Briggs crankshaft frozen to sump

[shipmaster]

I have an 18.5 hp B & S engine that I just tuned up for the season. It ran for about 5 minutes then seized up. I didn't hit anything, it just locked up. Upon disassembling the engine I found that the crankshaft will not come out of the engine sump no matter what I try. I've soaked it in WD40 for days and even tried heating it. No luck. Any ideas on how to separate the two??
Thanks in advance!!!

[bgsengine]

Model , type and code? there's several 18.5 B&S engines - the advice given may depend on whether it is an OHV or a Twin Opposed, or some other design.

But, sounds like crank seized in the sump, which typically would mean both are trashed - unless you have the machine shop and special tools, best recommendation would be shortblock or replace the engine... which leads to the question regarding model, type and code - in some cases, replacing (RePowering) may be a much better option - sometimes shortblock can cost as much as a new engine, and might even be able to recommend a drop-in replacement.