502 fuel system questions
 

How much fuel pressure and volume does it take to fuel a 502 up to 550 HP? My boat is set up for an electric fuel pump and a I want to make sure I am set up correctly. Pump feeds a single Demon 850 carb. Also is the standard 454 mag water separator restrictive enough to affect the fuel pressure?

Thanks

Re: 502 fuel system questions
 

I don't have the dyno sheet in front of me but I think my 502 was 232 lbs/hr at 5800 rpm. 232 lbs/hr is about 35 gallons/hr. Fuel pressure is set at 6 psi. After problems with the non bypass pumps I switched to an Aeromotive marine pump with a bypass regulator. So far so good.

Re: 502 fuel system questions
 

Its not only your pump,the complete system need to be upgraded.Make sure you run 1/2 line from tank to carb and make sure your pickup in your tank is also 1/2 or 5/8.Stock lines are 5/16 or 3/8 way to small to flow the volume you may or may not need.Better to have more fuel then you may need sitting at the carb then not enough.Also look at filter and all fittings,make sure they are high flow with no tight 90 degree turns,use all radius turns.

Nordic95

Re: 502 fuel system questions
 

Thanks guys
My 4 and 1/2 lbs seems to be on the short side as I thought.

Re: 502 fuel system questions
 

Use a rubber line to bypass your filter just to see if your pressure goes up at the carb.That will tell you if the filter is restrictive or not.

Nordic95