Post up your ported cylinder Artwork

[Ronie]

Isn’t the 268 50mm?

You're right, I thought we were talking about a 372, I guess he cut have a 61 piston cut.

 

[supertrooper]

Thanks for the input, part of the reason I left the intake high was so I could try it and re adjust if needed.
The saw is mainly going g to run a 24 in eastern hard wood, reason for the lower exhaust roof

 

[supertrooper]

I have a 630 jonsered piston that I tried and the intake would have been 79, I didn't want to start with an intake that low. My idea was to try it and see how it goes with different timing

 

[farminkarman]

Thanks for the input, part of the reason I left the intake high was so I could try it and re adjust if needed.
The saw is mainly going g to run a 24 in eastern hard wood, reason for the lower exhaust roof

When I did my 2165 the first time, I left the intake at 71. It just couldn’t hang in there with bigger cuts. Once I dropped the intake to 78, it picked up some needed torque, and it gained some throttle response too. I am curious to see what you think.

 

[supertrooper]

When I get it together I'll report back on how it runs

 

[Moparmyway]

I have a 630 jonsered piston that I tried and the intake would have been 79, I didn't want to start with an intake that low. My idea was to try it and see how it goes with different timing

I think 79-81 is perfect, and I suggest starting with that piston

 

[supertrooper]

I think 79-81 is perfect, and I suggest starting with that piston

Is there really any difference if I shave the skirt on the intake side or just lower the intake port, other than the cons of having a shorter intake skirt?

 

[huskihl]

Is there really any difference if I shave the skirt on the intake side or just lower the intake port, other than the cons of having a shorter intake skirt?

There’s some math involved but it (probably) doesn’t work for different porting styles. If the area of the port is less than that of the carburetor, I’d make the port bigger. How much wider vs how much lower I can’t answer

 

[farminkarman]

There’s some math involved but it (probably) doesn’t work for different porting styles. If the area of the port is less than that of the carburetor, I’d make the port bigger. How much wider vs how much lower I can’t answer

Good answer!

 

[huskihl]

Good answer!

Maybe. Idk. Just something that seems right in my head

 

[farminkarman]

Maybe. Idk. Just something that seems right in my head

Makes sense to me

 

[supertrooper]

Ya that does make quite a bit of sense. I'll probably cut the skirt because I measured the boot and matched my intake port to it so I wouldn't lose velocity.

 

[Moparmyway]

Is there really any difference if I shave the skirt on the intake side or just lower the intake port, other than the cons of having a shorter intake skirt?

There’s some math involved but it (probably) doesn’t work for different porting styles. If the area of the port is less than that of the carburetor, I’d make the port bigger. How much wider vs how much lower I can’t answer

I'm also going to add this:

What does the skirt do, other than open & close the intake port ?

It stabilizes the piston in the bore

Is it a good idea to remove some of that stabilization ?

 

[Canadian farm boy]

I'm also going to add this:

What does the skirt do, other than open & close the intake port ?

It stabilizes the piston in the bore

Is it a good idea to remove some of that stabilization ?

MS462 instantly comes to mind. Looks at the early production pistons and the problems they had vs the current.

 

[Ketchup]

Most any Strato piston is easy to kick off balance. I would cut a popup in a 630 piston before trimming the skirt on a 365. More gains for the same work.

 

[Canadian farm boy]

Dolmar 7900

 

[Canadian farm boy]

MS462

 

[huskihl]

Dolmar 7900View attachment 367866View attachment 367867View attachment 367868

79cc of springy antivibes

 

[Canadian farm boy]

The King. 395xp

 

[Mastermind]

The King. 395xpView attachment 370867View attachment 370868View attachment 370869View attachment 370870

Beautiful work Mike.