One ring vs two

[jmssaws]

From where

Everywhere you can. Aren't the pin bosses huge? Thin stuff down.

 

[Deets066]

Everywhere you can. Aren't the pin bosses huge? Thin stuff down.

Any time you grind below the rings you are decreasing velocity. Would lightening the piston be worth it? I could see it bringing up a few rpm but not gaining any torque. But I could be wrong

 

[Mastermind]

This is one of those "it depends on who you ask" sorta things......but if I lighten a piston, it's not so much for performance. I would do that to remove some reciprocating weight, and take some of the load off the rod bearings.

 

[paragonbuilder]

Yea I can. Basicly you have a bunch of ignorant, envious guys that would rather wallow in ignorance than learn something. Hard to respect that.

Ben, if you come back.
You often have great info to share. I've learned much from your posts on AS and here. But why even respond to the "ignorant and envious guys"? It's like any little thing and your panties are bunched. Let it go so we all can benefit! They aren't worth the stress for you or your time.


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[Deets066]

Ben, if you come back.
You often have great info to share. I've learned much from your posts on AS and here. But why even respond to the "ignorant and envious guys"? It's like any little thing and your panties are bunched. Let it go so we all can benefit! They aren't worth the stress for you or your time.


Sent from my iPhone using Tapatalk

"They" weren't the problem

 

[jmssaws]

Any time you grind below the rings you are decreasing velocity. Would lightening the piston be worth it? I could see it bringing up a few rpm but not gaining any torque. But I could be wrong

Your not gonna loose anything. The point of a 288 piston is the make things bigger.

 

[paragonbuilder]

"They" weren't the problem

Well yeah I know. But to him they are. And he does have quality content to add at times when he's not ragging.


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[jmssaws]

I'll take all the stress of the bottom end I can. I want to stress it with compression not a heavy piston.

 

[Deets066]

I'll take all the stress of the bottom end I can. I want to stress it with compression not a heavy piston.

Makes sense

 

[jmssaws]

"They" weren't the problem

Some people have a hard time seeing the truth.

 

[David Young]

In the carnage thread I said. Every piston I toasted taught me a lesson.

I built a gas muffler saw. Ran great until the lightened piston came apart.

Lesson the little weight you save from carving the piston is not worth the carnage to follow.

To Save some weight use a stihl wrist pin.

 

[tree monkey]

Well on a tight case such as the 7900 Dolmar, with bottom fed transfers, I think a full circle crank would have a limited amount of effectiveness. For one, the case is already pretty tight, and then the crank at least partially obstructs the flow path to the lower transfers.

they narrow the power band and increase rpm, great for a race saw, not so much for a long bar work saw

I would think an 066 would be a prime candidate for one! I bet Treemonkey has done it.

nave not done a 660, but I can

 

[tree monkey]

if you have room to do it you can cut a bunch right off the top of the piston. .050 from the crown is way more then you can get anywhere else

 

[jmssaws]

Think I'm gonna build one. Got a old flat top put back just for a head saw,I'll try a circle crank too.

 

[tree monkey]

ben is book smart. very little to none of his knowledge has anything to do with saws.

 

[tree monkey]

don't do it like this. it will explode

 

[jmssaws]

Ain't figure out yet how I'll do it.

 

[tree monkey]

I don't have a pic of the right way.
the ring has to be 1 piece all the way around the crank.
I turn the crank down some in the lath

 

[Deets066]

if you have room to do it you can cut a bunch right off the top of the piston. .050 from the crown is way more then you can get anywhere else

But the crown on the 288 is already so much shorter than a 066 piston

 

[Deets066]

Skirts on the 288 need to be trimmed, and removing castings would probly be all that I took off