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BB Head to Block Waterways Alignment
Posted: Tue Jun 28, 05 5:25 pm
by TyreFryer
I've got the heads off my 440 at the moment and have noticed something strange. The small (1/2") water holes between the bores/combustion chambers are offset to the left and right of the head bolt holes that they are next too. But in different directions on the head and block. This means that the holes in the block and head don't line up. Also rather than a hole in the head gasket there is a thin slot in the Fel-Pro gaskets I took off, that connects the holes, and a larger square hole in the steel Mr Gasket steel gaskets I'm replacing them with. In effect this means that the water passages come to a dead end at the head gasket with just a small slot the thickness of the compressed gasket joining them.
Anybody know why this is?
Posted: Tue Jun 28, 05 6:08 pm
by Dave-R
It is a deliberate restriction. You will also notice some holes are blocked off completely. Don't worry about it.
Posted: Tue Jun 28, 05 6:45 pm
by TyreFryer
Hi Dave,
so presumably I'll get less restricion with the steel gaskets larger slots, or are they larger to compensate for the thinner gasket?
Why restict the flow in any case?
Posted: Tue Jun 28, 05 6:50 pm
by Dave-R
Something to do with heat transfer probably.
Posted: Tue Jun 28, 05 8:17 pm
by TyreFryer
Just had this reply on Moparts for anybody whose interested:
"Think of the holes in the deck as core holes to facilitate the casting process, much the same as the expansion plug holes. The head gaskets seal them and the slits meter the coolant flow for even cooling. If there was unrestricted flow and all the holes lined up, coolant flow to the rear of block would suffer."
Posted: Tue Jun 28, 05 9:41 pm
by Dave-R
That sounds reasonable.
