1956 Packard Panther Project

Panther "Restomod" Projects

Fuel Delivery System Subproject

The stock Packard V-8 fuel delivery system was adequate in its day. However, today we have gasoline with 15% ethanol/85% gasoline mix plus who knows what other additives. Also, "Premium" grade is less octane rating than back in the day due to removing the lead additive and a changed measurement standard (average of the RON and the MON ratings and often written on pumps as (R+M)/2).

On a hot day in the Summertime, the stock fuel delivery system (mechanical pump only with no return line to tank) WILL vaporlock causing the engine to quit. Ask me how I know! The solution on a stock Packard V-8 is an auxilliary electric "pusher" fuel pump somewhere between the tank and the mechanical pump. Panther will require a system more robust than this!

Fuel Tank Modification

Besides the normal restoration cleaning and painting of the stock tank, I installed a Summit Racing fuel tank sump kit. This triangular sump is welded into the bottom rear of the tank after being cut down to one outlet. It serves three purposes:

  1. Since the sump is lower than the tank bottom, the last drop of fuel will be fed.
  2. Inertia will force the fuel into the fuel feed line under vehicle acceleration.
  3. The fuel feed line size is increased from 5/16" to 3/8".

The original 5/16" fuel line outlet was removed and plugged. The stock fuel level sender is retained. The inline fuel filter is in addition to the carburetor fuel filters.

Auxilliary "pusher" electric fuel pump

A Carter rotary-type 15PSI electric fuel pump was mounted behind the fuel tank on the rear frame rail.

Fuel feed line

Carter electric pump to fuel feed line on P-side rear frame rail.

Fuel feed line over rear kickup frame rail.

Fuel feed line over P-side rear T-L load arm/frame.

Fuel feed line thru Outrigger clearance hole.

Fuel feed line over front two "outriggers".

Fuel feed line under upper control arm to regulator.
The 3/8" aluminum line is from Summit Racing and came in a 25ft roll.

Fuel pressure regulator

The 15PSI output pressure from the Carter electric fuel pump in the rear must be reduced to about 5psi to the carburetor fuel inlets. This is accomplished with a Holley bypass-type adjustable fuel pressure regulator.

Left:inlet at 15PSI, Right: outlet at 5PSI, Bottom: bleed bypass return to tank.

The mechanical fuel pump is a Carter high performance unit originally for an Ford FE 428 engine. Surprisingly, it bolts right on the Packard V-8 and works great!

Fuel return line

The fuel return line from the regulator in the front to the tank in the rear is 1/2" diameter. It serves two purposes:

  1. It provides the bleed outlet so the regulator can control the outlet fuel pressure.
  2. It circulates fuel to reduce fuel temperature on a hot day.

Return line routing front-to-back:

Return line Tee'd into stock fuel filler vent line.
The 1/2" aluminum line is from Summit Racing and came in a 25ft roll.

Fuel tank filler relocated

I changed the fuel tank filler inlet from the D-side rear fender (with the hinged door) to a low-profile chrome cap on the top of that fender near the trunk lid pivot. I did this for two reasons:

  1. I wanted to weld the gas filler door closed to make a completely smooth fender surface.
  2. The filler and cap up on the top of the fender is more performance (racing) oriented.

NOTE: this is a trial fit. Duct tape will be removed and band clamps fitted in final assembly.

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