JC316

iTrader: (1)

Got a 97 Formula with a blown head gasket. Just pulled the drivers side head off, and I get this. I've seen some **** happen to a head gasket, but this is a new one for me. It looks like this engine has been apart in the past and the work looks pretty new. One part of me thinks detonation, but there is zero damage to the pistons or the head.

BSmiff

Wtfff looks like you got a hot spot there. Maybe when they did the work last time they didnt ensure the heads were milled.

JC316

iTrader: (1)

Odd place for a hot spot, you usually see them in the combustion chambers, not in the space between them. I will definitely have the heads checked out before I reassemble. The thing thats confusing me is that they are blown inward to both cylinders.

JC316

iTrader: (1)

Used a straight edge on it and the head isn't warped. Also no visible cracks. Could nitrous cause that kind of damage?

superspirit

Yes!!!!

JC316

iTrader: (1)

Passenger side was starting too, in the same spot. I can't find any evidence of nitrous anywhere on the car, but it seems to fit.

noice

Lean running? Nitrous tends to leave metal flakes on the ceramic of the spark plug if detonating lightly. Nitrous also pinches the ring lands and will show some visible damage on the top of the pistons.

However maybe you had a bad injector and were detonating in that cylinder.

I've run nitrous/methanol/race gas all together on stock gaskets and never burned it like that.

SS RRR

iTrader: (2)

I'm thinking the heads could be warped/improper torquing sequence if heads were ever off the car. Definitely check the head surface to make sure they are true.

JC316

iTrader: (1)

That and detonation seem to be the consensus view. The heads are flat, but the torque sequence could have been off. The drivers side was way looser than the passenger side.

Ken95Z28

iTrader: (1)

If you had no damaged to the head you got lucky. When that happened to me I had to get the head welded on because it torched the aluminum away. This happened running the thinner gasket. Lasted almost two seasons of racing. Now they get changed every year.

JC316

iTrader: (1)

Looks like detonation was the winner. Both 02 sensors were messed up and leaning it out way too far. It wouldn't even idle, so I can't imagine driving it like that.

FASTFATBOY

iTrader: (23)

You need to check the head AND the block surface to make sure they are true.

I have only seen that kind of failure on a boosted or NOS application, never normally aspirated.

JC316

iTrader: (1)

I did that, everything was fine. Only thing that I found was the 02 sensors were leaning it out to the point of not idling anymore. If someone was repeatedly flogging it with it that lean, the detonation could have caused that.

FASTFATBOY

iTrader: (23)

O2 sensors are shut off at wide open throttle, the ECM does not read them.

You should have other evidence of detonation "that bad".

JC316

iTrader: (1)

There was some minor pitting in the combustion chamber surface of the head, but I'm not sure if it was from the coolant or from detonation. I never found anything definitive that would have caused that level of damage. I know it's running great now and I did everything possible to diagnose it.