Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

At least Briggs has all this in writing on their website it you know enough to look for it.  Obviously Tecumseh and any other engine manufacturer follows this same rating procedure.  Pretty lousy numbers when you think about gross HP as opposed to BHP that we are really concerned with.  Still, they don't mention if this rating system takes into account the very lean EPA carburetors, so I'd have to say no, which means its even worse.  If you look at the last paragraph that I highlighted in RED, this supposedly 8 hp engine I have that is run in ACTUAL conditions and NOT in optimum laboratory conditions, has a pitiful rating, as do all of our engines.

Horsepower Ratings

The power ratings shown with the individual engine series on the preceding pages are established in accordance with SAE (Society of Automotive Engineers) code J1940 (Small Engine Power & Torque Rating Procedure) (Proposed Revision 2001-09). Power curve and engine performance data are obtained in accordance with SAE J1349 (Net) or J1995 (Gross) Engine Power Test Codes.

In accordance with SAE J1349 (Net) or J1995 (Gross) Engine Power Test Codes, power curves are developed from laboratory test engines and are corrected to standard conditions which are:

Altitude: 100 meters (328 ft)

Ambient Temperature: 77 F (25 C)

If the engine will be operated under ambient conditions different from above standard conditions, the following factors should be accounted for in estimating "on site" power output:

Engine power will decrease 3.5% for each 1000 ft (300 m) above sea level and 1% for each 10 F (5.6 C) above standard temperature of 60 F (15.6 C).

The actual "on site" power output will also vary depending on other factors including the manner in which the engine is operated, the fuel that is used, and the application in which it is installed.

The "Maximum BHP" curve represents maximum performance output of optimum laboratory test engines of a particular model. A statistical mean of production engines, with 95% confidence, will develop no less than 85% of the Maximum BHP when tested after run-in to reduce friction and after clean-out of combustion chamber, with valves, carburetor and ignition systems adjusted to laboratory standards.

The "Recommended Maximum Operating BHP" is a calculated curve and represents 85% of the maximum BHP curve. For practical operation, BHP load and speed should be within the limits shown in the "Recommended Maximum Operating BHP" curve.

If the maximum speed of the engine specified for a given application is governed to a speed less than the speed at which the Maximum BHP occurs, the engine will not achieve the Maximum BHP in that application. For applications requiring operation at other than the recommended engine speeds, complete details of the proposed engine installation should be referred to the factory for evaluation.

Source:  Briggs & Stratton Technical/Warranty
http://www.commercialpower.com/display/router.asp?DOCID=76491

Richie wrote:

Exactly what you been sayin Richie. Thus my thoughts as to when you are able to find the charts within operating range for it's application,Like for a snowblower.  3600RPM 8HP  then there is a 9 HP engine, no graphs same engine, etc But 9HP?

Did they just take it from the lab test's at a higher RPM.  All I can say is we haven't been able to find proof that they didn't.

All we can know for sure is they sure charge you more. no not just the motor, they gift wrap it into a little more glossier machine, where they increase to price for a percentage of the additional horsepower that you are not getting as both run at the same operating range.  Remember this all started for me after few years of repairing other peoples machines.  No big deal, moved to diff area word got around, now everybody that needs repairs is your best friend. yada yada. Only reason I mentioned that is that is how I was lucky enough to test out different types and horses, and torques of diff machines.  Cause I usually don't refuse a Snowblower,  more money to be made, and I like them.  When peoples lawnmowers etc break, they are more relaxed etcThey have time and is easier to borrow etc  and they can buy 89 dollar special.  When SB breaks, Oh my gawd a catastrophy, how am i gonna get out to road for work and a low end new one min 600 bucks.   I haven't ben able to do a side by side comparison say from an 8 and an11 or similar,  But it is my opinion if they are similar engines in bore an stroke and strength/size, runnin like just on crank pulley etc, you got always take the whole machine into consideration there ain't that much difference under the same type load. If there is any difference at all.   An that s the only way you can test em l either a dyno or a seat of the pants practical application.

Ben07

 

 

 

That part about Power loss at Elevation, Ive been preaching that for YEARS. Especially for our Higher up Western Customers. They are lucky to get Half the rated hoarsepower to the snow when you figure in Elevation, Temp, Driveline losses and Good Old wear and tear.

Bigger is almost always  BETTER.

Thanks Ben.

Any way you look at it, no matter what size engine you buy, as long as the manufacturers are allowed to rate the engines in this way, you most certainly should forget whatever HP rating they give it.  I can only say that I am very happy I didn't spend the extra $400.00 for the 11 HP OHV engine for my model. 

Richie wrote:

And you were saying ?

Hi Mountain,

I posted something in the wrong place, but I just fixed it.  I also do recall you mentioning the altitude issue somewhere.  Altitude really makes for some horrible numbers. 

No problem Richie, I believe you got another Bullseye on that briggs post, Right over the first Bullseye on the Lawnboy disclaimer.  Shootin one Bullseye thru another, where I come from is called "shootin Tacks".  Tacks are sharp.

Ben

youn will loose some ponies with altitude yes .

but you will also notice horsepower numbers are taken at 60 degrees...not much need for a snowblower then.

at realistic temp you will actually be making up for some lost power...when its cold the air is denser and you get a better burn.

the engines are also rated with all there emmisions carbs and if muffler has a calalyst in it then it must be installed.

most engines are tested without a muffler...or with a stack.

any questions.

later chris

snowshoveler wrote:

Hi Chris,

Well believe me, if the Boss fired everyone for disagreeing with him, I'd be out of a job along, long time ago...

You should see the bench he's designated for you.  It'll take you months just to find it under all the junk - no that's not the right word - crap - no, trash - no...well you get my point.

There's a power saw sitting there from 1950 and a 36 volt generator - so your work is all ready cut out for ya - when shall we expect you to be arriving?

Sherri

MissSnowshoveler wrote:

Hey Sherri,

That's good to know, thanks.  Hey, I love working on the old stuff, I'll get that Saw and Generator working in no time.

BTW...I'm actually buried under all that stuff.  The other day, while kneeling down trying to clean the place up, someone rolled a big heavy snowblower over my back and pinned me there.  I wish someone would come and help me, the tire chains are still digging into the back of my head

Richie wrote:
All the more reason for " OVER-POWERED IS USUALLY ADEQUATE"

Richie...

the lawnmower is a bit of a different story,your gonna love this.

the engine is capable of its 6.5 horsepower.however the blade is the limiting factor.

there is a certain rpm allowed for the length of blade installed on the mower.

basically it amounts to how many feet per minute the tips of the blade travels.

so in a sense you are CORRECT the numbers are crappy.

they take a high horse motor and slap it on a mower and then wind the throttle speed so far down that it can barley get out of its own way.

remember when we had those little 3.5 or even 2.75 horse 19 inch cut mowers.they would turn up like a racecar and would mow down anything you could push it through.

its all about the blade tip speed  and that even changed,i think it was 21000 feet per minute and now its 19000 .not positive on the actual number but you get the idea.

longer blade ,slower its allowed to go ...or it will break up and thats not pretty especially if you wear sandals.

ps i hope you get your butt out from that pile of junk...i have a bunch of work to get done .

later chris

MountainMan wrote:

Mountain,

I have to agree with you on that one  The problem is that over-powered or purchasing more engine than you may need is really expensive.  I suppose the way things are, it's a no win situation for the consumer.

snowshoveler wrote:

Chris,

.     

"I suppose the way things are, it's a no win situation for the consumer."

Well, that might be taking it a tad too far. LOL 

When you get down to the nut cutting, if you bought an engine that will throw your snow how you imagined it to be thrown with the HP you thought you bought, regardless of what the sticker says on the cowling, you're winning.




But, I know what you're saying.

Richie wrote:

Not much different than getting the upgraded larger motor in a truck.  I couldove bought the 9 HP 24", but went to a 1128. Noty like i was doubling the price.

On my 48" mower, price diff between a single cylinder and the Kawasaki twin was negligible, a worthwhile investment. The 15 HP is there when you need it, and if I ever selll it, will hold its value.

MountainMan wrote:

Mountain,

MountainMan wrote:
All the more reason for " OVER-POWERED IS USUALLY ADEQUATE"

Hey Mountain,

I think this qualifies in that area  Here is a really great way to make any OPE engine come to life.  It just goes to show you that no matter what size engine you have, you can always find a company that produces high performance products for it.  Too bad a snowblower would be difficult to modify for this type of thing.  Sure looks real cool and it could make a Briggs 5 HP or larger OPE engine scream

 http://www.hscsupercharger.com/

That would make a Go Cart a screamer!

Marshall wrote:

Marshall,

When I read that, the first thought in my head was as a kid I saw that Munster's episode when Herman decides to take Eddie's go-kart for a ride.  Of course it was filmed in fast forward to make it look like it was going much faster...LOL.  I could imagine that supercharger  on a go-kart, it wouldn't surprise me if that's how fast it would actually appear to go

I'm not sure what the fuss is about. My reading of the original post is that  what they are saying is this:

1. We tested our engines using the following independant standard;
2. Here are the implications of that standard;
3. Here is how production engines relate to the standard; and
4. Here is how we set up production engines, differently from the standard.

It seems very above board and a lot more honest than the so called "9HP" shop vacumns that run on a 115V 15A circuit.

Engines produce different HP under different conditions, that's why there are standard conditions, so you can compare apples to apples. The fact that the company is saying that under normal, non-ideal conditions for an extended period of time the engine produces less shouldn't surprise anyone. They, along with other manufacturers design to meet the standard. If they could come up with a design for an equal or lower price that causes more HP to appear  under "normal" conditions you can bet they would. The physics of the situation make that unlikely.

I'd also argue that "over powered is better" is not true. While it is convenient to have a machine that easily handles the one storm in a hundred it also means that you have too big a machine for the other 99 and have wasted a lot of resources and effort. The smaller machine that fits what you need most of the time will handle the big storm, just not as easily. I see three types of people buying snowblowers:

1. Doesn't research, walks in and gets something too small because its on sale;
2. Has more money than brains, buys biggest baddest  machine around and then wonders why its a pain to clear the 27" walkway; and
3. Everyone in this discussion area who always get exactly what they need .

I hope I've moved from about around 2.5 to 3. I have a 10/28 that I am pleased with and enjoy using. It is actually too big and heavy for my usage patterns and snow patterns. My next machine will be a 9/26 with different options, the 2 big things being an easier way to turn the thing and faster ground speed.

nibbler wrote:

The fuss is about any OPE engine supplier being allowed to place a sticker on an engine, stating a certain HP, yet being allowed to rate the HP and torque at a certain RPM, and actually delivering it to you at a much lower governed speed and never coming close to what it's supposed to be. 

This independent standard the industry is allowed to use is a complete joke.  Because of this, my 8 HP engine only produces somewhere maybe slightly above 6 HP.  A lawn mower generally doesn't require much HP unless the grass is wet or very over grown.  A snowblower or similar equipment usually requires the engine to work much harder.  It would be one thing to say I have an 8 HP engine, and once the power transfers from the crank to the gearbox, pulleys, belts and such, the power available is actually 6 HP.  That would be fine with me if they looked at that as gross Vs. net horse power.  I'd still be able to say I have an 8 HP engine, but that isn't the case here.

Too add to Richie's Great explanation.  There is also the question, of maybe selling the same powerplant, badged with two different HP numbers.  That could be legal if you add the disclaimer that Richie dug up from Briggs and Lawnboy. 

The test has a guideline that takes a reading (yes usually a percentage of) at the max hp produced on the HP graph..  So say thet we use a tech 9HP.  Seems the manufactured now maybe has two options,  He can put it on a machine and say it is an 8 as that is all that it will develop at the operating speed of the machine.  However from what we have been seeing, and somewhat really looking at to see if it can be disproved, is do they have the other option of Tagging the engine as a 9HP  and in the fine print, making note that your machine won't necessarily produce 9.   That along with the other aspects Richie  mentioned may all be a problem..

     If someone wants to ignor it, fine, no problem, as some of it may be false.  However ignoring it and disproving it with applying facts are two completely different aspects.

Richie tried to question it, fair amount of disbelief, however he then proved his side with facts.  You want to buy more machine, less, say the test is standard, which it is, however the results can be given to the consumer different contexts, thus allowed with hidden hard to find fine print disclaimers. That is fine and entirely your choice.In my opinion If you choose not to ignor it I think it enables you to be a better consumer.  Also a consumer who will know better ho to get a better value for their money.  Best example is the higher stated output  engine in the same category, probably has a higher mark-up from the manufacturers actual cost, It is probably not one of the machines that like home depot gets a lot of.  The manuf would supply more to the depot with the lower mark-up  and the higher mark-up to the dealer. Why cause the dealer needs more profit to survive, The manufacturer gets somewhat offset by the HD buyers not claiming as much warranty service for the miniscule problems. they fix them themselves.(the owner of the machine)  

An example of it helping you as a consumer would be to go into the dealer and saying why is it 400 dollars more for this machine.  before he speaks, you say it is not 400 for handwarners, 20 bucks cost for them, drift cutters,  20 bucks cost .  2 more inches of snow box.  maybe 75 dollars in manufacturing differential..  and I know that engine says a 9  but it is the exact same engine as the 8,  just the rating trick they seem to be allowed to use.  Sure he will maybe be stupid and loose your sell.  however he is gonna talk to the manufacturers and say I think we ought to cut this out,  or we are going to be out of business sooner or later, like your fathers oldsmobile.   (because of a negative image etc) or like lawnboy who tried to sell two lines of mowers, one a little cheaper to manufacturer.  Lawnboy still made the good high quality Supreme, however lot of consumers saying I heard lawnboys are now junk etc.  They lost a lot of market share there.  And to boot they had those problems when they did in no way disguise the lesser quality model by calling it a "utility" and stating that it had lesser features than the high end model.  Now we are talking about a marketing strategy that may be designed to give you less than what is advertized and really not adequately informing you, by disguizing it with a marketing ploy.  All that tells me is most of  the small engine manufacturers are in bed together.  kinda like a monopoly

Ben07