I saw a 400sbc with the steam holes filled in? Is there an advantage to that and what where the steams holes for in the first place?

 

Scott,

The steam holes are the only direct cooling means for areas between the siamesed cylinders on the SBC 400 casting. The common practice among street engine builders has been to enlarge the steam holes and correcsponding head gasket holes to provide a bit better cooling in these areas. Aside from these holes, the only other means of the cylinders rejecting heat is to conduct the heat throught the cast iron out to the side areas of the cylinders that are in contact with coolant jackets. The intermediate areas can get pretty warm by comparison, since iron castings are not the best conductors of heat.

I can only presume that a 400 with filled steam holes was intended for short-run use only, and not for general street use.

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
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