metal hg question

[arnold]

When doing the aaz metal hg upgrade on a 1.6 the gasket has a 3mm larger bore,so it creates a gap between the block deck and the cilinder head,creating uneven combustion proces.
Obviously a lot of people seem to run this upgrade without problems but i cant help questioning reliability on a daily driver ?

[the caveman]

It's the only type that VW dealers have been using for the past ten years or so on every diesel  car. I never saw a problem.

[Vincent Waldon]

it creates a gap between the block deck and the cilinder head,creating uneven combustion process

Hmmm.... interesting thought I don't think anyone's considered before!

Just my personal opinion:

If you think about it in terms of the big picture, it's 3mm times perhaps .01 mm. when it's compressed, vs. the 20+ cc volume (IIRC!) of the actual combustion chamber.

Another factor to consider would be that in IDI engines combustion takes place in the pre-chamber, which from a burn perspective is a consistent volume regardless of headgasket details.

It's also worth noting that there's already a tiny circular gap on a standard 1.6l headgasket as well, to accommodate for over-sized pistons.


I guess all in all my personal opinion would be... drive more, worry less!!