easiest set up would be a 3 Rotor Wankel and V drive, the 3 Rotor Wankel can be made to produce significant HP but 9000 would be a good upper limit if reliability is an issue, most Factory Wankel's will spin higher than 9000 but the Factory suggests 9000 as a upper limit for Redline

a small Hydro would be my choice as well.

its funny u say 3 rotor that was my intention yea they can rev very high but with turbo , that limits the higher rpm range to how high the hot side of the trubo will produce boost. ive never done a "PP" (peripheral port) 13b (2rotor) but they have the potential to rev 13k same as 20b (3 rotor) .. just a little hard to find a 20b with reasonable price tag in cali without importing the e-shaft from japan, newzeland or austrailia . questinon with hydro.. dont i need suficient lowend torque to make that baby pop on-top of the water ??????

I raced Mazda RX7's in the late 70's and early 80's , we ran Peripheral Port 12A's making around 270 HP at 9000

No you dont need to jump the tail up, actually I wrote an article on another site about the concept of Blowing the Tail on a hydro, I completely disagree with that concept and we used a Very shallow shaft angle and tried hard to keep the prop as far in the water as long as possible, because the props are more efficient in the water like a flat bottom, a hydro usually runs around 67%-73% prop eff, a flat bottom runs in the low 90% range

Opps, that was in the IMSA Racing series GTU class

it's a shame you dont have connections and some Titanium rotors for that deal, I am confident I can make a Titanium rotor live, if the Hydro was for competitive racing you should contact Maza Racing in Irvine and see if they would help you

now that would be amazing ! its going to b a weekend warrior if i had the deep pockets ide love to try a super lightweight titanium rotor engine the potential would b amazing but rotarys expell so much heat u think ti. would hold up ? if so a 26b or true 4 rotor turbo would more than likely shit on anything  excluding nitro boats

Yes, the Titanium rotor could handle it, if the rotor to housing clearances are adjusted to compensate, and the use of some ceramics are possibly in order, but a Titanium rotor 26b could see 18,000 RPM , the real issue is the Exhaust temp, and since the engines in a boat using water to cool the exhaust some to manageable numbers is an Option, and people think I'm Old School....LMAO

here is a 20B producing 1664 HP http://www.braptv.com/play.php?vid=123

The Turbo's make so much Noise you cant hear the engine at Max Power

sorry that should have been 26B

honestly i thought i was going to be laughed @ for the idea of putting a wenkel in a boat. yea that 4 rotor is not technically a 26b its 2 13b's bolted together a lil different intake spacing rather that of a true 26b e-shaft but yea , ti starts to loose stability or rigidity @ like 850F right ? the exhaust temp is way way higher than that (buddys a pipe fitter he was schooling me on melting points n what ever) another question is .... weight distrabution if in a hydo, prob. be a flat bottom because of major price and avalability, but this engine weighs a fraction to that of a bb..c hell u wanna hear rpm
http://www.youtube.com/watch?v=UgsKjjhib0o

Exhaust Temps are in the 1350 degree range, Oh I know a Rotary makes RPM, the Peripheral Port Engines make, 14,000 in drag cars, but arent real reliable at those RPM's, but they run pretty Fast

Ryan, I have been snubbed by many for my Ideas, and now many call me Old School because they think I am not up on Technology, but they really have No clue what I know, in 1973, a Well Known Super Stock Plymouth Owner Driver Thought I was Insane for trying to put a 69 440 Road runner in C/Stock formula 3 Automatic class, thats a 2 barrel class, ...the NationaL RECORD WAS A 12.20, MY little old 440 with a 2 barrel ran 11.80's at 118 mph.......4 tenths under the National record....I dont care what people think of me, or My Ideas.......let them eat Tire Smoke

I would build a scaled down flattie from 'glass over wood, maybe 13-14 foot. Make it light weight with 2 bucket seats. I worked at a Mazda delership in the 80's. Rotary motors are amazing. This sounds like a cool project whatever combo you choose.

John

John, I dont know that I would shorten the boat much, narrowing it wouldnt hurt though, there used to be a westcoast flat called the "Cheese Monster" it was short, handled badly and was pretty hard to drive as I recall.......just sayin

Speaking of the Cheese Monster...as I recall 50% of the pass was spent out of the water 100%...Should have called the boat "Pucker Factor"

Bruce...yep, thats the one....evil handling sucker ....

funny thing about flat bottom boats, they are wrong for the higher speeds, in order to make them stable you must bleed the air off the bottoms of the hulls, if not they tend to upset themselves at higher speeds causing one side to chine....then it's a little to late, my theory is, you don't want more hull in the water than you need, but you don't want the boat to far out or up in the front, if the rules allowed a shallow tunnel with say 4-6" wide runners on each side and one down the middle that would make a good place to start, or like I have seen where the boat rides high on a center dropped hull section, ...which is good as long as it's stable enough not to rock side to side...just my 2cents