MS 461 Saddle - What is the Purpose

[Canadian farm boy]

Nice work @nohoff.

View attachment 104546
View attachment 104547

That picture is worth more then a thousand words.

 

[paragonbuilder]

Thanks @nohoff!
So according to this document, there is a secondary flow guide element on the exhaust side as well. Is this on the 461/661? Or possibly for future designs?

Also it clearly states that it is used for reducing case volume, albeit in technical jargon.
In fact it mentions that it Is made hollow with thin walls to take up as much space as possible while adding as little weight as possible.

Very cool to read this. No pun intended...

 

[blsnelling]

There we have it. Thanks for digging up the facts for us.

In summary it:
1. Improves cooling of the piston
2. Improves cooling and lubrication the wrist pin bearings
3. Reduces the volume of the case

 

[blsnelling]

What this does not prove:
1. The saws which incorporate this technology otherwise have cooling issues
2. Removal of this part would lead to imminent over heating and failure of the saw

 

[tree monkey]

well getter done brad. you will need a few thing for the test.

2 new ms 461's
a climate controlled lab, you know, temperature, humidity, barometric pressure. that kind of stuff.
2 dynameters
2 of them muffler sniffers
2 tachometers
a hole bunch of temp sensors , egt, head, cylinder wall, bearings, piston, you get the idea
some sort of air flow sensor on the carb
determine how much fuel is being used per second of run time
determine that both saws run the same within these parameters, if not then buy more saws till you get 2 the same

nothing to it, now chop chop

anything less just would not be fact, right?

 

[blsnelling]

well getter done brad. you will need a few thing for the test.

2 new ms 461's
a climate controlled lab, you know, temperature, humidity, barometric pressure. that kind of stuff.
2 dynameters
2 of them muffler sniffers
2 tachometers
a hole bunch of temp sensors , egt, head, cylinder wall, bearings, piston, you get the idea
some sort of air flow sensor on the carb
determine how much fuel is being used per second of run time
determine that both saws run the same within these parameters, if not then buy more saws till you get 2 the same

nothing to it, now chop chop

anything less just would not be fact, right?

I leave all that to Julian!

 

[drf256]

Interesting stuff.

Makes one think.

In designs with side fed lowers. charge gets pressed through the piston side ribs, cooling the piston and rod/bearing. Without this bridge/flange, the charge would get pushed through the case to the front fed transfers and miss a lot of the piston.

I guess this answers why Stihl used an open sided piston in the 461/661 in lieu of a closed/full round piston. With a closed piston design, the upward directed flow would have nowhere to escape. This was a question I’ve seen asked a bunch of times as well.

So, I’m imagining, the guys who have cut in JMS style side wall transfers and have eliminated the front fed ones could safely eliminate the bridge. Would increase case volume though.

 

[paragonbuilder]

Interesting stuff.

Makes one think.

In designs with side fed lowers. charge gets pressed through the piston side ribs, cooling the piston and rod/bearing. Without this bridge/flange, the charge would get pushed through the case to the front fed transfers and miss a lot of the piston.

I guess this answers why Stihl used an open sided piston in the 461/661 in lieu of a closed/full round piston. With a closed piston design, the upward directed flow would have nowhere to escape. This was a question I’ve seen asked a bunch of times as well.

So, I’m imagining, the guys who have cut in JMS style side wall transfers and have eliminated the front fed ones could safely eliminate the bridge. Would increase case volume though.

Great observation Doc!

 

[Moparmyway]

Interesting stuff.
Makes one think.
the guys who have cut in JMS style side wall transfers .

He has tried to take credit for this idea in the past.
Truth be told, it wasnt even his idea to do so in the 661
I remember the day this all went down, even still have the text messages from it
Mike Lee suggested it
Jason cut in dual feeds
I cut in single feeds
The same day that Mike suggested it, Jason cut in his duals
The next day after Mike suggested it, I cut in mine

I know for sure, found out that week, others fed the 661 transferrs from the sides before any of us on here even tried

 

[huskyboy]

He has tried to take credit for this idea in the past.
Truth be told, it wasnt even his idea to do so in the 661
I remember the day this all went down, even still have the text messages from it
Mike Lee suggested it
Jason cut in dual feeds
I cut in single feeds
The same day that Mike suggested it, Jason cut in his duals
The next day after Mike suggested it, I cut in mine

I know for sure, found out that week, others fed the 661 transferrs from the sides before any of us on here even tried

So if I’m understanding correctly it would look like 395 style transfers with them done that way?

 

[mdavlee]

So if I’m understanding correctly it would look like 395 style transfers with them done that way?

Yes

 

[mdavlee]

He has tried to take credit for this idea in the past.
Truth be told, it wasnt even his idea to do so in the 661
I remember the day this all went down, even still have the text messages from it
Mike Lee suggested it
Jason cut in dual feeds
I cut in single feeds
The same day that Mike suggested it, Jason cut in his duals
The next day after Mike suggested it, I cut in mine

I know for sure, found out that week, others fed the 661 transferrs from the sides before any of us on here even tried

Yep. I did a single hole to feed the secondary similar to what treemonkey did on his 385 wild thing

 

[Moparmyway]

So if I’m understanding correctly it would look like 395 style transfers with them done that way?

 

[MustangMike]

What this does not prove:
1. The saws which incorporate this technology otherwise have cooling issues
2. Removal of this part would lead to imminent over heating and failure of the saw

I have a dead horse for sale if you would like to beat it.

 

[MustangMike]

Interesting stuff there Kevin, but I have some questions.

1) Do you leave the original opening open, or block it off? I'm thinking to make it work effectively you would block the port right under your opening to force the direction of flow.

2) In addition to a performance gain, do you notice a difference in the operating characteristics with this change? (like exchanging low end for high end, etc).

Thanks!

 

[Moparmyway]

Interesting stuff there Kevin, but I have some questions.

1) Do you leave the original opening open, or block it off? I'm thinking to make it work effectively you would block the port right under your opening to force the direction of flow.

2) In addition to a performance gain, do you notice a difference in the operating characteristics with this change? (like exchanging low end for high end, etc).

Thanks!

1. Some are blocking off the original port openings
2. It got angry, without any trade offs on either the high or low ends

 

[Marshy]

I have a dead horse for sale if you would like to beat it.

Must be a mustang.

 

[Brush Ape]

Ah, I guess I misunderstood. I thought you were saying I had to be a chemist to pass judgement on an oil, so figured you must be one.

No we were trying to get some dope.

 

[tree monkey]

1. Some are blocking off the original port openings
2. It got angry, without any trade offs on either the high or low ends

I seem to remember a john deere effect

 

[Moparmyway]

I seem to remember a john deere effect

What exactly is “the John Deere effect” ?