I did not change the port timing, wasn't a hundred percent sure how to do it properly. Decking the base and Port timing might be something I look into after this cutting season while I tear it down and give her a new top end.Did you change the port timing? If so, what numbers did you use?
OK, how about port widths at the cylinder bore?I did not change the port timing, wasn't a hundred percent sure how to do it properly. Decking the base and Port timing might be something I look into after this cutting season while I tear it down and give her a new top end.
I traced the port on the piston transfered that over to the cyl wall and held back 3 mills from the flat sides of the piston. The exhaust port ended at around 1 5/16 inches. So cut around 3/8 inch wider, didn't widen the transfers but maybe an 1/8 inch, center intake ports got around 1/8 inch each.OK, how about port widths at the cylinder bore?
From what I can tell you have the exhaust port at 72% of the bore, which is pretty wide. The concern is that the ring will want to expand out into the port as it goes by, and the wider it is the further it can go. Hopefully this won't cause any problems. Good luck with it!I traced the port on the piston transfered that over to the cyl wall and held back 3 mills from the flat sides of the piston. The exhaust port ended at around 1 5/16 inches. So cut around 3/8 inch wider, didn't widen the transfers but maybe an 1/8 inch, center intake ports got around 1/8 inch each.
Now I'm not a Machinist or a builder, just a hobbiest that cleaned up the porting on my dirt bikes as a kid. So far saw runs great I'm going to throw it to some big rounds after work today so I'll video it and post it up for fun.
Have you ported this motor? If so how wide have you gone? I ran the saw for 20 min or so to let the autotune adjust, so far ok. Im going to cut some rounds in an hour so I'll better know soonFrom what I can tell you have the exhaust port at 72% of the bore, which is pretty wide. The concern is that the ring will want to expand out into the port as it goes by, and the wider it is the further it can go. Hopefully this won't cause any problems. Good luck with it!
No I have not. The port width opening percentage is a generally applicable rule. I don't go beyond 60% of the bore diameter, but I believe others have.Have you ported this motor? If so how wide have you gone? I ran the saw for 20 min or so to let the autotune adjust, so far ok. Im going to cut some rounds in an hour so I'll better know soon
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