sr20det head tapping

[bmoreadi]

yesterday i was at the track and my car started acting wierd when i started to smoke and a loud tap is coming from the head and then in started to misfire please help.

[Neil]

sorry you're having troubles, but the extent of advice that anyone could provide at this point is something along the lines of "if you find the source of the problem and repair it, then you should be good to go." At least it happened on the track instead of the highway.

Unfortunately smoking + loud tap + misfire has a very small chance to not be a serious problem. Misfire means one or more of the cylinders can't make compression. A loss of compression could be a severely blown head gasket, but that doesn't make a loud tapping noise. I'm guessing that either a piston failed or the head dropped a valve. If the sound truely is coming from the head then the latter is most likely. Remove your valve cover and see if anything looks obviously irregular.

out of curiosity, are you running either: aftermarket cams with the original valve springs, or maybe some means of raising the rev limit without head mods?