064 660 hybrid with first fingerbanging attempt.

[NorcalFlyingsquirrel]

Opened up my trusty woods ported 064/66 and Wow! amazing it ran great for years but it was my first and i didnt check the squish very well, i guess.

 

[NorcalFlyingsquirrel]

 

[NorcalFlyingsquirrel]

Cut alot out of squish and base .06 or something, little freeport but my 44 hyb does amd it rips. ended up at 105 135 to 144 trans and 89 ex. Plan on ex to 103, trans to 118 / 126 and fingers at 115. jb intake to 83 and may jb inner lobe / upper edge of transfer to keep velocity up in the gaping hole.

 

[NorcalFlyingsquirrel]

Man the fingers are hard work! Has anyone jb'd the upper inside edge of the transfer to keep velocity up when removing so much from the opening edge?

 

[drf256]

Ive filler the entire transfer tract on an 066 China clone for the Buildoff we did 6 or so years ago. I re-carved the entire transfer lower/tunnel/upper through the JB to my liking and the saw is still used and alive. YMMV.

You added a lot of case volume to your saw. Your grinding looks nice, but I don’t think I’d run a second ring. There’s not much plating left to support it.

I assume you are flipping piston 180*?

 

[NorcalFlyingsquirrel]

Ive filler the entire transfer tract on an 066 China clone for the Buildoff we did 6 or so years ago. I re-carved the entire transfer lower/tunnel/upper through the JB to my liking and the saw is still used and alive. YMMV.

You added a lot of case volume to your saw. Your grinding looks nice, but I don’t think I’d run a second ring. There’s not much plating left to support it.

I assume you are flipping piston 180*?

Yessir, Flipping with one ring. thank you for your other posts on the double cut ball burr. Its easy to get carried away and Im amazed I have not gone through the cylinder , yet... still got one more to do. Do you think lower than 83 would benefit case pressure and would the saw be happier at 100 ex ? Im not cutting firewood all day, just topping and falling. so the saw can be a little closer to the ragged edge.

 

[Canadian farm boy]

You’ve lowered that cylinder a mile. How’s the ROD(ring of death) to piston ring looking?
You’re upper transfers will be huge raising them that much but that isn’t always an issue as long as you don’t going through the transfer roof trying to get the angles.
With the piston a BDC how much of the upper transfers are actually open?
I’ve had a few saws that I figured were going to have lazy transfers because the uppers were so big but the piston still covered almost 1/2 of the uppers at BDC and the saws ran quite well.

 

[NorcalFlyingsquirrel]

You’ve lowered that cylinder a mile. How’s the ROD(ring of death) to piston ring looking?
You’re upper transfers will be huge raising them that much but that isn’t always an issue as long as you don’t going through the transfer roof trying to get the angles.
With the piston a BDC how much of the upper transfers are actually open?
I’ve had a few saws that I figured were going to have lazy transfers because the uppers were so big but the piston still covered almost 1/2 of the uppers at BDC and the saws ran quite well.

cool, ROD looks fine, depth is only 3/4 of space above ring. I hadnt thought about the lip of the piston defining the lower edge, makes sense. I lowered the transfer about .1 and smoothed it from top and side without digging into tunnel. still going to glop some jb on the inside of the curve to to see if I cant tighten up the geometry for smooth, focusing inside curve and negate some case volume loss. Do the fingers look big enough or should I widen them?

 

[drf256]

Idk about your numbers and overall setup with that cylinder.

The 1122 are limited by the narrow piston skirt, so they tend to need more ex duration. I got my ass fully kicked by one done at a 94 roof, and that was with a 36” 404 full comp RS chain through a 36” knotty red oak stump, not a 16” poplar cant.

They don’t like a ton of compression either. 200 is about it. Your chamber must be tiny with that much out of the band. I’d open it.

A lot of us used to open fingers before the mains. It makes more sense to open them after to clear the piston crown and lift the charge. Unless you’re going for high end gains in a race saw, they are generally not worth the effort.

When you add fingers, you need slightly less blowdown because you increased transfer area. Kinda like a quad vs dual port. 1122 like an intake around 82. They do poorly with less.

The entire 066/660 is a bit of an enigma. They are just different than other saws. Stihl made the massive uppers and big intake for some reason, I’m still not 100% sure why. The 52mm 064 jug is way more traditional and can usually make more power than all but the rarest and best done 54mm 660 jugs.

These are just general observations. Your situation may indeed be different. We have all seen saws that have been done against normal doctrine that have raised many an eyebrow. Please post back results and videos if you can.

 

[NorcalFlyingsquirrel]

Idk about your numbers and overall setup with that cylinder.

The 1122 are limited by the narrow piston skirt, so they tend to need more ex duration. I got my ass fully kicked by one done at a 94 roof, and that was with a 36” 404 full comp RS chain through a 36” knotty red oak stump, not a 16” poplar cant.

They don’t like a ton of compression either. 200 is about it. Your chamber must be tiny with that much out of the band. I’d open it.

A lot of us used to open fingers before the mains. It makes more sense to open them after to clear the piston crown and lift the charge. Unless you’re going for high end gains in a race saw, they are generally not worth the effort.

When you add fingers, you need slightly less blowdown because you increased transfer area. Kinda like a quad vs dual port. 1122 like an intake around 82. They do poorly with less.

The entire 066/660 is a bit of an enigma. They are just different than other saws. Stihl made the massive uppers and big intake for some reason, I’m still not 100% sure why. The 52mm 064 jug is way more traditional and can usually make more power than all but the rarest and best done 54mm 660 jugs.

These are just general observations. Your situation may indeed be different. We have all seen saws that have been done against normal doctrine that have raised many an eyebrow. Please post back results and videos if you can.

I will do, I left ot at .030 squish with a gasket cause im too lazy to sand the squish down any more and I figure it will still quench and maybe keep it reasonable. I love my 210 psi hybrid 44, was hoping to replicate that kinda raw nastiness. Its so strange the different models are so different and how they all work so well, over square 661, echo strokers, there really arent any hard and fast general rules, just hard won model specific generalities.

 

[drf256]

The smaller the bore, the more compression they can tolerate. Too much compression is gonna add too much heat. You’ll notice you won’t hold tune after long cuts unless you fatten it up, then it blubbers for all the rest.

The Autotune saws can do this for you, so I am personally a bit more tolerant of higher compression in them.