Olds cams vs. fuel consumption?

[CrdStang]

I'm trying to decide between a stock cam: 276/278 duration, .474/.472 lift.
And a aftermarket grind, I was thinking something along the lines of the Crane Powermax H-284-2 with 284/292 duration, .480/.496 lift.
Of course a stock cam is dirt cheap, but if it's going to drink fuel like a climbing cargo jet no matter what cam it has, I might as well put a real cam in it and make some power.
I should note that I'm gonna be running in the ocean. 90% of the time speed will be limited by conditions or space (inside the break-water)

[moneysucker]

It is a jet boat. The gas milage is going to suck regardless of what cam you have in it. Might as well go with a performance cam or at least some kind of RV cam MSD helped my olds also.

[CrdStang]

Thanks Moneysucker
I'm deffinately going to run some kind of ignition box. I'm leaning towards a Crane HI-6 since I've had one in my Mach 1 for 3 years and it's never skipped a beat.
Anyone tried a Crane unit in a boat?

[Taylorman]

MSD is the way to go. A 6AL Box, dist and coil all from MSD cant be beat.
As far as cam goes, Im soon to change mine to a Comp cam recommended by Dwayne at HTP. He says that its the best performing cam in a 455 that he has ever seen. He has built plenty of 455's over the years so im sure he knows. Its Comp part number 42-225-4 i think. Good luck.

[Foggerjet]

I really like the looks of that cam that taylorman is talking about, I looked it up on comp's website: .541/.544 lift, 240/246@.050, 110 sep. I wish I'd seen this when the I was building mine. I went slightly more conservative with a Lunati 00083 .496/.520 224-234@.050 112 sep(reversion?). it sounds GOOD! and pulls hard to 5300, Thats all I get. 67 MPH. And yes it gets really shitty gas milage, Who knew?:D
fog

[sleekvino]

if your looking for a cam id stay away from anything that has bigger then a 110 lobe sep a 112 is not good for jet boats stick with around 108.my cam is a 548 lift and 248 258 at 50ths. its got a hell of a hole shot and tops out at 66.2 mph on the gps.

[Taylorman]

What piston's, intake, and heads are you all running?

[mrme]

This link will guide you
http://www.mondellotwister.com/Camshafts.htm
I run the JM-29 and love that lopeie sound.

[Foggerjet]

Taylorman, I run Speed-Pro: L2323F-060 Forged pistons, Heavily ported C heads, and a gasket matched Torker. 850 Demon DP carb.
fog

[mavjet]

Originally posted by CrdStang
I'm trying to decide between a stock cam: 276/278 duration, .474/.472 lift.
And a aftermarket grind, I was thinking something along the lines of the Crane Powermax H-284-2 with 284/292 duration, .480/.496 lift.
Of course a stock cam is dirt cheap, but if it's going to drink fuel like a climbing cargo jet no matter what cam it has, I might as well put a real cam in it and make some power.
I should note that I'm gonna be running in the ocean. 90% of the time speed will be limited by conditions or space (inside the break-water)
I used that cam spec in a 440 mopar on the street(69 Charger) and loved it.But I agree with the other guys,you can go more than that. When it comes to a jet boat,gas mileage depends on how you drive.I had an 78' Tahiti/454/750 holley with 18 gallon tank, years ago. I could run all day on a tank cruising,or burn a tank in a hour hauling a$$.
my2 cents.......

[CrdStang]

Originally posted by Taylorman
What piston's, intake, and heads are you all running?
Sorry I didn't respond sooner, my hard drive took a crap.
I'm running stock olds Ga heads. So far I only have the stock dual plane intake, but I'd like to pick up a Torker or some other single plane. No carb yet but I'm thinking Q-jet. Normally Holley would be my carb of choice, but I've had the needle & seats screw up and hose down my car's engine with gas a few too many times to put one in my boat.
The Olds is .060 over with what I'm told are the high compression pistons, so in the area of 10.25:1 compression. Unfortunately the cheap bastard who rebuilt the engine went with cast pistons. No nitrous for me..right, as if I'd need it, there's nobody here to race!
I'm running log manifolds.
I only have stock rockers right now too, are they weak/crappy/likely to break when I throw a real cam in it?

[jim lee]

For a basically stock olds & logs I'd not bther with the MSD or any of them fancy sparker things. Just do some sort of electronic ignition and call it done. HEI or magnetic pickup.
The big island inside the break water? That wouldn't be Rado Bay in Hilo would it? I lived in that there bay for about a month stern tied to the seawall. neat place!
Don't forget zinks.
-jim lee