Worlds largest piston engine - 100,000hp @102rpm

[Le Pirate]

so....uh....how many gallons per mile?




can you tell i'm not an engineer? 

[Capo]

Yes. Of course. Heenan & Freud.




  Seriously though, I'm not familiar and a quick search yielded nothing.  How does it work?

Its basically a water pump

What they don't know about dynamometers is not worth knowing.

http://www.froudehofmann.com/product_family_28.htm

http://cgi.ebay.co.uk/1963-Heenan-Froude-Worcester-Ship-Dynamometer-Advert_W0QQitemZ400023218583QQihZ027QQcategoryZ69515QQcmdZViewItem

[Langanobob]

That's F'n nuts, are you sure about that 10,000 rpm?

Dang, I hate it when this happens.  I made that post at midnight-30 and should have thought it through more better.  It's been about 9 years and I did some remembering and it was closer to 8,000 RPM (still pretty fast  ) and I'm not sure about the exact 6 foot rotor diameter.  It was a big sucker though.   If I can find some pictures I'll post them.  The rotor was aluminum, I think it was the compressor side that had the problems, and looking at the broken remnants you could see the internal area where the failure started, kind of like a star shaped crack.  I'm not a metallurgist but the failure analysis stuff is always interesting. I think the cause was bad forging or bad material.  Lots of politics and finger pointing and the manufacturer provided scatter shields like the ones on drag race clutches but there were no further problems.

[Langanobob]

No problem maan.......just take a toke on this spliff and evrthing be ok

See you're an old Jamaica hand, either that or you live in NYC  .  Try as I could, I never mastered Jamaican Patois, even though it's supposed to be based on Englsih.  Lots of fun trying.
Seriously, the Jamaicans I worked with were skilled, serious about their jobs and in general were a lot smarter and harder working than their US power plant operator counterparts.   Really enjoyed the Jamaican experience.

[superjohn]

OK. So what's so magical about 5252 ? Why is torque and HP the same at that rpm?

[Popeye the Sailor]

OK. So what's so magical about 5252 ? Why is torque and HP the same at that rpm?

Can't tell you. Secret engineering mystery 

[superjohn]

Can't tell you. Secret engineering mystery 

It's one of those Illuminati stone mason secrets isn't it?

[Popeye the Sailor]

It's one of those Illuminati stone mason secrets isn't it?

More like, you don't want to get into that level of geekiness. Seriously-we're in our own little world, and it's not pleasant.

[Capo]

HP=TORQUE X RPM / 5252

James Watt determined one horsepower as 150 pounds, 220 feet in one minute.

Convert 150 pounds of force to foot pounds torque.

Assume the force of 150 pounds is "applied" tangentially to a one foot radius circle. This would be 150 foot pounds torque.

Convert  220 feet in one minute to RPM.

The circumference of a one foot(from the assumption above) radius circle is 6.283186 ft. (Pi D)

The distance of 220 feet, divided by 6.283185 feet, equals 35.014 RPM

Factors are one horsepower,150 pounds of force (torque), and 35 RPM.

Constant (X) = 150 ft.lbs. * 35.014 RPM / 1hp

35.014 * 150 / 1 = 5252.1

Therefore the constant is equal to 5252

So then hp = torque * RPM / 5252

Below 5252 rpm any engine's torque number will always be higher than its horsepower number
Above 5252 rpm any engine's horsepower number will always be higher than its torque number
At 5252 rpm the horsepower and torque numbers will be exactly the same.

[Popeye the Sailor]

James Watt determined one horsepower as 150 pounds, 220 feet in one minute.

Most observers familiar with horses and their capabilities estimate that Watt was either a bit optimistic or intended to under promise and over deliver; few horses can maintain that effort for long.

[Capo]

I prefer to use the watt as a unit of power measurement as it is based on physics (one joule of energy per second) rather than observations of a horse.

HP however produces the larger number and that is what people want to see

[Popeye the Sailor]

I prefer to use the watt as a unit of power measurement as it is based on physics (one joule of energy per second) rather than observations of a horse.

HP however produces the larger number and that is what people want to see

Maybe I should start telling people the length of my junk in centimeters. 

[superjohn]

Maybe I should start telling people the length of my junk in centimeters. 

I do that. That's right ladies. 7.5..... Uh huh......

Thanks for the explanation Capo. That makes sense. I figured it had something to do with the definition of HP.

[Speedbag]

HP=TORQUE X RPM / 5252

James Watt determined one horsepower as 150 pounds, 220 feet in one minute.

Convert 150 pounds of force to foot pounds torque.

Assume the force of 150 pounds is "applied" tangentially to a one foot radius circle. This would be 150 foot pounds torque.

Convert  220 feet in one minute to RPM.

The circumference of a one foot(from the assumption above) radius circle is 6.283186 ft. (Pi D)

The distance of 220 feet, divided by 6.283185 feet, equals 35.014 RPM

Factors are one horsepower,150 pounds of force (torque), and 35 RPM.

Constant (X) = 150 ft.lbs. * 35.014 RPM / 1hp

35.014 * 150 / 1 = 5252.1

Therefore the constant is equal to 5252

So then hp = torque * RPM / 5252

Below 5252 rpm any engine's torque number will always be higher than its horsepower number
Above 5252 rpm any engine's horsepower number will always be higher than its torque number
At 5252 rpm the horsepower and torque numbers will be exactly the same.

Backed up by any dyno sheet which will show that the HP and torque curves for any engine always intersect at 5252 RPM. 

[Oldfisti]

Backed up by any dyno sheet which will show that the HP and torque curves for any engine always intersect at 5252 RPM. 

Now there's a man who knows his dyno sheets!     Much dyno experience?  I have a bit. Even though it's borderline bench racing I find it exiting finding HP on the dyno during tuning.