Return to the Tractors Forum | Post a Follow-Up

 o
B&S Torque Labeling

Posted by deerslayer Z5 NE IL (My Page) on
Sun, May 6, 07 at 12:17

Has anyone noticed that B&S is listing Gross Torque prominently on some of their engines? Is this the beginning of the end of the "Horsepower Wars"?

Here's a link to a B&S promotional video clip.

B&S Torque

IMO, their explanation of torque is confusing and inaccurate. They define torque as rotational power. Technically, torque is not power. Power has a time dimension whereas torque does not.

Has anyone seen a torque label on a tractor engine? Any thoughts on B&S's new focus?

-Deerslayer


Follow-Up Postings:

 o
RE: B&S Torque Labeling

  • Posted by canguy British Columbia (My Page) on
    Sun, May 6, 07 at 14:42

There certainly needs to be a better explanation as it means nothing to the general public.


 o
RE: B&S Torque Labeling

"gross power rating for individual gas engine models is labeled in accordance with SAE (Society of Automotive Engineers) code J1940 (Small Engine Power & Torque Rating Procedure), and rating performance has been obtained and corrected in accordance with SAE J1995 (Revision 2002-05). Torque values are derived at 3060 RPM; horsepower values are derived at 3600 RPM. Actual gross engine power will be lower and is affected by, among other things, ambient operating conditions and engine-to-engine variability. Given both the wide array of products on which engines are placed and the variety of environmental issues applicable to operating the equipment, the gas engine will not develop the rated gross power when used in a given piece of power equipment (actual on-site or net horsepower). This difference is due to a variety of factors including, but not limited to, accessories (air cleaner, exhaust, charging, cooling, carburetor, fuel pump, etc.), application limitations, ambient operating conditions (temperature, humidity, altitude), and engine-to-engine variability. Due to manufacturing and capacity limitations, Briggs & Stratton may substitute an engine of higher rated power for this Series engine)"


 o
RE: B&S Torque Labeling

Im a loyal follower of the Briggs motors, mainly because of my great luck with them ( my oldest motor is like 20 years old and still runs)- ive herd Briggs motors HP is a touch low then stamped on the motor ( an 11HP motor is meybe 10.5 or tad higher) - tecumseh motors are a genuine HP rating 12HP IS 12 HP. Alot of old skool tractor racers use the tecumsehs, while ive seen the newer ones use the Briggs OHV series ( from singles to twins) and highly modify them.
kidd


 o
RE: B&S Torque Labeling

Who cares?


 o
RE: B&S Torque Labeling

Deerslayer; Ifyou go the the sears site they have picked up The Briggs mantra on torque and are labeling walk behind lawn mowers, pressure washers, weedwackers etc. They do not appear to be using it on their riders and tractors. Someone needs to convince me that it is not nonsense.


 o
RE: B&S Torque Labeling

"Someone needs to convince me that it is not nonsense."

I agree. I think introducing another rating that is directly proportional to horsepower has more potential to confuse than to clarify.

-Deerslayer


 o
RE: B&S Torque Labeling

Using a rating that measures something at the RPM it is actually used rather than 3600 RPM makes a lot more sense!

Lawnmowers aren't operating at 3600 RPM. They are much closer to 3100 RPM. HP at that RPM is maybe 85% of "rated" HP.
It also varies between engine types, FH VS OHV etc. at the lower RPM's.

This new method will be much better when comparing one engine to another engine when using this same rating.
It's still not perfect, but it is somewhat more "honest".


 o
RE: B&S Torque Labeling

"Lawnmowers aren't operating at 3600 RPM. They are much closer to 3100 RPM...This new method will be much better when comparing one engine to another engine when using this same rating."

For purposes of comparison, it doesn't matter whether hp is measured at 3,000 or 3,600 rpm as long as all of the manufacturers are consistent.

-Deerslayer


 o
RE: B&S Torque Labeling

Not all engines have the same Torque-Horsepower curves.
OHV engines TEND to have a flatter torque peak at a higher RPM than a similar rated flathead.
For lawn mower engines, you're simply wrong.
IF they rated HP AT the governed speed, then I'd pretty much agree with you.


 o
RE: B&S Torque Labeling

"Not all engines have the same Torque-Horsepower curves."

I agree. The point I was trying to make is that horsepower measured at a consistent rpm is as good a measure as torque for comparison purposes. Remember that hp is simply torque x rpm x constant. Horsepower is directly proportional to torque at all rpms.

"This new method will be much better when comparing one engine to another engine when using this same rating."

Wrong...it's essentially the same thing.

-Deerslayer


 o
RE: B&S Torque Labeling

Marketing hype. It's a way to place a larger number(torque) on a smaller (Horsepower) engine. Example, Your last push mower was a 5.0 HP and you're looking at one now that has 6.5 on the shroud. Your mind say's "hmmmm....more power". My old (20 yrs.) Sears 22" SP w/ 5.0 HP Techumseh was alot more powerful than My new SP 22" 6.5 "torque rating" Briggs-Craftsman. Wonder what the actual HP is on the new one.


 o
RE: B&S Torque Labeling

"Wonder what the actual HP is on the new one."

torque x rpm / 5252 = hp

For example, if the torque was measured at 3000 rpm, the hp at 3000 rpm is:

6.5 x 3000 / 5252 = 3.7

-Deerslayer


 o
RE: B&S Torque Labeling

An interesting discussion of torque vs. horsepower.

http://vettenet.org/torquehp.html

t


 o
RE: B&S Torque Labeling

The best scenario for a dragster is to have torque peak at the highest possible rpm. This will produce the most hp and lowest ETs.

An LT or GT is a bit different. Since rpm is governed on both, the best situation is to have torque peak at governed rpm.

-Deerslayer


 o
RE: B&S Torque Labeling

I think it's the next step in the marketing game.
I feel the horsepower ratings have been oversaturated and now we need something new to get the consumer's attention.
Now Joe Suburb can walk around saying he has more torque (whatever that means cuz he doesn't have a clue,but it sounds good) than his low-life neighbor.
Your shrink calls it penis envy.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Tractors Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here