Cam in the 502 mag
#1
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Got a 99 272 bone stock except for the radio, I want to do some stuff to the motor, Cam is the first thing that comes to mind has anybody done a cam on this motor and if so what did you get out of it thanks. any other ideas will be appreciated as well.
#2
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Posts: 4,181
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From: ankeny,ia.
That's only part of the puzzle.
The rest of the valvetrain would need upgrading,
the ECM would need to be re-flashed.....then, there's
the stock exhaust, might as well upgrade that too.
Have I spent enough of your money yet ?

There's some other stuff like fuel pressure mods,
and the limitations of the factory MPI intake manifold
that come into play the more crazier you get.
Bottom line,
Plan on doing more than just replacing the cam
if you want to see any increases, and if you want it to
stay mechanically sound.
The rest of the valvetrain would need upgrading,
the ECM would need to be re-flashed.....then, there's
the stock exhaust, might as well upgrade that too.
Have I spent enough of your money yet ?


There's some other stuff like fuel pressure mods,
and the limitations of the factory MPI intake manifold
that come into play the more crazier you get.
Bottom line,
Plan on doing more than just replacing the cam
if you want to see any increases, and if you want it to
stay mechanically sound.
#3
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Joined: Sep 2007
Posts: 1,051
Likes: 0
From: Bettendorf, Iowa
That's only part of the puzzle.
The rest of the valvetrain would need upgrading,
the ECM would need to be re-flashed.....then, there's
the stock exhaust, might as well upgrade that too.
Have I spent enough of your money yet ?

There's some other stuff like fuel pressure mods,
and the limitations of the factory MPI intake manifold
that come into play the more crazier you get.
Bottom line,
Plan on doing more than just replacing the cam
if you want to see any increases, and if you want it to
stay mechanically sound.
The rest of the valvetrain would need upgrading,
the ECM would need to be re-flashed.....then, there's
the stock exhaust, might as well upgrade that too.
Have I spent enough of your money yet ?


There's some other stuff like fuel pressure mods,
and the limitations of the factory MPI intake manifold
that come into play the more crazier you get.
Bottom line,
Plan on doing more than just replacing the cam
if you want to see any increases, and if you want it to
stay mechanically sound.
ditto.... the only thing i had going for me is i am an auto tech. i still spent about 5 to 6 grand upgrading my 502 carb engine. but i can tell you that any help you need; all the good people on offshore only will help. you do have a good building block to start from but you are going to have to upgrade alot just to change that cam. if you want bolt on performance that you can use later with your cam you could get good exhaust that you know will never revert later when you do upgrade the internals. some brands say you can pick up 30hp on exhaust alone. and im sure your ecm has some avaialble calibration changes. good luck and keep us posted!
#4
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Joined: Oct 2002
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From: Indianapolis, IN
bigger cam, a set of Edelbrock alum. heads (or equivalent), maybe bump the compression to about 9:1 or so, trim the intake runners, put in adjustable fuel pressure regulator and run them to ~42lb., some headers, and you are looking at between 520-540 hp. on 89 octane.
#6
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Posts: 4,181
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From: ankeny,ia.
but putting them on a 10 year old engine
will probably bring out problems relatively quick.
freshen it up and set it up for supercharging
before you put a pro-charger on it.
#7
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Joined: Oct 2005
Posts: 1,899
Likes: 20
From: Millstadt, IL
Go to "General Q&A" and look what other guys have done. It is very expensive to do upgrades on marine engines. Learn from everyone elses mistakes and do a little research. If you are going to do one upgrade I would do the exhaust first. You will need it later if you plan on upgrading the cam. Be sure to get long risers and remove silent choice. I have a post called "Roller Cam Upgrade" take a look and see what I have done. Good Luck!!
#8
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Go to "General Q&A" and look what other guys have done. It is very expensive to do upgrades on marine engines. Learn from everyone elses mistakes and do a little research. If you are going to do one upgrade I would do the exhaust first. You will need it later if you plan on upgrading the cam. Be sure to get long risers and remove silent choice. I have a post called "Roller Cam Upgrade" take a look and see what I have done. Good Luck!!
#9
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Joined: Oct 2005
Posts: 1,899
Likes: 20
From: Millstadt, IL
I thought about that myself. Then fuel went up. All my buddies with twins could not afford to use thier boats. I was glad I upgraded what I had. If you think 3 MPG is bad try 1.5 MPG. Also 2x all the maintenance, oil, gear lube, filters, water pumps, ect....
#10
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Thats what stopped me the first time my buddy had a 30 o/l it was sweet but not twice the cash sweet.


