Thread: White smoke from breather and oil drops formed

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Jerry has mentioned steam holes twice and you have not indicated whether or not you drilled the heads for steam holes. Any 400 block that will be operated on the street at less than ~3,000 rpm's will need steam holes between the block and the heads. Race motors that are wound up tight all the time will not need them because there is enough movement to the coolant that steam pockets will be washed away, causing no problems. Street motors that are operated at lower rpm's have insufficient coolant speed to wash the steam pockets away, so these steam hole points in the block build temperature until the block material grows at these points, causing the deck to be uneven and the motor spits out the gasket due to lack of clamping force. At least that's how it has been explained to me and that makes sense. Even if the gasket is not compromised, the hot spots can cause detonation in the motor.

I suspect the head gasket(s) have already been compromised if you did not drill steam holes in the heads and did not use head gaskets with steam holes in them.
Technical Articles at Greg's Engine & Machine
Here is the gasket normally used on these 400 builds....
http://www.summitracing.com/parts/fe...make/chevrolet
Speedway Motors sells a shim gasket, but I could not find it in their catalog. Maybe a call to them would turn it up. I'd like to know where you ended up for squish and what gaskets you used.

I would like to know the particulars of the motor too.
Part number of pistons used.
Piston deck height used.
Squish.
Measured cylinder head cc's. If you bought these heads used, one or more previous owners could have decked them and you have no idea about the volume of the chambers. They could have even angle milled them, causing oily vapors from the crankcase to be pulled into the cylinders from the underside gap between the intake manifold and the head ports. That could be one cause of the oily plugs.

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