steam holes?

[exup]

Re the small holes in the head as per 325 heads , and not found on 731 heads , does any one know how efficent , these are , are ( as most of the 325 i ve seen in these were mostly blocked up any way )

I'm thinking of drilling them for out a bit bigger than std to , on my next 731 head , with the aim of improving temp gradient , / reducing hot spots across head, as a sort of insurance for future up grades etc
but having said that , the last ETA 's lumps i ve done , i just used std undrilled head and they have ben great so far.

any thoughts fella's

[WillG]

no havent heard of this being done on m20 heads myself

[Andyboy]

There are no corresponding steam holes on 2 litre blocks either so it's only worth doing if you're using an 84mm bore block (325i/525e).

[exup]

Yep

i m building 2.7 lumps using ETA short blocks, as the head gaskets the same as a 325 and has the holes in it , and its only setting up the angle bed on the drill , thought i would try it out, hopfully to advoid local hot spots / blown gaskets in future ?
the first is for Nos the second one will b for turbo , so thought any help cooling would be good thing

[Andyboy]

A BIG radiator, i.e 535i or similar.