Torque & Horsepower curves

[comin' unscrewed]

Can anyone here tell me why the torque and HP curves of any given engine always cross at 5250 RPM?

[Oldsquirt]

The answer to your question can be found in this thread:
http://free.***boat.net/ubb/Forum1/HTML/001434.html

[Havasu Hangin']

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[Infomaniac]

Looks like that link was a question for me. I did not see it until now.
Torque is a mechanical measurement done on a dyno.
Horsepower is a mathmatical calculation. To calculate horsepower you use the torque and the RPM. The constant is 5252.
So torque and HP are always equal at 5,252 RPM
This is extremely important to know when you select engine parts. The RPM you intend to operate the engine at will tell you if you should shoot for torque or horsepower.
Most boats engines(not outboards)should be built for maximum torque. Car boats as HB calls them.
need a spell check on these posts.
[This message has been edited by Infomaniac (edited May 15, 2002).]

[GasTurbine]

Originally posted by comin' unscrewed:
Can anyone here tell me why the torque and HP curves of any given engine always cross at 5250 RPM?
This is most certainly not true for "any given engine"...
I think you meant to say "piston" engine. http://free.***boat.net/ubb/smile.gif

[Infomaniac]

Maybe he should have said reasonably affordable engine http://free.***boat.net/ubb/smile.gif

[GasTurbine]

Originally posted by Infomaniac:
Maybe he should have said reasonably affordable engine http://free.***boat.net/ubb/smile.gif
Contray...I can get fresh 1150hp T-53s for about $3000.00.
And they will pump out that 1150hp all day long, with no complaints, little wear, and little chance of breaking. In fact...they are more at home at 100% than anywhere else.
How long would a 1000hp+ piston engine stay together running at redline with a full load?
Methinks, not so long. http://free.***boat.net/ubb/smile.gif
To each their own tho...as long as we are in the water, and havin' fun!
Happy Boatin'!

[mister460]

Hey Gas, I'll take two!!!

[GasTurbine]

Originally posted by mister460:
Hey Gas, I'll take two!!!
If your serious...email me. I havnt check stock for a while, but I can find out ASAP.
He also had some 1350hp units as well.
You *do* know the down side to turbines dont you?
1. Terrible milage (ours get 2 gallon per mile @ 100%...yes...you read that right)
2. Noise...there hidiously loud.
If you can live with that, you can have an indestructable plant that will last for years and years under heavy use.
Happy Boatin'!

[Stupid Fast]

Hey Gas turbine, I see that you are from the same area as me. Where do you boat? I would love to check out your rig.
Drop Me an email. Way cool boat.
Eric
[This message has been edited by Stupid Fast (edited May 16, 2002).]

[Infomaniac]

Originally posted by GasTurbine:
Contray...I can get fresh 1150hp T-53s for about $3000.00.
Add up the installation cost and the operating cost for a year and compare it then. I would like to have one. The noise would always be an issue.

[Unchained]

A guy I met in the Mi.Hot boat assn. has a 32' Skater turbine boat that he bought from Howard Arneson. He told me the boat has logged over 100hrs at over 100 mph and I guess it tops out at close to 150 mph. He said that when he fills her up he has the guy with the tanker truck with home heating oil come by and the fuel is less than 1$ per gal. That probably offsets some of the extreme fuel consumption. I don't think fuel cost is much of an issue to him anyway.

[GasTurbine]

Originally posted by Infomaniac:
Add up the installation cost and the operating cost for a year and compare it then. I would like to have one. The noise would always be an issue.
Installation costs are the same for a hi-perf piston engine.
Operating cost are offset, by not having to rebuild a 1150hp piston engine every 2 seasons.
But yes...noise is the biggest issue. http://free.***boat.net/ubb/frown.gif
Take care.

[Infomaniac]

Originally posted by GasTurbine:
Installation costs are the same for a hi-perf piston engine.
Come on now be honest. I looked in all my catalogs and did not see engine mounts for a turbine. Checked with Bassett and Rewarder. They did not have exhaust. The driveline folks did not even know what I was talking about. http://free.***boat.net/ubb/smile.gif http://free.***boat.net/ubb/smile.gif http://free.***boat.net/ubb/smile.gif http://free.***boat.net/ubb/smile.gif

[BOFH]

Can you get an adapter to mate it up to an Alpha drive unit? I could use a little boost in my VIP ski boat... The 4 cylinder is a little underpowered, and this should cover me. Will it fit under the existing cowelling?

[GasTurbine]

Originally posted by Infomaniac:
Come on now be honest. I looked in all my catalogs and did not see engine mounts for a turbine. Checked with Bassett and Rewarder. They did not have exhaust. The driveline folks did not even know what I was talking about. http://free.***boat.net/ubb/smile.gif http://free.***boat.net/ubb/smile.gif http://free.***boat.net/ubb/smile.gif http://free.***boat.net/ubb/smile.gif
We made our own mounts out of steel, and then had them chromed. About $30 worth of steel stock, a welder, a torch, and about an hours time...whala! You can see them at my web site.
There is no "exhaust" system for a turbine engine.
We drilled the output shaft flange to accept a standard Ford u-joint flange...piece of cake.
Now we did have to order our 2 HD drive shafts...that set us back $400, but hey, I know people that put that much into their out-drive yearly! http://free.***boat.net/ubb/smile.gif
Take care.

[GasTurbine]

Originally posted by BOFH:
Can you get an adapter to mate it up to an Alpha drive unit? I could use a little boost in my VIP ski boat... The 4 cylinder is a little underpowered, and this should cover me. Will it fit under the existing cowelling?
You can go to my web site, and look at all the pics on how we set ours up, but sure...you could hang an out-drive on it...but dont forget to beef it way up...turbines have linear torqe all thru their RPM range...it would certainly eat a stock drive in no time.
The T-53 is a pretty big engine (however, weighs less than a complete big-block), and has the output shaft oppisite the exhaust, so you would have the exhaust issue if you wanted to lay it down in the boat, with the shaft facing to the rear.
Pratt & Whitney makes a smaller (750hp?)turbine that is quite compact...I found a guy who put one in a jet boat, and he was able to enclose the whole thing. He also fabricated some stainless to route the exhaust thru the transom just above the water line...I believe he broke 100 if I remember correctly.
Happy boatin'!