saubouin

Anybody know how many lbs the stock injectors are? Is it like 42lbs or something?

Raylar

The stock injectors that all marine 8.1L-496 engines come equipped with are Delphi Multec II injectors that will flow a max of 43lbs./hr (400kpa) at 56 psi fuel pressure. On the 496 Mag and 496 Mag HO's the fuel pressure is fixed at 43psi and the injectors flow about 36lbs per hour at that pressure. we have run 496's up to about 640HP at a 52 psi fuel preeure before we hit the max the injector seems to want to supply. these type of horsepower & volume flows cannot be achieved with stock Mercury or Volvo cool fuel systems. The Mercury stock fuel system hits the wall at about 550HP. It requires a Aeromotive or similar electric fuel pump, a larger fuel water seperator and 1/2" supply from tank .To reliably get a 496 over 550HP to 575HP you will have to plan on upgrading your fuel supply system.

Ray @ Raylar

saubouin

Thanks Ray! What kind of duty cycle are the stock injectors seeing at WOT with your 525hp kit? Is it over 90%?

Dave_N

Ray,
When you say that the stock Merc Cool Fuel systems are only good for 550HP, how many GPH would that be? Are you talking about the GEN II or GEN III cool fuel system, or are they about the same?

Dave

Raylar

The pressure we run the injectors at on our HO525 kits is 50PSI and with the pulse width in the stock Merc ECM it represents about a 60% duty cycle max. The piggy back fuel programmer we use on our HO600 packages raises the duty cycle to about 70% and we keep the fuel pressure at 50psi. The Cool Fuels are both the II and III. The newest version Mercury "Cool Fuel" is patterned like Volvo Penta and it actually does not seem as strong and the version II "Cool Fuel". We bypass the fixed regulators in either system and use the stock GM adjustable regulator up on the fuel rail. Mercury want's to be so in control!

Ray @ Raylar

Seabrowner

Hi Raylar

I've got a Volvo Penta 8.1gi-EF 375HP up in BC Canada and I'm in a bit of a jam. Two of my OEM injectors have failed and I am trying to buy Delphi injectors from the local auto parts store here. Do you know which Delphi injectors will work for my application?

Thanks!