Piston skirt expanders

[Conn47D24]

Please tell me, what are these?

[Sharps40]

Old school fix for any combination of worn pistons, worn cylinders.  Basically, in the days of needin valve jobs, rebores, new pistons and ring jobs every 25000 to 50000 miles, it was an inexpensiver overhaul......freshin up the bore, expand the piston, new rings, roll another 10000 miles at lower overhaul cost.

 

Look at any copy of MotorAge  from the 30s and 40s and you'll see scads of ads showing piston skirt expanders, ring expanders and telling the shop managers how to sell more "oil jobs" at lower cost to customer (less machining), higher profit for the shop and fewer returns.

 

So.....a half assed engine rebuild.  But it was common in those days....many shops did the overhauls.  Remove the hood, install a sunnon hone to the block, stand on the fenders and hone the bore.  Expanders could potentially eliminate much of that work standing over the stripped engine with the hood off.....if the bores were not too badly scored or tapered, or oversize.

Edited January 26, 2016 by Sharps40

[Conn47D24]

Thank you for reply and detail. Weird item for sure!

[BigDaddyO]

I was thinkin' you meant petticoats.

Edited January 26, 2016 by BigDaddyO