Din Hp

[django]

If this has been asked before, I apologize. This forum is just too huge to check every post. What is DIN Horsepower specifically?
I know it's a Euro measurement, But what is it? It's always higher than BHP.

 

[dbabcock]

DIN (Deutsches Instut fuer Normung) standard PS, or Pferde Starken (Horse Strength) is converted to SAE Horsepower as:

PS (DIN) = 1.014 HP (SAE)

 

[glens]

There are really two groups of two things each which can be used in various combinations.

<ul><li>Horsepower values:
<ul>
<li><b>DIN</b>&nbsp; lift 450,000 kg one cm in one minute for one PS (HP).<li><b>SAE</b>&nbsp; lift 33,000 lbs one foot in one minute for one HP.</ul>
<li>Rating methods:
<ul>
<li><b>Calculated</b>&nbsp; (theoretical)<li><b>Measured</b>&nbsp; (actual, or in this case, BHP)</ul></ul>
One DIN horsepower is approx. 1.0139 SAE horsepower so for all intents and purposes (especially in the range of power we deal with in handheld chainsaws) they are the same.&nbsp; The biggest difference is that ratings are given of either <i>calculated</i> or <i>actual</i> values.&nbsp; If the value is represented as BHP then it must have been actually achieved (under whatever conditions) whereas if no representation is made it could be either theoretical or real.

Glen

 

[django]

Thanks guys. Now me and my 7hp (DIN, has got to be theoretical) Sachs 119 (61cc) gotta go cut.

 

[glens]

It probably <i>is</i> making 7 HP on top of the piston, but by the time the now-open exhaust port bleeds off a little, various frictional, internal mass deceleration and acceleration, fuel and bar oil pumping, spark generating (and handle/carb-heating if present), cooling air blowing, and combustion air sucking requirements are all accounted for, it's likely more in the neighborhood of everyone else's 61cc saws - somewhere in the 4's.

Glen

 

[bwalker]

horsepower so for all intents and purposes (especially in the range of power we deal with in handheld chainsaws

Its enough for husky to use to show there prodcuts make more hp when in reality they do not. I would bet most saws are actually rated at the crank so the only parasitic losses would be from the oil pump and the weight of the chain break clutch.

 

[glens]

Ben,

It appears to me after reviewing a few of your posts regarding this issue that you're a little confused.&nbsp; I perceive you're saying that Husky is using DIN so that they can claim higher HP figures as opposed to what they'd be able to show using SAE.&nbsp; Using DIN rather than SAE will result in <i>lower</i> numbers, not higher.&nbsp; In any event, a kiloWatt is a kiloWatt.&nbsp; The real question is "where, how, and under what conditions are the figures obtained?".

I agree the figures are likely obtained without bar oil being pumped (if the pump is even installed; same probably for the air filter and any shrouds/ductwork).&nbsp; On the one hand I think I know what you're talking about, but on the other I know I don't.&nbsp; What exactly is a "chain break clutch" and why would it's weight have an effect on power output?

On a side note, there is something I've been eagerly watching for.&nbsp; You'd talked about doing comparative timed cuts with a 440 and a 372.&nbsp; What were you able to determine?

Glen

 

[bwalker]

Glens, you are confused. Go look up the numbers in KW for the ms 440 and the 372 xp. The ms 440 has a slight edge. Now go look up the th numbers for hp you will see the husky is higher. Husky uses DIN and Stihl uses SAE BHP. Also check out this site and see for yourself.
http://www.flash.net/~lorint/lorin/convert.htm
BY using their convertor I get the 5.4 sae bhp= 5.47 DIN hp

What exactly is a "chain break clutch" and why would it's weight have an effect on power output?

My wording was retarded. What I ment was the saws clutch thats by the chain break. It takes power to spin the clutch. In reality this would be slight parasitic loss.

On a side note, there is something I've been eagerly watching for. You'd talked about doing comparative timed cuts with a 440 and a 372. What were you able to determine?

When both are completly stock for all intents and puposes they are equal. When I get around to doing a complete test I will post the results. I will be including the real weights also. I hear from Tony Snyder that Elux advertised weight doesnt include the sprocket cover and bar nuts. The husky does feel ever so slightly lighter and feels a bit differant in the cut. Both are good saws.Half a dozen to one 6 to the other. I must admit the husky is growing on me.

 

[glens]

I guess I need to belly up to the plate of crow.&nbsp; I don't need to visit the site and enable javascript, I've got my trusty HP48 ROM image running in an X window.&nbsp; Removing the time constant and normalizing to kg and m units, one DIN PS is working with 4500kg*m, and one SAE HP is working with 4562.4135kg*m.&nbsp; So one SAE HP is doing almost 1.4% more work.&nbsp; It's a pretty darn close metric equivalent of an English unit of measurement.

I was looking at the ratio upside-down.&nbsp; It would not be 1 PS (DIN) = 1.014 HP (SAE) but rather 1.014 PS (DIN) = 1 HP (SAE).

Still a totally insignificant difference in the single-digit horsepower range, however.

I'm sure the discrepancies you're noting in the manufacturer's literature can be solely accounted-for by the use of so few significant digits and the resultant rounding error.&nbsp; The Husky figures of 3.9kW/5.2hp are within 0.6% of each other while the Stihl figures of 4.0kW/5.36hp are within 0.07%.&nbsp; Strictly a difference in the extra significant digit introduced by Stihl.&nbsp; They could just as easily used 5.4hp and it would have jumped to 0.7%.

If Husky were in fact using DIN PS figures, their 5.2hp would actually translate to 3.8kW, while 3.9kW would translate to 5.3hp.&nbsp; They're obviously not using DIN there.

The greater care Stihl exhibits in dealing with their catalog figures must surely indicate superiority of their product :<tt>)</tt>

I'd like to run comparable Husky and Stihl saws together and compare them.&nbsp; I've always been a Stihl fan, and fondling the Huskies, the impression they leave is one of, well, cheesiness for lack of a better term.&nbsp; Actually buying one has always been out of the question since I don't like to mail-order stuff like that and around here, if you can find a dealer (especially one who's willing to carry the full line of outdoor equipment just so they can compete in chainsaw sales against Lowes or their kin), they're much higher priced than the comparable Stihl offering.&nbsp; One day soon I hope to be able to arrange a fair evaluation, but in the mean time, I look forward to your report.

Glen

 

[bwalker]

I guess I need to belly up to the plate of crow

Been there done that.

the impression they leave is one of, well, cheesiness for lack of a better term.

I agree they definantly are not a smoothly engineered as a Stihl. the Germans are dang good. Just look at their cars. Some of the parts on a stihl just look tougher and of higher quality. That being said my 372 is a ???? good saw. Hasnt given me a lick of trouble and I think it is equal in quality to a Stihl despite ther looks of things. In fact I believe that stihl and husky both subcontract their pison and cylinder assemblys to the German company Mahle. The same company that is a oem for Porsche.

 

[bwalker]

Glen, actually Husky claims for the 372 3.9 kW/5.4 hp while Stihl claims 5.36 bhp/4.0 kW for the 440. Converting the husky from KW to sae you get 5.229 while converting the Stihl KW to SAE you get 5.36 just like Stihl advertises. BTW I doubt either comapny fudges there figures as Ford got in big trouble for doing this.

 

[dbabcock]

Maybe I stated it wrong, but my car is made in Germany and it's rated at 394 HP SAE and 400 PS DIN. I can see where the confusion lies.

 

[glens]

Ben, I just saw on a couple of Husky's web sites where they are using a figure with a point or two higher rating on the horsepower side for a couple of their saws (357 and 372 I think), and those ratings don't jibe with the Watt figures.&nbsp; The numbers I was using were from their printed 2002 catalog, and they correlate very well (kW to hp) across the board in that dead tree item.&nbsp; I believe much greater care is taken in the printed medium, even though it probably gets fewer customer eyeballs than the web pages.&nbsp; Go figure.&nbsp; Not to mention that there is all manner of MS scat visible in the source of the web pages and the crap is even serving them...

Doug, we both got that wrong.&nbsp; Great minds think alike?

 

[bwalker]

and those ratings don't jibe with the Watt figures

Exactly. You would think their website would have the most up to date numbers.

 

[Tony Snyder]

The Husky/Jonsereds may look cheap to you guys, but Stihls break just as often if not more, rugged looks or not.

Where are you e-lux fans we have let these guys get several unanswered punches in on us.

 

[bwalker]

That being said my 372 is a ???? good saw. Hasnt given me a lick of trouble and I think it is equal in quality to a Stihl despite ther looks of

Tony, see the above comment I made.

 

[django]

Sorry Tony, can't help you. As we all know, Dolmar (Sachs or not) is the way to go!!