cars 1990-1992 got the L98 cam. It's been proven with dynos and with actual measurements from removed cams.

fireball451

Thing is, me and the previous owner has been all over the car replacing sensors, distributor, tune-up, computor, etc.......
Really thinking its something inside the motor not letting it make upper rpm power.
Got a LT1 cam and thought why not since its not that much more work.
Just don't want the computor to buck the cam.
Really want to find out what is going on so that when I do a motor rebuild (possibly 350), I'm not still diagnosing this problem in case it is in the electronics or wiring of the car.

BigWhiteGTP

You say there is ticking, maybe a bad lifter or so. And a loose timing chain. I think putting in a cam, especially an LT1 cam, isn't worth the hassle right now. You should really focus on what's wrong with the motor and also do a compression test.

As for the computer, it should be fine because the LT1 cam isn't much different.

fireball451

Thats what I am doing.
I am trying to find the problem.
Just needed to know if the cam will go fine with out any problems.
It has gotten down to inside the motor has to be the problem.
Just trying to decide what to do while I am there.
Nothing major or anything that will cost alot of money.

fireball451

Glad I decided to do a little cam swap while it was tore down.
Look what I found.
(sorry the pics are small.)
Bet this it the intermittent knnock I am hearing.

Orr89RocZ

iTrader: (20)

small pics but from what i can see, that could cause a problem. make sure your lifters are good still

the LT1 cam will definately help you out tho. a good bit more lift on the cam than a L98 cam. that will get some good air in. its just that the duration is alittle less than the L98 cam i believe. but then again, i think the lt1 cam has a tigher LSA which also helps the power band out over the really wide L98 cam.