That is a new one for me.  Does it use some form of valve, like a COX reed to control the timing?

Ken

That is a new one for me.  Does it use some form of valve, like a COX reed to control the timing?

   I am sure it is a rotary value (probably a disk valve) - you can see the axle for it in the center of the backplate. Works like a front rotary valve, the crankpin drives a disk with a hole in it, it aligns with the port at the right times when there is low pressure in the case, etc. This allows much better control over the intake timing than a reed valve, which just opens any time there is a pressure differential.

  The engine is strange, I can't recall ever seeing one or knowing that it existed (i.e. that ST made an engine like that - of course there have been many rear-intake disk and drum valve engines over the years all the way back to the Dooling and McCoy).

   Brett

Brett,  I think you are correct.  I can see the disc when I look in the intake port there.  Been a while since I dug this uot so forgot about it.    I did find a couple of ST reviews uploaded  that talka bout the G60 R and RV engine's.  Looks like the frist ones were reviewed in 1965 or 66 maybe.  Looking at this G60R review, and seeing the same prop spinner base, I suspect mine may be the G65 R.  I'll have to clean it and and all and see what condition it is really in.  You can see the disc in the picture on page two. I did add  a post in the Carrier section., will see what we turn up!