I've been stalking the forum for a while now while working on what I guess I would call a "mini" jet boat build (nope, not another NZ river mini.... think mini Southwind TD or Placecraft... ), and I'd like to ask for some help with a final detail on the design before I start the build.......
For a little background, the hull is based on a little 11' outboard runabout design by Glen-L Marine called the TNT that I've modified into a 12' 6" Mod-VP style tunnel hull with a drive extension pod and converting it into an inboard jet drive using the powertrain from a 2004 Honda R12X PWC. The center pod is 12" wide and extends 12" beyond the transom as a "drive extension pod" and very low deadrise with 2 degrees at the transom. The pump intake is 15" from the lead-in to the front edge of the shoe assembly and 6.5" wide. The lead-in is also 21" from the end cap of the drive extension and the intake and surrounding mount flange is dead flat.
I've got the design pretty well scienced out but I'm having some trouble coming up with the best design for the pump intake area at the rear of the center pod / drive extension for best performance and keeping the pump loaded properly at higher speeds. During my research I've come across a design that I guess I would call a "drop keel running pad" and would like to get some thoughts on using something like this on the build and whether it would work or not? And if not, what works on this type of hull?
.......and this is what I came up with based on research.
The "drop keel running pad" shown is 5' 6" long by 11" wide by ~ .75" below the keel. the pad is flat with vertical side walls 39" forward of the drive extension end cap and then gently tapers and slopes to a point with the sides angled as shown in the pics