Horsepuppy

[mikenixon]

LOL! I was thinking more along the lines of model-glue (toluene) smell... But I get you.

[5speed]

another interesting read..
is there a difference between horsepower and "brake horsepower". Brits use that term..

"Brake" is an engineering term originally meaning "measured" (technically, a dynomometer is called a "brake"), but as willy pointed out, it came later to refer to "at the crankshaft" and in reality it's virtually always computed and not measured. Not because crank dynos aren't used, they are, but in powersports they're much rarer than rear wheel dynos, more common in the auto trade. Having spent a considerable portion of my working years at manufacturer's corporate offices and thoroughly trained by the manufacturers, I can say with confidence they never think or talk in terms of rear wheel horsepower. It's only the end user, including race shops, that do. So one more of those things where the manufacterer and the customer talk different languages. And thus the war/debate that seems to rage between the validity of the two methods. They are both valid, with different purposes. And after all, the most common use of a dyno at the consumer level is more as a comparator anyway, not as an absolute measurer.

The next question that comes up is how much loss is there in the transmission and drivetrain. Again, that's unimportant unless you're comparing rear wheel to crankshaft, and the shop with the dyno bay doesn't care about that, only in before and after readings, at least not in powersports. Fifteen to twenty-five percent are popular assumptions for the loss in powersports, varying with the type of drive and other factors.

Something you might find more interesting is brake and chain problems show on a dyno. You can inuit their causing losses, and you can even read those losses on the dyno graph.

I worked in a speed shop years ago that had engine pieces still embedded in the ceiling. And I once built a big inch Harley that on the dyno failed the only original part left in the buildup, the lifters.

Tks for the explination Mike..
then there is Newton meters...
I googled that one. lol

[gltriker]

Hello Mike.
When I started reading this article this past Wednesday, almost immediately some of your first paragraph's words took me back to the Summer of 1971. (I was 22 years old. ) The same year I had registered and insured my now ready to go 1953 Servi-Car, for legal operation on the road.

anyways those words are... "Wonderfully elemental mechanical sounds; shatteringly violent,"

I had stopped at the Syracuse Harley-Davidson dealer to pickup a few quarts of H-D Regular Heavy (60W) oil for my Servi-Car's engine. As I entered the store, I noticed a paperboard advertisement for a motorcycle hill climb propped up inside the storefront showcase window. Sounded interesting and a few hours later I told my, chopped Indian Chief riding, buddy about the event. Let's go!!
It was going to be about 15 miles south of the city in a rural area on a farmer's land. At the lower end of a paved, steep and narrow twisty road nicknamed, "The 13 Curves." Turned out that on the other side of the ridge separating the hill climb area from the 13 Curves road, was a dry streambed gulley.
When we parked in a farmer's field and walked up to the advertised competition area, the starting line was at the base of a maybe 30 feet wide incline . About 50 feet up the hill from the starting groove was a naturally occurring wet seam across the climb path. I can't remember how long the hill was, though. Guesstimating 150 feet.

I most vividly remember a race team of fellows from somewhere in Ohio in their matching H-D jerseys and straw hats.
They had several looong hardtail frames hill climbers, powered by side valve w/ magneto ignited engines, springer forks and heavily chained up rear tires.
I abruptly learned they used a nitromethane fuel mix, too, when I was exhaust blasted from behind, as a result of unknowingly sitting on the ground behind one of those pro hill climber bikes when it was started. To this day I loathe the smell of chlorine.
There was a mix of other bikes and riders there, too, but nothing matched the thunder of their sidevalve engines and the huge roostertail of dirt and stones they deposited on unaware spectators. A woman sitting on a higher elevated natural terrace was struck in the forehead by a small stone at least 100 feet behind the staging area. Drew blood and tears from her, too.
All of this commotion on that very memorable day, came back to me as "shatteringly violent", 50 years later .

A Kawasaki H1 500cc triple cylinder made a run at the hill, with "tuned pipes". An awful racket. Can't recall whether it made a full climb though. I saw my first and only time since, American Eagle motorcycle that day, too. At the time, because I didn't know what I was looking at, I reckoned it must be a Honda clone. I believe, now, it was the Laverda 750cc engine model.
Sorry for getting carried away to my memories from a half century ago. But, you knew this article would reignite readers' memories!
I have another one, of a fuel motorcycle drag racer back in the 60s and 70s, and I'll bet you would recognize quite a few of the pro circuit racers' names he raced with. I knew him briefly in the early 2000s, because he and I worked in the Service Department for the same TORO distributorship. Different branch locations, though. Me in Syracuse. Him in Buffalo.
Come to think of it now, Maybe whiskerfish knew him, too!
Until I searched the internet for his name after I started this longwinded contribution, I eventually found he had passed away in 2018. I never knew he was nicknamed the, "Buffalo Bullet." Or, that he had owned a bike shop in Buffalo, N.Y.
If you are somewhat interested in this old time racer and his equipment , although he passed away in 2018, you can find a lot of his pictures on Facebook. Al Charlier is his name. Also, investigate Al's wife FB. Her name is Patty Charlier.

Thanks, Mike!!

[gltriker]

. It was Thursday.

[mikenixon]

Wow. Great memories. Found Al's picture on the 'net. Apparently a very much liked guy. Saw a comment by his daughter Trish.

[77Gowing]

I'm always fascinated by why certain numbers are settled upon instead of others. So why 550lbs? Instead of say 500lbs, 100lbs or 1000lbs.

Your answer probably lies in the resolving of unit fractions.
I remember still a bit of this poetry from my days in the dyno labs for the US Army.
Mike, is always entertaining with his writting eloquence.

[mikenixon]

[Sidecar Bob]

This video explains how the term "horsepower" was coined for marketing purposes

[mikenixon]