Well that sucks...... I wonder if it's a bent valve, or a bad valve seat





Currently #4 in Ecotec Forced Induction horsepower ratings. 505.8 WHP 414WTQ!!!
Currently 3rd quickest Ecotec on the .org - 10.949 @ 131.50 MPH!!!

blackbirdracing wrote:Yeah, 100% sure. Cams were in the "rest" position. As if I was timing the engine. Crank at tdc.
Cause I actually re did the timing to see if that was it. It was timed right.

well that sucks.



FU Tuning

Eh... No biggie. New gaskets and bolts, and a few bucks at the machine shop. I'll be back in business.

Dam that sucks.

Seriously not that big a deal. At least I found the problem... It will only cost me a couple hundred, I figure.

Good attitude Travis

Better to find it out now than have a Curtis happen at the track again!

Pulled the head. Off to the machine shop tomorrow.

Burned up an intake valve... No big deal.

Valve at machine shop, waiting to be installed.

New gaskets and bolts at dealer waiting to be picked up.

Once it gets running, I gotta install the new intake mani with LS1 throttle body, and Msd.

I hate to say this especially after you just tore everything down, but the single valve being burnt was not likely causing the condition you described (although good you found it and repaired it). The Comp Turbo grinds will in fact cause the exact same symptoms you have described under high boost. It's in the tune......... on top of that I am experimenting this weekend with the ignition systems capabilities to handle the cylinder pressure differences with this cam combination. Now there will be significant differences with your setup and mine simply because I run 10:1 cr whereas you are running the 8.9:1cr but I suspect the condition you described may actually be the result and need for a re-tune.

(by the way I too have a soft spot in my heart for the AFPR simply because for many years that was our only choice and it can be a fantastic supplement on top of HPT for certain situations)

I am curious to see if the condition is persistent after the repair. Just out of curiosity do you have any idea what cell the adaptive learning is sitting at in the idle position? You may not have done any data logging before the tear down but figured I would ask if you knew. I ask because after the cam install on mine the adaptive learning cell went from minimum to nearly max (19) the entire time trying to pull fuel to reach 14.7:1 (closed loop). This indicates right off the bat that the comp cams create a significantly richer condition at idle. The ECU was able to stabilize it but not until after considerable effort on its part in closed loop.



ASE Master Certified Automotive Technician