After reading MINTI's thread on his busted crank I thought it might be interesting to do a comparison on various busted cranks.
I am aware that the big journal cranks have a habit of breaking but what I am interested in is a bit of info on the following items and then I can start to put this info with some torsional vibration calcs and see what stress loads have been applied.

ITEMS
1 engine type I.E. 1275 etc
2 journal diameter and crank type IE std/nitrited/ en40b etc.
3 stroke of crank IE std or stroker and bore diameter and comp ratio
4 was the crank/attachments balanced
5 what was being done to the eng at time of breakage.IE changing gears.
6 condition and type of balancer fitted
7 revs used and rpm at breakage
8 is the engine N/A or forced induction. if forced what boost.

Now this item is very important to the calcs. It is the peak pressure of the cylinders, that is the maximum firing pressure, which I can calculate if you have a compression test pressure of the engine and the degree of the inlet valve closing.

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