no boost after installing new head

[chrisff521]

I had bent valves on my original head from jumped timing. So i replaced the head with a used one. After everything the turbo would boost very weak. The boost guage would lag before it goes up and its so weak. And also im blowing white smoke out the exhaust. Compression is good. No shaft play. New plugs.

 

[LiquidX]

Was the used head checked for damage or warping. Were the head studs torques down properly and did you do a leak down test?

 

[gvr4550]

leakdown test
turbo can still leak oil by the seals and not have much shaftplay

 

[RadDsm]

Have you checked your timing?
How does the car run otherwise?

 

[crash89]

Boost leak test!

 

[chrisff521]

Idk how to do a boost leak test or leak down test. And I torque the Arp head studs down to 90 ft lbs. From 30-60-90 in sequence.

And the cat runs great. and also I was wrong it boosts but it seems very weak. and has a very weak blow off compared to what is used to be.

 

[chrisff521]

I'm thinking its the cas timing because I never set it correctly. Could that be a cause? I don't have a datalogger or that type scanner so I havnt been able to set it.

 

[LiquidX]

Do a boost leak test. You wont get anywhere withot doing one. Unless you took off the CAS from behind the cam gear then it's fine. Only the 1g has an adjustable CAS.

If you have it flipped over then you may or may not be able to start the car, fuel and spark is being injected at 180* time (opposite of firing cylinder).

If that's the case, then you would be at extreme timing retard and you would need to flip the sensor around.

 

[chrisff521]

I have a 1g sensor. I have a 6bolt. And I aligned the little marks on the inside of the sensor and the car starts and runs but doesnt boost hard.

 

[boostNmetal]

White smoke = burning coolant... As LiquidX said above, do a compression test and leak down test. You likely didn't get a proper seal on the head gasket.

 

[chrisff521]

Could it have been from overtorqing the head studs? I had ARP head bolts and I torqued them down to 100FT LBS.

 

[boostNmetal]

Again, as said above by LiquidX, did you just slap the "new" old head on your block? If the mating surfaces aren't perfectly true you may run into sealing issues. I bet this is your problem. Do a compression test!!!!!

 

[chrisff521]

I did a compression test. It was around 155 on three except cylinder 1 was 170. IDK if its ok for it to be that high when the others are low.