Twisted Up 56 Mirrometer 660 Jug Build.

Moparmyway · Mar 20, 2018

tree monkey said:
yes
yes
yes

Thank you Sir !

MustangMike · Mar 20, 2018

That is news to me also! Guess we will see if there is more than one way to skin the cat!

huskihl · Mar 20, 2018

EBay gonna be out of jb weld by tomorrow with everybody filling 6° worth of finger ports

srcarr52 · Mar 21, 2018

Opening up the fingers that far before the mains is causing the transfers to stall. The mix coming in from the fingers will eventually get reversed by the mains. That's why you have carbon across the majority of the piston, the fresh charge is just sitting there.

How I've always thought of fingers is that they should accelerate the main transfer flow up the intake wall, therefor you want them to open right before the charge front of the mains hits the intake wall. Then the steeper entrance angle of the fingers or boost ports will initiate the loop scavenging faster than just normal transfers yielding more power at higher RPM.

drf256 · Mar 22, 2018

srcarr52 said:
Opening up the fingers that far before the mains is causing the transfers to stall. The mix coming in from the fingers will eventually get reversed by the mains. That's why you have carbon across the majority of the piston, the fresh charge is just sitting there.

How I've always thought of fingers is that they should accelerate the main transfer flow up the intake wall, therefor you want them to open right before the charge front of the mains hits the intake wall. Then the steeper entrance angle of the fingers or boost ports will initiate the loop scavenging faster than just normal transfers yielding more power at higher RPM.

I see it the same

Ex was 100, now 96.5

The fingers opened at 117

then the ex side main at 118 and then the int side at 119

So they do open just before the charge from the uppers. In addition, they have far less cross sectional area than the mains do. They may have more velocity, but much less volume.

I personally see the ex pressure being too high and stalling flow, the fingers having the pressure to temporarily overcome that, then the mains not having time to do their jobs. Thats why i raised the Exhaust roof.

paragonbuilder · Mar 22, 2018

drf256 said:
I see it the same

Ex was 100, now 96.5

The fingers opened at 117

then the ex side main at 118 and then the int side at 119

So they do open just before the charge from the uppers. In addition, they have far less cross sectional area than the mains do. They may have more velocity, but much less volume.

I personally see the ex pressure being too high and stalling flow, the fingers having the pressure to temporarily overcome that, then the mains not having time to do their jobs. Thats why i raised the Exhaust roof.

I think Shaun meant fingers open after the mains, timed to open just as the charge from the mains is getting to the intake wall. Then the fingers push that charge up and sweep the chamber. Obviously this would be at target rpm.

srcarr52 · Mar 22, 2018

paragonbuilder said:
I think Shaun meant fingers open after the mains, timed to open just as the charge from the mains is getting to the intake wall. Then the fingers push that charge up and sweep the chamber. Obviously this would be at target rpm.

Exactly.

drf256 · Apr 14, 2018

Exhaust raising made this saw come alive.

I guess it was too little Blowdown that hindered it.

Next one will be 100/122-125

The saw is pretty impressive now, but I made the cardinal mistake of many changes at once. It’s got a new Tilly 320 instead of a Chiwaneses carb, a maxflo, and the Ex at 96-97* with a slightly flatter roof arc.

Anyone at the NY GTG will be able to run it. Mike has dubbed it “KingKong”. I’m not sure it’s worthy of that title, but you form your own opinions.

Here’s @angelo c at the CT GTG giving it its first run in oak.

MustangMike · Apr 14, 2018

Looks to me like Angelo pushes that bar through Oak as if it were Pine!

Thank You Al, I'm really looking forward to running it myself at the NY GTG!

And Thank You Dan, in advance, for the transportation.

If doing several things at once results in a Beast, I'm good with that! It likely benefited from all the changes.

brshephard · Apr 14, 2018

So, on these saws, if you increase transfer area should you always expect to need extra blowdown?

Chainsaw Jim · Apr 14, 2018

Put a bar on that thing!

angelo c · Apr 14, 2018

MustangMike said:
Looks to me like Angelo pushes that bar through Oak as if it were Pine!

.

I think Dan had that stuff flown in special for the GTG.... I believe it was a "West Coast Pine/Oak" blend....

the chain was sure as heck sharp as heck... !!!!
be proud to run that saw any day all day.

angelo c · Apr 14, 2018

Chainsaw Jim said:
Put a bar on that thing!

Jim,
How many times do I have to tell ya ?

its not the size of the wand but the magic in the operator that matters...

RI Chevy · Apr 14, 2018

Chainsaw Jim said:
Put a bar on that thing!

Jim: I was running my 660 with that 20" bar and chain. Doc brought me the saw and said throw a bar on it. So my easiest fix and comparison was to just switch my 660 bar to that China conglomeration. lol
The chain was super sharp, albeit it only 20". lol
BUT IT WILL CUT! And Mike's saw ran super strong.

huskyboy · Apr 14, 2018

Was that a 7 or 8 pin?

RI Chevy · Apr 14, 2018

8 pin 3/8 round file

MustangMike · Apr 14, 2018

My saws run 7 pin. (Unless it was changed).

RI Chevy · Apr 14, 2018

Looked like Doc had an 8 pin on it.

Chainsaw Jim · Apr 14, 2018

RI Chevy said:
Jim: I was running my 660 with that 20" bar and chain. Doc brought me the saw and said throw a bar on it. So my easiest fix and comparison was to just switch my 660 bar to that China conglomeration. lol
The chain was super sharp, albeit it only 20". lol
BUT IT WILL CUT! And Mike's saw ran super strong.

I never assumed anyone reached past a long bar for a short one and I hope it didn't come across that way. It was general curiosity that motivated the comment.

RI Chevy · Apr 14, 2018

Lol. No worries.
Angelo and I made several cuts with Mike's saw. That 20" bar was buried to the teeth in every cut. Almost a whole tank of fuel through the saw. Lol
We put it through the ringer. Gave it a run for the money.

Twisted Up 56 Mirrometer 660 Jug Build.

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Muh fingers look really big

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