articfriends

iTrader: (1)

You summed it up pretty good, also keep in mind if ANYTHING is near the end of its life or marginal it will break much sooner!!!

pullmytrigger

My buddy has two of them in his 32 Active Thunder it think it only maxes out at 6psi

KCHOTBOAT

It was on a HTM.

KCHOTBOAT

Yes it was on the high side and the motor was just a 7.4. I ran it hard for three seasons with that setup.

4bus

iTrader: (4)

7.4, as in the cast 300 hp version? That is pretty amazing!

Have a friend with a cast 300 running a roots style 177 blower at 5.5 psi for 5 years now, 200 hrs with blower, 500 hrs total. Rect port blower intake goign to peanut heads lol

KCHOTBOAT

Yes carb 7.4. All stock but ProCharger, lighting headers and upgraded fuel system.

indysupra

iTrader: (3)

I have them on my 96 scarab 502's. Have about 165 hrs on the engines and blowers. I do have an upgraded fuel system over the pc kit. My only complaint is the blowers are not louder! I crack the hatch sometimes when cruising so i can hear them. I would not do the kit without upgrading the fuel system and doing and ecu tune if your efi.

Young Performance

Bad Monkey,
IMO, there are several things that should be done if you want it to live a long life and run to its potential.
First, you should change the head gaskets to Cometics. if you are going to run over about 3 psi, then the exhaust valves should be changed to something like Manley's Inconel valves. You will also need to upgrade the fuel system. Take the Procharger regulator and throw it in the garbage. Use a standard 1:1 boost referenced regulator, like an Aeromotive. I would replace not only the fuel filter head to a larger one, but also the fuel lines and the pickup in the tank if it isn't large enough.(most are not large enough in production type boats)

Depending on the year of the 502 mags, there were 3 different versions of the fuel rails. The pre 99 versions have a few issues. The supply hole to the #7 injector needs to be opened up in a mill. Also, the rail should be fed fuel from both ends so that one end isn't run dry. There are quite a few other mods that needs to be done to the rail in order to make it really work correctly. The 99 and up rail needs less mods. It still should be fed from both ends, but it is already threaded for 1/4" NPT, so it's much easier to do.

With 5 psi boost, you should be in the 625 hp area. The stock injectors are good to about 650 hp without killing them by running them to hard. You can make more than 650, but it takes its toll on the injectors. If you have a pre 99 fuel rail, then you will have the Keihin injectors. There are no drop in replacements that are larger than the stockers. You can install larger injectors but it requires drilling out both the intake and the rails. If you have a 99 and up, they use the shorty injectors, so they can be replaced with larger ones if you want to make more power.

The other thing that must be addressed in the ecm. Obviously, it will need to be retuned. The best bet is to put it on the dyno and tune it.

We have done a TON of these. I actually have a few in the shop now that we are doing. If you have any questions or need any help, don't hesitate to give me a call anytime.
Eddie
615-216-7449 shop
504-416-3607 cell

badmonkey

Eddie,

Thank you so much for the terrific insight. I will be contacting you within the coming week.

Best Regards,

CHAOS REIGNS

been down this road.. did it myself only to have all sorts of issues. Ended up blowing a head gasket.

took mine to Eddie - was phenomenal after he was done with it. Don't scrimp on the money do it right the first time and you will be much happier.

his dyno of my motor --

http://youtu.be/U6vwwONBPEE