Fuel System: Question on converting to an electric fuel pump

[wdills]

Our 54 Commander seems to be having a lot of trouble with vapor lock on hot days. I am planning to convert to an electric pump and pressure regulator. But instead of just removing the mechanical pump and installing a block-off plate, I am thinking about removing the guts of the mechanical pump and leaving it mounted on the side of the oil fill tube. That mounting location is pretty unique and I would like to keep the look.

I plan to remove the inlet / outlet check valves, diaphragm, spring, etc. I will fabricate a sheet-metal disc with gaskets on both sides to mount where the diaphragm was. The idea will be that the fuel from the electric pump will just flow through the glass bowl "filter" and the top side of the mechanical pump housing on its way to the carb. The oil line to the bottom side will remain as well and oil will just flow down the oil fill tube as usual.

Is there any reason this will not work? It seems so simple that I am afraid there is some major flaw in my plan and I am just not thinking about it.

Second question. There is some sort of push-rod that comes up through the oil fill tube to drive the mechanical pump. Can that rod be easily removed? Does it just lift out or what do I have to do to get it out of there?

[nckid4u]

If you removed the lever and had longer bolts, you could likely mount the old pump with a block off plate sandwiched between the pump and the engine.

[tim333]

Fix the problem instead of an electric fuel pump bandaid.

[gordr]

Electric pump is not a bandaid. Today's fuel is much different than what was available when our cars were new. Boils much more readily, so more prone to vapor lock and carb percolation, and simply evaporating from the carb when car is idle for a few days.

Wayne, I think the fuel pump push rod can simply be lifted out if the oil fill tube is removed. I like the idea in post #2, and would recommend a block-off plate made of bakelite or fiber, or other heat-resistant plastic to reduce heat soak through the oil pump stand, and into the fuel-filled pump body.

[wdills]

The only thing I don't like about the post #2 idea of the block off plate is that I would have to remove the oil line feeding the fuel pump. I wanted to keep all that in place so the equipment looks correct when you pop the hood. Just curious, what is the advantage of adding the block off plate?

[gordr]

The only thing I don't like about the post #2 idea of the block off plate is that I would have to remove the oil line feeding the fuel pump. I wanted to keep all that in place so the equipment looks correct when you pop the hood. Just curious, what is the advantage of adding the block off plate?

The pump is mounted on the oil filler standpipe, which is cast iron. After a decent period of running, that standpipe will be nearly as hot as the rest of the engine block, or easily hot enough to boil modern gas. A heat-insulating spacer between that standpipe, and your non-working, but still fuel-filled, pump would help prevent vapor lock and/or percolation. I don't remember an oil line to the pump itself, but thereturn line from the oil filter empties into the oil filler standpipe. If there is indeed an oil line to the pump, you could plug it at the oil source fitting, since there is no need for oil if the pump no longer has moving parts in it.

[TWChamp]

I like your idea, but as Gord said, today's gas sucks compared to what we had in the 60's and 70's, and the added heat picked up at the pump could still cause trouble. My 50 Land Cruiser does OK on non-ox gas with 4 ounces MMO added to each 10 gallons. I've also heard good results from someone adding a quart of diesel to each tank of gas. I'd give that a try before doing the fuel pump mods. I'd also insulate the fuel lines and add heat shields where needed.

[Studeguy61]

I mounted a low fuel volume from NAPA and mounted it in front of the gas tank and operate it from a toggle switch. I use the stock fuel pump and use the electric as a way of keeping the gas flow. I drive in a lot of hot weather and many miles and it has not vapor locked since. The h\key is it has to be a very low pressure pump.

[wdills]

I have considered other options to try to modify the original system so it will work with todays gas, but at the end of the day, I decided on a conversion to an electric pump because that is what I did on my Hawk and it has never had any hint of fuel delivery problems regardless of temperature or grade of fuel used. On my Hawk I used a normal pump (airpax I think) and a Holley pressure reducer and adjusted it for about 2.5 lbs at the carb inlet. I plan to do the same on this car.

I like the argument Gord made regarding heat soak into the mechanical fuel pump body. I guess I will remove and plug the oil line to the pump and make a "block-off plate" out of glastic board to help with heat soak. The arm of the mechanical pump will be removed and the push rod that drives that arm will also be removed if just lifts out as Gord described.

Thanks for all the input.

[rkapteyn]

The fuel pump mounting on the early "V8" was corrected later by mounting the pump below the engine.
I never thought it was a good idea to mount the fuel pump above the engine with hot gasoline leaking on the engine in case of failure.

[showbizkid]

Wayne, Larry Claypool's excellent article titled "Pumping With Volts" in the March 2011 issue of TW explores several different types of electric pumps and mounting considerations. If you have access, it's worth reading. If you don't have it, let me know.