RE: 46 engine comparison
I had 5 SF's, including a ringed version -- nice motor -- but no match for the newer 46's in power.
The FX, AX & TT Pro blow it away power-wise, & the AX & TT Pro are a fair bit more user friendly.
While I didn't have any liner failures, the SF was the start of the OS swan-song with liner problems -- except the ringed SF, which was just plain good.
It is still manufactured today -- many of the Chinese clones are SF's -- even to parts interchangeability. The LEO 46 Pro for example is an SF in disguise & the MECOA 46 Tomcat is so close that the differences are almost unnoticeable. If you want to compare SF performance with a modern 46, just put a MECOA up against a TT or AX & watch the difference.