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View Full Version : Back from "Ultra" test run and new prop.



Lenny
10-07-2004, 10:12 PM
Man, what a difference as Matty said. The boat sits higher in the water, aired out a whole lot more, I don;t believe anything is in the water, or at least it "feels" that way, has waaay more bite and really sticks in turns with no blow out at third hole. It is a 14 x 24 P.

The elephant ear that was on it is of NO comparison.

My 3000rpm cruise, (GPS) has gone up about 5mph.
The tach, bouncing around a bit mind you is seeing about 5300, more than 5200 for sure. I wouldn't mind trying one more inch, either diameter or pitch. Best top speed was 58.4 and then I went into a run of waves rather too fast cuz I had to focus on the floor and try and find the GPS :rolleyes: This is with 400 pounds of gas, I had JUST filled up the tank and dunked her, as well, there wasn't a ripple on the ocean, reflectively calm like a mirror, other than the odd boat wake I found. So I figure, with 1/4 or less tank of gas, and a 1' chop I would see 60-62 ???

BUT the thing (port helm) is now spinning right and I have to literally grab the wheel between my knees and hang on hard with my right hand at any speed to keep it from going immediately to port. This is way beyond popeye stuff. This is WWF. I will search out a left hand prop during the winter 'cuz this won't do, plus it has added a slight bit of port heel and it does not have tabs.

Now, about the "prop shaft drilling" :rolleyes:
The mechanic pulled the shaft out this morning at 9am. I got a call at about 9:30am. He said the shaft was bent :eek: I said it seemed fine with little-no vibration. He said, "that's great, but your shaft is bent. I explained that I would like to upgrade the drive anyway in the near future and to just put a hole in it. No problem. Then an hour later, he called back to say he couldn't put the hole in it 'cuz it was too far out of whack and he couldn't even begin to get the tailstock to bore and sit in center. It would have ruined his equipment and given me a terrible, (no worky) hole. Bottom line, $300US for a "used" one that was straight and already had the internal thread. I said go for it. All done ($560US bill), grease job, fresh drive oil, Zincs, seal kit etc, and I was on the water by 5pm and just got in. GREAT run. There is no comparison now to what it was like. It is simply smooth. The prop is amazing. The shaft, now a bar souvenier for "Thunderboat Alley", was, get this, (and I saw it in the vise being rotated against the dial indicator) out by 50 thou :eek: That equated to close to 1/8" of deflection from linear through one full rotation. When we were spinning it it was horrific to look at.

Now, I have to get rid of the NICSON exhaust on there, and look into some sort of hydraulic steering for the Volvo 280, and find a left hand 15 x 24 Ultra or 14 x ??. I must change the rotation back.

Tons of fun. :D

Somehow my slip calculations aren't working out for a 1:61 tho. I get about 25% slip with these numbers at 58.4 @ 5300. I believe I have a set of 1:89's in there hence why I can pull the 24's to redline. What do you think? That would be 8%...

boxy
10-07-2004, 10:31 PM
Lenny, sounds like you are having a great time, keep your phone on Sunday if you can, on the way to my folks place I'll stop in and see this buddy of my Dad's who is a Prop Doctor, he's got a warehouse full of old cool stuff.....

Lenny
10-07-2004, 10:40 PM
Will do Steve. ;) LH 14 x 24 Ultra please :D

Will have a 14 x 24 RH Ultra for sale once I do.

Tony
10-08-2004, 10:41 AM
I cupped my 14 x 24 LH Ultra for an extra bit of pitch...1" I think they say. I believe the hydrodynamics of the AQ200 is limiting my top speed, as I have plenty of HP. Also, the boat gets quite "skittish" at 60mph, likely due to a bit of "helmet slop". With my ample horsepower I would love to try a 290 DP, but have yet to find anyone who wants to give me one cheap!

I bought my Ultra from a shop in Virginia, let me know if you want me to look it up for you...

EricG
10-08-2004, 04:11 PM
Sounds like the boat is really coming together Len....

Just remember, I may know where you can find a 24" LH Ultra :biggrin: :biggrin:

Hopefully you have better boatin' weather up there than we have down here...

-EG

Lenny
10-08-2004, 05:07 PM
Eric, something might be in the works here. Will know on Monday or so. :)

RickR
10-08-2004, 07:40 PM
Lenny
Have you done a torque tab adjustment? Are larger tabs available for the Volvo?

Is your skeg straight?

Lenny
10-08-2004, 07:55 PM
Rick, I have reversed my original problem by changing prop rotation and prop so it is "steering related", cable/drive slop whatever.

Just that now it is basically undrivable at any speed due to the forces to turn it. Sure runs flat, aired out and nice tho. I could probably hang a left better than one of Greg K's go-carts :D

It is not beating me up 'cuz I have lots of stuff to do and 4 or 5 months to accomplish it.

As far as the torque tab Rick ???, ...it would have to be the size of the rudder off of the "USS Abraham Lincoln" if it was to have any effect.

penbroke
10-08-2004, 10:15 PM
:biggrin: I found the same thing. Added about 5 mph at any RPM once on plane.

I think the only Ultras available out of the box were 14x22, 14x24 and 14x26. All in either LH or RH.

From your numbers I expect you do indeed have 1.61 gears. Your numbers are pretty close to mine and from what I've seen slip numbers are generally pretty high for Volvos. High teens to low 20s. It's a lot like pushing a brick through the water...

Play with the torque tab. It doesn't take much to make a big difference in steering effort. You might be suprised...


Frank

Lenny
10-08-2004, 10:22 PM
WOW :eek: , 20% , never knew that. The analogy is a little sad mind you... :( I am saving for a new brick... :D

I was seeing 34 mph at 3000, now I am at 39.5-40 on GPS, which translates into almost no slip at this rpm range.

Certainly tho, there is no comparison against the elephant ear. Yes, about 5-6 mph is exactly right. Sure fun tho and "light" . "USS Abraham Lincoln" Torque tab issues will get addressed.