Thanks! spent lots of time on the head, hope I can do as good on the cylinder and find a good porting idea for my very hi compression ratioI think it looks fantastic and done well! l hope other can advise you on a good porting recipe but my you have alresdy demonstated some true talent making a two piece head. I don't think this looks like a 'practice' cylinder so maybe a second cylinder may be a good idea to test various porting ideas so you get a top result on the two piece. Very inspiring!!
normally you file the keyway on the flywheel to advance the timing and leave the coil stationary. only takes .020 or so off the keyway to give as much advance as you'll need but advancing/retarding timing is a very big trial and error mod. some engines like more timing and some like less. that changes with the specific saw your dealing with as well as the mods you have done.Does anyone know if changing the timing buy slotting the coil to give the fire some advance could help at high rpm?
Thanks, I'll try filing the keyway, sounds better than filling the coilnormally you file the keyway on the flywheel to advance the timing and leave the coil stationary. only takes .020 or so off the keyway to give as much advance as you'll need but advancing/retarding timing is a very big trial and error mod. some engines like more timing and some like less. that changes with the specific saw your dealing with as well as the mods you have done.
How did you do the calculations for the pipe?
You can play with it, but the 372 is one saw that I do not advance the ignition on.
Port timing is going to be quite different if this is to be a dedicated pipe saw. You need a higher exhaust port with a lot more blow down. My piped 390XP is all the way up at 83° on the exhaust, 115° on the transfers, and 85° on the intake. That gives you 32° of blowdown. These numbers are WAY different than I would run for a muffler saw.
You can play with it, but the 372 is one saw that I do not advance the ignition on.
Port timing is going to be quite different if this is to be a dedicated pipe saw. You need a higher exhaust port with a lot more blow down. My piped 390XP is all the way up at 83° on the exhaust, 115° on the transfers, and 85° on the intake. That gives you 32° of blowdown. These numbers are WAY different than I would run for a muffler saw.