MS 461 Saddle - What is the Purpose

[Redfin]

461 and 661 both have lower fed tunnels opposite in the crankcase from this saddle.

 

[Moparmyway]

Did thoso paticular saws behave any differently with in cut rpm?

They were brought in as runners to be ported, they seemed to lack any oomph, but I’m used to ported 90cc saws too

 

[Keith Gandy]

They were brought in as runners to be ported, they seemed to lack any oomph, but I’m used to ported 90cc saws too

I was just thinkin how the back pressure and slower velocity in the transfers would make the saw act

 

[Fruecrue]

I was just thinkin how the back pressure and slower velocity in the transfers would make the saw act

Similar to a full open EGR valve.
Less fuel / air mix volume
Lower peak combustion temp
Better to please EPA

 

[treesmith]

Anyone evwr tried modifying the shape?

 

[huskihl]

Could also act as a crankcase stuffer to compensate for the larger tunnels

 

[paragonbuilder]

I wonder if it acts like a crank scraper and windage tray.

Please elaborate.

 

[paragonbuilder]

Similar to a full open EGR valve.
Less fuel / air mix volume
Lower peak combustion temp
Better to please EPA

Lower temps??? Interesting.
Different engine though...

 

[tree monkey]

it is in there to help cool the cylinder wall

 

[paragonbuilder]

it is in there to help cool the cylinder wall

And how do you know that? Stihl documentation?

 

[Marshy]

Please elaborate.

Well, crank scraper are typically found in high performance 4 cycle engines. I just thought maybe they intended it to act like a crank scraper. Crank scrapers lessen rotating mass for the engine because they remove oil droplets from the windage cloud around the crank. The reduced drag free up power and keep the cylinder walls from being overloaded with oil. They improve efficiency. Do they work in two strokes? Idk. Some of what they do might be counterproductive for two stroke engines?

https://www.crank-scrapers.com/What is a crank-scraper.html

 

[tree monkey]

common sence, look at the voids between the cylinder wall and the cylinder fins, how else is it going to cool?

 

[Dub11]

it is in there to help cool the cylinder wall

You telling people run there saws long enough to get hot?

 

[blsnelling]

Everything said here is guessing and speculation until you get it straight from a Stihl engineers mouth, not just anyone from Stihl.

 

[Marshy]

Everything said here is guessing and speculation until you get it straight from a Stihl engineers mouth, not just anyone from Stihl.

Yes, that is implied isn't it?

 

[DELETED (Struggle)]

All I know is Scott ported my 461 and I would consider him the voice of reason on this since my saw is still screaming.


Sent from my iPhone using Tapatalk

 

[tree monkey]

Everything said here is guessing and speculation until you get it straight from a Stihl engineers mouth, not just anyone from Stihl.

are you an engineer?

 

[MustangMike]

Let's see ... Stihl engineer/TM ... Stihl engineer/TM ... emm ... I'll take TM!!!

 

[blsnelling]

are you an engineer?

Nope, and I'm not claiming to know what it's for. AFAIK, it's irrelevant. If I had a 461 of my own I'd be tempted to remove it and bury a 28" bar in Oak for repeated cuts.

 

[tree monkey]

you should brad, and use stihl oil mixed 100/1 with 20% eth fuel cause that's what the stihl engineers says is safe to use