Originally posted by j*b
Do the valve seats actually have cooling passages inside them? If they do, that's pretty trick.

We initially filled the blocks we used for racing to support the cylinder walls. We really weren’t all that concerned about the effects on cooling. We just wanted a bigger bore so we could stuff a bigger intake valve in the engine. Another way we used to "stiffen" the cylinder walls was to run high pressure in the cooling system, and it worked well. A buddy at Ford told me about it, it was kind of a serendipitous find for them and is the reason Ford engines had screw in freeze plugs. It seems this solved a lot of problems they were having with the old 427 NASCAR engines.


Right, so it's coming back to the point where you have more control over cylinder flex, the more horsepower you can extract from the engine.

I may mention that Mr Vizard was supporting the idea of these partially filled blocks for street use. The block filler acted as an insulator between the crankcase and the water jacket thus getting different temperatures for the water and the oil, the oil by the way was a synthetic brand, probably something like mobil 1