circle crank ms660

[Stihl working Hard]

Awesome thread guys riveting stuff

 

[Brewz]

I have a question to help me understand all this better.

What is the big advantage in reduced case capacity?

 

[Keith Gandy]

I have a question to help me understand all this better.

What is the big advantage in reduced case capacity?

Rpm in the cut from what im seeing in the 2 044 hybrids ive built. I still like a regular 460 for the extra torque for work

 

[mdavlee]

Rpm in the cut from what im seeing in the 2 044 hybrids ive built. I still like a regular 460 for the extra torque for work

Some older saws had full circle cranks and pulled long bars fine. I think this will help keep torque with a higher exhaust.

 

[Keith Gandy]

Im interested to see this fullcircle against one of Jasons ported 066s

 

[mdavlee]

Im interested to see this fullcircle against one of Jasons ported 066s

Might be later today. Storms coming through right now.

 

[jmssaws]

I've got a crank case here with a stock crank that I'm going to put the cylinder on and just see exactly what the crank is doing.

 

[jmssaws]

Im interested to see this fullcircle against one of Jasons ported 066s

It's as fast now.
What's the wrap break part number? I need to order a handle anyway.

 

[mdavlee]

It's as fast now.
What's the wrap break part number? I need to order a handle anyway.

If you're not positive call Madsens. They'll be able to tell you which you need for that handle bar.

 

[jmssaws]

If you're not positive call Madsens. They'll be able to tell you which you need for that handle bar.

I didn't check if it worked but I had to rob the handle off my 066 so I gotta get one and it may as well get the right one.

 

[drf256]

There's only one way to get the same amount of air flow through an engine that's taking smaller gulps each cycle. Increase the amount of gulps it takes.

 

[Keith Gandy]

It's as fast now.
What's the wrap break part number? I need to order a handle anyway.

It will be about 4 this evening before I get to the shop and ill let u know for sure which one it is Jason

 

[Keith Gandy]

There's only one way to get the same amount of air flow through an engine that's taking smaller gulps each cycle. Increase the amount of gulps it takes.

It is about the push and pull!! Lol!! Mdavlee may be right that all he needs is that exhaust up alil to make her speed up and really take more gulps!!

 

[Keith Gandy]

Might be later today. Storms coming through right now.

Its storming here right now and headin Jasons way

 

[mdavlee]

Its storming here right now and headin Jasons way

Just had one come through about a half hour ago. Probably raining up there now

 

[jmssaws]

It's raining hard.

 

[jmssaws]

I have a question to help me understand all this better.

What is the big advantage in reduced case capacity?

Increasing velocity

 

[MustangMike]

One thing I'm really confounded about with chainsaw motors. With all the RPMs they run, why is balancing the engine not more critical?

Why doesn't a 440 crank with an 460 piston blow up?

And if you shave the counter weights, won't it exaggerate the problem even more?

I know if car engines, we would always want to have it re balanced if we changed rods or pistons, and we generally kept them under 7,000 RPM. I did not even like externally balanced engines (like the 428 and Boss 302) because they seemed less durable than the internally balanced ones. (External balancing is done with a weight on the flywheel, internally balanced is done on the crank counterweights).

 

[jmssaws]

Balance hasn't changed, if anything it's smoother.

 

[Keith Gandy]

Balance hasn't changed, if anything it's smoother.

Is it hard to build that fullcircle and keep it balanced? It thought the stuffers on my 550 was pretty neat when I ported it. 1st time Ive seen them