ilikemy944

Someone told me they saw an overrevved SBC motor break rings in all of its cylinders one time.
A bit of a stretch, but hey anything is possible at this point.

Tom M'Guinn

What happened to prompt the head work in the first place?

Duke

I find it pretty hard to seal the adapter that screws into the spark plug fitting in the head.
And you will probably have some leakage through the rings on the cold engine. So perhaps some air is leaking past the ring, but the majority of the air is going somewhere else?

Hey what's the compression numbers!? With 80% blowby you would probably don't have much compression. Do a comp. test and get back
If the engine was running before you pulled the head I would definately think something else is going on, and not that all cylinders all of a sudden are complete toast.

Josh B

Car wouldn't start and compression and leakdown numbers were poor. Leakdown air was coming out of the intake. I took the head to the shop and they said all four intake valves were very slightly bent. I think I over revved on a downshift at the track as that is where it wouldn't start.

Hi Duke - seems really strange to me too that all four cylinders would be go bad. Compression numbers were 52, 52, 87, 52 with a tester that I would usually get 135 across all four cylinders.

cruise98

Josh: I am sorry to read about all the engine trials you are having. Sounds like it is time to pull the engine and replace the rings at a minimum. Have you tried pouring any concoctions into the bores that could loosen up the carbon on the rings and in the piston grooves? My keyboard theory from 150 miles away is that the rings are frozen in the pistons or lost their tension for some reason. Maybe they got too hot.

Duke

Ahh interesting. Now it seems more likely that something else is up.
But still, bad results on all cylinders is suspicious.

Duke

IIRC someone else asked about if there's any pressure in the cooling system when doing the leak down?
Perhaps the head or block is cracked.

Josh B

Hmm - I think i was getting some blow by on the turbo. Maybe the initial problem was the bent intake valves but then the rings froze up sitting for a couple weeks? What sort of concoction could I use?

A crack is certainly a possibility. I currenlty don't have any water in the car - was trying to get it to start first. I could seal back up the cooling system though. Since I am getting lots of air out of the AOS on leakdown that is probably a bad enough sign.