82FanTC

iTrader: (9)

I have a Mallory Comp 70 that is overheating regularily now and stops working. Once cooled it has, so far, started to work again. Any tricks to keep it running cool? Any sort of special blankets or heat sinks or something?

I currently do not run a return on it because with the stock return lines I cant achieve low enough pressure for my weber 45 DCOE.

Are my only 2 options to either run a return or go with a different pump? I HATED how loud my holley was so please don't refer me back to it....

Thanks

trochoid

iTrader: (6)

The fuel running through the pump is a major part of the pumps cooling. Deadheading the pump limits the amount of fuel passing through the pump for cooling. Location of the pump can be another factor. I would add a Mallory 4309 return style fpr and use the stock return line off of it.

82FanTC

iTrader: (9)

I have a mallory 4309 and when I had it hooked up I couldn't get fuel pressure below 9 PSI! Forum lead me to believe it was because the stock return is too small.

Pump is located on the frame rail in front of the axle where most folks locate their pumps.

trochoid

iTrader: (6)

What fpr are you using now? The Mallory 70 us rated at 70/gpm, which is a lower flow rating than the Holley blue, red and black series. You should have no problem running the 4309 with the Comp 70. Did you remove the inline re-stricter from the stock return line? If you still have the 4309, take it apart and check it for burrs, debris, etc..

I used to run a Comp 140 with 3/8" supply/return lines with no issues. That pump is way too big for our need, btw.

Just as a thought, check your rubber lines near the pump for possible kinks/restrictions.

82FanTC

iTrader: (9)

I'm going to go hook the 4309 back up again and see what it does.

By inline restrictor are you talking about the one way valve or is there something else I should remove?

82FanTC

iTrader: (9)

Well tried the Mallory 4309 FPR again and pretty much the same as before. Pressure will not drop below about 6 PSI when hooked up to stock return.

Tried he return pumping to a bucket and I could dial well below the advertised 3PSI minimum.

Guess I will either have to change fuel pumps again... or put in 3/8 return line.

My question is if I plumb in 3/8 fuel line from the FPR to the tank how do I get into the tank since the stock outlet is still going to be 1/4...?

trochoid

iTrader: (6)

I was fortunate in that I have an 85 model year. The S3 model has a removable supply/return unit in the tank so I swapped the 12A one for the larger tubed FI one. Since you have an earlier tank, you would need to removed the existing return tube and braze in a larger one. If so, the tube needs to terminate within 1" of the bottom of the tank. De-braze the existing return from the tank and use it as a pattern.

I'm not sure what size return line the Comp 70 requires. If you can find the pdf manual for it, it will spec it in there. The Comp 140 requires a 3/8" minimum return line. You should find the manual on the Mallory website.

Before you go to all that trouble, check your return line from end to end for any restriction, kinks, etc.. The re-stricter I mentioned is a one way valve that's installed in the rubber return fuel line between the carb and the hardline at the firewall.

trochoid

iTrader: (6)

As luck would have it, I just happened to find that PDF on my comp. The following is a cut & paste and slightly edited version of it. The diagrams refereed to here don't translate into MS Word. If you need them you can find them in the original PDF at Mallory.

ORM #1394 (REV. B) 8/0.


INSTALLATION INSTRUCTION.


COMP PUMP® SERIES 7.
ELECTRIC FUEL PUMP

PART NO. 4070L.

NOTE: DO NOT RUN THIS PUMP WITHOUT FUEL.
(EXCEPT FOR BRIEF PERIODS WHILE PRIMING).


PARTS INCLUDED IN THIS KIT:
.
Electric Fuel Pump.
.
Nuts, 5/16" . 2.
.
Bolts, Steel 5/16.
.
Washers, Steel 5/16" Fla.
.
Splice Connector.
.
Ring Terminal


GENERAL INFORMATION


The COMP PUMP® 70 Series Electric Fuel Pump is a low volume fuel
pump designed for automotive applications. The operating fuel pressure is factory set at 3-4 PSI. A fuel pressure regulator is not used.
We recommend a 5/16" or larger fuel line with this fuel system.


When installing the fuel pump fittings, use a thread sealant compound.
(you can find this at a hardware store) on the fitting threads. Do not
use Teflon tape. Teflon tape can get into the Gerotor and lock the
pump. Also, do not over tighten the fittings. This could damage the fuel
chamber.


The fuel pump output pressure can be slightly adjusted on the vehicle.
using a fuel pressure gauge. To change the fuel pump output.
pressure, release the jam nut and remove bypass plug. Clean the
bypass plug. Apply thread sealant compound to the bypass plug
threads. Install bypass plug. Turning the bypass plug clockwise.
increases fuel pressure. Tighten the jam nut.
Be sure to install a suitable fuel filter (minimum 40 micron filtration)
between the fuel tank and the fuel pump. The Mallory COMP FILTER.
Series Part Nos. 3140 is recommended. This prevents debris from.
becoming wedged in the fuel pump’s Gerotor and locking it.


SPECIFICATION.


Operating pressure.
3.4 PS.
Fuel pump inlet/outlet thread sizes.
3/8" NP.
Oil pressure switch rating.
5 AMP
Fuel pump over current protection.
5 AMP fuse.
Fuel applications.
Gasoline.


Service Part.
PN 3146.
Brush Kit.
PN 316.
Seal/Repair Kit, Gasoline.


MOUNTING PROCEDURE


Step 1


Mount the pump as close as possible to the fuel tank (at or below the.
level of the fuel tank pickup) in a well ventilated area with minimal.
exposure to road debris. Avoid exposing the pump and fuel lines t.
moving parts and hot surfaces, such as the exhaust system. NOTE.
Increasing distance between the pump and tank will decrease.
pump efficiency.


Step 2


Using the pump mounting bracket as a template, locate mounting.
holes on a solid member, such as the vehicle chassis. Drill holes for 5.
16" bolts. See Figure 1. NOTE: To ensure against a potential fir.
hazard from pump flooding, mount the pump in a vertical.
position with the motor on top.


Step 3


Connect fuel lines as shown in Figure 2. If your fuel system requires .
fuel pressure regulator, proceed to the instructions with the fuel
pressure regulator.

WIRING PROCEDURE


Wiring the pump to an oil pressure switch will provide power only when.
the ignition switch is on and the engine is running. This will prevent the pump from running if your engine stalls. Use 14 gauge wire or large.
and be sure to disconnect the battery ground cable before wiring the
pump. Refer to Figure 3 when connecting the pump to an oil pressure
switch.


The pump may be wired directly to the ignition switch .ON. terminal
and grounded to the frame or battery. Refer to Figure 4 when
connecting the pump to the ignition switch .ON. terminal.


PUMP MAINTENANCE DIS-ASSEMBLY


If your pump fails to produce adequate pressure, it may require
cleaning. Follow the steps below to disassemble and clean you.
Mallory Electric Fuel Pump. Refer to Figure 5 while performing the
following steps.


Step 1


Remove the pump from the vehicle and clean pump exterior. Place the
pump on its side on a clean work surface. Scribe or draw a line across
the pump housing, port plate and fuel chamber so that you ca.
reassemble the pump correctly.


Step 2


Remove the two fuel chamber screws from the bottom of the pump.
Remove the fuel chamber and port plate. NOTE: Do not drop the
Gerotor from the pump cavity.


Step 3


Separate the port plate from the fuel chamber. Inspect the flame
arrestor screen in the fuel chamber and clean it if necessary.


Step 4


Place your hand beneath the Gerotor and hold the pump in an upright
position. The Gerotor should slide out of the pump housing and into
your hand. NOTE: Observe the position of the Gerotor and b.
careful not to reverse it when you reassemble the pump.


Step 5


Release the jam nut on the bypass plug. Mark the bypass plug location
and count the number of turns required to remove it. Remove the
bypass spring and plunger. Inspect the plunger. The plunger surface
should be clean and slide freely in the chamber. Check the plunger pa.
and remove any debris embedded in its surface. Reinstall the bypass
spring and plunger. Clean the bypass plug. Apply thread sealant
compound to the bypass plug threads. Install the bypass plug. Tighten
the jam nut.


Step 6


Clean the Gerotor and install it in the pump housing. Inspect the o-ring
and gasket. Replace them if necessary. Place the gasket and port plate
on the fuel chamber. Install the fuel chamber assembly on the pump
housing. Torque the fuel chamber screws to 24 in/lbs.


BLACK WIRE (-)


FIGURE 1
3/8" NPT OUTLET3/8" NPT INLET
BYPASS ADJUSTMENT (BYPASS PLUG AND JAM NUT)

RED WIRE (+)

MALLORY IS A DIVISION OF THE MR. GASKET PERFORMANCE GROUP FORM #139.
550 MALLORY WAY, CARSON CITY, NEVADA 89701 REV. B (8/00.
(775) 882-6600 FAX (775) 887-4326 MADE IN US.

82FanTC

iTrader: (9)

I swapped in a 3/8 OD hard fuel line over the weekend from the Mallory 4309 to the existing stock 1/4" line on the fuel tank and used 3/8" hose to connect the two with a really tight hose clamp.

No leaks yet. Put on about 50miles with this setup. Fuel pressure holds steady at about 2.8 PSI.

I also let the car sit and idle for about 10 minutes in the driveway in 90* heat and the fuel pump never overheated. Hope I solved my problem!

pinoyremix

for my dellorto..we just did a gsl se fuel system swap...we swapped the tank and the hard lines and fed it to the mallory 4309 fpr...

Jeezus

iTrader: (4)

3/8ths line is ideal. I have a Carter on my car with a 45DCOE as well, deadheaded. Never ran
into an overheating pump. Yet.