1971 Hallett V-Drive Speed Question?????

[DansBlown73Nordic]

A friend has a 71 Hallett with a 396 BBC. It turns 5000 rpm,s and runs 60 on GPS. Not sure on gears. 15s or 18s im sure. Im thinking this is about as good as it gets. I had a 66 Stevens and with lots of time spent it was about 65 with a 396. Just curious what everybody thinks.

[GofastRacer]

Well, that depends on how well the boat is setup, I ran 85 in my Lavey with a 396, oval port heads, flat tappet cam and a tunnelram with two 390's!..

[Jim W]

Well, the boat is mine and I just spoke with Dan on the phone. Dan said he posted this question up, I will fill in the blanks....
I have the boat sold if I can get it into the 75 MPH range +/-. I think a 100-125 HP shot of nitrous might be the cheapest way but you guys let me know.
Starting up at the top.....396 BBC 60 hrs on rebuild.
Speed Demon 850 (yes I know too big) I do have a old Holley 3310 with vac secondaries that would need a rebuild kit.
Edelbrock RPM air gap
Cast iron unported heads Code8872702 these are oval port closed chamber, with a 3 angle valve job, 1 hr run time
Forged TRW pistons with very small pop ups
Forged crank, rods but dont know rod bolt size??? Want to stay below 6,000
Cam is a Comp Cam PN# 11-236-4 Hydraulic cam
Gross intake lift 544---Duration @ .050 226
Gross ex lift 547---Duration @ .050 236
110 C/L and is installed straight up
I tried to check the gears in the v-drive by turning the engine 1 rev and watching the prop. The prop went about 3'' past the starting point after 1 rev. 1:20 gears???
The boat just turns 5,000 RPM
Should I just get the nitrous kit or play with the v-drive gears and prop or even a cam change?
Nitrous kit would be $400.00 brand new shipped.
Bottom line---- I need to go from 60 MPH to 75 MPH on the cheap side.
Be good, Jim

[058]

Find another buyer and sell it "as is" The buyer you have now wants you to foot the bill to go fast and we all know that speed cost money, [how fast do you want to go?] You just might spend a small fortune to get another 15 mph out of it.

[V-DRIVE VIDEO]

Well, the boat is mine and I just spoke with Dan on the phone. Dan said he posted this question up, I will fill in the blanks....
I have the boat sold if I can get it into the 75 MPH range +/-. I think a 100-125 HP shot of nitrous might be the cheapest way but you guys let me know.
Starting up at the top.....396 BBC 60 hrs on rebuild.
Speed Demon 850 (yes I know too big) I do have a old Holley 3310 with vac secondaries that would need a rebuild kit.
Edelbrock RPM air gap
Cast iron unported heads Code8872702 these are oval port closed chamber, with a 3 angle valve job, 1 hr run time
Forged TRW pistons with very small pop ups
Forged crank, rods but dont know rod bolt size??? Want to stay below 6,000
Cam is a Comp Cam PN# 11-236-4 Hydraulic cam
Gross intake lift 544---Duration @ .050 226
Gross ex lift 547---Duration @ .050 236
110 C/L and is installed straight up
I tried to check the gears in the v-drive by turning the engine 1 rev and watching the prop. The prop went about 3'' past the starting point after 1 rev. 1:20 gears???
The boat just turns 5,000 RPM
Should I just get the nitrous kit or play with the v-drive gears and prop or even a cam change?
Nitrous kit would be $400.00 brand new shipped.
Bottom line---- I need to go from 60 MPH to 75 MPH on the cheap side.
Be good, Jim
Those heads are probably 3872702 65' 66' 396-427 heads.
If it has a 3 blade propeller switching to a 2 blade will help.
Is the engine healthy? Does it have good compression? If its new it should.
If it were my boat and I had a healthy engine to work with. I would have it professionally tuned.
If the tuning and propeller didn't get me there, I would tear down the engine and look at replacing the cam with a larger one and porting the heads.
Just my .02

[DMOORE]

Find another buyer and sell it "as is" The buyer you have now wants you to foot the bill to go fast and we all know that speed cost money, [how fast do you want to go?] You just might spend a small fortune to get another 15 mph out of it.
+1. If the buyer is so interested in a number, let him chase it himself. Tell him if he buyes it now, you'll throw in the 400 bucks for the nitrous set up. My guess is he will run like a scared cat.
Darrell.

[Jim W]

Find another buyer and sell it "as is" The buyer you have now wants you to foot the bill to go fast and we all know that speed cost money, [how fast do you want to go?] You just might spend a small fortune to get another 15 mph out of it.
Well, 2 things.
1-- Here in the the north east, it's hard to find a buyer for this type of boat. The guy likes the boat but wants more speed than a GPS'ed 60 MPH as opposed to the E-bay 110 MPH boats. I >guessed< that the boat ran 70-75 MPH and he came with a GPS thinking he would see something in the 70's and was dissapointed with 60 MPH.....
2-- I dont know but would a $400.00 nitrous kit (100-150 HP) get me 15 MPH??? If that is what it takes to get the boat sold, I would do it and go on to my next project. To me, $400.00 is not a small fortune....
Be good, Jim

[058]

Well, 2 things.
1-- Here in the the north east, it's hard to find a buyer for this type of boat. The guy likes the boat but wants more speed than a GPS'ed 60 MPH as opposed to the E-bay 110 MPH boats. I >guessed< that the boat ran 70-75 MPH and he came with a GPS thinking he would see something in the 70's and was dissapointed with 60 MPH.....
2-- I dont know but would a $400.00 nitrous kit (100-150 HP) get me 15 MPH??? If that is what it takes to get the boat sold, I would do it and go on to my next project. To me, $400.00 is not a small fortune....
Be good, Jim
And if the N2o does not do it? Who gets stuck with the boat? Seems to me if it doesn't you will still own the boat AND a $400.00 nitrous system, a no-win situation for you. I stand by my advice, find another buyer or lower the price enough to make the boat a decent deal for a 60 mph boat. :idea: edit: Upon looking at your specs there is a couple of things you might try. First zero lash the valves, lifters might be pumping up limiting your rpms to 5K. Your cam looks healthy enough to get 5500 rpms or more with no more than an adjustment. Second, check your igniton timing, it may be way off futher limiting hp. Third, Kit the Holley 750 and play with the jetting. 3310s use 72s in the primary and try 76s to 80s in the secondarys. Use a 6.5 power valve in the pri. Make sure the carb gets enough fuel. No pressure drop at WOT. These 3 things will cost you nothing but time and a carb kit and might get you to your [his] goal.

[coolchange]

You don't want to spin it over 6000 because of the rod bolts but your willing to put a 150 sshot on it?:idea: Speed in that dealio means rpms and a 2 blade as stated. Had a friend with a Hondo back in the day. 396 .06 gears, small 2blade. Ran like a raped ape to about 80 mph. Like was stated before, offer him a break and walk away or you'll have a broken 0 mph boat.

[Roaddogg 4040]

Jim... I hope you don't get burnt with this buyer by spending a bunch of time and money on the boat and then have him back out after you do everything... There is nothing from keeping him from backing out after you hold up your side of the deal. For what it is worth I would just tell him pound salt and try to sell it to someone else.
I know that finding buyers is tough but this guy sounds like a pud... Just my $0.02 worth...
Steve

[SnoC653]

What size/type prop is on this boat now? If nothing else see if you can borrow a prop and try changing props and see if it picks up speed. If going to more pitch drops your top end RPM, you're running out of HP and the NOS might get you there. But, if you add the NOS to make it go 75 he'll say he wants to be able to cruise that speed all day. So, it's doubtful he'd be happy with that solution. I think the tune up and prop are the keys to getting it where you want it.