getrdunn

iTrader: (7)

I'd have to agree if it wasn't for the cast Pistons. I ran the livin dog**** out 454/330 short blocks with mag Pistons however they were very well balanced with 480 hp. Given the right situation and on a budget I'd do it again.

mcollinstn

You aren't going to spin a 330 bottom end more than 5,000 revs much or else you are gonna have a bad day.
You aren't going to get 500 hp from 454 low compression cubic inches at less than 5,000 revs unless you put a blower on it.

A 5 psi blower will get you 430+ hp at under 5,000 revs but you will need to run 93 octane.

On a heavy boat, you are peeing into the wind.
Will your boat achieve a FULL plane? If it won't, then a hp bump may put you over the edge, and if that's the case then you will enjoy that. If your boat will ALREADY achieve Full Plane, then adding 100 hp is only going to give you some small improvement.

Adding traditional normally aspirated goodies to the motor is going to shift your torque curve upwards.
What that means is that you are going to lose some torque down low.
While you may think "I can stand to lose some bottom end", you also got to remember that you are going to be adding prop pitch to take advantage of your higher rpm output. So you will lose some bottom end AND go up a size on the prop. On a heavy boat, this is usually DISASTER and the boat may not achieve planing speeds due to the loss of low end torque.

It's a dice roll.
But a blower is your best bet.
They aren't expensive, and you don't need to throw a bunch of parts at it (assuming you run up to 5psi).

Optimally, you would want to zero deck the block and set the squish around .036" as well, but now you are spending money on a cast, non Mag again.

Best of luck.

Swamplizard

good info. may not have physical room since motors under the cockpit floor. it is more about torque...arneson drives need it to get on plane. once on plane she takes off and i back it down to cruise. sub 4200 rpm cruise usually.

Swamplizard

did you change heads?

Swamplizard

did you have stock 454 heads?

getrdunn

iTrader: (7)

No I used cast dart oval port heads that I had ported pretty well and used with 502 465hp cam (134561) with torker 2 intake and Holley 800 cfm carb. Dyno'd 481 hp and ran extremely hard at 5,700 however had balanced. Twin app. Night and day difference than the original 330's.

Swamplizard

Thanks

14 apache

iTrader: (1)

Look for a 365,370,400,420 HP 454 they all have good internals priced with in reason. All of those engines have 4 bolt blocks steel cranks and 7/16 rods with forged pistons. I know the 370,420 had roller rockers from the factory maybe more but not sure. Good starting point. Another good one is the 425hp gm crate engine I have used these in many boats with no problems.