262xp build and port for the Treemonkey raffle

[jmssaws]

It's back together at 103 123 77 and is a different saw entirely.

 

[jmssaws]

 

[Tor R]

It's back together at 103 123 77 and is a different saw entirely.

what was your stock number on this Mahle jug Jason?
It sounds like it has picked up far more rpm with those timings compared to where you had tr 127, also better throttle respond.

 

[jmssaws]

I didn't even check it before machine work.

I'm happy with it now

 

[malk315]

Huge difference. Wish you were nearby so we could have put it on dyno before and after...

Bill is converting the dyno from brake setup to hydraulic. Once it's working again you guys will be first to know.
I'm hoping to replicate the electronics over the summer and make them smaller too.
Someday hoping you saw builders will have one to use regularly!

 

[jmssaws]

So what have we learned?

I've always thought a saw could be as strong as it can be with lots of different timing,this saw was strong with the low exhaust and it's strong now with it raised,the difference is with a higher exhaust the power is moved up in the rpm,so if it made ?hp before at 9000 rpm
It could very well be the same hp now but at 11000 rpm and with the power that high it's faster than the low exhaust one.
I knew I would have to raise everything but I wanted to do a before and after to show the difference.

I'm not saying you can raise the exhaust and gain everytime there's to many variables but you don't have to have a low exhaust to have tourqe.

If a saw at 107 will turn a chain at 10500 in the wood but at 103 it turns 12000,which has more "tourqe"?

 

[Magnumitis]

Based off of my limited knowledge, I'd say the higher exhaust saw will make more peak torque and the lower exhaust saw might make more available torque over a slightly wider range in rpm.

The first being more appealing to us saw fanatics who can properly tune and sharpen a chain. The second would probably serve the average user more betterer.

 

[rjames]

Looks like this here:

Do you have a picture of what that looks like on the piston?

Sent from my XT1585 using Tapatalk

 

[rjames]

By the way, very nice job on the saw J, that thing is one rippin' sumbich.

 

[drf256]

View attachment 24786

Nicest transfers I've seen in a while, if not ever.

 

[drf256]

So what have we learned?

I've always thought a saw could be as strong as it can be with lots of different timing,this saw was strong with the low exhaust and it's strong now with it raised,the difference is with a higher exhaust the power is moved up in the rpm,so if it made ?hp before at 9000 rpm
It could very well be the same hp now but at 11000 rpm and with the power that high it's faster than the low exhaust one.
I knew I would have to raise everything but I wanted to do a before and after to show the difference.

I'm not saying you can raise the exhaust and gain everytime there's to many variables but you don't have to have a low exhaust to have tourqe.

If a saw at 107 will turn a chain at 10500 in the wood but at 103 it turns 12000,which has more "tourqe"?

Torque is measured, power is calculated. The curves will always cross at the same rpm on every chart, I believe that number to be 5250. IIRC, HP is torque x rpm /5250.

Many times we are losing overall torque (work) to make more power (work over time).

Torque should be made in a saw by properly filling and purging a cylinder with fresh charge, compressing and igniting it efficiently, and venting exhaust gasses after usable pressure falls below drag.

I'd say that your transfers being too low were inhibiting proper cylinder filling and you increased overall torque when you raised them. By raising the exhaust you may have lost some peak torque, but you made it at a higher rpm-hence more power.

I think the intended saw use and users preference are what matters most when building a saw. A cant cutter shouldn't be built/designed the same as a long bar firewood saw.

 

[jmssaws]

Just raising the exhaust wouldn't have got it where it is,like everything on these it's a combination of things,usually when you raise the exhaust you need to raise the transfers and in some cases give it some intake which is what this saw needed.

Hp and tourqe numbers for a saw are Kool but I'm more interested in what rpm max output is at,a 10hp saw is useless if it makes it at 6000 rpm but at 11000 it's a monster.

 

[jmssaws]

We can get to caught up in numbers,I almost never build 2 saws alike numbers wise but they will run equal.

 

[drf256]

Just raising the exhaust wouldn't have got it where it is,like everything on these it's a combination of things,usually when you raise the exhaust you need to raise the transfers and in some cases give it some intake which is what this saw needed.

Hp and tourqe numbers for a saw are Kool but I'm more interested in what rpm max output is at,a 10hp saw is useless if it makes it at 6000 rpm but at 11000 it's a monster.

100%

It's the puzzle of the piston ported 2 stroke that intrigues me.

 

[jmssaws]

No pics of transfers... might as well not even make a build thread.

I got a old 066 you ported in on trade,got a chance to run it today and it is a great running saw,nice work!

 

[Mattyo]

The docs 262 he did for my saw.

I'll let him tell numbers. It runs fine....nuff said

 

[Canadian farm boy]

The docs 262 he did for my saw.

I'll let him tell numbers. It runs fine....nuff said

View attachment 24910 View attachment 24911

Why did you take it apart Matt?

 

[Mattyo]

he only did the jug for me ... I bought the saw locally and was convinced the jug no good.... with the docs female like soft hands, he massaged it back to life for me

 

[Mattyo]

 

[Mattyo]

I got tired of those stupid metal clips digging into my knuckles, so I stopped pulling. its likely higher than 200psi