The great wall of 4200-4500 rpm

[Scoobum]

Thought some one told you it needs valve Springs

I've also said at least 3 or 4 times they where replaced during the rebuild...... I don't think a new set of valve springs is going to wear out that fast in 20 km?? All I'm asking is can a cam sensor cause big issues and can a whipped cam lobe make a car pretty gutless?

You see him change them...or see the engine being rebuilt? Never take anyones word for anything. Beat on a set of stock or 980 valve springs with enuf boost or rpm's and they'll go soft in a hurry...ask me how I know. Run a compression check on the engine and then post the numbers for us...and if they're within acceptable limits then swap in a new set of valve springs. I was in the car...and it had a helluva time bringing the revs up and "hit a wall" about 4500 rpm's. If the engine is sound...then why the hell rebuild it?
 

[firebird_1252]

i personally would never ignore a tick. my motor is noisy as hell due to it being a full roller motor. there is a difference between noisy and a tick. no motor running 100% should have a tick.. imo. your not beating the hell out of the car but and i believe it was something ed said years ago. just because you see the knock dont mean its not doing damage. its slowly chipping away at things. my bet is still valve springs.

[phil_long]

These cars are a pain in the ass. Sometimes I wonder why i love mine so much.

[YGspider]

These cars are a pain in the ass. Sometimes I wonder why i love mine so much.

Because you know that when the day comes when you need to stomp down a Subaru or Dodge or any car she will be there for you. 
 
So I'm going to do three things to try and sort this problem out.
1: disconnect the solenoid to the trans
2: new valve springs for the guys that wanted to see that done. If this doesn't fix the problem.
3: pull off the headers and crossover and inspect for cracks. It should be a lot easier with them off the car. I'm really starting to think my header is cracked as well because it seems in park when the car is cold the blm's are 128 as the car warms up to operating them the blms rise to 135 and the car starts clicking or tapping. can a crack in the headers affect rpms that much though? 
 

[TexasT]

If your driver manifold is stock and has not been repaired you can bet it is cracked at the y of the rear two cylinder tubes. Might as well plan to have it repaired while you have it off.


Seeing as you "looked down the oil fill hole(or is it the 710 orifice?)" and saw what you think are non stock valve springs this cant be the problem? You have a few of the TOP internet diagnosticians telling you remedies and you constantly refute their solutions without even trying them. I guess I am missing something. Valve springs are a common problem. Yours are of unknown source. I see this as an easy remedy, change em out. Easy, peasy, lemon squeezy. Why are you fighting it? You, yourself, posted the engine builder was a shyster, what makes you thing he didn't skimp on the valve springs?


Change the valve springs, get the header repaired and get back to us. It will be like a whole new car if you did the repairs right.

[YGspider]

That's the plan my man. But I'm going to try some smaller things first before I swap in new comp cam 980 springs. But I'm sure even with stock springs wont the car get to at least 5 G of rpm?

[motorhead]

Sigh.

Dude, take the boost pressure off the backside of the valves and report back.

[YGspider]

Sigh.

Dude, take the boost pressure off the backside of the valves and report back.

I'm going to do that. I also purchased a set of 980-12 valve springs, picked them up for 40 dollars or so. I'm still sure a header is cracked as well.

[firebird_1252]

A cracked header would still let it rev up.

[dyermullet]

3: pull off the headers and crossover and inspect for cracks. It should be a lot easier with them off the car. I'm really starting to think my header is cracked as well because it seems in park when the car is cold the blm's are 128 as the car warms up to operating them the blms rise to 135 and the car starts clicking or tapping. can a crack in the headers affect rpms that much though?

Start engine let idle until warm, or drive around until warm
Turn off engine
Unplug the maf sensor.
Remove the up-pipe to the throttle body
Reinstall up-pipe upside down so it acts like a funnel.
Start engine maybe take two trys
With engine running very slowly pour a very small stream of seafoam into throttle body through the upipe.  use your other hand on the throttle to try to keep the engine running.  Eventully the the car will stall from being flooded. 
Turn ignition switch off and left sit for ~15 minutes. 
Put up-pipe back and plug maf sensor back in
After 15-20 minutes restart the engine, all the carbon broke loose will cause a ton of smoke.  Any exhaust leaks will show up.

[YGspider]

I've heard a lot of debate on seafoam dose it have any side effects or any issues that it can cause?  Just wondering because I do like that idea.

[PacecarTA]

the proper way to use seafoam on a turbo buick is 
 start the car
let it warm up
throw the seafaom in the trash
drive the car

[YGspider]

the proper way to use seafoam on a turbo buick is 
 start the car
let it warm up
throw the seafaom in the trash
drive the car

   That was funny.

[278CIKILLER]

Good one Brother.

[PacecarTA]

I'm really starting to think my header is cracked as well because it seems in park when the car is cold the blm's are 128 as the car warms up to operating them the blms rise to 135 and the car starts clicking or tapping. can a crack in the headers affect rpms that much though? 
 

the blm change is due to the rpm
the blms arent changing , you are looking at a  different blm cell ,
when the rpm is above warm idle rpm you are looking at the next cell (cell 2) of the 16 blm cells
when it warms up and rpm drops its now in the idle cell or cell 1

135 isnt a real issue at warm idle , just increase fuel pressure about 1 psi and done

http://www.gnttype.org/techarea/faq/BLMINT.html

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