A MS440 ported from the factory???
- Thread starter blsnelling
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I did 2 with the same numbers and one with windows and one without. Both had popups and were in the 190-200 lbs of compression. The one without windows was a decent bit stronger. Both were at Terrys 372 build off gtg.
ive went from flush with bottom of cylinder to as much as 2mm above i have not scalloped any of them in a work saw. i have had good results with the windowed piston. i usually use a 268xp piston that is already windowed and cut about a .035 pop up in it and dont have to cut the cylinder base.
Terry did one that had windows and it was stronger than both I did. I don't know what timing he uses so I can't say what's the real difference. I'm not sure what the other guys that had saws ahead of mine did in theirs. I know treemonkey said his didn't have a popup and the squish band machined and base machined.
I did come up with one coil on the 372 that I had to drill the holes out bigger so I could mount it that gained 1.5 seconds over the blue coil on it.
066 stihl
ArboristSite Operative
All coils are not the same in making hp.
On the bottom of the transfers cut the wall out alot. Raise the inside wall up up and up. Make sure you leave some room below the bottom of the rings.
066 stihl
On the bottom of the transfers cut the wall out alot. Raise the inside wall up up and up. Make sure you leave some room below the bottom of the rings.
066 stihl
WadePatton
ArboristSite Guru
dang, all my secrets are getting out...:msp_wink:
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Teddy.Scout
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WadePatton
ArboristSite Guru
I started on it the other night but headcold put me out of the mood. I got the piston cleaned up and rings on and quit. You're dead-on on the squish (you called the numbers), pulled the gasket and it's still fat. Need to knock about 20 off the jug-tell me who you might use in the area. And forgot to order a cutter for getting all that aluminum out of the way of proper fueling.
Got three loads out in two days, Off today, firewood tomorrow. Got some white oak ash maple and cherry last 3 loads too--even had elm and hackberry tie logs in last load. (like them fatter checks and better tops). Let Ward try my 7900 with 8-pin and fresh square ground. He like, but says it's loud...but they don't plug their ears. I like the deeper sound of the 7900 (to his 460). His ears will really buzz if i can get him to run the 2100. I plan to run the one i got from you as a free-hand slabber/big tree cutter w 30". Will run the one I got outta BC on the mill-it's a bunch rougher than the one i got from you-no dogs, etc.
Oh yeah, back to secrets...
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if you were not so far away i could cut the cylinder for you. myself i hit the woods tues,wed,thurs,couple hrs fri morn. i got out two loads of white oak staves,2 loads of grade logs,4 loads of ties logs and 63 ton of hardwood pulp. not a really good week but atleast im making some money.
I've been busy tiling my master bath. I just spent 8 hours in there
I raise the cylinder wall flush with the cylinder base. I also started using windowed pistons. What's your though on that? My 372BB really seemed to wake up with those two mods.
Some of the BB kits have really improved, especially the 066BB. It's on about it's 4th revision, so has had a lot more opportunities for improvements. No more free porting at the bottom of the piston. The combustion chamber and squish band is greatly improved. My biggest complaint with some of them is the converse exhaust ports. Couple that with already high exhaust port timing, and it can be a problem.
BTW, Ricky, thanks for dropping in and sharing some of your knowledge and experience
Metals406
Granfodder Runningsaw
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