Size of holes for water passages in Head Gasket.

[OgreOwner]

One of the things that made me stop and thiink as I was taking the heads off my 6.5LT engine is that the block and head have approx 1 inch holes in them for water, but the head gasket has all of an 1/8 inch hole. That would severly inhibit water flow and lead to overheating... Am I missing something or should I enlarge the holes on the new head gaskets so that water can flow thru the new head freely?

Karl

[john8662]

I think the main purpose of these holes is to allow air to pass. Enlarging the holes will change the path of coolant flow through the heads, possibly leading to the back of the engine running hotter.

J

[AndyL]

My guess is to get all of the sand out during casting.

[Hubert]

Ogreowner

Which holes are you reffering to? The small holes along the lenght are to allow a little circulation up each cylinder wall water jacket. You don't want too much flow at each cylinder because cylinder block wall will stay too cool compared to piston and head. You don't want big temp gradients in block. The heads are the real source of heat. The "holes" in the block are I think for water volume to facilitate cooling. I don't know maybe also the small holes may jet some cooler water and turbulate volume to increase cooling too somewhat? I think the rear gasket opening is where a majority of the coolant flows to the heads or something like that.

Exact coolant flow is pretty dang important and hopefully is correct for your gaskets. I would not go opening up gasket holes unless you have a really good idea of results and plan. Do a search on the forum here (and good luck headgasket is common thread) there is info on head flow, balance flow, rear head coolant flow increase etc. for some more ideas, reasons/logic etc.

[Kennedy]

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=25230