Ill do a little chiming in. With the center two pistons at TDC and pumping compressed air into each cylinder...cylinder 2 holds steady with no leaks but cylinder 3 you can hear air leaking out of the exhaust(enough to even spin the turbine wheel) and out of the valve cover breather hole making me think its a bad valve/valve seal. Same thing is happening to one of the outside pistons at TDC(forget which one) When the engine was built the head was left untouched just had the cams swapped. It has the same dual springs he bought the car with as well as the factory(yellow/brown?) valve seals.

 

Updated see post #72

 

was the motor ever clayed to ensure it had enough piston to valve clearance?

 

As I said from the start it looks like more of a mechanical problem with engine than a restriction.. if its not timing as we now know then bent valves possible or hurt pistons..

Mike

 

No the motor was never clayed to see if there was enough clearance. we are probably going to pull the head off this weekend and send the head to the machine shop.

 

i have a turbo xs catback and i made 600+ no sweat on pump/93.

 

Wow your compression looks pretty low across the board even with 1 and 3 being lower.

 

As choppy as it is and the fact that its down on power I am going to go with the reluctor is in backwards (180* out) on the exhaust cam.

 

haha damn.
good job finding the problem rather than just throwing money at it.

 

Don't forget, bent valves or bad valve seals can also do that. The air has nowhere to go but up through the valve stem into the valve cover. #3 had some coming out of the breather tube as well.

 

Yeah that won't be happening anymore. From now on it will be done by me or Bosco(or a combination of both) Im tired of my brother wasting money on labor when it can be done for free.

 

Today we did a leak down test, all 4 cylinders have between 0-1 percent leak down. after that we re-did the compression test with a battery charger hooked up to the mini battery.
#1-125 #2- 120 #3- 125 #4-125. then we checked the cam sensors and they were both installed correctly. then we re-checked the cam timing and it was also good. now we are back to square one. the manifold is coming off and the gsc junk (so called) "s3s" are also coming out. and back to the dyno to make power.

 

S3 are very far from Junk.. Ill show you tomorrow or monday what 800+hp looks like on S3's.. I have already seen preliminary tuning with them on our customers car but tomorrow or monday it will be on KILL..

Mike

 

I agree with mike the S3's are probably the last thing that's is causing the power problems. The S3's are a bad *** cam.

You need to start looking at something else.

 

S3s power 1117whp, revise statement please.

Check the reluctor on the exhaust cam, seriously. Valves are bent or not, 0-1% leakdown is obvious thats not the problem. They only have 11.5mm of lift and 238@1mm duration so they arent hitting, I dont think they would even hit on stock pistons. I am running a similar combo right now with 12mm lift and no issues