Vinny P

This year the warranty is up on my 454 magnum, so I am in the process of gathering information on either upgrading it or trying to get an H.P.500E.F.I. Unfortunetly, as with some of us on this board, I don't have an unlimited cash supply. I feel that the price for an H.P.500E.F.I. is a little extreme for the 95 horse power difference I am going to get from it. The worst part is that Merc. doesn't even make a closed cooling kit for it. And I am a firm believer in closed cooling, I wont run without it. The only real value I see in that motor is the fact that it is a Blue Merc. motor which adds to the resale value of your boat.
I have talked to a few members on this board about adding a supercharger to my motor, but for the lousy 100 or 150 horsepower I am looking to gain, supercharging seems like it is a bit overkill. I know it is easy to get that kind of increase in power with a supercharger but to me it makes things too complicated. I feel that supercharging is the best option for the big power guys on this board. I want to do it by adding a good set of ported Dart heads (possibly the Iron Eagles ) milled down to kick the stock compression up to maybe 9 or 9.2 . A good cam with some lift and duration ( I already have Gil Wet-Offshore Exhaust) I already have an MSD 6M-2. Possibly an injector change and definitley a re-programed E.C.U. Thats the part that I don't like. I have built many engines , all be it mostly for cars. All of them had Holley carbs. The easiest thing in the world to tune. Now, along comes E.F.I. you spend X amount of dollars on building or upgrading your motor. But, the most important part , the fuel mixture and the timing curve is decided by a guy who is half way across the country sitting in an office in front of a computer. What if he guesses wrong on your combination? Is he going to stand behind a burned piston? I don't think so!
So that is my dilemma. Have any of you guys had success with increasing power by the ways that I have described? If so, what is your combination? I know alot of guys here have had the E.C.U.'s re-programmed are there any horror stories to tell with that?

Thanks for any help.

Gunfighter

I went through the same thing, asked a lot of questions and they all said put a blower on it. So I bought a different boat.

I think Tyler Crocket has some info on what you are doing and AZ Speed knows a bunch about the ECU. That's the two I would recomend.
Vonbongo

CheckmateF1

I would check with Lingamfelter(sp?) about the fuel injection upgrades. I read an artical about him. He has done a lot of big power tuning with the 454/502 Mag fuel injection system. Bigger fuel pump with adjustable regulator, big injectors, big throttle body, Extrude Honed upper and lower intake and some nice flowing aluminum heads with a matching cam. Then have AZ speed set up the ECU.

Good luck! Eric

KAAMA

iTrader: (1)

I was going to go with the Fuel Injection at one time as well, but I had decided to stay with the carbs because it's a whole lot less of a pain to set up, tune, etc. Besides fuel injection is EXREMELY expensive! Don't get me wrong, fuel injection is tops when it's working well, and once I started pricing everything out it costs of parts are staggaring and then you have add all the installation and set-up costs which all takes time---hard to see the light at the end of the tunnel: intake $350, fuel rails $180, injectors $500, electric fuel pump $500, fuel filtration system $225, fuel regulators $50, wiring harnesses $175, throttle body $700, ECU brain boxes/maping systems $2000...for a twin engine application the total comes to just under $10,000----I think I will stick with the carbs for now

Raypanic

Take a look at this article: http://www.azspeed-marine.com/articles-1.html

This is similar to what you want, on a 502 Mag MPI he can get the HP up to arround 500HP on a 454 Mag you will have to call Him.

FBRONCO

iTrader: (1)

I did what you want to do last season with my 95 Gen V 454 Mag EFI. I had the head done by Tyler Crockett. (Milled, larger intake and exhaust valves, new seals, locks, guides, and springs). Added a new roller cam, lifters, pushrods, roller rockers, stainless marine exhaust, adjustable fuel pressure regulator, ECU reprogram, Flame arrestor. At the same time I replaced the main and rod bearings, honed the block and put new rings in it. I was supposed to get 100 hp, which would put me right at the 470 hp you get from a 500 hp. Not sure what I got in HP numbers, never ran it on a dyno. I gained about 3 - 4 mph on a 24 outlaw. 74 on speedometer at about 5300 rpms. Had the prop reworked and I'm getting 74 on speedometer at 5200 rpms. Motor runs great, just not sure the 3 - 4 mph was worth it. Good learning experience though. If you want more specifics, please ask. This year I am only adding a MSD 6m2 box to it. Easy bolt on, no work.

KAAMA

iTrader: (1)

Fbronco, with your speed increase of 3-4mph it sounds you made somewhere around a 60-80hp gain. I think I'd be a little disappointed too, but I'll bet it sure SOUNDS a whole lot better with that exhaust system on it! That MSD system may help you out a bit if the stock ignition is holding you back.
Did you have any porting done to the intake manifold??? It didn't look like you mentioned it, but Arizona Speed & Marine does what they call an extrude hone in the intake manifold which is like a porting job that opens up the runners of the manifold. I remember speaking to them a few years ago and they said it increases the engines breathing capacity (not the power) by about 30%. I can't remember how much power that translates into though.

MIKEHTMSR24

it takes tons of hp to see a difference.
FBRONCO case: 15 to 20 hp to gain 1 mph
This is common. You can spend a few thousand and gain a few mph. That's fine if you will stay happy with that and leave it alone. Then their is that little speed demon inside your head that says more power Scotty, we need more power. In the long run blowers are cheap when it comes to speed/$$$.
Just don't take shortcuts and don't let the demon take over the boost control valve.
I did tons of work to my 540: Full port and polish heads and intake, bigger cam, bigger valves, better headers. I gained about 100 more hp and about 4 to 5 more hp. I put the motor together and keep up with all of the money flying out of my wallet. Like I said I did many things to my motor to make it last. The total was 10k. The motor dynoed 683 hp @ 5680 and 676 tq @ 4700. Was it worth it HELL NO. Try convincing the demon in my head that

liquid lounge

Check- About the only time I "chime in " here is when the subject of fuel injection comes up. I just cant stand to see a fellow enthusiast pour thousands of dollars into a system, trying to make it something it cant be and having less than optimal results. While the factory Merc. setup works very nicely for its intended use, it can become comprimised very quickly in closed loop operation when modifications are made. This is due to several factors, the main one being the long runners of the lower intake. modifide versions [you know, the $800 dollar ones] still have very long runners as there is only so much you can pratically mill, and as far as "extrude honing" while a neat process for some applications, gross airflow of the lower intake won't be your biggest problem when modifying this system. Yes, it is possibe to max out at close to 600HP whith highly modified [lots and lots of cash] versions of this system, but at some point around 500hp on a big inch motor, a carburator is going to be superior from bottom to top. Just on this board alone you can read countless stories of HP500efi guys complaining of soot on their transoms, gas in their oil, etc....and they have a better, higher flowing intake and plenum than you do. Other than instant starts, I dont think the new HP is much of an improvement on the old one.
Here is what I would do within a reasonable budget:
Cam- 224/230 with higher lift[appx .600 w/1.7] Stay away from the radical assymetrical lobes like Ultradyne as the intake reversion will play havoc with the MAP sensor. The idea here is to minimize overlap. If you keep the lift to around .570 ,you can retain your original lifters[providing its a gen 6]
Heads- the edlebrock "rovals" are almost a perfect match for your lower intake, as the roof on the manifold runner is nearly 3/8" shorter than the port on your current heads. They now make a marine version with inconel exhaust valves for a very reasonable price.....they are aluminum so they are perfect for your closed cooling, the smaller chambers will give you a safe boost in compression.
Buy an adjustable fuel pressure regulator. The flame arrestor might just be a waste of money.
With these mods you will be making much better power within your current rev limit, and will be needing a higher pitched prop. Do the prop first and you can have the rev limit raised on the MEFI later if you wish.
I think this setup would cost less than $2500 [without exhaust] and still keep you very happy with your efi and last a long time. Gotta get to my wifes house, Have Fun

Vinny P

Thanks guys, I got alot of good input. Remember as I said, I am not looking to make killer power here. 100 extra horsepower , total of about 500 doesn't seem too unreasonable for a 454" motor.

Liquid lounge:
As we both know, there is no better way to tune or make power than with a carb. BUT, since I got used to running a boat with E.F.I. I just don't want to go back to carbs. Besides, I don't think that I am asking for too much of a gain. I understand that I probably will only see 3-5 m.p.h. from this and am willing to except and be happy with that. My concern does not lie with being able to make the additional power but relying on someone elses program to control vital engine functions. I do agree about the long intake runners, it is a problem. But, again I don't think that expecting 500 h.p. out of it is being over ambiteous. P.S. I already have Gil exhaust.

CheckmateF1:
I didn't know that Lingenfelter did work on marine motors. I know all about his reputation as one of the countries premier automotive engine builders. I could only imagine what prices he gets for his work.

Fbronco:
Sounds to me like you did o.k. with getting 3-4 m.p.h. After all, with what you did and what I want to do, we are not going to get big numbers.

Kaama:
You are right. Fuel injection is expensive and can be a problem. But, I am dedicated to making it work. That's why I am starting to research this now. I have lots of time to make a decision.

Raypanic:
Great article! Thats just what I am looking to do only I am willing to upgrade the cylinder heads to either Dart or Brodix. Providing that those numbers are real, me getting 100 h.p. with changing the heads doesn't seem to far out of reach.