adding Procharger to stock 502?
 

I'm asking this question for the buyer of my 91 27' Fountain. a couple issues have been pointed out and I wanted to get the power of OSO members involved. He was told that a couple concerns and the first being that the heads don't have enough head bolts and that this is proned to blowing head gaskets? and the next is that the crank should be steel and not cast?

In my uneducated perspective I can see that these could be true as a week link from too much boost. Can these limits be identified or should improvements just be made as part of the prochagers installation?

Any other tips, big and small are appreciated. thanks in advance.

A stock 502 should hold up if he only goes up to a 5 psi boost any more and I would say he will have trouble I have a bunch of friends that have 5 psi super chargers on there boats and have had 200 trouble free hours on them I'm doing a set on my scarab right now have not run them yet mark at precision marine is starting on the second one next week If he does do the pro chargers I would say he should have the motors pulled and sent to a good engine builder and have them installed and dyno tuned thats the right way to do it I had a marine center tell me they could do it and all they did was f**k it up

I agree with trc2 , the dyno is the place to do the tuning not on the water or a hose. They are NOT a bolt on and go part . You will spend the money one way or an other just a lot easyer doing it right the first time.

We never had good experience with pro chargers in boats, great in cars.

a 1991 502 carb is probably only putting out 400 hp at most, I would suggest pulling it and send it to a professional builder. For what the procharger / Installation and 93 oct fuel will end up costing, probably beyyer off just building the motor up.

Good builder will get that 502 up to a "reliable" 500hp on 87 oct.

WILL:D

Great advice.
I belive he plans to be conservative with the boost. Is the possibility of adding head bolts a real option? If creating more then 5 lbs what will be the first to break?
How do you feel about the stock exhaust? Will this be able to breath with minimal boost?

Agree with Baja Will. I had prochargers on my last boat. $$$ will be better spent on good engine parts.

what are the bad experiences?

Do not get me wrong you can make lots of power with them. I run them on hp500's and make over 740hp & over 800 ft. lb torque. But they where done on the dyno not in the boat . The first thing to break will be the outdrive !!!!!!!!!!! Good luck with your project . Jeff :ernaehrung004:

I have a nice M-1 with intercooler set up for the 502 EFI if you are interested.


The engine will be fine with the proper set up and low boost.

new or used?

uuuhhh noooo thanks............
 

Unless the guy selling the fountain can show receipts hes been inside the engine and replaced cast parts, did the exhaust seats etc., upgraded injectors, remapped ECU & there's a good manifold or better yet tube exhaust system ....... tell him to stay away from from it.


All the "bolt on blower" stories pretty much end the same and usually within about 20 hours of the beginning of the story. (doesnt matter the brand and Im not knocking the procharger its a nice unit)
Im stating emphatically NOT to" bolt on" any blower without a long list of upgrades.

I learned all this the expensive way.

"Uncle Dave"

I agree. If you want to run a Procharger you should at the very min. have your motor spec'd to a 500 HP. Use notched pistons, Roller Valve train...etc. etc.

Our problems were basically trying to fix, what other people think is just a "Bolt on Application" fue/air mixture, fuel pressure, its just more than "bolt on". Oh and yes within one or two seasons, motors trashes. Now these were all stock, black motors.

Your asking a 18 yr motor to put out HP it was never designed to do. I am being straight up with you, even if you do a professional job, its going to break. Each their own, but you will wish you had just build up the motor.

WILL:cool-smiley-026:

I to have learned the expensive way I now have in to these motors what I bought the whole boat for. Its best to just send out the motors and have them professional built and dyno

One engine is done dyno at 521 H/P and this is a small block 350 was 300 H/P

Is this a carb. engine or is it EFI???

this is carbed.

If you go with the pro charger let me know I can give you some good base numbers to start with. Jet sizes & timing if you want . Carbs are a lot easyer to set up than efi , with no computer to mess with. :ernaehrung004:

Ditto Jeff. The problem is not so much with the extra stress on the internal but the lack of adjustiblity of the fuel and timing. If it is carbed and you run it reletivly rich and with about 30* total advance, it will last a long time. A valve job with good valves, head gaskets and bolts even better and you would be good to go with the "bolt ons".

BT :cool: