Big Block Aluminum Heads

[Garrett0742]

I don't know too much when it comes to engines but i am debating on buying some aluminum heads for my 454.
They are pretty pricey, I just don't know if it would be worth it power and performance wise or it is mainly for shedding weight?
The cast heads are pretty heavy as you would know..anyone with some input on this? would it make a huge difference?

[Slidin Gator]

Aluminum is for shedding weight.

Performance wise, aluminum is not for Hp, but normally custom aluminum heads are made to improve power. Depending on what you are looking at, they may require matching cam, intake, pistons, rods etc. or you might even loose power where you need it. Of course, the matching intake is aluminum, so you save more weight (for another $300-$400).

But once you add all that new "potential" power to the boat, you find your gear and/or prop needs to change to use it, so it's another $3-5K to spend.

Talk your riders into buying their own boat, they probably don't chip in on gas anyway, so that's a free way to decrease weight.

Wife and kids riding, you might have to spring for aluminum.

[Joe]

Aluminum is just for shedding weight?!?!?
There are so many advantages to aluminum heads, weight is just one and is low on the totem pole. Picking the right head for what you have is paramount. Just saying you have a 454 and thinking of aluminum heads is not enough info for a rational opinion. So much more info is needed. What 454, what hp is it now,do you know what pistons are in it cam specs gear box ratio,prop info, are heads the only thing you plan to change?

[Garrett0742]

I don't have the reduction, prop and all of that yet so the options are endless. I don't mind spending a little $$ it beats buying a new engine
from what I see. I will be mainly hauling around the wife, kid and all of my gear but want enough hp/trq in case I took some
buddies.

[Slidin Gator]

Joe is correct, Aluminum is part of the power package, thanks for the correction.

You need to start at the beginning, what do you have? Boat, weight, motor as it stands now, prop, gear and what it turns at WOT. You are looking to spend some money, so it is best to plan it out now to get the results you are looking for.

Also note, you may not know much about engines now, but you will have to learn to make this work out correctly. Otherwise you are better off spending the money on a pro to implement.

[Garrett0742]

Aluminum is just for shedding weight?!?!?
There are so many advantages to aluminum heads, weight is just one and is low on the totem pole. Picking the right head for what you have is paramount. Just saying you have a 454 and thinking of aluminum heads is not enough info for a rational opinion. So much more info is needed. What 454, what hp is it now,do you know what pistons are in it cam specs gear box ratio,prop info, are heads the only thing you plan to change?

It's a Mark IV 454 pretty much stock. I've rebuilt it a few years ago and bored it .30 over and installed a RV cam I believe it is duration 208/218 lobe-112. Along with a hyd flat tappet valve job and forged pistons. I have a edelbrock performer 2-0 intake and 750 double pumper. I haven't put it on a dyno or anything but im thinking around the 440 hp mark and maybe a little more trq than that. I've been doing a lot of reading and you-tubing so I wanted to mimic a build ive found. So go with WPM aluminum heads 330cc Rectangle Port, Edelbrock Victor Jr. intake with a 850 carb. 4340 Forged Crank stroked 4.500 or 4.750, change rod length and go with forged rods etc. I want to go with a hyd roller cam and roller rockers but stay within a good rpm range. 2500-5000 I want the most amount of torque at the lowest
possible rpm. Rather have a bulldozer than a speed demon. I don't have the reduction and prop yet so I could change it up as long as I keep making OT I might add the boat is 18x8 Trailboss. Wanting to run dry fully loaded with no problem.

Thanks for the input

[Garrett0742]

Joe is correct, Aluminum is part of the power package, thanks for the correction.

You need to start at the beginning, what do you have? Boat, weight, motor as it stands now, prop, gear and what it turns at WOT. You are looking to spend some money, so it is best to plan it out now to get the results you are looking for.

Also note, you may not know much about engines now, but you will have to learn to make this work out correctly. Otherwise you are better off spending the money on a pro to implement.

I have came to the conclusion on the money situation and its no big deal. It will be a little cheaper than a new one. But not much lol
And you are right, I figured out I better learn a thing or two so the last week I've been swamping my brain on the entire subject.

Thanks for the input and advice

[loudmouse]

What compression is the engine now? A 750 is too small for a BBC in any performance application. Victor JR intake is not a good choice IMO. My suggestion would be to build the top end for 6000 rpm, prop it for about 5400, make a wise choice in cam based on the head you choose, intake and carb are just as crucial for a total package to achieve a common goal. If compression is around 10.5/1 with matching parts, tuned you can be in the 600hp range.

[Joe]

I would go oval port. They make power lower in the rpm range. Rectangle ports work better on the higher end of the rpm range. I agree with loud mouse the victor jr intake is wrong. I'm a firm believer in the edlebrock rpm airgap intake for an airboat big or small block.
An RV cam is never a good cam for an airboat IMO. Don't be afraid of lift. In my 454 with stock casting iron heads my cam lobes are just under and just above 600 lift intake and exhaust. FELBER put it best, the cam is only and the top for a fraction of a second,it's at .050 twice as long.
4.5 to 4.75 stroke is alot in a 454 for a boat but it would be neat to hear how it performs and lasts!! What ever you build good luck and have fun doing it!! And it's been said here before,when building one,the devil is in the details. Alot of power can be lost with one missed detail.

[loudmouse]

The 300cc ovalports is a very good choice and at $1000 a pair even better. The rpm(airgap) intake is a good one and a few others work well also. A cam depending on compression and head choice, to maximize head flow on a shorter duration to hold cylinder pressure would make a very stout engine for $ spent. I have built quite a few of this exact engine that would run high 11s in 3600# vehicles on pump gas.

[Garrett0742]

Thank you all for your opinions and advice. I decided to go ahead and pull the trigger on a new engine. Ordered a 572 Big block. lol
Its going to be a beast! It should be done in a few weeks. Built to exactly what I was wanting.

[Slidin Gator]

That ought to work! Good luck, post pics.