katchup

well, he says 00-01 runs even richer. i am starting to think about where i wanna go with my set-up tho.

trying to find that balance between LOUD and making some gains.

and come inspection time

TelosHedge

i'm not sure a test pipe would cause a lean enough condition to cause this. even if it was possible, i really doubt it would be cylinder #2. when i was out getting tuned at jeff evans i was watching him here and there. towards the end he made minor fuel trim adjustments overall to cylinder #4 - which he told me tends to be the leanest cylinder for whatever reason. i would think a lean condition would rear its head there instead of #2, but i've honestly never heard of anything close to that situation.

a car without a test pipe would also only see different than stock AFRs if it was running in open loop - aka WOT. i still believe this was not that case on the last night the car was driven, but lean situations over a long period of time could technically loosen up a plug or melt it away slowly and cause a recipe for future disaster.

this car does have a test pipe. i'd love to hear bill and jeff's opinions on this.

Billman250

Lets start here:

Take out the two exhaust valves in the same cylinder as the broken intake valves, and spin them in a drill. see if they are bent.

Do any of the coil packs show any black powderish substance on the tips?

dales2000

i thought it was the 06+ models that saw this AFR? Aren't the 06+ leaner than the 04-05 models?

orangebarius

i was talking about this last night at the humpday meet with jeff. its hard to tell what exactly happened. its all assumptions and opinions at this point. we dont know what exactly happened. did the driver misshift? ap2 retainers dont crack and break....or at least no one has seen any like in the ap1, but was 10k+ rpms hit and did the piston hit the valves? was it oem retainers or was is the Chevy IRL's? was it the spark plug? was it running lean? no one really knows.


letting jeff and bill chime in is a good idea. they're the real s2k mechanics here.

TelosHedge

no need to take them out. i remember ONE was bent enough to see by eye.

the coil packs looked ok to me, but i don't remember to be honest. maybe i can run over there later and have a better look.

barry - they are not stock springs and retainers. there was definite contact with the piston, but obviously the valves were broken and then wedged in 90 degrees offset!

i really don't think the kid misshifted. i believe him 100%. he's got no reason to lie about it.

Billman250

Check the rest of the exhaust valves for straightness...

Deception

You dont need a cat to pass inspection, as long as the CEL is off its not a big deal. No one does visual checks.

Anuj

in NJ they look under your car

Deception

hes in NY though