10,000 Horsepower in a Small Racing Boat
- Thread starter Winston
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You ever see the lobes on a cam of one of those blown nitro burners? Lobe is almost 3/4 around the cam!
I often wonder what kind of torque is on those props? They have to be pretty tough to spin up that fast in water!
I often wonder what kind of torque is on those props? They have to be pretty tough to spin up that fast in water!
dr wogz
Fly caster
the shape of the props too!!
I remember many many years ago we were down in the keys. and I was admiring one of the 'go-fast' cigarette boats moored along the boardwalk. The props weren't a standard 'hub with blades' but more of a tapered cone with long vanes. It looked more like a coarse wood screw.. Which, I guess at those speeds, makes more sence..
I remember many many years ago we were down in the keys. and I was admiring one of the 'go-fast' cigarette boats moored along the boardwalk. The props weren't a standard 'hub with blades' but more of a tapered cone with long vanes. It looked more like a coarse wood screw.. Which, I guess at those speeds, makes more sence..
rharshberger
Well-Known Member
iirc the Unlimited Hydroplanes that run at the Atomic/Columbia Cup use something like a 1 in 24" pitch ( and depending on conditions can be more or less). The shafts are also under extreme strain as they load and unload torque as each blade enters and exits the water.
Titan II
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boatgeek
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You can see the prop at 0:44. It's really skewed (swept back as it rotates) so that it doesn't have as big a shock when it hits the water surface. How much torque? Let's guess 5000 RPM for the engine. No idea if it's right, but probably not too far off. That plus 10000 HP plus an online calculator gives us 10,500 ft-lbs of torque. The shaft looks like it's an inch or two diameter, so it must be a heck of a fancy material.
I was really surprised how much steering the driver seemed to be doing. I would have thought the boats would be tuned to minimize steering inputs since steering is slow.
I was really surprised how much steering the driver seemed to be doing. I would have thought the boats would be tuned to minimize steering inputs since steering is slow.
rharshberger
Well-Known Member
Unlimited Hydros and drag boatsusually only have one prop blade in the water and the other two points of contact are at the rear of the sponsons.
Blown Top Fuel motor(which that is) in that boat isn't quite as powerful as one on the track, but that motor can turn 7000-10,000HP, again depends how much fuel they run through all the injectors and the blower speed. If you could see inside it's nearly full of liquid until the plugs fire.
Sooner Boomer
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They race these just up the road a bit. Search youtube for "boat racing okc". The Oklahoma River runs just south of downtown Okla. City. On quieter days, they race hulls (rowboats).
Nytrunner
Pop lugs, not drugs
What's this? Winston posting a video under 10 minutes that's reasonably viewable on break at work? Astounding!
Geez those screws/props make our hobby cheap in comparison
Geez those screws/props make our hobby cheap in comparison
