OK WTF. Just got back from the shop, I can really only explain this in a timeline sort of way, so here goes.
Car ran like ass today after finishing install on nitrous kit. Even though I tested both solenoids before installing, somehow the fuel solenoid got stuck open. That huge amount of fuel (~70hp worth) at idle was making it smoke and misfire and run like junk. I fouled all 4 plugs and barely made it back to the shop.
Pulled plugs, cleaned them, put back in. unhooked the fuel supply line to nitrous kit and reconnected the main fuel lines like they were before.
Go to start the car...won't start. making clacking and crunching sounds while cranking the starter which seem to be coming from the tranny side of the engine. My immediate mental image was hydrolocking the engine on fuel and major damage to valves, broke piston, cracked ring lands, thrown rockers, valvetrain damage.
Pull plugs again...slightly wet but should fire. no oil.
Remove valvecover and Tbelt upper cover. Tbelt is lined up perfect. all rockers are on. nothing abnormal in the head. oil looks clean. sigh of relieve
lift up car...inspect the flywheel ring gear teeth from below thinking maybe bendix in the starter motor went bad and the grinding is the teeth not engaging. but it isn't a smooth grind sound of high rpm, it's a clunk clunk clunk clunk rythmic sound. If you can imagine the sound a 4g motor makes when you mixup the plug wires (inner to outer mixup..totally out) when you crank it kicks back against the starter and eventually give you a scarey backfire out the exhaust. Anyway...flywheel looks good from the back, teeth on flywheel seem normal. ring gear is solid.
Turn crankshaft over lots of times with 1/2" ratchet. back and forth. turns smooth. If a piston was broke, you would hear it now crunching around.
put car down. run the starter motor without spark plugs in.....motor turns smoothly. no odd sounds at all. again...if piston was busted, Id hear something now too.
decide to do compression test. unplug injector balast resistor & start with #4 since that would be most likely to hydrolock first. 155psi cold. pretty much what it gets normally. But Im hearing a clacky/crunchy sound again. f***
#3 compression was 155 also, again crunching sound. Same deal with #2 but slightly less crunch sound. I don't test #1 as the crunch sound is freaking me out, I bet it would be 155 as well, it's least likely to hydrolock.
After comp test Im thinking there is no way the motor could be hurt and test this well. bent rod or broken piston would see major compression loss, ditto on any valvetrain damage.
crank the starter without any plugs in....no sounds & smooth spinning.
decide to unplug the lower clutch switch so I can crank motor without my left hand holding down clutch pedal....no change in anything.
Put a set of old ngk plugs in, set valvecover back down, put on the plug wires and crank starter...engine fires and runs for like 5 seconds. (without injector balast resistor...must have been running on residual fuel in manifold) engine ran with no odd sounds.
crank it a little more trying to restart (forgot balast resistor still unplugged) and Im getting the crunchy/clanky sound.
plug in balast resistor & crank starter. engine fires and runs great after a couple revolutions on starter and making one "clank" sound. no missfire. no studdering. no crazy sounds. it revs up clean, no sounds that would indicate any damage.
Seems the clunk sound only happens when cranking on the starter when the cyl are making compression via either spark plugs or compression tester. There is no abnormal sounds cranking the starter with the spark plugs out. No abnormal sounds after the engine fires and starter disengages.
Any ideas from the peanut gallery? I'm seriously out of it and can't think straight after a day like this. Im now leaning to the conclusion that the engine is fine and there must be something wrong with the starter motor. The starter motor failing could either be coincidence that it happened on the same day I install a nos kit w/ bad noid. Could it be possible the starter motor was damaged from cranking the engine in a hydrolock situation but the engine survived fine? Maybe the starter was damaged previously due to the loose trans bolt issue and I didn't notice it till today, possibly since it always fired up instantly and today I was riding the starter for a long time with the over rich/fouled plug deal?