JamesShort wrote:
Vincent Keene wrote:
I'd be interested to know how this (warpage measurement) turns out Rodney. I've never heard that a head gasket was a wear item.
So the reason boxer engines are harder on head gaskets is because, unlike v or i engines, where the coolant can flow downward leaving it such that it is not in direct contact with the HG anymore, on boxer engines, the coolant will just 'flatten' in the coolant passage and sit there all night long. Then chemical reactions blah blah blah go on and break down the HG. Subaru has a coolant conditioner that they require for coolant changes to help reduce these chemical reactions.
In that link above, it shows some cool pictures demonstrating this. On the 'bad' HGs, only the lower portion of the holes in the HG for coolant passages show corrosion (ie where the coolant is in contact with when the engine is off and it's just sitting there).
Not arguing, but aren't I and V engines full of coolant to the top all the time too? Bled = no air = full of coolant to the top of the passages in the head = wet gasket all the time.
Maybe the boxer is more susceptible to corrosion because of ingress of stuff from the combustion chamber itself? In I and V engines the combustion gases, condensation, oil vapor, etc can wash down the walls, in a boxer it can pool or collect.
Or maybe Subaru just doesn't know how to build engines

My old MGB head gasket would spray coolant out the side for no other reason than it was British. I'd call non-warpage HG failures engineering design related, especially if more modern boxers don't have the problem.
I dunno....
_________________
Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1