Pratt & Whitney R-1830 Twin Wasp.

Sorry, didn’t see your post about my Kestrel rods; I’ll have to think about it.

Thank you for the P&W ID.
Kestrel rod experiments are part of this thread on Gilman bearings :
http://forum.keypublishing.com/showthread.php?128767-RR-Kestrel-Gilman-bearings&highlight=

Latest is to stay entirely away from berryllium copper, highly, highly toxic !
But enough information has now been gathered to try and rediscover the lost process of centrifugally cast copper lead bearings…