Rage

On the Merc 'Cool Fuel' system the stock non adjustable fuel pressure regulator bolts on to the fuel heat exchanger and one fuel passage is an oring seal interface against the fuel heat exchanger . In other words this is not a fuel line in/fuel line out connection that is simple to replace. This is for a 100hp NA up grade to increase the fuel pressure from 43 psi to ~50-58 psi.

What design/ hardware for installing an adjustable fuel pressure regulator will work on a 496HO MPFI with the Merc 'Cool Fuel' system?

stevesxm

what i did on mine was to take all those dedicated fittings out , cut them off the lines leaving a 1/2 nub of steel line and then silver solder -6 aeroquip fitting on them... that got me out of these insane dedicated lines that merc makes and allowed me to put the components where ever i wanted... if you do that that allows you to seal off the regulator port, use the output line to go into your after market free return type regulator and you are home free. remember... you can't and should NOT use a NON return type regulator. your fuel should flow into a regulated T with one leg in from the cooler, one leg out to the free return regulator and tank and the other to the fuel rail . it can be done nicely and neatly in any number of ways.

racinfever

I think VORTEC has ajustable kit for your regulator, be carefull over 50 psi may jam your injectors !

stevesxm

curious why you would say that ? these are typical bosch type 5v solonoid type injectors... used routinely up to 120 psi that i know of... where did you get this 5o psi figure from ?

racinfever

BOB ENDRESS VORTEC MARINE cautioned us to not turn pressure up over much over 50 it may be that the module is not able to cycle fire with hi pressure? your thoughts appr. !

stevesxm

no idea... these injectors have been used in excess of 50 psi from beginning of time... and ecu shouldn't care as they gennerally just adjust mixture w/ pulse width assuming mostly fixed fuel press.... but who knows. am certain bob who built the system has good reason for saying that and is correct. i was just surpised at the number... made no sense to me.

Rage

Can you give any more detail on where to find VORTEC products. Google is striking out for me.

racinfever

RAGE Vortech's # 805-247-0226

racinfever

Steve I'm only guessing but I think the automotive computer is much larger and more sophisticated in it's ability to control spark and fuel systems where as mercury's little delphi module is limited.

stevesxm

well...i suppose... but not talking anything cutting edge or rocket science here.... a handful of sensor inputs into a look up table algorythim that defines the fuel curve demand... and as such , the pulse width for the injector opening and timing...

but either way... injector hardware not pressure limited in any reasonable sense that i am aware of...