A well-known fact when adding forced-induction to an engine originally designed for naturally-aspirated applications, is that it may be necessary to reduce the compression ratio to counter the increased risk of pre-ignition/detonation.
A cost-effective way to do this is to use a thicker head gasket. I came across an article which makes a rather interesting claim (emphasis my own):
A thicker gasket will reduce the compression ratio by a small fraction, probably only by .1 or .2. This is by far the easiest method of reducing compression but the risk is gasket failure and the gains in lower compression are minimal.
The physics behind this assertion is not clear to me. My questions are:
- with all other factors held constant, is it true that a thicker head gasket is likely to fail?
if so, what is it about a thicker head gasket that makes it more prone to failure?
Is it just that there is more surface area for the combustion gases to interact with the gasket, causing the head gasket to erode more quickly?
Or is it that a thicker head gasket will bulge more under compression, creating regions of higher stress concentration in the process?