Mastermind Meets The MS500i

[TreeLife]

Very nice, the shorter duration saw sounded better. I agree, a 36" or 32" test/comparison with a saw of similar engine size would be very cool.

 

[Mastermind]

The only difference between saws 1 and 2 are three degrees of intake timing.

Took .040” out of the squish.....047” off the base.

Ex: 103° = .945”
Tr: 124° = 1.148”
In: 83° = .720”

The measurements in inches are how far it is from the squish band to the top of the port on the exhaust and the transfers. On the intake use a .720" piece of card stock above the piston, and mark the bottom of the skirt. The intake side and the exhaust side of the piston are a little different, so watch that.

 

[redlight066]

I feel like we should all sit in a circle, hold hands and sing Kumbaya.

 

[andyshine77]

Well I watched the videos before reading this thread, and I thought that the second saw ran and sounded better to my ears.[emoji106]

 

[Mastermind]

Well I watched the videos before reading this thread, and I thought that the second saw ran and sounded better to my ears.[emoji106]

I knew which one was better after the first piss rev. LOL

 

[andyshine77]

I knew which one was better after the first piss rev. LOL

Yeah we don't need no stinking dyno! [emoji1]

 

[huskihl]

You should try one with the intake at 80

 

[traffic903]

You should try one with the intake at 80

That's where I'm going to put mine I think.

 

[Mastermind]

You should try one with the intake at 80

Well....that's next.

 

[Cobby08]

Is it done yet already?! Gawwwd.... I'm getting old you you slow old bastard.

 

[Mastermind]

Is it done yet already?! Gawwwd.... I'm getting old you you slow old bastard.

Go back to bed Cobb Job.

 

[Lightning Performance]

78

 

[MG porting]

78

Which would be fine if yo like a 20"r.

 

[mettee]

I guess my thoughts are how does the amount you removed from the band and base effect the actual porting? Could you adjust those cuts to the band and base to optimise the intake/exhaust numbers better. I'm mostly new to porting saws but I've worked on auto engines so the grinding part is familiar at least.

I like the inch measurements that mastermind gave that is a sweet bit of info to have!

 

[Mastermind]

I guess my thoughts are how does the amount you removed from the band and base effect the actual porting? Could you adjust those cuts to the band and base to optimise the intake/exhaust numbers better. I'm mostly new to porting saws but I've worked on auto engines so the grinding part is familiar at least.

I like the inch measurements that mastermind gave that is a sweet bit of info to have!

A bump in compression is worth the trouble in most cases. Once you figure out where the transfers work the best.....you can take a little more, or less out of the squish band to make those land where there will be less grinding. The transfers are also the easiest to muck up, so the less you have to move them....the better.

Now....one of the reasons I don't post about saws as much as I once did is because I don't want to lead anyone astray. There are so many different designs, and so many different ways of achieving the goal, that there is no "right" way to do this stuff. You gotta get in there and see what works for you.

 

[Cobby08]

A bump in compression is worth the trouble in most cases. Once you figure out where the transfers work the best.....you can take a little more, or less out of the squish band to make those land where there will be less grinding. The transfers are also the easiest to muck up, so the less you have to move them....the better.

Now....one of the reasons I don't post about saws as much as I once did is because I don't want to lead anyone astray. There are so many different designs, and so many different ways of achieving the goal, that there is no "right" way to do this stuff. You gotta get in there and see what works for you.

Don't lie, its because you hate us...

 

[huskyboy]

Randy, the non windowed piston is very interesting. The first in a new stihl for a while it seems. Seems like they must be figuring more base compression is a good thing in a bottom fed cylinder? Just like dolmar did with changing the windowed 7900 piston to the non windowed 7910 piston.

 

[Stihl working Hard]

I agree. The owners of these four saws are incredibly anxious to get their hands on em, so I'll have to rely on feedback from them as to whether or not they get stronger over time.

I can’t say I blame them great thread as per usual Randy

 

[MG porting]

A bump in compression is worth the trouble in most cases. Once you figure out where the transfers work the best.....you can take a little more, or less out of the squish band to make those land where there will be less grinding. The transfers are also the easiest to muck up, so the less you have to move them....the better.

Now....one of the reasons I don't post about saws as much as I once did is because I don't want to lead anyone astray. There are so many different designs, and so many different ways of achieving the goal, that there is no "right" way to do this stuff. You gotta get in there and see what works for you.

Well said.

 

[Mastermind]

Don't lie, its because you hate us...

I don't hate everyone. Just you Mark.

Randy, the non windowed piston is very interesting. The first in a new stihl for a while it seems. Seems like they must be figuring more base compression is a good thing in a bottom fed cylinder? Just like dolmar did with changing the windowed 7900 piston to the non windowed 7910 piston.

I think base compression matters. But....what do I know?