92 3.1 gone wrong

[SS_EURO]

Hey all listen I got a big problem. I walked a cam in my motor.Changed cam to a performance cam, new chain,guide for chain, lifters,pushrods, and rockers. Car runs like crap. No engine light and it is not a miss but man there is no power at all. I,ve reached my end with this car and need help or insight.Maybe I,m thinking too much or not enough, Timing chain is dead on. no pushrods are mixed up. valve train is a little noisey and there,s a rattley kind of almost knock that is definantly not in the bottom end. I,m lost and wore out help please.

[geoffinbc]

How much preload did you put on the lifters? Sounds like valves are open when they are on the base circle and you are not getting compression. Its a common mistake.

[SS_EURO]

Preload???? I was told to run the car @ 2000rpm for 1/2 hour. I also have cam specs they are as follows

cam lift int.: 0.281 exh.:0.296
valve lift int.:0.422 exh.:0.444
lobe ctrs int.: 107 exh.:117
lash hot : hyd

I was told this cam was able to run in my car just fine and am yet to see it. But i think you are right. How do I fix this?

[Hybird]

Preload???? I was told to run the car @ 2000rpm for 1/2 hour. I also have cam specs they are as follows

cam lift int.: 0.281 exh.:0.296
valve lift int.:0.422 exh.:0.444
lobe ctrs int.: 107 exh.:117
lash hot : hyd

I was told this cam was able to run in my car just fine and am yet to see it. But i think you are right. How do I fix this?

If you tightened down the rocker arms too much, then your valves will never sit completely sealed and you will leak compression. Do a compression test and see what the cylinders are up to. If its stock CR you should have about 145 psi cylinder pressure.

[geoffinbc]

By the sounds of your response I gotta ask. How did you adjust your valves? On a gen II they tighten down onto the shoulder of the stud and thats it done deal. But with an aftermarket cam and lifters that may not be the case. Are you still using stock rockers and studs?

[SS_EURO]

yeah I'm still using stock rockers and studs. The guy @ engine parts warehouse told me everything would be fine. I didn't need adjustable stuff this would all work just fine. I tightened the rockers down to that shoulder and let her rip. Now your telling me I need to spend more?? this is getting expensive very quick. Is it possible to get a used adjustable setup or is this one of those parts you cant do that with.

[Doubt_Incarnate]

i thougt only the gen 3 stuff was a tighten down operation, on the gen 2 i thought it was like the gen 1's where you snugged it so the pushrod dint moveor spin, then an extra 1/3rd or half turn

[RacerX11]

nope.

[v6h.o.]

What specific Camshaft did you put in?


As to the rocker arm thing, Only early early 2.8L Gen2 engines had the adjustable rocker studs.
From 89/90 On they were all torque to spec shouldered studs with a small M8 top nut.
Older adjustables were a full M10 threaded stud.

[geoffinbc]

Dont instantly asume this is your problem. I just said it "sounds like" your problem. Thats why I asked what the preload is and others said to check your compression. You should measure it. It should be about .020 to .060 preload with about 145 psi compression.

[SS_EURO]

Well i dont have the tools to do the compression test nor the money to pay a shop, but I had the car running great with the rockers backed off but i cant lock the nut in those positions the nut keeps backing off(obviously). So i think it,s time for adjustables but are these gonna need me to get anything else or is this just replacing a bunch of stubbern rocker studs to an older adjustable set of studs?I,m also thinking the cat is plugged so i,m gonna put a straight pipe in and take off the flow master as it will be too loud at that point. But i'll make it run right first.Also she runs very hot like this but i asume thats because of the rocker issue.

[geoffinbc]

I have 2 sets of rockers and studs. Make me an offer and its yours. Plus shipping of course

[SS_EURO]

Well im not sure how much is fair but my work has a ups account so if you come up with some numbers and pm me about it I'm sure I can make something happen in the next week or so.