... what would be your build-data on something like this ?

NOTHING super-sensitive that could not take some daily running of up-to 6 hours or so ...... (this is being considered for a X-drag-boat ... now going to be a "cruiser") ...

DEstroked 383/400 ? ........ Super lite pistons and rods ? ...... etc

My opinion? For a boat I'd look for some lite rods & pistons, perhaps a good 440 crank with the usual mods, a Milodon oiling set-up with an accumulator and (believe it or not) a cam similiar to what Mopar ran in the old cop car motors but perhaps with hydraulic rollers. Top it off with some Edelbrock heads & a dual-plane intake & I think you'd be set.
My thought here is to be looking for some steady, mid-RPM power that can run cool all day & not devour fuel like a race motor. After all the old, big Mopar cop motors would idle all day, run good top-end speeds on the freeways, stay cool and would do it for years (literally!) without any major work.

What do you call "really high winding"?

My old de-stroked 383 use to turn 9500... light pistons
and rods.... with a good balance... with nice heads

whats yopur budget? I have many bbm. v-drive combos if your interested

Gotcha, I would definately consider 9,000 rpm`s high and I have no clue or answer in terms of engine combos but I`m sure they will be rolling in soon.......good luck.

VERY impressive boat there br572 ... is that really a 572 ?

As I write this I have Bad Boats 2 in my VCR ....with Kyle Walker and Freddy Bray !

Mr P .... TALK TO ME on that combo !

Its a 572" and I spin it to 8400 on every pass thats with 52% gears in the v-drive! High rpms
have their place at the races ,but very un feasable at the lake.put a bigger gear in your v-drive instead and your motor will last mucccch longer. I have owned many flatbottoms and found that a 18 gear with a 15 pitch prop worked very well or a 15 gear and 16 pitch prop that will put you at 100 mph at around 7200 rpms, typical prop slip is between 25 to 30 percent. my lake boat(21ft Belmont) 468 bbc it spins 6500 and pushes that big boat 86mph with a 18 gear in the v-drive

Mr P .... TALK TO ME on that combo !

---

Basically it was a 350... alum rods, light pistons for
the day... mushroom tappet big duration(cant recall
what it was).720 lift, alum heads ported with a 4 speed
tunnel ram with 2 850s in a 2800# Valiant, with ladder
bars

9000?? Why??

25-30% slip ? .... at WOT at big-speed ??


This boat is a Stevens shovel-nose hydro with (I think) a Thro-bred? v-drive ... gearing I think is 30-over(I don't think I can get any parts for it)... prop is a 12" 3-blade cleaver.

I am just putting this together .... total newbie at this. I have fooled-around with a Hydrostream ... that had a habit of chine-walking at 80 mph !

Props on a boat and a airplane are like gears in a car, sometimes it is better to lug the motor in between the peak torque and peak HP for best performance If you want a tempermental high winding BB try a 4.5 or bigger bore with a 3.7 or shorter stroke, max out B1 heads or Predators and two big carbs or a good hair dryer or blower and a good EFI system NOT CHEAP, may not live long either but it will make bookoo HP at high RPM for a while

Like Cab suggested, I had planned on building a 477" RB for my Horizon with a 4.5 bore Mega Block and a 3.75 stroke. In speaking with Herb McCandless, he said it could be done, but would be very, very hard on the valvetrain. He stated simply that it was not designed for that kind of RPM.

If you do go through with this, you'll probably want to talk with these people: http://www.jesel.com

FWIW, I ended up building a 528 (4.5x4.15)

25 to 30 percent is about right on.the prop is way to big direct drive about 11" 2 blade or 10 1/2 3-blade is what you want. I run only three blades on my race boat. thats with a clutch and two speed for pro elimator (8 sec. bracket) all out she runns in the 6.8 range at over 170

CB .... my thoughts on all this ...is this.

There is NO WAY that I will be able to ever run this boat flat-out anywhere around here. SURE ...you can run 160 plus out in Lake MI .... but a boat like this would stuff-itself on the first 2 foot roller.

ALL I want is a boat that will GATE SHOT like a bear. And my thoughts are(br572 would know better) ... is that from a dead-stop OR a slight-roll .... the prop-slip would be HUGE. SO ... my need for an RPM motor that would do-so ....RIGHT NOW.

The prop on my boat slips very little from a dead stop. clutch+two step at 5000 rpms+52 gear=lots of prop speed ,little slip and consistant rt.no boat out there without a blower or nos can out half track me. 4teens to the 1/8!!!!!!!!!!!!!!

Big question would be what stroke you looking at Doc. The RPM will be in the abilty for the heads to flow, and the cam and valve train that would support it.... Long arm engine like a 4.5" stoke will take much more head than the same engine with a 3.75 stroke. High winding to me might mean something diff to someone else.
above 8K to me is high winding. stoke stroke 440 with a set of fully ported B1's will get it done.
Anything from the facory on this type build would be a waste of time and money.