Thread: He did the math
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Old 07-10-2013, 02:38 PM   #29 (permalink)
wdb
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Quote:
Originally Posted by RedDevil View Post
AFAIK any 4+ cylinder engine has at least one open valve at any time during normal operation, so that if the timing belt/chain/whatever alignment fails it is inevitable that valves get hit, unless there is some mechanism to physically close them (lift the camshaft?) right when the belt tension drops.
There are engines in which the valves and the pistons never touch, even if the valves are wide open when the pistons reach top dead center. If a valvetrain failure were to occur on one of these engines, no valves would be bent nor pistons damaged.

Then there are engines where the valves and pistons occupy the same space at (hopefully) different times. In these engines, valvetrain failure can result in bent and dented stuff.

Interference engine - Wikipedia, the free encyclopedia

You're quite right about interference engines being much more common than just Honda. Lots of manufacturers build them.
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