Chainsaw Repair

357 XP has stuffers.
Shep

I don't think a muffler motor is gonna have the ability to fill the crankcase and take advantage of the extra volume like a motor with tuned pipe, so smaller may pump more efficiently granted the ports are designed to keep the added flow from going out the exhaust . Lots of conflicting info about case volume and pumping efficiency online, hard to make sense of what's optimum

Blast from the past.

Funny thing is I noticed a Partner I got in has that T port deal that Adam had talked about on the P100 a page or so back.  On the P55 they said it was for this reason.   Features built in decompression system located at exhaust port. Named "T Port" system.

This case volume reduction thing could get rather complex .Full circle cranks,more stuffer would raise the crankcase pressure which would increase the velocity  of transfer .Theoretically with decreased volume by lowering the cylinder to raise compression it might not require as much actual crankcase volume .As to  how much remains a good question .With a tuned pipe it's going to back charge part of it back in .With a pressure can it's going to stop the transfer when the pressure rise equals the exhaust out pressure .With a megaphone or open exhaust it would all leak out ---makes my head hurt thinking about it -----