Quick fuel regulator/delivery system question
 

I’m adding a return style fuel pressure regulator (Mallory 4309) to my boat. The problem is that I don’t have a return line to the fuel tank. I was hoping that I could “T” into the fuel line before the filter and fuel pump, then plumb into this “T” from the return-to-tank port on the fuel pressure regulator. In theory, I don’t see any problem with this. I’m not sure if the fuel system has a one way valve between the fuel pump, and the fuel tank. Even then, it should work, since the demand for fuel should continually bleed the system. Does anybody know if it is typical to have a one way valve in the fuel supply line? The boat is a 1993 Fountain Fever. Also, does anybody see a problem with this configuration?

Thanks
Dan Suitor

Re: Quick fuel regulator/delivery system question
 

You'll need to remove the anit-siphon valve from the fitting on the tank. Other than that I don't see a problem with doing this other than the possibility of heating up the fuel by repumping so many times.

Re: Quick fuel regulator/delivery system question
 

Mr. Velocity,
Where would you suggest that I look for the access panel to the fuel tank / anti-siphon valve? Also, would you anticipate a significant increase in fuel temperature?
Thanks
Dan

Re: Quick fuel regulator/delivery system question
 

The return you desribe is how i have my boat plumbed also,works just fine. As far as the checkball in the tank,until you are pumping so much gas that your pressure won't hold wide open it is not completetly necessary to remove it. I ran my stock 272 baja with the big aeromotive pump feeding a efi w/procharger and didn't have fuel delivery suction problems with stock checkball. I later removed it when going to a bigger engine,it involved pulling most of the interior out and pulling up gas tank panel in the floor (not a easy job),just my .02

Re: Quick fuel regulator/delivery system question
 

Articfriends,
This is the confirmation I was hoping for. I figured that it would be difficult to get to the tank, as I have not seen an easy access point for it. I’ll be plumbing it this weekend. I too have a Procharger system, and the pump/regulator combo sold to me by the supposed experts was not correct. Overriding the internal regulator on the pump (Mallory 140GPH), and swapping out the regulator with the boost reference / return style should provide me with the flow, pressure, and pressure referencing that I need.
Thanks again.
Dan

Re: Quick fuel regulator/delivery system question
 

You may need to replumb anyway. There is a chance you have 3/8 lines that should be upgraded to 1/2". The access should be at the back of the tank. A single place that houses the fuel sender and the connection for the fuel line. Be sure to install a fuel pressure gauge just to make sure you don't run into a lean condition.

Re: Quick fuel regulator/delivery system question
 

I recently removed my check valve and ran 1/2" line from tank to the mechanical fuel pump with the built in boost reference line from Procharger on my stock 454 mag with 5* boost and 324 intercooler and I am still lean. I now have to add a feeder pump between tank and mechanical pump. So keep in mind that Procharger can make chitty suggestions. They also sent me the wrong oil fittings for relocating the oil filter. My crossover kit from procharger also looked like hell......it looked like they powder coated it and then rolled it in a pile of metal shavings.

Re: Quick fuel regulator/delivery system question
 

The efi systems w/electric fuel pump must be able to pull fuel from tk better than the carb systems w/mechanical. I ran the m-3 procharger w/8-9 #'s boost thru 3/8's id line w/factory check valve in place,never had a fuel delivery problem. On my boat there was a 6" or 8" gas tk acess towards back of tank but all you could access thru it was the wire for gas gauge,the fittings going into tank were not directly under the access cover and were too tight to gas tk cover to get to. When i did finally pull the whole gas tank cover and re-plumb it right (i was going to a 540 motor) the threaded bung going into gas tk was still only 3/8's npt,i used a full flow 3/8 by -10 an adapter and bored fitting bigger on 3/8's end to try to maximize flow. As far as procharger quality and tech help,the supercharger is a nice piece and has held up well BUT-there junk oil fittings,and fuel regulator caused me MUCH grief! The regulator constantly stuck,especially when you were expecting it to boost reference,they replaced it and the new one was just as bad. I ended up replacing regulator with a quality aeormotive regulator that didn't boost reference and a second bell industrys regulator to boost reference on outlet of first regulator,this works flawleslly. This was a efi setup though and it was trying to boost reference at a 3-1 to 5-1 rate so i don't imagine the carb setups have the same problems. Tech- i got a different answer everytime i called them,poor tech support!Smitty

Re: Quick fuel regulator/delivery system question
 

Depends on how hot it is where you are, and how big a fuel pump, but if you need to idle around a lot, a pump like the A1000 from Aeromotive is pumping 1000 HP worth of fuel all the time. This will get the fuel hot after a while and could cause cavitation at the pump. Because it is a pain to get a return line to the tank on most boats, many people use fuel coolers. Vortech sells them, so does Arizona Speed & Marine.

This is what it looks like installed in the water line between the sea water pump and the oil cooler. We return the cool fuel to a big water separating fuel filter in front of the pump. It acts as a reservoir of cool fuel and primes the pump. We use -8 lines on the return as well as the supply, since they have to handle 99% of the fuel flow at idle.

Re: Quick fuel regulator/delivery system question
 

In the race boat we returned the fuel to the tank. We had an electric pump mounted on the firewall in the AB locker just above the tank that fed the engines stock fuel pump. On my pleasure boat I have two pumps in parallel. The electric pump is mounted in the fire wall and I have a high volume mechanical pump on the engine. Both of these pumps are fed with -10 line. At the engine I have a manifold that takes the output from both pumps, combines them, then outputs -8 to each float bowl on the Dominators. I never see anything less than 7 psi of fuel pressure.

Don't skimp when it comes to setting up your fuel system, nothing will kill an engine faster than running into a lean condition.