BergerMan

It was "street tire" night at my local track this past Tuesday night, so I figured what the hell, lets see it will do. After getting a feel of what the car needed to launch worth a damn (on 285/30/20 tires), I got a good jump but I missed 4th gear and was still able to muster a 12.40 @ 117 with a 2.21 60' time. Well I got a little greedy and decided to make a few more runs and hit the rev limiter with and without a load. The car just didn't have the same feel as before so I stopped for the night. On the way home I noticed that it had a slight shudder cruising at about 2000rpm. I also noticed that the exhaust sound at cruise was just a little flat. The next day I removed the rocker covers to check the springs and they were all fine. I removed the plugs and they were all fine except #7. It was dark. It wasn't wet and it didn't have any deposits on it, it was just black. I decided to do a compression test. All were 215psi except #7 was 110psi. Well I think I may have bent a valve.
Any other suggestions?

Scalpel

iTrader: (4)

Unless you mechanically overrevved the car you can't bend a valve by taggin' the rev limiter. The piston must make contact with the valve to bend it and this just doesn't happen unless you mechanically overrev it or break a spring.

boomcase

Bent pushrod will tell all.

v8maro

iTrader: (4)

turn the spring, i didn't notice mine was broken till i turned it
-Steve

Phil99vette

iTrader: (11)

I have bent a total of 8 valve since I installed my BIG xer cam. I am starting to feel that a cam over 232 XER is too big for a daily driver. This car is a complete pain in the *** since we installed the 232/238 XER cam. Floats valves or bends them. A bent valve is easy to fix but a bent pushrod is easier.
Phillip

BergerMan

I removed both rockers and did a leakdown test. I could hear a little air through the throttle body. If I push real hard with the palm of my hand on each spring I can push them down. They both are really hard to push so I don't think its a broken spring. I will fill the cylinder up with air and remove the spring just to be sure. Damn I hate when things go bad.

Visceral

iTrader: (1)

Watch for a clunking noise down low in case you stretched a rod bolt. Sounds like you tagged a valve though. Try laying a straight edge along the tops of the valvestems. A bent valve will be slightly lower, although if it holds that much compression it might be very minor and hard to see without taking off the heads.

chris

Phil99vette

iTrader: (11)

I am willing to put money you dusted or bent an intake valve. Seeing as I have bent a few already I am 99% sure thats what happened.
Phillip

BergerMan

Well the verdict is in... Its a bad valve! Now I say bad valve with caution because after very close inspection of the piston top and the valve itself, I DO NOT see any evidence of contact with the piston. I put a bright light in the intake port and you can see light around the valve, only in certain spots. Its hard to explain, but it looks like the valve is making contact in a few spots like its warped not bent. Oh well, I spoke with Jay @ AS and he will fix it for me, NO CHARGE! Can't argue with that. Guess I'll be down for a few weeks!
It also got me thinking that if the valve wasn't right from the beginning, it could have been the cause of my low HP #'s, you never know!