Ms461 saw design

[Gologit]

How are you liking it compared to the 660 ? Is it getting the same job done ?

I miss the 660. This particular 461, which is basically stock, isn't the saw the 660 was but it's really not fair to compare it with the Treeslingr 660 either. That 660 was probably one of the best saws I've ever ran.
The 660 never had anything but a 36 or 42" bar and the 461 has a 32" with JGX. I'm going to try the 36" on the 461 next week for a few oversize trees. It oils the 32" real well and I don't see any problems with the longer bar. Cut times will be a little slower than the 660 but that's to be expected. Treeslingr's saw spoiled me.

With the dp muffler and some good tuning I think the 461 will run right with a stock-from-the-box 660 if both were wearing the same bar and chain. I've never run a ported 461 but from what I can tell from runn ing the stocker a good woods port would make an impressive saw out of it. If a guy wanted to use one for his primary falling saw a woods port would probably pay for itself over the life of the saw.

The guys back east that like to run short bars for firewood or clearing would probably like the 461 just fine.

The 461 does what I bought it for and it does it well. It's light and nimble and the power is decent for a stock saw. The powerband is wide and the torque seems to stay constant when you need to really reef on it.. It's good for medium size timber and it's a great landing saw. It's just not enough saw for big timber work...four or five foot dbh... on a steady basis. It would do it but you wouldn't set any production records.

I let the 660 go because I had a 661 on order...I got to actually look at it at the saw shop before it went back to Stihl... and when they come in I'm first on the list. 'Til then the 461 will do the job well enough to get by.

 

[KG441c]

I miss the 660. This particular 461, which is basically stock, isn't the saw the 660 was but it's really not fair to compare it with the Treeslingr 660 either. That 660 was probably one of the best saws I've ever ran.
The 660 never had anything but a 36 or 42" bar and the 461 has a 32" with JGX. I'm going to try the 36" on the 461 next week for a few oversize trees. It oils the 32" real well and I don't see any problems with the longer bar. Cut times will be a little slower than the 660 but that's to be expected. Treeslingr's saw spoiled me.

With the dp muffler and some good tuning I think the 461 will run right with a stock-from-the-box 660 if both were wearing the same bar and chain. I've never run a ported 461 but from what I can tell from runn ing the stocker a good woods port would make an impressive saw out of it. If a guy wanted to use one for his primary falling saw a woods port would probably pay for itself over the life of the saw.

The guys back east that like to run short bars for firewood or clearing would probably like the 461 just fine.

The 461 does what I bought it for and it does it well. It's light and nimble and the power is decent for a stock saw. The powerband is wide and the torque seems to stay constant when you need to really reef on it.. It's good for medium size timber and it's a great landing saw. It's just not enough saw for big timber work...four or five foot dbh... on a steady basis. It would do it but you wouldn't set any production records.

I let the 660 go because I had a 661 on order...I got to actually look at it at the saw shop before it went back to Stihl... and when they come in I'm first on the list. 'Til then the 461 will do the job well enough to get by.

Ill be interested to hear how the 661 runs compared to a stock 660. I will say what one of the top porters here told me was a properly ported 461 would smoke a stock 660

 

[wigglesworth]

I wonder why all the guys that really know and understand chainsaws just up and left?

I'm here now....


What's stock timing numbers on a 461?

 

[Mastermind]

Compression: 165psi
Squish: .026
Ex: 103°
Tr: 123°
In: 71°

The transfers are angled for progressive opening also.

 

[wigglesworth]

Compression: 165psi
Squish: .026
Ex: 103°
Tr: 123°
In: 71°

So in 20 degrees of blowdown, it's supposed to have enough combustion pressure left to back stuff combustion gasses into the uppers?

Also, If your intake has already closed at 71 degrees, its already had 32 degrees with of crankcase pressure increase from the downward piston motion. Isn't the crankcase super tight as well?

I'm no retired engineer, but.... The math don't add up for me to conclude that it actually stuffs the uppers with exhaust gasses...

 

[Hedgerow]

So in 20 degrees of blowdown, it's supposed to have enough combustion pressure left to back stuff combustion gasses into the uppers?

Also, If your intake has already closed at 71 degrees, its already had 32 degrees with of crankcase pressure increase from the downward piston motion. Isn't the crankcase super tight as well?

I'm no retired engineer, but.... The math don't add up for me to conclude that it actually stuffs the uppers with exhaust gasses...

Maybe with real short runners, it can make a shield of exhaust gasses over the fresh charge like "the force" and keep it at bay as the cc pressure builds on the down stroke...

Or not...

 

[Marshy]

TACO CAT spelled backwards is TACO CAT

Think about it.

 

[Mastermind]

So in 20 degrees of blowdown, it's supposed to have enough combustion pressure left to back stuff combustion gasses into the uppers?

Also, If your intake has already closed at 71 degrees, its already had 32 degrees with of crankcase pressure increase from the downward piston motion. Isn't the crankcase super tight as well?

I'm no retired engineer, but.... The math don't add up for me to conclude that it actually stuffs the uppers with exhaust gasses...

What you are saying makes perfect sense Jeremy.......no room for that on Arborist Site these days.

 

[CR888]

Well l can't tell you much about blowdown, combustion pressure, port timing or squish band velocity but l can say l got a near new MS660 sitting in the waiting room at Mastermind Work Saws....don't need to worry about all that confusing stuff..

 

[Chris-PA]

There sure doesn't seem to be anything special in those timing numbers. If they're getting extra exhaust pressure blowing into the transfers as they claim, it would have to be from a plugged up muffler - but that is hardly new or unusual either. It doesn't pass the smell test that you can get such a stratification effect without actually changing much.

The only thing that makes me wonder is why they went to the trouble adding that piston cooling deflector. Although it doesn't say that thing is at all related to the supposed exhaust driven delayed scavenging either.

Remember, these guys gave a fancy marketing name of "Intellicarb" to just placing the diaphragm vent downstream of the air filter, and that's been common practice on most engines forever. My old McCinderblock has it. So just because they make a fuss about it in some pretty literature doesn't mean much.

 

[treesmith]

I've ran a 461 a few times at work and I really liked it, I was talking to one of the boys with a 460 and he said the new version (461) isn't as good as his older 460. I looked at the two saws and saw straight away the 460 had a dual port cover but also had a much bigger stock port too
They were both bought new from Stihl as is

 

[Ron660]

If the exhaust is partially entering the transfer ports before exiting to the muffler, wouldn't this increase carbon buildup??

 

[Mastermind]

There sure doesn't seem to be anything special in those timing numbers. If they're getting extra exhaust pressure blowing into the transfers as they claim, it would have to be from a plugged up muffler - but that is hardly new or unusual either. It doesn't pass the smell test that you can get such a stratification effect without actually changing much.

The only thing that makes me wonder is why they went to the trouble adding that piston cooling deflector. Although it doesn't say that thing is at all related to the supposed exhaust driven delayed scavenging either.

Remember, these guys gave a fancy marketing name of "Intellicarb" to just placing the diaphragm vent downstream of the air filter, and that's been common practice on most engines forever. My old McCinderblock has it. So just because they make a fuss about it in some pretty literature doesn't mean much.

The 460 and 461 both use the same muffler.

That deflector under piston seems to be a stuffer of sorts. Granted, it does direct the incoming flow upward and into the piston, it also displaces a certain amount of crankcase volume. The transfers tunnels are very long......so I wonder if that helps increase flow velocity.

The thing I was going on about with the carb is just this......if a person takes the time to really study the design of the carb, he would see that regardless of main jet size, the high speed needle allows the user to richen the mixture to any degree he chooses. Both passages, the one thru the main, and the one thru the adjustable jet end up at the same place......the metering nozzle. Adding a larger main jet (and I've done that many times) just allows the adjustable jet to be closed more.

The 046 has a larger main jet than a MS660......does that make the MS660 a stratified engine?

 

[Mastermind]

If the exhaust is partially entering the transfer ports before exiting to the muffler, wouldn't this increase carbon buildup??

Bingo.....

And I've never torn into a 461 to find any sign of this supposed event. The transfers are always as clean as any other engine.

 

[Chris-PA]

The 460 and 461 both use the same muffler.

That deflector under piston seems to be a stuffer of sorts. Granted, it does direct the incoming flow upward and into the piston, it also displaces a certain amount of crankcase volume. The transfers tunnels are very long......so I wonder if that helps increase flow velocity.

The thing I was going on about with the carb is just this......if a person takes the time to really study the design of the carb, he would see that regardless of main jet size, the high speed needle allows the user to richen the mixture to any degree he chooses. Both passages, the one thru the main, and the one thru the adjustable jet end up at the same place......the metering nozzle. Adding a larger main jet (and I've done that many times) just allows the adjustable jet to be closed more.

The 046 has a larger main jet than a MS660......does that make the MS660 a stratified engine?

Well then the only remaining difference is the long transfers - that would not increase the volume of exhaust that went down the transfers if there were a pressure differential when the transfers open, but it might prevent it from getting all the way to the case. Or I guess it might prevent it from mixing with the fuel/air in the case, and keep it "stratified". Seems like a small difference given the claims made. Although some of the Huskies do use long transfers, maybe to keep the strato air from getting all the way to the case.

And yeah, the only thing that matters on the fuel jet is the total area. It makes no difference what combination of fixed and adjustable parts you use to get there.

 

[KG441c]

The 460 and 461 both use the same muffler.

That deflector under piston seems to be a stuffer of sorts. Granted, it does direct the incoming flow upward and ito the piston, it also displaces a certain amountof crankcase volume. The transfers tunnels are very long......so I wonder if that helps increase flow velocity.

The thing I was going on about with the carb is just this......if a person takes the time to really study the design of the carb, he would see that regardless of main jet size, the high speed needle allows the user to richen the mixture to any degree he chooses. Both passages, the one thru the main, and the one thru the adjustable jet end up at the same place......the metering nozzle. Adding a larger main jet (and I've done that many times) just allows the adjustable jet to be closed more.

The 046 has a larger main jet than a MS660......does that make the MS660 a stratified engine?

Thanks for the explanations!!! Now we r cookin with hot grease!!! Lol

 

[Mastermind]

I'm thinking it's magic. Some Harry Potter stuff going on inside that motor.

 

[mweba]

So in 20 degrees of blowdown, it's supposed to have enough combustion pressure left to back stuff combustion gasses into the uppers?

Also, If your intake has already closed at 71 degrees, its already had 32 degrees with of crankcase pressure increase from the downward piston motion. Isn't the crankcase super tight as well?

I'm no retired engineer, but.... The math don't add up for me to conclude that it actually stuffs the uppers with exhaust gasses...

Truck runnin yet?

 

[KG441c]

Bigger hunk of metal n front on muffler inlet plusa do hicky for cooling in crankcase= Stihl Delayed Stratified Technology!! Crap probably cost me 400$ more

 

[wigglesworth]

Truck runnin yet?

Negative.

I think my strato is plugged up....