WANTED OEM 064 Cylinder

[Nutball]

What altitude are you at?

I'm up at 5800 ft

 

[srcarr52]

It's fine, at 5800' elevation and 0.027" squish 140 psi is perfect.

 

[farminkarman]

It's fine, at 5800' elevation and 0.027" squish 140 psi is perfect.

that is what I was thinking

 

[jacktheripper]

That makes me feel better, but I still wonder... My 266 and 5105 are super high compression, even at this altitude. I know people can get tripped up on compression numbers, and maybe I've just proven myself to be one of them I suppose.

 

[farminkarman]

That makes me feel better, but I still wonder... My 266 and 5105 are super high compression, even at this altitude. I know people can get tripped up on compression numbers, and maybe I've just proven myself to be one of them I suppose.

If you want to set that 064 free, send it to @srcarr52 Here is the dyno sheet for one he did:

Post in thread 'Another chainsaw dyno...'

Jan 9, 2023

Here is the graph for an 064 I recently acquired from Shaun:

• farminkarman

• 
• 

 

[jacktheripper]

If you want to set that 064 free, send it to @srcarr52 Here is the dyno sheet for one he did:

Post in thread 'Another chainsaw dyno...'

Jan 9, 2023

Here is the graph for an 064 I recently acquired from Shaun:

• farminkarman

• 
• 

10.5 HP is just wild. Is that a work saw?

 

[farminkarman]

10.5 HP is just wild. Is that a work saw?

Yeah.

 

[Woodwackr]

Not worn. It's a new Meteor. Very little slop when in the cylinder.

B or C cyl ? Meteors are all Bs unless you specifically order an A. At least that’s in my limited experience.
Shave the cyl base for better squish?

 

[Woodwackr]

10.5 HP is just wild. Is that a work saw?

And, 7.5hp, stock? Sure ain’t what Stihl published for those

 

[jacktheripper]

B or C cyl ? Meteors are all Bs unless you specifically order an A. At least that’s in my limited experience.
Shave the cyl base for better squish?

I'll have more info on this soon

 

[farminkarman]

And, 7.5hp, stock? Sure ain’t what Stihl published for those

I’m not exactly sure what Joe used as a comparison curve.

 

[Powerstroke Cowboy]

Dynos are a great comparison tool. If all parameters are the same you get to see a good before and after idea. Both numbers might be off since it depends on the information entered. But, if both are tested the same way with the same data you get to see your gain, or loss. Dynos are a great tool.

 

[srcarr52]

And, 7.5hp, stock? Sure ain’t what Stihl published for those

That was a muffler modded stock porting saw.

 

[srcarr52]

That makes me feel better, but I still wonder... My 266 and 5105 are super high compression, even at this altitude. I know people can get tripped up on compression numbers, and maybe I've just proven myself to be one of them I suppose.

Both of those saws have pretty high cranking compression to begin with.

 

[Stump Shot]

I'll have more info on this soon

While not common, it is possible, especially for older well used saws, for the cylinder to have some ever so slight warping to it. This will take some time for your rings to fully shape to. As long as you're saw is making enough to start and run, keep running it, one day it will surprise you.
I actually had one this summer that was so bad it wouldn't start with new piston and rings the compression was so low and had to be replaced. This being on an old loggers saw, with lots of use.

 

[mrxlh]

Best answer…

 

[jacktheripper]

So I tore it down again today - finally got around to it. It is a Mahle B cylinder running a Meteor B piston with Caber F cast rings that have about three tanks on them. Ring end gap measures .013"+. Plating all looks good.

I also have the original Mahle piston on the shelf, which wore through almost all of the machining marks on it but still fits fairly tight in the bore. The original rings on it were at .015" end gap.

Maybe throw the Mahle piston back in with a light ball hone job in the cylinder and new set of regular Caber rings, and then just run the piss out of it to get rings to seat?

 

[jacktheripper]

I have a set of Cabers and a set of HL Supply no-name rings coming in the mail. I'll see how the ring end gap is, maybe one has a smaller gap than the other.