Hydro Strut Position

[Terry Heddin]

I see some unlimited/GP style hydroplanes run with the strut (even with flex shaft drive) thru the bottom of the hull, forward of the transom, and others with the strut hanging off the back of the hull.
Which is best, or does it depend on the boat?

 

[RaceMechaniX]

It's likely due to rules in the different organizations as well as class specifics.

 

[Hydro Junkie]

The R/C Unlimiteds, in Washington State, rules state the following:
"The forward-most part of the stock propeller hub shall not lie behind the transom plane, unless scaled from dimension
of the real boat". This almost requires the strut to be under the hull to meet that requirement.

When you look at the transom of the 1973 Pay'N Pak, you can see how the strut is mounted to the bottom of the hull, thus requiring a scale model of this boat to conform to that requirement.

 

[Terry Heddin]

This a "sport" boat, not a racer. Just for screwing around.
Just wanted to know if it has any effect on the way the boat runs.

 

[Kevin Sheren]

If it is a sport boat hang it off the back of the transom. I will also be easier to tune the ride.

 

[Terry Heddin]

If it is a sport boat hang it off the back of the transom. I will also be easier to tune the ride.

Thanks.
That makes sense.

 

[Hydro Junkie]

I was just adding to Tyler's comment about rules dictating strut locations.