mgunn33

Need some help on what to do with my 454 Gen 5. It is the regular 7.4 non mag. I have a holley carb and corsa exhaust.
I am wanting a little more power and nice sound. Not trying to run 80 or anything. Just a nice cam hit, and power. Where should I start? Heads are round ports. 97 BAJA.

Thanks
Michael

Knot 4 Me

If you do a search you will find a lot of threads on this very topic.

mr3dman

What he said, but a quick summary of a search woul read like this:
get new heads and intake-install a cam and new valvetrain- and buy a new carb. Without touching the bottom and you do the work you are looking around 4k for decent parts.Your better option is selling yours and buying a newer takeout or rebuilt 454mag efi/ 502/ 496 etc... I would only reccomend messing with your current motor if you want the experience of wrenching on it. You may feel you can save$$ by just adding a few hp to your current setup but experience has shown that on your cast motor people who tackle this project end up spending more than they would have if they just bought a rebuilt or low hour take out motor. Just my .02

mgunn33

Hey thanks for the info. I have searched and I have seen so many mixed reviews on this. I just wanted someone to weigh in on my set up.
I am a drag racer, engine builder and Aircraft Turbine mechanic. I can do the wrenching my self. I guess I should have explained more. This is my first performance boat. What I need to know, is swapping out my peanut ports, for some Rectangle (MAG) heads, Cam, and aluminum intake. Be a good idea.
Also I have been told on Cam that reversion is an issue with too much Duration. What do I need to do to get around this? Is it the exhaust manifold change? Headers? Basically how do I run a dry exhaust so I don't have to worry about reversion? Or can I get a Cam to work with the exhaust I have?
Thanks

Also I would hope I could do a set of rectangle port heads, cam and intake for under 4k. If not I need to go back to drag racing.

mr3dman

The big problem with the boat vs drag motor is that you need to build a drag motor that will operate at near full throttle for extended periods of time. The oiling and cooling requirements are so much different in a boat setup, and they change as you add HP's to the equasion. If you are only looking for a few hp's you can change the heads to iron rectangles,put in a cam from a stock 502 marine motor, throw a performer air gap intake and a 750-800 cfm carb and call it a day. Or you can go with iron or aluminum heads, bump up the compression a bit, throw a more aggressive cam like a hydraulic cam around 218*/226* at .050" lift on 110* lift .515"/.515" with a LSA of 112 -114 or get a cam from Bob Madera phn# 585-654-8583 (he can do wonders). You mentioned going with a smaller LSA to squeese more hp's but now you have to put dry exhaust on the motor and that will cost you a few K.
It all boils down to how much time and $$ you want to spend on it. Your weak point is your cast internals, keep that in mind. If your only looking to get mbe 400hp at most party on, if you want reliable power and more Hp move up in cubes and better parts. Just my .02

mgunn33

Hey thanks for the info. Thats exactly what I was looking for. No 400hp is more than enough. I don't see any reason for more than that. What kind of idle does the Mag cam have?

Thank you again!

picklenjim

If you plan on keeping it consertive as you say and at 454 inch's you would be better to go with large oval heads instead of the rectangular ports. You would see more usuable torque in your case. You could even trick up your peanuts a little and make over 400hp.

mr3dman

mag cam idles at 700rpm smooth. you can pick them up off ebay or cp performance cheap

mgunn33

Hey thanks guys. Yea probably will get old and I will build a big motor, I was just trying to keep this one conservative. This boat is only a 21ft bow rider. I figured it wouldn't hold too much anyway. It show 68 on speedo now, and it feels good right there. I just wanted to make it a little better!

1BIGJIM

iTrader: (1)

If you are interesteed I have a brand new 502 mag roller cam out of a Gen 6. Comes with springs and retainers.
$100 + shipping

send me a PM if you are interested.

And good luck on your project. Lots of good advise on OSO

Any good build starts with the exhaust, you can put all the money you want in the engine but if you do not have a good exhaust system you are throwing your money away.
My 2 cents...