boating4me

Hello, I have a 1999 EFI 502 with IMCO Powerflow exhaust and KN filter. I have toying with the idea of a M1SC procharger in hopes of having 600 HP without losing any reliability

I have a friend suggesting that instead of the Procharger I should get a set of Brodex heads claiming that I can get 100 HP bolt on HP without changing anything else on the motor. He also suggested that I can get even more gains by the heads and cam only.

Any input? Can heads alone (or with cam, etc) make that big of HP difference ?

Brodex makes many different modles of heads, which one is that I would want? Are there other brands of heads that work well? (Cheaper?)

Thanks in advance,
Mike
Portland Oregon

getrdunn

iTrader: (7)

Mild port job on dart pro 310's and cam would very comfortably get you 600 plus hp without giving up any reliability however not sure what limits you have with EFI. If your dead set on brodix heads those will work well also however will potentially require some more work to achieve same gains.

Depends on how far you want to go with it etc. pro chargers would be a good option also.

getrdunn

iTrader: (7)

Here is some good info on the pro chargers etc.
http://www.offshoreonly.com/forums/g...-psi-help.html

Stock injectors?

boating4me

I will never want anything more than 600HP and I am not set on any brand (I am not smart enough to have an opinion). I am open to any suggestions.

Am I correct in my assumption that I can have shop install a set of heads and new cam without removing the motor from the boat in a relative short amount of time?

Anyone now of anyone in the North West that is up for this kind of work? (I am in Portland Oregon but willing to travel a few hundred miles if needed)

14 apache

iTrader: (1)

Brodix has a head for you to achieve that kind of power out of the box but how high do you want to rev your boat motor? 600 plus hp might not be that easy to do out of a 502 under 6000rpm. Probably need a better intake for that power.Most people are unhappy after a day on the dyno.

MILD THUNDER

iTrader: (3)

Save yourself alot of wondering, and get in touch with Alex Haxby, at http://haxbyspeed.com/ He's in your region, and is well versed in this topic.

phragle

iTrader: (3)

really depends on the boat, you have to have room in front of the motor to slide the cam out, some boats have room some boats it would be a lot easier pulling the motor. You also said its an EFI so there will be some recalibration of the ecm involved.. It can be done pretty easy, but not bolting on chrome valve cover easy. The stock efi stuff will be on the ragged edge at 600, that is a stretch for it. Arcticfriends just did a nice thread on dyno tunning and changes to one.

14 apache

iTrader: (1)

Changed the cams in my boat once stagerd set up rear motor no problem front motor no problem with a hole saw.

Black Baja

iTrader: (2)

Did you take the intakes off?

14 apache

iTrader: (1)

Yes I did. But I have changed the lifters through the distributor hole before pain in the a-- but it can be done.