Providing
parts are still available, probably the easiest and least expensive solution is rebuilding or partially rebuilding the 5411. The good thing is that the liners are bore-able to .020 oversize or can be replaced.
A
service manual is found here:
http://www.westerbeke.com/onlinemanu...hnical_man.pdf
To get the
engine unsiezed, take off the
head (loosen the bolts incrementally in the reverse order shown on page 12 of the above manual.)
Take off the
oil pan.
Take off the connecting rod cap bolts and caps. Do not mix them up. keep them with their respective rod. Take a long, preferably hardwood dowel, and insert it as best you can into the underside of the piston and drive the piston out through the top of the block with a medium heavy
steel hammer. Do the same with the other piston.
You'll probably find that this frees up the
engine, the bottom end of these engines is exceptionally robust. If there was no
water in the crankcase and the crank spins freely, it's probably ok. The condition of the rod bearings can tell you a lot.
I did a poor mans'
rebuild (rod brgs. rings, honed the cylinders, unstuck and cleaned the injection
pump, replaced governor bearings) on a severely flooded M20 about 12 years ago, at the time I
lost track of it about 4 years ago it was still running strong.
Your intended use of the
boat could reflect the amount of expense you invest in the engine.....