I going to bring the squish down to around .016 and may do a small pop up, opening the exhaust to 65% of the bore and square up the intake. I'm also going to try and bore out the carb to 15mm. Hope that will make it a good runner.Wouldn’t be terrible. Normally you want to tighten the squish and reshape the intake. They take a little timing advance ok. The muffler is easy to open up. Widening the ex a little will help Careful you don’t get too wide and flat
I had a closed port 55 with a 20" bar on it, it didn't do to bad for what it was.I put a 55 top end on a 51 and suddenly I had a chainsaw that would run with my 257 and pull a 20" bar and chain.
I’d stay closer to .018 a popup works well but be careful you get in a pinch taking much off the base and the impulse passage will open up. If you have the stock piston I think skirts are only 60% just be careful there.I going to bring the squish down to around .016 and may do a small pop up, opening the exhaust to 65% of the bore and square up the intake. I'm also going to try and bore out the carb to 15mm. Hope that will make it a good runner.
I read in the porting threads that the dual ports need less blow down but I wasn't sure on how much less they need. Filling that area with JB Weld is a great idea, I'll pick up some and get that area filled in. Thanks for the suggestions!I know little about this conversion, but being you already have the JB weld out, I’d fill this area in and smooth it
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I am assuming you had to match a side fed jug to a case fed lower case. I’d want it smooth personally. In addition, I think you added case volume, so I’d bring the transfer roofs up to 120 myself. You’ll still have 45* of cranking compression. It’s a dual port, so it needs more time to flow, plus the uppers look a bit big and lazy (no offense I hope-just what I see).