MHG versus OEM Fibreboard, a thought....

[Rochester]

Spent a lot of time reading posts about Metal Head Gaskets and their use....

It occurred to me, are they really any better than the OEM fibre type HG ?

Bear with me... In order to fit an MHG succesfully you need to skim the head and deck the block down to almost mirror smooth 20 / 30 RA, then take great care in torquing down etc.

It struck me that if you took that much care with the head and block before fitting an ordinary gasket would it not be likely to perform just as well ?

Which is perhaps the answer why certain members - the sort who do take that care - have been able to run OEM HG's up to 450+ without trouble..... ?

[turbonutter]

its not just about the power. mhg's are multiuse and dont degrade like the fibre ones

[alanjuggler]

Spent a lot of time reading posts about Metal Head Gaskets and their use....

It occurred to me, are they really any better than the OEM fibre type HG ?

Bear with me... In order to fit an MHG succesfully you need to skim the head and deck the block down to almost mirror smooth 20 / 30 RA, then take great care in torquing down etc.

It struck me that if you took that much care with the head and block before fitting an ordinary gasket would it not be likely to perform just as well ?

Which is perhaps the answer why certain members - the sort who do take that care - have been able to run OEM HG's up to 450+ without trouble..... ?

I've come to pretty much the same conclusion - the fact that Noz managed to run 2x standard CA headgaskets sandwiched to drop the compression is a lasting testament that stuck in my mind, since that clearly shouldn't have worked

the problem is that not all machine shops are equal, some use older machines, different cutting bits etc - for aluminium, you're looking for an industrial diamond bit (PCD) to get that kind of surface finish you're talking about.

Given all this - I've chosen to go with a standard type HG on my RB - plans to allow up to 550bhp - det will kill HGs more than outright cylinder pressures.