Stihl 660

[brshephard]

I haven’t seen 17 bd any better than 18, even running no muffler

Primary compression is what must be considered, can’t gain primary compression without gaining BD

How do you find primary compression?
Is it from intake closing to transfer opening?

 

[Moparmyway]

Yes

 

[brshephard]

So what if a guy went to 16 BD, then epoxied the intake to restore case compression.
You could ditch the bottom ring and grind up to replace time/area in the intake.

What do you think?

 

[Moparmyway]

So what if a guy went to 16 BD, then epoxied the intake to restore case compression.
You could ditch the bottom ring and grind up to replace time/area in the intake.

What do you think?

Is this a worksaw or a playsaw ?

For a worksaw, I would avoid it

For a playsaw, try it

 

[brshephard]

Is this a worksaw or a playsaw ?

For a worksaw, I would avoid it

For a playsaw, try it

I got a mahle jug with some broke fins for a play saw.
I think I'll try what you originally suggested. My goal is to outcut my 064 that has 101/123/75.
Then I might try the short blowdown.

What's your recipe for maximum torque?

 

[Moparmyway]

I got a mahle jug with some broke fins for a play saw.
I think I'll try what you originally suggested. My goal is to outcut my 064 that has 101/123/75.
Then I might try the short blowdown.

What's your recipe for maximum torque?

79 intake

20-21 blowdown with a very great flowing pair of muffler openings

Get compression above 185

MUST be tuned in wood for max rpm under load