454, upgrades?
 

I am looking at a boat with a carb. 454. The dealer is going to look up the #'s on the engine to be sure of the horsepower but they are advertising it as 385hp. But I think it may possibly be a 330hp motor.

Either way, can I get a builder to build it up to 525hp or better and still be reliable or would it be more cost effective to just buy a new motor? I would like to be able to just have an engine builder take the existing motor and build it so reinstallation would be simple. Any estimates on how much it would cost to do this would be appreciated. I am trying to figure in the upgrades I would make to the boat before I make an offer.

Thanks,
Rob

taking a 330hp 454 to 525 will take replacing EVERYTHING (crank, rods, pistons, etc). Your answer depends on whether you have the Mag or the MPI.

he states carb...so no mpi

I think he meant mag or 330.

Thats the deciding factor. I went from non mags to MAGS rather than replacing one non mag last spring.

HUGE difference between the two, non mag is all cast internals with small oval port heads and cast intake.
MAG is ALL forged internals, large rectangle ports and aluminum intake.

Going from 454MAG to 420/425/525 is all simple bolt on stuff, going from 330 is a waste of time, start over with 500EFI or better at that point.

So if it is the 385 hp then it is a mag and not too big of a deal to pump up the hp? This bot has just under 300 hours on it so it would be nice to keep it.

365hp if it's carbed

It is simple to tell the difference between a 454mag/365hp and a 454/330hp. The intake manifolds are completely different. The 454/385hp were EFI's or MPI only.

BTW, some of the early 454/330hp's were called 454mags. What year engine are talking about???????

The boat is a 96

If it has an aluminum high rise intake, then its a mag engine. If it has an iron low rise intake then its a 310 or 330.

Looks like a 365hp mag to me, but the angle is tough. One thing I see right off is the port riser spacer is leaking. Not good usually. What boat are you looking at Rob?

The expensive part of building it up whether mag or not is going to be the exhaust. That is the same exhaust my 365hp mags came with and the spacers are leakers and then valve head droppers. Also to make power you need better exhaust. Once you have that you can do a cam and better carb and some head work and make close to 500hp for probably another 3g.

Dave

Thanks Dave, This is in a 253 Checkmate at Tomes. I ran the engine #'s today and merc. told me It is a '96 454 350 hp. (I guess that it at the prop.) I verified it has the forged aluminum pistons and forged steel crank. and the rectangular ports. From what I have been told 525hp is doable on this platform. That would put this boat in the mid 70's which is good enough for me.

If it is indeed a Mag engine then you could get buy with just freshening up the bottom end. You will have to go roller to get the performance. Call RMbuilder for your cam, lifters and springs. Freshen up your heads while you have them out. Get a good set of aftermarket exhaust with long risers. Allow some money to upgrade the oiling system, with better flowing fittings and hoses. Make sure the oil cooler is large enough for the added power. You will probably need a bigger carb also. Be prepaired to spend a bunch of money to do it correctly. Good luck with your project!!

right on thanks. I would plan on having a proffesional do any motor mods. As I don't see the value in doing the work wrong the first time. All it will take is one rookie mistake and I am floating down the bay getting towed in by some jetski...

I do all my own wrench work. Like assembly, pulling the engine ect... I have a local machine shop do the technical stuff.

If its a mag I would put a blower on and run the stock cam. Then you can get by with that exhaust and just a carb change. That would be wisest if the engine is in good condition.

If you want a second opinion or anything say the word. I am off next week and available. I love boat shopping :bong:

PS, I just always wanted to use that smiley, nothing intended there. Now where did I leave those doritos......

I am not huge blower fan but it does seem like the easiest way to gain hp.

If you just want to swap it out, I have 2 engines for sale. Matched set of 468's. 580hp on carb. Long blocks for sale with 14qt oil pans and I have intake I'll toss in. All your accessories will bolt on. Forged lower ends, eagle rods, Merlin heads, roller valve train. One is ready to go $5K. The second is apart needs assembly. It spun 2 rod bearings, lack of oil. Block is checked, align bored, honed, crand is checked, cut .010 on rods, new set of rods, bearings, gaskets, rings, 8.5 pistons. $3K. I'm right up in Philly. Pm me if interested after you get estimates on having an engine built. I also have a set of B&M 250 blowers that will go on these engines and make around 700hp. I will seperate them. Bill

Thanks Bill, I bought the boat and will run it next year as is. I am going to take my time and possibly next winter add some hp but first I want to run it for a season to make sure there arer not any issues I "need" to take care of first before I do the option al upgrades.