Fuel system plan for conversion from carb to mpfi
 

Hi,

This was posted in an earlier thread, but I am converting from carb to MPFI and have the following idea in my head for the fuel system. Please let me know your thoughts or criticism of the design. The mechanical pump is being used as a lift pump to avoid suction issues with the electric high pressure pump.

https://cimg1.ibsrv.net/gimg/www.off...ba03409f67.jpg

I don't think you need the cooler. The loop back to the tank should keep it cool. And unless you have the tank really low, I do not think you would need the mechanical pump but that's me.

typically fuel is cooled prier to going into the engine not on the back end, how much power are you trying to support in this application ?

I agree, should not need mech pump or cooler. Just mount elect pump low on a stringer.

The engine will be about 600HP. I know the Aeromotive is a little large for that power level ,but I really can’t find a USCG approved electric high pressure pump of a lower flow rate. I thought the fuel cooler would help keep the temp down from the excess fuel flow.

Its good stuff made not far from me, Im running their stuff on my EFI Whipples..........you can return the excess fuel from the regulator to the filter head if you dont want to go all the way to the tank, this is how the Whipple kits are designed

Don't think the mechanical pump can supply all the fuel the Aeromotive will draw, it will turn into a restriction

Weldon pumps can lift as well as push and are USCG approved.

https://www.weldonracing.com/store/D...rine-p56797122

I see your fitting size is -6.....Id run -8 from the tank all the way through to support 600 hp and a -6 on the return side.........-6 is like 3/8 ID

I'm running Gen 2 cool fuel with 530HP (probably 500 at the prop) with stock Merc lines and return to tank

What's the HP limit for the Cool Fuel system?

Don't know, but the pump has no issues with mine and I'm a heavy cruiser. My guess is Eddie Young or Smitty would know

I did look at the Weldon pumps but thought they would flow way too much. I do know they have the pump controller that can slow it down but I think that is installed right next to the pump and not sure if it is USCG approved.

Just re-did my fuel system for procharger. I ran return line back to fuel water sep the fuel cooler was needed to keep the circulated fuel cool. Works like a champ. I have two tanks Y both together went to fuel water sep, went to A1000 pump low on stringer, out to regulator, then to fuel rail. Factory Merc runs return line back to fuel water sep with the cool fuel system that’s how i keep mine. I have ran mine about 40 mile stretch on way at lake ran perfect. Help was from Arizona Speed and Marine for setup based on their exp.