7.5 Hydro Design
 

I got a 7.5cc k&B and I am working on a hydro. I normally race full size outboards but like to run RCs every now and again. I am working on a design for a scaled down copy of my race boat but need some dimensions to make sure it will run well with the other boats. So if anyone knows overall length, after plane length, bottom width, engine placement, anything that I could use to help the design I would love it. Thanks Zach

RE: 7.5 Hydro Design
 

Not knowing what kind of hull design your looking at, I'm going to throw out some generic numbers:
Length 36"(+2)
Width 18"(+1)
Tunnel 9.75"(+1)
After Plane 15"(+2)
Engine Just behind the sponson transoms
Prop Weight 1.25lb(+.25)
Hope this helps

RE: 7.5 Hydro Design
 

Thanks for the help. When you said tunnel, are you talking about a tunnel in the bottom of the boat starting 9.75in from the back transome and how wide do you make it. i am not sure if your familar with a Hemp design boat, but that is what i am going to use. i am building one full size to run in OSY 400 and thought it would work well as an RC boat.

RE: 7.5 Hydro Design
 

No, the tunnel I'm refering to is the width between the sponsons. As for a Hemp design, I'm not familiar with it, so if you could post a pick or two....................