Prop Help

[Joe Reese]

I need some assestance with a decision. The prop i have now is modifiyed and when the engine hits the pipe the rear of the boat lifts and wants to roll to the right(porpusing). the props seen to raise the hull and then gravity takes over and the prop shoots the hull rite back out of the water.

Depth and angel are not the fix,But a smaller prop is with a reduction of speed.

I had been reading on some tech notes and the outter edge could be adjusted to reduce lift by tuning in the blades outter edge. would this be some thing that is recommended to try out to try to control the lift.

Whould that be concidered the raking affect?

Thanks

 

[shoboat]

Hey Joe,

What kind of boat? You should try backcutting the trailing edge of the propeller,

this will take out some of the lift that is causing your problem. Cupping the

prop will also take out some of the lift also. Try reducing the blade diameter

that will help a lot. Send it to me if you would like. A little more information on

your setup would help a lot. It sounds like the wrong propeller for your boat.

You may have too much cup in the prop also if you have tried all of these things.

Thanks,

Mark Sholund

Props-4-U

4830 Arbor Grove Drive

Traverse City, MI 49684-7266

 

[Joe Reese]

All that has been done!

 

[Grimracer]

Joe

There is a good chance that you will have to run an X prop for the time being.

Why is it that you do not have one on there? Im quite sure you run a cut lifting prop..

Just a question..

Grim

 

[shoboat]

Joe,

Is this on a Tunnel boat? If you would give us a little more information

we could help you more. Setup is so important ,and maybe you have

overlooked something. Joe, a proper sized and pitched propeller will

not slow you down either,I think you just need an adjustment, from

a PROP DOCTOR :lol: :lol: :lol:

Thanks,

Mark Sholund

Props-4-U

 

[Joe Reese]

I run a mod Rossi on a WOF hull (tunnel).

I think I have stated this in many other postes, LOL

So far all the ABC props I have used are the top of the top for this hull. Good engine RPM ( wishing the pipe could be longer ), Great top speed......

The props need to become non lifting, meaning the hull lifts when at top RPM and twistes to the right when gravity pulls to the waterthe engine will not slow down it twists the prop to lift the hull and prop line rite to the surface. Lawless lower out of the water................

 

[Grimracer]

Joe

Dont fight it.. let it go.. be the prop joe...

Truthfully you could be fighting a up hill battle and taking the fun out of racing the boat. There is a good chance that (at the current rate) you will go faster and better with an X prop.

No question about it that you can get the props you have to work but at the frustration of losing races. (at least for the time being)..I know for me it would be frustrating.

Get an X-448 or X-450 and get a base line. After you have maxed out the performance of this setup start applying the bad boys to the stub shaft.

Its also not a bad idea to talk to mark the prop doc. He can help you and the first step is to admit you have a problem...

Stick with us Joe.. you are real close to having the boat up front..

Your racing bud…Grim

 

[shoboat]

Joe,

I see you must have a 7.5 tunnel hull,what propellers are you trying to run?

1450's right? A pitched up X-447 works real well on a 7.5 tunnel also. When

you get the right diameter figured out you will then start to really improve. I

just gave you the answer to your problem.

Thanks,

Mark Sholund

 

[Joe Reese]

All of you guys are great!

Mark looking at my chart I have tried the X447X3, H-7 mod cup, 1450 cut,back cut and cupped, and the 52x70 cut, cackcut, cupped.

So far the X447 I tried was treeked and was real reponsive, Still lifted with no push pull affect on the water (torque twist)

Mike it was a bummer

I had the boat running the night be for. At the race, what a bummer.

<_< thinking about the day when I got home I thought I was about to loose sleep over it.

On the other hand one of the members came down with a Prather hull and a K&B that was in storage for a few years. we found a hair ball in the carb then it started to rain, we still played and wow that old boat ran!

He ran it on a 225. It was up and gone.

I personaly like that prop for break in.

Helping one out that is having problems with their equipment is part of the fun and it made us feal good to releave the frustration of others.

Thanks

 

[shoboat]

Joe,

You may want to try a Prather 230 or a X-447 two blade pitched up a little.

I would take 2 mm out of the 230 and maybe even a little backcut and

HOLD ON TIGHT :lol: :lol: :lol: . The P-447 maybe a good propeller to

try also with a little backcut. I have all these propellers in stock if you want

to get CREATIVE.

Joe, I still think your answer is 47mm of diameter.

Thanks,

Mark Sholund

 

[Joe Reese]

guys do you think hes getting his polish on?

View attachment 2431

 

[Roy Munoz]

He's checking a nick....

 

[Propjockey]

"..................d@mn turtles.........................."

 

[Joe Reese]

LOL

LOOK AT WHAT SOME OF TOES PROPS WILL DO!

Leaves other drivers in a rain shower.

View attachment 2447

 

[Joe Reese]

I'm not tring to fight the prop I'm going to work it.

But first I have a question??

What will the prop do if I cut the tips level with the hub =|