Quote:
Good point about piston wall clearance and varying metal expansion ratios.
For factory engines in daily driver vehicles instead of race engines,
what about wear with mileage ?
Let's just assume that a new & well assembled engine
with attention paid to each cylinder individually
will hit at 0.025 at 5500 rpm.
What would be people's guesses
as to how much increased head to crown clearance is necessary
to avoid hitting at 5500 rpm
when the engine ages to, say
50,000 miles ?
100,000 miles?
200,000 miles ?
Related question:
does a head gasket compress a wee bit more with additional years and tighten effective quench ... or does it relax instead and increase quench clearance for the worse?
THis is a corollary to my previous post.
Modern factory engines have a number of, well for lack of a better word, tricks in them to resolve these questions.
thinner, moly faced rings, specific cylinder wall finishes, specific piston to wall clearnces, specific ring land specifications, etc. All to run nice tight quench, control excess oil into the combustion chamber, and so on.
Which is why our old school engines are somewhagt expensive to setup right. Heck, today's production line maching is on par with the expensive race shop machine work of not so long ago. Bubba at the local machine and horseshoe shop cannot match it.
They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.
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