[lawnbouy]

I have a Ramjet 502 in a 1934 Ford. Stock fuel injection, fuel rail and regulator. Engine space is tight to say the least, so air flow under the intake is limited. I have found that on a hot day, with less than 1/4 tank of fuel, the fuel will actually boil in the tank! It does not run when this happens! The set up was - stock tank and large Aeromotive external fuel pump, placed below the tank. I have replaced the tank and pump with a new TanksInc SS version with the internal pump. I do have higher fuel pressure now but have not had a hot enough day to determine if I still have a fuel heating problem. My next step will be to install transmission cooler with electric fan on the return side - should the problem still exist. It is possible (hoping) that the in-tank pump will not circulate as much fuel.
Just wondering if anyone else has run into this situation?

 

[35WINDOW]

I don't know which Pump you have (and, are you running the GM ECU?)-

-anyway, depending on your brand of Pump you could use a PWM controller to slow down the return rate-side benefit would be that if your Pump is noisy this would quiet it somewhat-

Certain brands of ECU's can also do this internally-

Here is an Aeromotive PWM controller:

http://www.summitracing.com/parts/aei-16306

and, here is one from Weldon:

// WELDON RACING PUMPS // Electronic Pump Controller -- Weldon Racing Pumps

Also, what are you using for a Regulator?

 

[ogre]

i think that with a ramjet 502, a 1/4 tank is out of gas

you may have had a bad pump that was overheating, but more likely
your pushing too much fuel past the regulator with a big pump
with more pressure on the new pump your problem may get worse
the cooler would help, but a smaller pump will too

i have a ramjet 350 with the same basic fuel regulator
i run an in tank pump, the pump is an oem replacement for a 350
no problems or overheating and i have a constant 45 psi

 

[lawnbouy]

The pump I have installed is smaller and hopefully will not move as much fuel. The pressure is way better now with this in-tank pump it is the TanksInc 450 hp version. It has no problem holding a steady 48 psi. I did have the regulator turned in with the other external pump and it had trouble getting a steady 38 psi. This is the pump I had: Aeromotive 11106 Aeromotive 11106, Aeromotive 700 HP Fuel Pumps | Aeromotive and this is the pump I have now In-Tank Fuel Pump Module - GPA-Series

 

[ogre]

I did have the regulator turned in with the other external pump

the regulator on the rj350 is non adjustable, the rj502 may have a different setup

 

[lawnbouy]

Fuel Still too hot

I made a run on a hot day this week-end and although it ran fine, when I stopped the fuel was boiling in the tank - I could hear it at the vent. I have added fans now to the cooler I installed, but I think there still will be a heating issue. I am thinking I should open up the factory fuel regulator (no restriction) and block off its return and do my regulating back at the tank. This way there will be no heat picked up at the engine. The fuel pump can supply plenty of pressure - I currently have it set at 52 psi. The high pressure should keep it from vapor locking in the rail. Has anyone else tried this?

 

[lawnbouy]

Problem Solved

By installing an Aeromotive regulator back near the tank I have avoided picking up heat in the engine compartment.