HP to speed question???

[Jim W]

Hi all,
I just bought a 1971 Hallett with a v-drive, freshly rebuilt 396 BBC with a Weiand tunnel ram and 2 650 Holleys, Hyd. cam and runs on pump gas. So far I dont have prop or gearing info. I am going to guess it has something like 400 HP? I was told the boat will do an honest 65MPH and might be closer to 70.
So my question is----- what HP do I need to do 80-90-100 MPH?
I have a new B&M 420 mega blower that I could put on the 396. I have been around blown motors for years and 468 BBC in DIRT Modifieds and dont know what it takes to get a 396 to really run. What kind of HP/RPM they can take without changing cranks/rods/pistons?? How hard can you push a 396 stocker?
Thanks guys, Jim

[sgdiv7]

That blower might get you 10 mph, if your lucky. Show us some photos of your ride. We like photos :D

[Moneypitt]

If you are going to go to all the work and expense to modify the 96 for the blower, why not leave it alone and start building a blown 4" stroke motor? I am sure you know that if you just stick the huffer on the existing 96 you will need a dust pan and a broom.......Another thing to remember is that speed is relative to alot more than just horsepower. The gear, the prop and the way the boat is set up will be the controling factors when it comes to top speed. A little research, and some minor "boat" changes may suprise you....MP

[coolchange]

had a friend with a 96 in an old flat. ran 6s w 2blade, spun it about 7000. ran pretty good in a river race but was done in 700 feet and ran about 75.

[Jim W]

Money pit,
I do have a unfired 427 all done up to the B&M spec sheet and should be just under 800 HP. I was just thinking I could take the blower and manifold off (which is not mounted on just sitting on the block) and put it on the 396. Might be fun to soo what I can get out of the old 396?
As far as the blower adding 10 MPH. I would think the blower would add about 200 HP with less than 10 psi boost. Wouldnt that get me more than 10 MPH??
I may just pull the 396 and drop in the 427. I just thought it would be fun to play with the 396 for a while.
Sorry I dont know how to get a pic posted. You can see the boat at boat trader.com 1971 Hallett located in Las Vegas, zip code 89032, white with blue stripes. Just do a search.
Thanks guys, Jim

[Jim W]

http://hallettrtside

[Floored]

My 396 ran in my Camaro running 8200 rpm.4 spd 4.56's 12.8 compression. was street driven for over a year before car caught fire. then in a 67 chevelle for another year. dollar for dollar 454 is cheaper hp though.