Torque ratings - I'm bored

[flea]

Understanding the concept is easy, the units get ugly.

Work done is force or torque applied through a distance
Power is work done per unit of time
Rpm is the distance turned in a unit of time,

so torque times rpm is power, with a bunch of unit conversions.


HP is (torque ft-lbs) x (rpm) / 5252

or (T inch-lbs x rpm) / ( 5252 x 12) = (t in-lbs x rpm ) / 63024

so algebra, rearranging to T = (HP x 63024 ) / rpm


I don't have the unit conversons here for newtons meters etc.

kcj

The answer is
yellow

 

[harrygrey382]

I understand the comparisons, even if my post didn't show it. I'll wait for the labels.

bloody photobucket's down at the mo... I've labeled it all, saws I've found stats for:
MS200
MS240
MS260
MS280
MS341
MS360
MS361
041av
MS440
MS460
051av
MS650
MS660
070av
090g
076av
MS880
090av
346xp
242xp
262xp
357xp
575xp
362xp
372xp
385xp
394xp
6400
7900

Omissions - 056, I'd love a service manual for one of these (for specs and for my 056), can someon send me one?
3120 - yet to find online specs
5100 - is this the same as the 5000/5000S, lots of these but no mention of a 5100...
Huskies - maybe some others, but don't know much about the models.
Are there any others people are interested in? Can anyone comment on the monster 070 torque?

 

[harrygrey382]

it's back up...

 

[harrygrey382]

anybody got any more figures they could share, I'd like to get the 5100 up there, and also a MAC 125 and Jred 111S... Could someone look these up in a service manual? I'd love to see paper comparisons with them and the big Stihls, I'm sure lots would even!

 

[SawTroll]

.... 3120 - yet to find online specs
5100 - is this the same as the 5000/5000S, lots of these but no mention of a 5100...
.....

The 3120 started out at 9.2hp, and are now down to 8.4. No torque data.


The engine in the 5100S is the same as in the 5000, but at least the coil, crank and handlebar (LOL) is different. Initially the published power specs on the 5100S were higher, but the gap is closing.....

 

[harrygrey382]

The 3120 started out at 9.2hp, and are now down to 8.4. No torque data.

LOL, glad to see we're going forward... that's the EPA right?

 

[NPKenny]

Thank you for adding the labels. This is a helpful display.

Just want to clarify the markings on the graph. The triangles go with the torque readings and the squares go with the HP readings, as labelled. Are they reversed??? The reason for asking is the way it is would show the 660 as having ~4.5hp and ~7lb-ft. of torque, which is not correct according to my knowledge of the 660's hp.

 

[BlackCatBone]

What's up with the 357xp ratings? My manual says 4.4hp.

 

[Dibbs]

Hey harry, if you want extreme torque from a standard saw then you want a Stihl ContraGS, 137cc engine running through the gears which would be double the torque (at the drive sprocket) of a 090AV.

 

[harrygrey382]

Thank you for adding the labels. This is a helpful display.

Just want to clarify the markings on the graph. The triangles go with the torque readings and the squares go with the HP readings, as labelled. Are they reversed??? The reason for asking is the way it is would show the 660 as having ~4.5hp and ~7lb-ft. of torque, which is not correct according to my knowledge of the 660's hp.

hmm, I think I got it wrong last night - the last one is updated, triangles are HP => for 660 7hp, 4.5ft-lbs

What's up with the 357xp ratings? My manual says 4.4hp.

DLG test report says 2.5kW, that's 3.4 hp... http://www.dlg-test.de/pbdocs/4842.pdf
other than that I can't comment, but someone must've made a mistake!

 

[SawTroll]

What's up with the 357xp ratings? My manual says 4.4hp.

Yep, but it did really bad in the DLG/KWF dyno tests, the only saw model I have seen putting out as much as .2kW less than advertised in those tests, but the tested saws may have been from a bad batch, or ?????

Actually, the 254xp, that it replaced, put out more, a nd more than advertised.

The main focus of those tests are safety, performance is secondary.

 

[SawTroll]

...


DLG test report says 2.5kW, that's 3.4 hp... http://www.dlg-test.de/pbdocs/4842.pdf
other than that I can't comment, but someone must've made a mistake!

That is the old 45cc 346xp.......

 

[Lakeside53]

That is the old 45cc 346xp.......

you mean the one that almost everyone has?:greenchainsaw:

 

[bigtrout]

Sorry to bring up an old thread but I have the torque numbers for the Dolmar 5100S, these come straight from my manual.

Max power at speed 3.9HP @10,000rpm
Max torque at speed 3.1Nm@7,000 rpm

 

[tdi-rick]

Precisely Troll. We would need to look at area under the curves to really see who is the paper champ

ding ding.

Give the man a beer !

 

[fullpower_65]

Dyno anyone?

Good thread. It makes me think it would be fun to build a chainsaw dyno. Should be able to throw one together with a clutch, tach and a good quality spring scale. Perhaps when I get my workshop reno finished...

No doubt some folks on here have built or used dynos for their saws? It would be interesting to see RPM vs torque/hp curves for some of the common models.

 

[Crofter]

Good thread. It makes me think it would be fun to build a chainsaw dyno. Should be able to throw one together with a clutch, tach and a good quality spring scale. Perhaps when I get my workshop reno finished...

You got all the basics there; it would be nice to drive a generator, a fan or a pump rather than a slip clutch so that you could sustain the load for a number of minutes and stabilize engine temperatures. More or less momentary peak outputs are sometimes rather optimistic for real world relevance. It sure would be a good tool to make comparisons and rule out a lot of induced variables.

 

[Brownpot Deaton]

wow..this is so ironic in away...

working on a minature drivetrain setup as a hybrid to create a model of our college's racecar...(and by model i mean, getting in the ballpark, more abour figuring out how to control both engines....)...so we are connecting a gas motor(chainsaw) to and electric drive motor(from elctric drill...) and inputting into a larger electric motor to measure the out put and rpm....just realized this is also a chainsaw dyno....(when we finish in week or two...)...


hows that for redneck engineering....

maybe we can start doing independent testing of chainsaws for manufacturers or modded chainsaw...all at a price of course...HAHAHA...just kidding

 

[Crofter]

wow..this is so ironic in away...

working on a minature drivetrain setup as a hybrid to create a model of our college's racecar...(and by model i mean, getting in the ballpark, more abour figuring out how to control both engines....)...so we are connecting a gas motor(chainsaw) to and electric drive motor(from elctric drill...) and inputting into a larger electric motor to measure the out put and rpm....just realized this is also a chainsaw dyno....(when we finish in week or two...)...


hows that for redneck engineering....

maybe we can start doing independent testing of chainsaws for manufacturers or modded chainsaw...all at a price of course...HAHAHA...just kidding

You ought'a get Timberwolf into the project. He likes the computer readouts and the Excel spreadsheets so you can chart and compare the results and export it anywhere in cyberspace! :biggrinbounce2:

 

[Tzed250]

Eddy current dyno please...