Brush Ape
The Port Authority
Right.
I call B.S. on Stihl. My dyno doesn't lie. MS 461 is king over MS 660
- Thread starter chadihman
- Start date
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Right.
Deets066
Firewood hack
Everything with a torch
Deets066
Firewood hack
Thanks, spent a good piece of time makin it right. When I get some play time I'll make a vid of it in action and start a new thread.
Deets066
Firewood hack
I used cardboard, then after I cut one tooth out of plate I used that to lay out the rest.
HuskStihl
Chairin'em for the sound
Those dynometers things are always wrong, or their operators are fudging the numbers. The other day a guy told my the new V-6 camaro made more hp than my bitchin' IROC Z!! Uh....my car has 2 more cylinders and 100 more cubes. No way it has less power.
On a more serious note, early 066's and later year 660's aren't the same thing, and don't respond the same to a DP muffler
On a more serious note, early 066's and later year 660's aren't the same thing, and don't respond the same to a DP muffler
Deets066
Firewood hack
You talking about full dyno that you strap the car down and runs off the tires? Or something else?
DexterDay
Addicted to ArboristSite
Peak HP & Torque will not occur at the same RPM (usually). Larger cubic inch engines with shorter duration cams will usually produce more torque (well suited for a large luxury car or truck). The max power will usually be at a lower RPM. Intake & exhaust are usually smaller in comparison to the engine size to provide good throttle response. They also usually have less timing advance. Often, a high torque engine will focus more stroke than bore.
Max HP engines have more of a focus on high RPM than on cubic inches (shorter stroke & larger bore, although with today's modern materials that is changing), have more aggressive cams (more lift & duration), larger valves, intake & exhaust (in relation to the engine size) and more aggressive timing advance.
(I'm talking old school here, a lot of the newer engines with variable cam timing, etc. seem to have power across the board).
Engines built for maximum HP often sacrifice low end power. Engines built for maximum torque often sacrifice high end power.
Max HP engines have more of a focus on high RPM than on cubic inches (shorter stroke & larger bore, although with today's modern materials that is changing), have more aggressive cams (more lift & duration), larger valves, intake & exhaust (in relation to the engine size) and more aggressive timing advance.
(I'm talking old school here, a lot of the newer engines with variable cam timing, etc. seem to have power across the board).
Engines built for maximum HP often sacrifice low end power. Engines built for maximum torque often sacrifice high end power.
SawTroll
Information Collector
The 461 doesn't look impressive at all according to the German KWF tests, that includes a dyno test. Apart from that I know nothing that is relevant to this thread.
Troll, what was the HP for the 461 according to them?
Also Troll I think I owe you a thank you. I printed something the other day that I think you posted to another website years ago regarding German tests and wt of various saws. I know the wt varied from year to year, but it did list both the wt of a 044 and 440. I was surprised the 440 was a little lighter (6.2 kg instead of 6.3). Likely that was due to the heavier flywheel that Brian had mentioned was on some 044s. According to my calculations, that puts the 044 at almost 13.9 lbs.
Also Troll I think I owe you a thank you. I printed something the other day that I think you posted to another website years ago regarding German tests and wt of various saws. I know the wt varied from year to year, but it did list both the wt of a 044 and 440. I was surprised the 440 was a little lighter (6.2 kg instead of 6.3). Likely that was due to the heavier flywheel that Brian had mentioned was on some 044s. According to my calculations, that puts the 044 at almost 13.9 lbs.
SawTroll
Information Collector
4.4 kW. http://www.kwf-online.de/deutsch/pruef/pruefergebnisse/aagw/motorsaegen/6391_12.pdf
I stopped trusting that test site when they started collaborating with Dolmar around 2005 though. At about the same time, it got more obvious that it was a German test site.
weedkilla
Ain't no guru of nuthin'
Anything you could tell us about how saws are chosen for testing, how many saws are tested, or anything else about the process would be interesting to at least myself. I've considered those to be quite independent tests - but without any real knowledge of their processes. I at least put more weight in their results than spec sheets.....
My school level German isn't sufficient to chase up any of that knowledge myself.
I think this may be worthy of cluttering my sig for a few days.
Seriously though, maybe you guys can clarify this for me. If 'torque' is a measurement of how much power the engine produces and HP is just an extrapolation of torque and RPM, why couldn't a diesel with gobs of torque and a variable ratio transmission that keeps the engine at peak torque rpm during acceleration stomp a peaky gas engine with much less torque but more hp?
I guess a simpler way of saying it is.. if torque is what does the work, why does the rpm the engine has to run to produce it matter? The engine with the most torque should win if it's geared correctly.
Wouldn't be a great AS thread without Nikko slidding in for a one sentence STIHL bashing post.
Cheers ST!
Cheers ST!
weedkilla
Ain't no guru of nuthin'
Actually ST is alluding to something very interesting. The supposedly independent test/certification mob in Germany have gotten some results on these two saws that don't add up to the experiences that USA users are reporting.
Although they are similar to what Aussie users are reporting.
Now, I think it's time for me to hunt up the bits and build an 064, with a good 066 top end.
Mastermind
Work Saw Specialist
I build saws that make torque. I don't look for additional unloaded RPM at all.
My reasoning is that by making more power.....the engine will hold more RPM in the cut. At about 10,500 - 11,000 RPM.
Now, here's the thing. My engines don't do well in cant races....even with taller gearing.
Discuss?
Tough to find the KS 066 top ends these days.....just stick with the 064 top end if you wanna really fun saw.
KG441c
Keith
I would be interested in hearing in what part of the porting process makes the most torque?I build saws that make torque. I don't look for additional unloaded RPM at all.
My reasoning is that by making more power.....the engine will hold more RPM in the cut. At about 10,500 - 11,000 RPM.
uld u
Now, here's the thing. My engines don't do well in cant races....even with taller gearing.
Discuss?
Tough to find the KS 066 top ends these days.....just stick with the 064 top end if you wanna really fun saw.
one.man.band
ArboristSite Guru
suggest you look at the data for the MS461 again.
in fact, for saw offerings in the 74cc through 76.5cc ........including: dolmar, husqvarna, solo and stihl...
the MS461 is at the top of the heap in the following: BMEP; Specific Power; Power to Weight Ratio; Torque to Weight Ratio; Thermal Efficiency @ Peak Power and Torque; and lastly tied for first in Peak Torque.
the MS461 is in second place to the Solo, in Peak Power.
-omb
-interesting that statistics can be discounted for some brands as inaccurate when tested by the same facility. in addition, that manufacturer's who do not use statistics for advertising, can be discounted as inferior.
-they are are just motor's with chains to me, irregardless of who manufactures them.
Mastermind
Work Saw Specialist
Most of the time I see that a modern saw engine will run at plenty of RPM just because of the design. (Transfer design, tight case capacity, etc)
Because the RPM is there already, I look for ways to improve the power in the working range.
I've come up with a exhaust height to displacement rule that I adhere to. It seems to be working very well. I believe that if the exhaust is too high (and of course there are gonna be exceptions) the engine will make peak power at an RPM that is unattainable in the cut. So I shoot for maximum power at working RPM.
I realize that is a quick and dirty answer, but you'd have to see the advances in design compared to less modern designs that have been made in the last couple of decades to get what I'm talking about.
