Gas Scale Belly Pans

[Tim Strange]

As I struggle with building from scratch and trying to figure the optimal motor placement, I've found that regardless of how far forward I move the airtrap a belly pan will be necessary.

The IMPBA rule VI.C.4.b states: Belly pans are acceptable to clear engine and/or flywheel but maximum width shall be no greater than 5". Belly pan may not be used as a form of planing surface and can not exceed the depth of any riding surface or recovery surface.

The last part makes perfect sense to me because you would be adding a lot of drag and you would end up with anything but a 3-point hydro. My issue is with the 5" width. There is no such restriction for 1/8 scale and Section 4 for both classes states "Hull bottom will not be judged or checked".

I think that making the belly pan as narrow as possible is the best plan (I may be able to make it 3" wide). But since gas boats use a 5" rail, why not make it 5 1/2"? This would include the 5" I.D. width plus two 1/4" rails. I think that an increase in width would be beneficial to ease of construction and strength. Of course, why is it there anyway if the hull bottom will not be judged?

Also, if I am not mistaken...NAMBA and PNWTA has the same 5" restriction.

Tim

 

[SayMikey]

If you need 5 inches or more ya better rethink it

 

[scott williamson]

If you need 5 inches or more ya better rethink it

. That's the same thing I said to my wife.

 

[Hydro Junkie]

I think part of the issue is that, if made too wide, the belly pan starts to act like an air dam. Since an air dam can affect how the boat performs, it could be used to help tune the boat's ride. This, in turn, can give a boat with a pan an advantage over a non-panned boat during a race

 

[wayne middlemiss]

Lol Scott

 

[Tim Strange]

If you need 5 inches or more ya better rethink it

. That's the same thing I said to my wife.

Now that is funny!