If the headgaskets blown, how do you check the rings?

Information on the naturally-aspirated KA24E and KA24DE engines.
aelhatta
Posts: 1
Joined: Fri Mar 22, 2013 12:00 am
Car: '93 d21 pickup KA24E

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I had a little bit of trouble with my first timing job (damn oil pump gear) so the motor ran ,but wasn't driven, with advanced timing, and then driven round the block with retarded timing (I thought I turned it one tooth but it was two). The head gasket blew, coolant in the oil and compression of 90-80-70-65. What I'm wondering is how damaging detonation and retardation can be? I had no idea they could do damage when I was working on the truck, I just thought it wouldn't run well or at all if the ignition timing was off. Could I have blown the rings as well, and how could I tell if I already know for sure the head gasket is blown? as of now it's idling well but I'm hearing a tapping up top when it warms up and a quiet knocking that fades in and out.


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CSUPUEBLOTIM
Posts: 742
Joined: Mon Mar 31, 2008 3:45 pm
Car: 1992 240sx Sr20det Coupe Silvia Front

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You can inspect the cylinder bores with the head off. But at the same time coolant in the lower end will eat it up. Might just do a rebuild to freshen it up. I would start with pulling the head first and see how everything looks with that out of the way. Is the car smoking really bad You can see what results you get performing a leak down test. I think you can rent the tool for autozone.

GarageGuy
Posts: 20
Joined: Thu Apr 04, 2013 2:21 pm
Car: 92 nissan hardbody pickup

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If an engine is ran hard enough, detonation and pre-ignition can blow it. But retarding/advancing the timing wrong is when a new hole in the block can occur. If the valve is still open (pushed into the cylinder) when the piston comes back up bad things will happen. May not be an instant thing but its a time bomb. Piston tags the valve, valve eventually breaks from stress, said valve is now in cylinder and destroying piston, once piston is gone con rod is etxhing the cylinder wall until it falls into the crank case and binds up, once that connecting rod gets into a place that wont let the rotating assembly turn either the crank breaks into two separate pieces or you have a new hole in the block.

Someone double check me with this, i know this is what happens on a v-type motor. Pretty sure it would be the same though.


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