Tunnel Ram Time!

[HotHallet]

I am getting ready to stick a Holley tunnel ram on my 460 in my boat topped by a pair of Holley 450 carbs. Don't think there will be too huge of a difference until I put on the Edelbrock aluminum heads and swap the cam but the motor will atleast look cooler. With the right camshaft, the new heads, and the tunnel ram and carbs combined with some pump work she should start moving pretty good. I am thinking an A/B impeller. I would like to spin the motor about 5,500. Anyone take any guesses on how fast she will go? I have a manual place diverter to get the boat out of the water. If she hits 70 I will be happy. Once the tunnel ram and carbs go on and the heads the horsepower will bump up to about 479. That is with the isky 280 Mega Hydraulic flat tappet cam I have now. I need Cam ideas for the cam swap. Someone I talked to recommended Comp. My ultimate goal for the boat is 80 eventually but that is going to take some bottom end work and some serious pump work and I don't quite have the green for that right now. Anyway I will keep everyone posted with pics. Oh my boat is a '77 Hallet bubble deck 19. Your guesstimations are welcomed.

[Blown 472]

I would get some bigger carbs than that, you are now going to be moving more air and those carbs will choke it down.

[tom b]

hi h.h.
sounds good, you know theres no end to the green that can be dumped in these things, i have a 74 bubble deck hallet and i'm doing another engine rebuild this year. The motor i just took out was dynoed at 500 hp and i had a new aluminium A impeller from mpd,no other pump work was done, the engine was brand new out of the box and DNE did some tweaking and some new parts to get it up to that hp rating, right before i took the engine out we went to Elsinore and gps for a base line,and i got 70 mph. just my $.02
Tom

[HotHallet]

Hey 472- Will those carbs choke it down even with the camshaft I have now because I am not definitley sure I am going to change it.

[BrendellaJet]

Just because you will have the intake to deliver more air, does not mean your motor is going to use it. I would wait until you are positive about your cam selection, but either way- It seems to me that those carbs would be fine. I dont want to start shit here 472...but if you are certain, perhaps you could elaborate(for us rookies) on why you think more carb is necessary
[ May 07, 2003, 10:49 AM: Message edited by: BrendellaJet ]

[sleekster]

i run a tunnel ram and (2) 450 holley's on a bbc the cam is a dur. 325int 336exh lift 553int 571exh 114 lobe separation this motor puts out on the dyno 474.8hp @5500 and 501.6 toque @4250 these carbs were out of the box with a few shooter adjustments and were all she needed. this motor is in a 1979 sleekcraft with a berkeley 12jg rebuilt with a tanzoli impelor and ran 80.4 mph on gps. hope you find this helpfull.

[Blown 472]

When I was going to a tunnel ram on my engine, I was talking to Jack at MPD and thinking along the same way and he told me something about increased air flow and the need for bigger carbs on a tunnel ram, I cant remember just what he said, maybe hbjet might know, I just remember he said to run bigger carbs, and it made sense to me but that was alot of brain cells ago.
No need to worry bout starting shit, I dont get worked up just passing along stuff I learned/heard thats all.

[Hotcrusader76]

It's not that you will run out of air necessarily, it's the fact that your motor's vacuum and how it works with the smaller venturi on those little 450s that will prevent them from giving your motor more fuel.
Going to a set of dual 600s or 650s would give you an increase in top-end, which moves the fuel curve up so that the fuel will continue to pull in larger amounts.
The 450s have little .130" booster holes which only allow so much fuel to be delivered. The 600s and 650s have .139-140" size booster holes which deliver alot more fuel in comparison.
450s will work, but under the most carefully planned systems. IE Sleekster and his 80+mph boat with dual 450s. BBC is a little different than the BBF when it comes to carb selection. BBFs like the larger carburetors, but then again every motor likes dual 650+ over 450s.
Don't go out a toss them away quite yet, many people have used them and you just might like them. Hell ya will never know how good a set of 650/750s are until you run a stock set of 450s.
Hope this offered some better insight...
~Ty

[TRG]

all's i know is that ol'hot hallett's trailer makes that "ruby red squirt"er look like it does a "hunerd"!!! 10-4 good buddy :D im out!!!

[Jake W]

I have been told to put 2 750 Dp mecanical secondares on it and be done with it.Jake

[LakesOnly]

HotHallet:
I am getting ready to stick a Holley tunnel ram on my 460 in my boat topped by a pair of Holley 450 carbs. Don't think there will be too huge of a difference until I put on the Edelbrock aluminum heads and swap the cam but the motor will atleast look cooler. With the right camshaft, the new heads, and the tunnel ram and carbs combined with some pump work she should start moving pretty good.HotHallet,
To get the max potential out of aluminum heads (in your boat) would require some signifcant changes to your motor's bottom end. Have you bought them yet?
What heads do you have on your 460 right now and what pistons?
LO

[Bense468]

Is the setup HBjets old setup? Personally I would go with something a little bigger like 650's if you want to stick with the tunnel ram. I tend to believe the tunnel rams work a lot better on flattie that spin High Rpms. I would stick with a High po single plain manifold and a single carb if you want to stick in the 5000 rpm range. Everyone has their own advise and thats what I would do on your Hallet Travis.

[HotHallet]

Thanks everyone for your advice. I am going to throw the T ram and 450's on and see how it goes. I can always to switch to bigger carbs later.Truth be told I am very happy with my boat. It will not go a whole shit ton faster until I dive head and wallet first into the bottom end and the desire to actually go boating this season is going to prevent that at this time. Also to handle the 600 or so horse motor I eventually plan to install the pump is going to need a rebuild and a cut down impeller to turn the r's required to hit 80-85. The installation of the tunnel ram now is just to increase the looks factor. Hopefully the heads will help later down the road. I have another complete pan to carb 460 sitting in my garage the I plan to build and that will be the motor that gets the inches. Thanks Todd 'n' Juzz for the vote of confidence on the trailer. I got her pinstriped two weekends ago and the caps for the custom Weld wheels were machined out yesterday to fit over the boddy bearings. The trailer is looking sweet. All that is left is to put the inner fender panels on and she's all finished. I will post some completed pics!

[HBjet]

I've ran dual 450's that where tricked by Dave at DNE. My motor was a 454, .030 over, Rect. port heads, Weiand tunnel ram, Comp Cam 292H, and turning an Alum. B impeller and GPS'd at 80.6mph.
I would say don't run a A/B, run a B cut impeller for sure. The problem I noticed with the 450's was the top end. You'll be fine, and you won't burn a lot of gas using them!
HBjet
[ May 08, 2003, 02:41 PM: Message edited by: HBjet ]

[joe schmoe]

HBjet:
I've ran dual 450's that where tricked by Dave at DNE. My motor was a 454, .030 over, Rect. port heads, Weiand tunnel ram, Comp Cam 292H, and turning an Alum. B impeller and GPS'd at 80.6mph.
I would say don't run a A/B, run a B cut impeller for sure. The problem I noticed with the 450's was the top end. You'll be fine, and you won't burn a lot of gas using them!
HBjet wow 80.6 that is so fast! almost like you were riding in a car! :rolleyes:
with all your new motor changes what do you think that your new speed will be atleast 100mph eek!

[HBjet]

Well joe schmoe, I have no idea what it will top out at, but I'm guessing it will be faster then 80.6mph!
BTW, welcome to the boards. Have you been lurking, or is this the first time you have ever visited this website?
What kind of boat/motor are you running?
HBjet
[ May 08, 2003, 03:21 PM: Message edited by: HBjet ]

[joe schmoe]

ive got a 89' skeeter with a 2.5 on the back! it dose pretty good but i would have to say that your 80.6 is about as fast as i drive home from the river in my tahoe. wink

[78Eliminator]

I've got a 7.5" skeeter :)

[HOSS]

9.5 here with a pad!

[78Eliminator]

HOSS:
9.5 here with a pad! Come on Hoss, you can't start measuring from your ass hole :)

[HOSS]

Good one! But I`m starting from the last hair folicle! :D

[jetboy]

what do you guys think about the holley 660 center squiters?
And does any one have a cam suggestion for a 460+30 with ported dove heads cj rods, j+e reverse dome pistons, weiand tunnel ram, 660 holleys, and basetts. 10.2/1 on a 19 ft daytona with an "A" impeller?

[Cs19]

oh shi* ,that was funny.

[HBjet]

joe schmoe:
ive got a 89' skeeter with a 2.5 on the back! it dose pretty good but i would have to say that your 80.6 is about as fast as i drive home from the river in my tahoe. wink Cool, Hamilton Beach Racing huh?
Yeah, when pulling the boat, I drive around 70ish, without, 90ish.
HBjet

[DEL51]

It is amazing how much info someone can get from dyno time. Carbs that are box stock or modified for the application can't work as good as they can without testing. There is always that extra 10-20 horsepower.Even with EFI systems.Take a systems aproach and find a good dyno man.If you can't afford a dyno test try to emulate a similar setup.If you went with bigger carbs, save the old ones for a direct comparison.