Y2K props
12-23-2004 | 07:59 PM
#41
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Joined: Oct 2002
Posts: 5,246
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From: Ivoryton, CT
Re: Y2K props
I think Mike said the prop shaft was 3" below the bottom before he changed the drive.
Now it is 1" below with the Speed Master.
The 24' Super I/Os have the X at 18" or so. My Pantera was the same. The prop shaft is 5" below the point of the V on my boat and 6-1-/2" below the pad on the step 24' I/O.
Condor 24 re-rigged his 1-1/2" to 2" higher than mine. we'll see how he makes out.
How is the 30' Y2K set up?
Now it is 1" below with the Speed Master.
The 24' Super I/Os have the X at 18" or so. My Pantera was the same. The prop shaft is 5" below the point of the V on my boat and 6-1-/2" below the pad on the step 24' I/O.
Condor 24 re-rigged his 1-1/2" to 2" higher than mine. we'll see how he makes out.
How is the 30' Y2K set up?
__________________
Patrick
Patrick
Last edited by Pat McPherson; 12-23-2004 at 08:10 PM.
12-24-2004 | 09:53 AM
#42
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Joined: Feb 2003
Posts: 1,661
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From: BABYLON NY
Re: Y2K props
Sometimes its best just to sit back and listen.Singles do need alot of bow lift.The original set up was 2 below with a neutral box=3 below plus leverage from the box.All = to 86-87 with 550n hp.nothing fancy with props.Now with the speedy IV the motor was able to be lowered 1.5 inches in the boat for better center of gravity and prop still 1 below the bottom.And yes they do make spacers from the 1-3 inches.So changing the X will be effortless.With the speedy case being so narrow you get to use alot more blade surface of the prop so im hoping on not going to low with the drive and still being effective.But we all know its a trial in error.
12-24-2004 | 01:25 PM
#44
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Joined: Jan 2004
Posts: 798
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From: "SUPERBOATLAND" LONG ISLAND - NEW YORK
Re: Y2K props
Originally Posted by jcap
Thrust is a mechanical force which is generated through the reaction of accelerating a mass of gas, as explained by Newton's third law of motion. The gas or working fluid is accelerated to the rear and the engine and craft are accelerated in the opposite direction.
From Newton's second law of motion, we can define a force F to be the change in momentum of an object with a change in time. Momentum is the object's mass m times the velocity V. So, between two times t1 and t2, the force is given by:
F = ((m * V)2 - (m * V)1) / (t2 - t1)
If we keep the mass constant and just change the velocity with time we obtain the simple force equation - force equals mass time acceleration a
F = m * a
If we are dealing with a solid, keeping track of the mass is relatively easy; the molecules of a solid are closely bound to each other and a solid retains its shape. But if we are dealing with a fluid (liquid or gas) and particularly if we are dealing with a moving fluid, keeping track of the mass gets tricky. For a moving fluid, the important parameter is the mass flow rate. Mass flow rate is the amount of mass moving through a given plane over some amount of time. Its dimensions are mass/time (kg/sec, slug/sec, ...) and it is equal to the density r times the velocity V times the area A. Aerodynamicists denote this parameter as m dot (m with a little dot over the top).
Jim
From Newton's second law of motion, we can define a force F to be the change in momentum of an object with a change in time. Momentum is the object's mass m times the velocity V. So, between two times t1 and t2, the force is given by:
F = ((m * V)2 - (m * V)1) / (t2 - t1)
If we keep the mass constant and just change the velocity with time we obtain the simple force equation - force equals mass time acceleration a
F = m * a
If we are dealing with a solid, keeping track of the mass is relatively easy; the molecules of a solid are closely bound to each other and a solid retains its shape. But if we are dealing with a fluid (liquid or gas) and particularly if we are dealing with a moving fluid, keeping track of the mass gets tricky. For a moving fluid, the important parameter is the mass flow rate. Mass flow rate is the amount of mass moving through a given plane over some amount of time. Its dimensions are mass/time (kg/sec, slug/sec, ...) and it is equal to the density r times the velocity V times the area A. Aerodynamicists denote this parameter as m dot (m with a little dot over the top).
Jim
12-24-2004 | 01:37 PM
#46
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Joined: Apr 2004
Posts: 927
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From: Texas Gulf Coast
Re: Y2K props
Pat - come to Texas again, I'll meet you and get you for a ride in the SB!!! JCap, my heads spinning just like Bash above - we were LOL at the image he attached!
I do agree there's nothing that beats trials - get out there and report back - we finally hit some cold weather so I don't know when I can report on the 5 blade, but i'll do it as soon as I can
Keth
I do agree there's nothing that beats trials - get out there and report back - we finally hit some cold weather so I don't know when I can report on the 5 blade, but i'll do it as soon as I can
Keth
12-24-2004 | 01:41 PM
#47
Gold Member
Joined: Oct 2000
Posts: 5,664
Likes: 140
From: Hollywood, MD, USA
Re: Y2K props
Originally Posted by Pat McPherson
Hey Dave M.
What do you think? Got an extra $1000 in the budjet?
I know we both need new props....
What do you think? Got an extra $1000 in the budjet?
I know we both need new props....
12-24-2004 | 05:45 PM
#50
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Joined: Sep 2002
Posts: 364
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From: babylon ny
Re: Y2K props
Mike ,
Try going deeper, a spacer is cheaper than a speedy prop anyhow ! I gained 5 mph by adding a 2 inch spacer , I know that goes against what most of us have been taught but it worked for me. Deeper drive also aids bow lift
Try going deeper, a spacer is cheaper than a speedy prop anyhow ! I gained 5 mph by adding a 2 inch spacer , I know that goes against what most of us have been taught but it worked for me. Deeper drive also aids bow lift
