Zeek

So I want to put a procharger on my 502 efi. Like the title says where do I start. I want to make this motor strong but yet very reliable. What all needs upgraded, and is it really worth it?

ezstriper

forget the procharger instructions on fuel system, trash all the merc stuff, run a aeromotive A1000 pump(which they use now) boost referenced regulator and decent lines with a RETURN to the tank, and you will need someone to tune the ecm properly, ck with eddie young on here...I love my setup..but if you just throw the unit on as procharger says..like pulling the pin...Rob

28Eliminator

+1
How many hours are on the 502? As exsptriper said "all merc stuff" including a good fuel water seperator, like a Flomax 300 - Ramco. The merc just can't flow enough fuel. I would also never install one without changing the head gaskets. Any of the ones I have done without replacing them have blown the head gaskets within the next year or 2 depending on usage. The stock ones are just not up to the task.
2nd on ecm tune, even though the instructions say nothing about that, it won't run right.
Is it worth it? I say yes, you will love the added power, but there is a fair amount of messing around with a procharger. Whipple has more of a complete setup and is very popular.

Zeek

There is about 300 hours on the boat. I was planning on tearing it down and changing the pistons and rings, doing head work (rollers instead of hydraulic) mild cam, and exhaust. Now with that being said, what is recommended as far as internals. Last summer 68 was the best I did and wanted at least mid 70's anything more is a bonus. I just want it done right the first time.

4bus

iTrader: (4)

Inconel valves are a must if you are going to rebuild.

You really have a lot of options here, but doing everything right to the top you may have 20gs in this by the time you are done. Are you prepared for this?

Option one- rebuild engine, add procharger, fuel system mods, ecm programming, everything else that you will find along the way. Most expensive and you will lose the investment when it is time to sell the boat. My estimate is 20 grand.

Option two. Pull stock engine, purchase a used clean blower motor done. Maybe even a stock merc blower motor (525sc, 575sci, 600sc) drop in and go. When it is time to sell replace stock engine, sell mod engine separate. Or do this and sell stock engine complete for $5-6k, This will help control losses. $10-18k for new engine, that will no depreciate as much as modifying what you have. Also consider a 500EFI or 525EFI, these engines will raise the resale of your ride.

Option three...the gamble- Pull off all efi stuff and store it away. Buy roots style blower with blower carb, used or new...but slightly used and proven may be better for you. Run low boost and leave internals as is. 4PSI will get you well over 70. This can also be removed at a later date and stock efi can go back on.

Whipple Charged

As ezstripper said, throw there instructions and fuel system away. Then, make an appointment with someone that can tune the MEFI properly, put a 2-bar map sensor on, 63lb/hr injectors, Aeromotive #11008 fuel pump (A1000 is not USGC approved), Aeromotive #13114 fuel PSI regulator, a fuel cooler (for return side of fuel), fuel pump relay harness 12awg wire minimum and a fuel filter/water separator with at least 1/2" NPT, preferably 3/4" NPT.

Exhaust systems always help if you have the stock cast iron. At least replace the riser with a Imco stainless raiser, and install a 18mm bung for O2. Otherwise, Imco Powerflow are nice and make more power., CMI's are always good.....

Do it right the first time otherwise you'll have 8 ash-trays and broken down in the middle of summer.

GPM

Maybe just build a 540.

Pismo10

Yes, build a 540 with some good AFR heads, cam, and good exhaust and you will reach your speed goals with good reliability.

Zeek

Well I am trying to budget under 8k, I already have the super charger. I just dont want to be like the gangsters with $10k wheels on a $2k car. As you can see I have a VIP, who knows how long it will hold up. Bottom line on my boat is I basically bought the motor, outdrive, Kplains, and gauges and got everything else for free.

TooLateVTEC

iTrader: (1)

What ezstriper and Whipple said.

If all you're looking for is mid 70's and its already gone 68 then I think just freshening the motor, upgrading the exhaust and added the blower (and the supporting mods) you wont need to change the cam unless you have more money left over in the budget.

Not sure whats on the boat now, but dont forget about the prop changed you might need.