ThreeHonks has endless issues

[ThreeHonks]

everything looks wet in that cylinder lol when I pulled the motor that exhaust valve was open and there was nothing on the stem to lead me to believe its just a valve seal

[DETROITMUSCLE]

could be blow by but that wouldn't explain why the other cylinders all run differently.

[ThreeHonks]

I cleaned the heads up and the #4 cylinder with the "oil" the exhaust valve was white too (showing coolant burn). I think maybe the coolant was just mixing with carbon and the combustion gases to give it that neasty dark look.

Im thinking its a head gasket only now on both sides and NOT ring/oil realted for these issues:

1.) white plugs and exhaust vavles.
2.) there was never and smoke that came out of my breathers. NONE.
3.) the car on the dyno did not burn oil at all.
4.) the coolant smell/slight smoke was coming out of the bank where cylinder #4 is located.

The plan is to buy new gaskets and put it back together, after checking the block and heads for straightness.

comments? agree/disagree?

[JoeliusZ28]

does anyone here know if the 4"bore of a stock gasket will cause issues with his 355?

[prorac1]

I thought those .026 gaskets were 4.10 bore? Or is he using the factory Impala SS gaskets? I wouldnt recomend it. I would use a Mr. Gasket 5716. Its also a good idea to get the head cleaned up after using a steel shim gasket, even if it is straight. It could still have some slight brinteling. Eric L

[meissen]

Hrm... you know, I never did think anything about the head gaskets when I built the 357 - I just used regular felpro head gaskets. *knocks on wood* Never thought about the 0.040 bore making a difference with the gasket.

[ThreeHonks]

Im going to go with a victor reinz .026" head gasket. It is the same exact one as the mr gasket, but it is packaged better.

I used a straight edge, and the block was dead straight. The heads were just milled by a reputable machine shop

[farmington]

Looks like 1,2, and 3 are running leaner than the others. You probably didn't do it, but WHENEVER a motor is being taken down due to a problem like yours, ALWAYS do a leakdown and compression test before taking it apart. REally helps to pinpoint a diagnosis. The cylinder that has the oil in it probably has a busted oil ring or collapsed ring land. That oil can migrate through the intake to other cylinders.

[Bad_Z28]

When I bought head gaskets for my stock lower end LT1, they already measured out to 4.08". I beleive they already thrown in a small factor for bored engines.

[ThreeHonks]

Looks like 1,2, and 3 are running leaner than the others. You probably didn't do it, but WHENEVER a motor is being taken down due to a problem like yours, ALWAYS do a leakdown and compression test before taking it apart. REally helps to pinpoint a diagnosis. The cylinder that has the oil in it probably has a busted oil ring or collapsed ring land. That oil can migrate through the intake to other cylinders.

they arent lean. There was coolant in those cylinders so it basically steam cleans everything, including the plug. If it was lean it would miss and sure wouldnt have made good numbers.

I'm almost positive that the oil issue is more of coolant mixing with combustion gases and a little carbon/blowby. That is the cylinder where the head gasket issue is most prominent, that and the one next to it.

I also might have some excessive oil from the PCV system. This motor revs to 7600rpm and I dont think that helps matters. I am adding a catch can when i put everything back together.

[1BADAIR]

ahh, time to put a 305 in it