how to analyze a marine engine engine crankshaft deflection?

Answer 1

mark t correct. But, I did a search for; "measuring crankshaft deflection" and found this;
http://www.tribotechindia.com/pro-prisma-di4.htm
There other results to search too.

Answer 2

The only way I know how to do that is to use "Plasti-Gauge" strips. They are little plastic strips that you put under the main bearings and torque them down. Then you remove the bearing and measure the squish of the plasti-gauge. You compare that with a chart to get the actual bearing tolerance and see if you need new bearings. I don't know of any other way to check and analyze deflection.