Engine Number Mystery

[verwachst]

Hello.  My 1952 Kaiser Manhattan Supersonic engine doesn

[joefrazer]

It's a replacement block. The numbers stamped on the boss are more than likely from a rebuilder. My guess is that the original block was too damaged to reuse so the rebuilder found a replacement block. This had to have been done many years ago as replacement blocks haven't been available for some time.

[verwachst]

The engine used to be painted in light blue.  I wondered if the color was an indicator whether Sears Roebuck under the "Allstate" name sold that replacement engine or maybe Montgomery Ward.  I'd be surprised if this was a Kaiser replacement engine.  Weren't those painted red?  And what does P.S. mean? 

[joefrazer]

Sears used dark blue for their rebuilt engines. I would agree, probably not a KF factory rebuilt - more than likely another rebuilder obtained a bare replacement block and built an engine from there. I've had a couple over the years.