circle crank ms660

[Deets066]

With the velocity you have you may want all the flow the lowers will give you

 

[jmssaws]

With the velocity you have you may want all the flow the lowers will give you

Very possible. I like the way it runs now but it feels like the transfers and exhaust need to go up a smidge but I could be wrong. It runs like one that has to much blow down.

 

[awol]

I'm gonna put a few tanks through it tomorrow to limber things up then do some grinding.

How wide of a exhaust have you guys gotten away with?

75% with a good bevel and fairly flat roof in a play saw.

 

[jmssaws]

75% with a good bevel and fairly flat roof in a play saw.

That's the answer i was looking for.

 

[Deets066]

I widen mine as much as the skirt will allow

 

[jmssaws]

I widen mine as much as the skirt will allow

The exhaust?

 

[Deets066]

The exhaust?

Yes, and intake

 

[Deets066]

Yes, and intake

What goes in must come out

 

[jmssaws]

With a stihl piston you can do that but with a 288 piston you can't go that far.

 

[jmssaws]

I almost forgot, every new peice on this saw came from @Definitive Dave .

Great guy,great parts so buy some.

The aftermarket covers are beautiful and the complete rubber kits are tits. Thanks dave

 

[jmssaws]

Accept the wrap,it came from madsens

 

[Jughead]

Gonna be stout?the damn things throwing some serious shavings now.new crank bearings in the build? It's still got a few tanks to go before opening up.

 

[Keith Gandy]

Accept the wrap,it came from madsens

I love the pro safety bars. Just put new tubing on my 372. Talkin about a pain!! Used water/dawn and 30 psi air to get it on

 

[cgraham1]

Does your chain brake work with that handle, @jmssaws ? I tried one of those on my o64, and it didn't clear the brake handle, and the brake handle angle looks like it doesn't match up with the handlebar on yours, either. ?

 

[cgraham1]

I sent the one I had to some *a-hole in Canada, and he never paid me for it.

 

[Keith Gandy]

Does your chain brake work with that handle, @jmssaws ? I tried one of those on my o64, and it didn't clear the brake handle, and the brake handle angle looks like it doesn't match up with the handlebar on yours, either. ?

It takea either a 1/2 wrap or a full wrap brake. Ones straight and one is at an angle

 

[cgraham1]

The reason I ask, is the Pro Safety wouldn't clear the brake handle on my saw, which is why I made mine the way I did. The one on the left is my saw, the one on the right is a saw with a factory wrap handle. The brake handle on Jason's saw looks a lot like the one on mine.

 

[Keith Gandy]

Ya Clint mine was like that but they make the brake handle that fits. 1122 790 1904 or 1905 but id have to look when I get home. It depends on early 066 or later version

 

[drf256]

J,

My little brain thinks you should raise the intake to 75 and do nothing else first.

You've suddenly got less case volume, so your ratio has changed. You can't overstuff the case, it's only gonna fill so much. Too much intake will just cause loads of blowback and less case compression. You should have a smaller volume higher velocity transfer charge.

So you should need LESS intake duration. You should need less everything duration.

But your saw should rev higher than a similar 066. You created a smaller motor that should spin higher and the torque peak should be at a higher rpm. Think about the changes you like when you put a 66 jug on a 64, or a 46 jug on a 44. The changes those hybrids like should apply here. You've created a hybrid with the same parts.

That's how I see it, and I may be 100% wrong. Try it first and see what happens. You can always grind some JB weld out.

 

[Brewz]

^^^^^ This makes sense to my engineers mind.