Purchased almost new engines at a swap meet. The St is an older Itailan made version,my question is this: Should I change the liner to the C/L version when I swap the carbs? I'm currently a sport flier,not competing. I assume the timing is different, but as a sport flier will I notice a big difference. My experience level is still low, consider myself fortunate to bring the plane home in one piece. By the way, this engine is destined for Pat King's FS45( if you haven't seen the plans you should check them out).
My other question is in regards to the TT Gp25. I want to change it to a venturi and needle. Should I contact SSW(they are local) or try and order parts thru www.thundertiger4u.com . Has anyone dealt with them in the past? This engine will power one of thevintage combat planes I'm building to test the reflexes of some retired fast combat competitors, I know I'll have to shorten the lines to 52' to get the speeds up, just hoping to give them a taste of the past.

thanks

Steve

Ray
Thanks for the info,hopefully the Super Satan, or Voodoo will put some smiles on their faces, might even put that old steely glare back in their eyes. Do you think the GP 25 would be overpropped with a 9x6? I guess I could cut them down if need be.

Thanks again

Steve

Thanks for the info,hopefully the Super Satan, or Voodoo will put some smiles on their faces, might even put that old steely glare back in their eyes. Do you think the GP 25 would be overpropped with a 9x6? I guess I could cut them down if need be.

This all presupposes that the GP25s are very closely cloned from the FP 25s, which enjoy revving more than the G21-35s and 36X-BBs used to.  Modern Fast Combat 36s are running with 8-6 props, and the 25 FPs could  be slowed to under 75 mph with 8-4s and fullsize AMA fast foamies, so I'm still suggesting 8-5s, bladders, and fairly unrestricted intakes for the GP25s and more speed than that.