Uncle Toys

DanL - Thanks, I really appreciate the information. When you eat a drive like that, what exactly happens in the water? Does the prop stop spinning or does it windmill? When you say it just continued straight each time, was there much the driver had to do to keep it going straight? What was the fastest speed it happened to you at? And to go back to what RonP was talking about, were your props turning in or out?

Really appreciate your time - thanks!

Philip

Uncle Toys, and anyone else who would like to read turning "In" vs "out", look under "Great moments in Cat History" starting on page 3, T2X posted on this subject, and GJL, "Mr. George Linder",
Philip
» Great Moments in Cat History (Page 3

DanL

my first memory is that the tach pegs and I pulled the throttles back and the boat just settles in the water. We ran the engines pretty high and there is alot of aerodynamic influence so the loss of propulsion from one side was negligible. The boat never tried to hook or turn hard. On the twin cats, I never turned my props in. At high speed, the thing was all over the place. One thing of note is that 2 Skaters, a 24 and a 32, 2 vs 3 outboards, the 24 was always faster in the smoother water and the 32 was faster in the 3-4 footers, but not because of waterline, which does make a difference in real sloppy conditions. The 24 would accelerate harder in the smooth stuff, but because of the 3 props on 32, it hooked up harder on re-entry and would gallop a boat length at a time as you sawed the throttles.

[ 02-05-2002: Message edited by: DanL ]

Ron P

I brought it back to the top for you and others to read. It was probably one of the most interesting threads on this board.

Here is the answer to your question from T2x.
====================================

Ron P.--My thoughts on "spinning" in..... Simple physics.... Right hand rotation propellers,torque (lean) the boat to the left. Left hand rotation propellers torque the boat to the right. In a twin engine boat spinning outboard or , RH on right side, LH on left, the torque of the propellers tends to return the boat to level when one side or the other leans outward. When props are spun inboard RH on left, LH on right, or counter rotated the torque tends to make the lean worse. This occurs because as a boat(Cat or Vee) leans to one side, the prop on that side buries deeper and exerts more force, while the prop on the other side rises (in some cases out of the water) and exerts less force. So...... If a RH prop is spinning on the right side of a boat leaning to the right, the prop tends to push the hull back over to the left. (spinning Outboard). If, however, the left hand prop is on the right side in a right hand lean , the prop tends to continue to roll the boat over. I submit that this is why there has been such a dramatic increase in barrel rolls (even in straight-aways) in races in recent years. When I flew over races for 16 years, I could always spot the counter rotated boats, because they behaved very differently (and definitely not better)than their properly spun (outboard rotation) competitors.
The reason that many people spin them "backwards" is the fact that on some hulls the boat may gain a mile or two per hour at top speed....or..... the boat has a bottom tune that needs more bow lift. The speed can generally be achieved in other ways without using an unnatural rotation as a "bandaid" (This is particularly problematical on stepped bottom boats that skid first, then catch suddenly, then roll outward......get the picture?)
One can re-tune most bottoms to add rocker to provide bow lift without resorting to ill advised prop rotation changes.

Counter rotation is adviseable on SINGLE engine race boats when the courses change from counter-clockwise to clockwise. LH props like right turns and handle better, RH props like left turns. Since the Bravo drive allows for a simple flick of a lever to reverse rotation, one would expect that Factory 1 racers would have a supply of left and right props depending on the course ....... up until this year most F1 racers don't...... I guess nobody has "invented" this yet.

It's T2x....NOT "Tx2" please

Philip

DanL,
I have found the 32' (2) engine is faster then the 28' (2) engine, in the rough due to the tunnel height and length, never had 3rd engine on the 32' to compare 2 vs 3. Always spun the props out except one day. Next day went back to spinning out.
Philip

DanL

Props do not generate equal thrust at each blade at all positions in rotation. The descending blade generates greater torque but the ascending blade exerts more thrust. In aviation its called p factor.

Intolerant1

Having worked several actual homocide cases, I can tell you that most of the information the police will look at will come from the Medical Examiner, or Coroners Office. An attempt to determine cause of death will be made. Unless there is evidence of foul play ie. gunshot wound, witness account of an explosion, etc., there wont be much more to investigate. The "Homocide" Investigators the press reffered to may be nothing more than an Investigator for the Medical Examiners office looking over the scene prior to putting their signature on a report. The press likes to use words like "Homocide" and "murder"...even when they dont apply. Dont read to much into it. It only takes one stupid rumor to make this harder on the friends and family of those lost.

MIKEHTMSR24

This boat did come with full hyd. steering as standard equipment. To the helm.

If you don't have it to the helm please find out what can happen if you throw a power steering belt off while running. Everyone should be aware of this danger and keep a close eye on your ps belt and the pulley alignments.

JFM311

I know it may be apples/oranges but i have a video of a kilo run at 130mph plus--1 tranny blew-up--the boat reacted violently--they did save it but barely--it was a 388 slingshot--john

thisistank

L.A. County Sheriffs Dept. (who is investigating this accident) Will commonly send actual Homocide detectives to situations like this until it can be determined no foul play occurred. All they will learn from the coroners office is cause of death i.e. blunt force trauma and/or drowning. In a situation like this it is probable that they will look into why the motor came out of the motor mounts and look into the lay up of the boat to further determine foul play and/or liability. I can assure you the insurance companies and lawyers will be looking into this aspect of the investigation. But until the Sheriff's dept. finds convincing evidence that there was no foul play involved, Homocide investigators will be investigating this accident. That is normal for L.A. Co. Sheriffs Dept.

Tank