Radio Box and Fuel Tank poistion on a Scale

[BobGutsell]

Hi Guys

**** I wish these forums had an auto spell check!

Looking through the galleries and build photos from some of the top guys on here, I notice that quite a few put the tank up front and the radio box on the side behind the engine.

Does the boat trim get adversely affected as the tank drains or is that more an academic argument?

I'm keen to know what you guys think because my 8200 build will get a whole lot easier if I do it this way.

Cheers

Bob

 

[Glenn Gates]

Hi Guys

**** I wish these forums had an auto spell check!

Looking through the galleries and build photos from some of the top guys on here, I notice that quite a few put the tank up front and the radio box on the side behind the engine.

Does the boat trim get adversely affected as the tank drains or is that more an academic argument?

I'm keen to know what you guys think because my 8200 build will get a whole lot easier if I do it this way.

Cheers

Bob

I'm definitaly not one of the top guys but I think the popular opinion is to place the radio box in the front and the fuel tank at the cg or balance point. That way the balance point will not change as fuel gets burned off.

 

[BobGutsell]

Yeah have always thought the same. After seeing some guys doing it the other way I'm wondering if it works just the same?

 

[SayMikey]

Ive done it both ways with no concern,just start with the cg in the right spot

 

[Lennard Cuenco]

i started main tanks at the cg, hopper in front of the motor...made a couple of spots for each tank so i can adjust based on what happens on the water

im guessing every boat is different cuz of weight, speed...etc etc

 

[Glenn Gates]

Ive done it both ways with no concern,just start with the cg in the right spot

Same here, I've tried to build with the balance point1/2- 3/4" behind sponson transoms and haven't had bad results so far. But one thing I've noticed is the boats tend to lift the left sponson near the end of the straights. Next time (if there is one) I'll have a 10 or 12 Oz. tank in each sponson and a small hopper tank and plumb it so the right hand tank drains first.

 

[Bert Dygert]

Glenn,

Prop torque is what is lifting the left sponson at the end of the straight away. If you can move weight to the left hand sponson as far forward as you can go.

I just went through this problem with my Circus two wing hull. Boat was blowing off the water right at the end of the straight away. I had to add weight (last resort) to the left sponson to keep the boat on the water. Strut depth , Strut offset and angle had no effect on keeping the sponson on the water.

Happy Building

Bert Dygert

 

[Glenn Gates]

Glenn,

Prop torque is what is lifting the left sponson at the end of the straight away. If you can move weight to the left hand sponson as far forward as you can go.

I just went through this problem with my Circus two wing hull. Boat was blowing off the water right at the end of the straight away. I had to add weight (last resort) to the left sponson to keep the boat on the water. Strut depth , Strut offset and angle had no effect on keeping the sponson on the water.

Happy Building

Bert Dygert

Thanks Bert, Last time I ran the boats was@ 4300 ft. elevation and they were right on the edge but never blew off. Just moved down to sea level and talked to one of the locals and he has a pound of lead in the sponson.

 

[BobGutsell]

Thanks for your comments guys, the 8200 hull has very little head room in the "normal" tank position, for anything but a custom tank. However a Radio box fits in their nicely.

I run my tanks and radio boxes on the left side to try and prevent that spnson lifting thing. Rightly or wrongly, I also put my rudder on the left.

This will be my first time to run the tank up front.

Cheers

Bob