Post up your ported cylinder Artwork

[Deets066]

MS660
Built to permanently run 36" 3/8 8 pin
View attachment 38432 View attachment 38433

Nice clean grinding! Looks good.

Is there reason you don't square up the intake more?

 

[Deets066]

This is how I like em

036 with the bottom filled a touch

 

[CR500]

I thought that too Al but, every time I've used them they seem to gain and hold better in cut RPM. They're main purpose is to get the previous charge moving towards/out the exhaust with a super high pressure burst of mixture with minimal volume.

It probably does add some additional volume to the new charge but it really about more efficent scavenging with minimal mix of the charge.

Thats my understanding of it anyway..... could be completely ass about.

Always thought Fingers were cool

Wonder why some guys went away from them?

I can see if you have good transfers you may not need them.

Sent from my non internal combustion device.

 

[paragonbuilder]

Always thought Fingers were cool

Wonder why some guys went away from them?

I can see if you have good transfers you may not need them.

Sent from my non internal combustion device.

You answered your own question. [emoji2]

 

[Savage Saws]

I normally squre them up just like the 036 cylinder you posted Deets. However, i was wanting to see if keeping the port area the same as the intake boot area would help with keeping the charge velocity up through the intake tract.

The way i understand it is that the intake port should never exceed the boots total area or you charge velocity will drop making the port less efficient at filling. Also, a big sqaure port floor on the intake will take a bigger gulp of fuel than a more gradual opening.

This saw was built for the Arborist who is training me. It has to be fuel effecient because it will be used up a tree for blocking down and less refuels means higher productivity on the job site.

Its all just theory really, i may be leaving a but tone of power on the table!? But, building saws for professionals every week has taught me power is only a small piece of the pie....

 

[drf256]

I thought that too Al but, every time I've used them they seem to gain and hold better in cut RPM. They're main purpose is to get the previous charge moving towards/out the exhaust with a super high pressure burst of mixture with minimal volume.

It probably does add some additional volume to the new charge but it really about more efficent scavenging with minimal mix of the charge.

Thats my understanding of it anyway..... could be completely ass about.

Sheet, I think I love you.

Good thing you're a half a planet away.

 

[Deets066]

I normally squre them up just like the 036 cylinder you posted Deets. However, i was wanting to see if keeping the port area the same as the intake boot area would help with keeping the charge velocity up through the intake tract.

The way i understand it is that the intake port should never exceed the boots total area or you charge velocity will drop making the port less efficient at filling. Also, a big sqaure port floor on the intake will take a bigger gulp of fuel than a more gradual opening.

This saw was built for the Arborist who is training me. It has to be fuel effecient because it will be used up a tree for blocking down and less refuels means higher productivity on the job site.

Its all just theory really, i may be leaving a but tone of power on the table!? But, building saws for professionals every week has taught me power is only a small piece of the pie....

Well put, and I think your definitely on the right track with all the theory I've come to believe as well

 

[drf256]

Thanks again for sharing Sandy.

Looking forward to your input around here.

 

[BGE541]

Nothing a mazing but here is a few random ones that I have.

 

[jmssaws]

I've tried every intake shape I can think of on 1122 and about the only thing that changes is gas mileage,never been able to tell a difference in power

 

[Savage Saws]

I hoped you wouldn't say that Jason. I've only been doing this for 4 years now and I'm still developing/testing theories.

You've got a good 6 years of R&D on me dude

 

[drf256]

I hoped you wouldn't say that Jason. I've only been doing this for 4 years now and I'm still developing/testing theories.

You've got a good 6 years of R&D on me dude

Sandy, how do you see fingers working and how much sooner do you open them before the mains?

I can see them working better on the exhaust side, honestly.

Did you flip the piston around on that 660, or did you use a husky slug?

 

[Savage Saws]

Well Al, I do remeber a long time ago seeing old Scott Kunz asking Randy if he'd tried exhaust side fingers on the 026....

Personally, I haven't tried it yet but, its on my ever growing to-do list!

That saw used a OEM KS piston spun around. The numbers are

Ex 101.5
Trans 122
Fingers 120
Int 78.5

I generally open fingers 2 degrees before the mains but, in my Partner 500 i have them opening 3.5 degrees before the mains and that saw is a weapon!

I think they can work up to 4 degrees before but any more and the flow probably gets to judery and not a fluid motion like it needs to be.

Hows that for armchair poting babble!

 

[drf256]

I'm loving it Sandy. We should bring the Porting Theory thread back for you to contribute.

What are your thoughts on bridge ports? I used to do them, then stopped. I thought they aided in direction, but I haven't found any difference in saws with or without them.

I see them lowering transfer pressure and little else. After the upper opens, charge should take the path of least resistance which wouldn't be through the bridge ports.

 

[jmssaws]

I'm loving it Sandy. We should bring the Porting Theory thread back for you to contribute.

What are your thoughts on bridge ports? I used to do them, then stopped. I thought they aided in direction, but I haven't found any difference in saws with or without them.

I see them lowering transfer pressure and little else. After the upper opens, charge should take the path of least resistance which wouldn't be through the bridge ports.

I use to do bridges and fingers and never noticed a gain, if anything it hurt them.
Maybe I did it wrong but the saws I port are stronger without them.

I think if it's strong with them it would be stronger without but someone else's way might be more suited than mine.

 

[Savage Saws]

I'm not so sure Al. I have a rather strong Partner R20T (closed dual port 65cc,) no port work. I cut the base to set squish at .0196", 10 degree advance then put it back together and ran it. It was quite racey but, it would bog under load.

I then pulled the cylinder again and ground to bridge ports in but! I took a long time drawing them into the cylinder and extended the sharpie lines right up to the combustion chamber untill i got them
Converging at the intersection of the intake cylinder wall and combustion chamber, then ground them in.

The saw performed just like i had ground in fingers. It held rpm in the cut better and I could lean on the saw better.

I think a strong saw has perfect port placement/ angle and perfect SYMMETRY!

I spend for ever on my uppers to get the angles and size indentical. I also use a feeler gauge to check port opening.

I'm probably rambling now. Balls back in you court.....

 

[jmssaws]

I think a strong saw has perfect port placement/ angle and perfect SYMMETRY!

I 100% agree.

 

[drf256]

I'm not so sure Al. I have a rather strong Partner R20T (closed dual port 65cc,) no port work. I cut the base to set squish at .0196", 10 degree advance then put it back together and ran it. It was quite racey but, it would bog under load.

I then pulled the cylinder again and ground to bridge ports in but! I took a long time drawing them into the cylinder and extended the sharpie lines right up to the combustion chamber untill i got them
Converging at the intersection of the intake cylinder wall and combustion chamber, then ground them in.

The saw performed just like i had ground in fingers. It held rpm in the cut better and I could lean on the saw better.

I think a strong saw has perfect port placement/ angle and perfect SYMMETRY!

I spend for ever on my uppers to get the angles and size indentical. I also use a feeler gauge to check port opening.

I'm probably rambling now. Balls back in you court.....

Interesting stuff. I don't have a court, per se.

Some saws I've always done bridges in. They work, so I'm afraid to stop.

It's good to hear the same saw performing differently with only one single mod.

My gut on fingers and bridges is that they aren't about flow. They're about changing the shape and direction of the plume shooting out of the upper transfer.

If you get it right, chances are fingers and bridges won't do anything. If it's aimed less than optimally, they should help.

 

[Savage Saws]

This is why I love this site Jason. So many people willing to brain storm. As i said, i'm only a pup in this porting game and you better believe i'm planing on trying to get my uppers better (precise angle and symmetry.) Scott kunz has been doing this for over 20 years and say he doesn't use them either. I'm not a kunz groupie either, its just guys like you and him do things for a reason due to experience.

I feel like they work for me and my style of building but, i also feel like i'm completely in the dark too. Frustraighting and exhilerating all at once!

 

[drf256]

This is why I love this site Jason. So many people willing to brain storm. As i said, i'm only a pup in this porting game and you better believe i'm planing on trying to get my uppers better (precise angle and symmetry.) Scott kunz has been doing this for over 20 years and say he doesn't use them either. I'm not a kunz groupie either, its just guys like you and him do things for a reason due to experience.

I feel like they work for me and my style of building but, i also feel like i'm completely in the dark too. Frustraighting and exhilerating all at once!

The puzzle keeps me intrigued.

Recently I had a 440 tune 300 rpm higher with adding an airfilter when there was none prior. Maybe it was the spitback protector on the 440.

An 026 dropped 1000 rpm with the addition of a filter, but the 15,200 filtered saw cut faster than the 16200 no airfilter saw.

I'm still scratching my head on this.