Inexpensive upgrades for a 454

[SickSation]

Got a 454 mpi and was curious what are some inexpensive upgrades to get more ponies. Im assuming heads, cam, intake. what are some other bang for your buck upgrades? Also, any recomendations on cams heads intake ect. Any info is much appreciated.

[DAREDEVIL]

I would start with a good exhaust, like Stainless Marine High tourge II or III.

Then some head work and porting on the intake, who ever does that should tell u which cam.

Or go with a PROCHARGER !! But still start with exhaust.

[SickSation]

I would start with a good exhaust, like Stainless Marine High tourge II or III.

Then some head work and porting on the intake, who ever does that should tell u which cam.

Or go with a PROCHARGER !! But still start with exhaust.

Thanks man. Id like to stay normally aspirated to keep the turn key reliability.

Ill look into some exhaust. Aluminum heads?

[Chris]

Go enjoy your boat. Once you start, it will never stop.

The engine you have is constructed from parts that are equivalently matched for the horsepower and RPM range the designers targeted. Big moves on the top end are going to place loads on the block and reciprocating assembly that they weren't designed to withstand.

Here's what's going to happen. You're going to spend $3500+ on an exhaust (because nothing else you do is going to work without that being done) then another $4k on heads, manifold and cam. That extra 150 horse is going to break the bottom. So now you put $6k into a new shortblock and your problem now moves to the drive and gimbal. So after it's all said and done you're $20K deep into a boat that you've raised the value of about $5k and you've missed some nice sized chunks of a boating season or two. And that's if you get really lucky and the guy doing the work actually does the work, does it on time, does it correctly and doesn't either rip you off or go out of business in the process.

Enjoy your boat. Use it the way it is. Spend your time learning how to operate it as proficiently as you can in various water conditions. Spend that money on fuel and enjoy it. And when you want more, go buy something that's already what you want. Remember, you can make the boat you have faster, but you're not going to make it bigger or make it into a Cig, Apache or OuterLimits. And pretty shortly that's what you're going to want anyway.

[SickSation]

Go enjoy your boat. Once you start, it will never stop.

The engine you have is constructed from parts that are equivalently matched for the horsepower and RPM range the designers targeted. Big moves on the top end are going to place loads on the block and reciprocating assembly that they weren't designed to withstand.

Here's what's going to happen. You're going to spend $3500+ on an exhaust (because nothing else you do is going to work without that being done) then another $4k on heads, manifold and cam. That extra 150 horse is going to break the bottom. So now you put $6k into a new shortblock and your problem now moves to the drive and gimbal. So after it's all said and done you're $20K deep into a boat that you've raised the value of about $5k and you've missed some nice sized chunks of a boating season or two. And that's if you get really lucky and the guy doing the work actually does the work, does it on time, does it correctly and doesn't either rip you off or go out of business in the process.

Enjoy your boat. Use it the way it is. Spend your time learning how to operate it as proficiently as you can in various water conditions. Spend that money on fuel and enjoy it. And when you want more, go buy something that's already what you want. Remember, you can make the boat you have faster, but you're not going to make it bigger or make it into a Cig, Apache or OuterLimits. And pretty shortly that's what you're going to want anyway.

Well put. I planned on getting a 288 in about 2 years. I just figured there some inexpensive upgrades to get 30-50 hp's without having to get into the bottem end or worrying about the outdrive. Not lookin for a big increase. thanks for your input though.

[MattBMiller]

The Aggressor is a fun boat with about 550-600 horsies! Also a light boat, never had any issues running a stock Bravo on mine.

I vote for heads, cam and a set of headers.

[Trim'd Up]

Chris is right. I have more money in my motor than what my boat was worth, and I built it myself. On the other hand, none of us ever listen and still end up upgrading. If you do, the best bet is to just sell your complete engine and buy or build something else. The 7.4's don't have any useful parts for a performance build, besides the block, and 454 blocks are a dime a dozen anyway. Just find a low hour 502 or 496, or maybe even a 500efi and drop it in. You will come out money ahead and help the resale of your boat.

[Chris]

To start with, I'd hate to lose the turn-key reliability of the MPI injection. And to do more, you need the 500 EFI stuff. Or go carbureted. One is expensive. The other loses that reliability and that wonderful idle.

30-50 horsepower is going to net you a barely noticeable increase in midrange pull and another 1 maybe 2 mph.

[SickSation]

To start with, I'd hate to lose the turn-key reliability of the MPI injection. And to do more, you need the 500 EFI stuff. Or go carbureted. One is expensive. The other loses that reliability and that wonderful idle.

30-50 horsepower is going to net you a barely noticeable increase in midrange pull and another 1 maybe 2 mph.

If thats the case i agree. Not worth messing with for that little bit of gains.

[Ratickle]

I'll get one of my engine guru's on it. From what I know, 50 hp is a lot to hope for at a reasonable price...

[Perlmudder]

what about just trying different props and seeing if you can pick up some more top end?

[MOBILEMERCMAN]

Focus on the FUN METER not the speedometer.

If that means wrenching and playing in the bilge god bless ya. If not just try to burn the belts off.

[PARADOX]

Rule of thumb.
First + MPH. $1,000- $2,000, Prop work.
Next + 1 MPH +$5,000
After $10,000 per ea. MPH. (if you lucky)

[ROGUE]

All good advice. Wish I had every dollar and minute I spent trying to do the same thing. Not that I regret doing it and learning all I learned and having something unique, but in hindsight, I should have left them alone. The learning curve is expensive and time consuming and the rewards are elusive and quickly forgotten everytime something breaks. I used to run WOT all the time until I got old and tired of hanging upside down wrenching on things. Theres always somebody faster-all it takes is lots of money. Inexpensive is not in the go-fast dictionary.

[Ratickle]

Rule of thumb.
First + MPH. $1,000- $2,000, Prop work.
Next + 1 MPH +$5,000
After $10,000 per ea. MPH. (if you lucky)

You need a better assist man Peter.....

[Ratickle]

All good advice. Wish I had every dollar and minute I spent trying to do the same thing. Not that I regret doing it and learning all I learned and having something unique, but in hindsight, I should have left them alone. The learning curve is expensive and time consuming and the rewards are elusive and quickly forgotten everytime something breaks. I used to run WOT all the time until I got old and tired of hanging upside down wrenching on things. Theres always somebody faster-all it takes is lots of money. Inexpensive is not in the go-fast dictionary.

Depends on what you start with. On many engines, the initial package is so mild it's easy to make more horsepower. The old 542" Bulldog from Merc comes to mind. 470hp stock with easy, and reasonable, upgrades for reliable power. I don't know enough about the 454 (7.4?) MPI engine to even say if it has good internals......

[Sledge Hammer]

I guess I go in a different direction on this one. I get a pile of satisfaction out of the modifications and the fact that my boat is a lot more than one or two MPH from everyone elses out there. I am running a Baja Hammer with a 610 HP 540 at 85 MPH on the GPS. I have put more money into the boat than I can reasonably get back out of it, but at the same time I don't have anywhere near into it what it would take to just buy a boat that would go 85. Most that will run that fast are bigger for sure. The advice to run it and have a good time is good advice, but modifying and improving them is just another element of fun. I think the easiest and perhaps the most inexpensive way to go is to sell the engine you have and buy one with more HP and 4 bolt mains. You are going to need exhaust as well as the stock factory exhaust will choke it to death. There are two ways to go, have fun with what you have and wish you had more or get more have fun with it and still wish you had more. It is a never ending arms race.

[jeffswav]

If you are only going to keep the boat 2 years leave it alone. If you are going to keep the boat for several years start with the exhaust. Get a Roller cam and valvetrain from RMbuilder. If you have the standard 454 (Non Mag) it has cast internals. You could bore and stroke it fo a 489 or 496 with forged crank, rods and pistons. Speed is expensive but to purchace a boat that runs70+ MPH will cost more than what you would have in the upgades.