getrdunn

Works every time.

getrdunn

Seriously. Lol. Have heard of that before also but would never recommend it.

Correction Factors? Ah maybe overlooked.

14 apache

That is a boat load of power rite there.

SB

Bingo !

As we all know, the kit from Procharger does not cover you exactly. Their FMU set up sucks, will need programming, fuel rail mods to flow more fuel, headgaskets (factory ones are suspectible) and etc.

NA can be done with the MPI, however, tons of intake mods, reprogramming, fuel rail mods, etc,etc.

AFR/Brodix/RHS/ etc heads, 850-950 Holley, Victor Jr, Crane 741 or the like, Stainless MArine Exhaust or etc, bang...600hp and you don't need a laptop. EFI distributor can be used standalone, module inside takes care of timing in carbed applications.

Diamond Dave

I am In Portland also and I have yet to find anyone here local that I trust for what you are asking. Let me know if you run across anyone though....

Black Baja

With Brodix heads the lifters will come out the Hole in the center of the heads.

14 apache

The set I did was a customers boat they where brodix heads but did not have shaft rockers. Still took some time to fish the lifters in. I think I did them through the distributer hole.

sutphen 30

what kind of boat do you have?most boats will need a hole saw to change cams in the boat.

No Coast

Let's talk reality for a minute. What you want is what most boat owners want, 600 horsepower easy and inexpensive. If it could be done it would be sold in kit form by the hundreds. Your engine is 502 cubic inch, has 088 rectangular port heads and the Mercruiser MPI mag intake. It makes about 440 hp bobtail on the dyno. The heads are as cast and the intake valve is 2.19 diameter, exhaust is 1.88 and must be modified for higher lift springs to allow more cam. Search the arctic friends thread on improving this engine, it can make about 520 hp, the restriction is the intake and throttle body not cylinder heads. Next comparison is the 500 EFI Mercruiser engine. The intake is less restrictive, the heads have 2.25 intake valves, the intake runner is throat cut for increased flow and this package makes 550 hp bobtail on the dyno. The intake is maxed out due to throttle body and runners. Many different cams have been tried in both engines, my opinion is 230-232 intake and 236-238 exhaust duration at .050 is maximum for marine applications. Bigger cam shafts make less peak torque and need more rpm, my opinion is a given cubic inch will produce a certain level of torque, the camshaft controls when this will occur. Again the restriction is the intake throttle body combo, not cylinder heads. To make 600 N/A you need aftermarket Efi intake like Holley system with a 4150 style throttle body. Check out Young Performance for this application description. Now the procharger kit. Yes it is capable of making 600 hp using your intake and throttle body. It is in no way a bolt on kit!!! You must have this system installed by a marine experienced technician. The fuel rail needs to be modified, the entire fuel system must be upgraded from line size, filters, new pump and return style regulator system. The ecu must be re-programmed and I always feed the inter cooler with a separate pick-up. The oil cooler must be increased and the oil filter and housing should be upgraded. I would also suggest the head gaskets be changed to Cometic and the head bolts should be upgraded. I like switching to a stamped roller rocker because space is limited and you still retain the drippers cast into the valve cover. You may need a little more camshaft to get to your goal but it should be close. I have no idea how you are going to seal the oil pan back up if you change a camshaft in the boat. Good luck with that. Reality is you are better off selling your existing engine running and then purchasing an engine that makes the power you expect from a marine engine builder or Mercruiser. Fuel, oil, and cooling systems all must match the application. Going fast costs money. Good luck with your project.

getrdunn

Some valid points! I don't think he was necessarily trying do this for the cost of a happy meal though. At least I didn't understand it that way. He may have referenced a cheaper way however just weighing out options, pros and cons etc.

I guess it would help if there was a budget in mind?