weird h22 explosion?

[cp[mike]]

ok when trying to start a newly installed H22, turned the key on and off a couple times to get the fuel pump running and get fuel back into the lines/rail... tried starting, it just cranked and didnt spark... pulled out a plug wire and held it near the valve cover to see if it was getting any spark, turned the key and there was like an explosion, the other three spark plug wires popped up out of their holes, and the valve cover gasket popped out of its groove... pulled the valve cover off and there is still smoke kinda lingering around inside of the head. pulled the spark plugs and look clean and still new, recently properly installed the timing belt and it was not off timing... so wtf? what would cause an explosion inside of the HEAD!? it was so loud that people inside the house heard it and came outside...

[cp[mike]]

no ideas?

[Maple50175]

an explosion hmm what the hell... did you hook up something wrong? and its making the gas go up in fire or something like a little bomb in the head?

[mixmatch]

mayb it backfired? or one of the valve seals isnt seating properly and it let the combustion enter the head that way?

[91accord4door]

detonation?

[cp[mike]]

cant be detonation, thats inside of the cylinder.

i was thinking about broken/bent valves or something but that wouldnt let fuel into the HEAD, it would let it into the intake/exhaust runners.

wasnt a backfire, it actually blew the valve cover gasket out, and popped off the spark plug wires from the force.

i guess it could possibly be a/some valve stem seal(s). but its weird that there was only a problem once a wire was pulled to see if it had spark... like when it was trying to start there was no sign of problems.

very weird right? what to do, what to do... please, any suggestions would help.

[GrayCar]

Well, any of the vapors inside of a motor could explod. Heck, they have grain mill explosions pretty often and that's wheat.

Yes, I know, two different things, so spare me the Mr. Wizard stuff...

When you held the plug wire to the valve cover, you probably ended up generating a spark inside the valve cover and to the block.

Any of the gases, oil or fuel, would have blown.

You may have a leak some where that would allow gas under the valve cover, but that would also show up in your oil.

[cp[mike]]

tried starting it again with the jdm internal dizzy, turn the key and nothing, motor didnt even crank. tapped the starter and it cranked super slow, no spark no start. swapped an usdm external dizzy onto it, cranked super slow still. pulled all the spark plugs and they all looked good, put them back in, tried starting the car again. it cranked and started and idled up at like 3k, lots of smoke coming out of the valve cover, 10 seconds later the motor completely died by itself. and heres the cool part of the story:

pulled spark plug #4 and it was completely bashed in. the other three were fine. used a stick to check the height of each piston - 2 and 3 were up, 1 was down, and 4 was gone. couldnt even find it, it was WAY down there.

guess a rod snapped?

[ZigenBallZ]

Originally posted by cpmike
guess a rod snapped?

Damn man...

Sorry to hear that...

[xScott]

Damn, that sucks ass. Got any kind of warrenty on the motor?

[deevergote]

Dood, that sucks! Not sure what could've happened, but you definitely broke something there... Time to yank the head and see what's up. I'm thinking that whatever may have broken something inside the block may have created enough force to blow past the valves. If you remove the head, I'm pretty sure you'll find some broken valves for #4.

If you did break a rod, then you may also have damaged the cylinder walls. I'm not sure if you can do anything to fix the FRM sleeves... You may have to look into getting Golden Eagle sleeves or something... And if you do that, get some low compression pistons while you're at it... and stronger rods. Then we can start planning that turbo project you never really considered

[accordztech]

just as i feared, i knew one of the plugs had to be bashed in...

that was probbably half the boom...

but shit, didnt u get the motor for dirt cheap though?

[WiKKeDV16]

i think u should buy a f20a and make it a 2.0L h22a. lol i know ur broke but my question is.. isnt the sleeve totally fucked now.. since the rod or piston went to shit???? damn FRM sleeves.. i dunno mike... ur gonna have to rip it apart.. to find out.. but yeah usually when a piston/rod goes out on an h22a especially that kind of an explostion the sleeve will definetly be scar'd

and resleeving will cost more than buying another long block..


it may just be cheaper to buy another longblock and sell the one you have for parts.. sigh.

[92accordDx]

damn man i would fucking cry if it was my motor. was this your motor mike or someone elses?

[accordztech]

it sucks that they got it out of another car that was working, and when they put it in it wasnt! sucks!