Tom M'Guinn

Anyone here have experience drilling extra coolant holes into the head gasket? Did you drill for all passages, like marked in this picture -- or just do the No. 4 or just the big ports or ?? Thanks.

KuHL 951

It probably wouldn't hurt if it doesn't disrupt flow. I think those black lines are a heat activated sealant and I'm not sure if that would matter or not on the new holes. I know when I tried to reuse a virtually new BMW HG that leaked from a warped head I bought it would not seal again after the first heat cycle. I put on a new HG that looked identical and it sealed...go figure.

Chris White

What do you want to accomplish with the extra holes?
I am not saying it’s a bad idea – I am just interested in what you are trying to do.

Here are some pictures of my current favorite paperweights….something to think about!

BTW - this is cylinder #4....

Thom

Thanks much for that Chris.
These pictures will spare me from cutting a head apart.

I suppose more holes in the HG would mean less coolant flow between the front and the back of the head?

DLS

hm maybe i should put the drill in the head and do the corleone style vent

gt37vgt

Great thanks chris .. send me the 16v ones please
i would/ will drill small holes 1or2mm in all the spots that would relieve an air pocket under the gasket so where the bores join on the exhaust side the highest pot on each water jacket along the inlet side ..
I've also drilled the little square spot shown on the left of Chris's second pic and and drilled inside it so through to the water jacket .
if the holes are small they will bleed the air but hardly effect the flow ..
i wouldn't drill any bigger untill i had plenty of data and plenty of time