Packard Forum Index » Post-War (1946-54)

A 5% mixture of diesel to gasoline has worked well for me in eliminating vapor lock.

Vapor lock tends to occur in the unpressurized part of the fuel system, mostly in the line between the fuel tank and the fuel pump; in the suction side of the fuel pump; and in the carburetor bowl. So, clothes pins on the pressurized line between the pump and carburetor only helps clothes pin makers.

(o{}o)

Clothes Pin on fuel lines...... Oh I am always amazed how myths spread.

No scientific reason they would do anything unless they were used as a physical spacer to keep the fuel line from touching something close by.

Maybe aluminum clothes pin used some type of heat sink!

I mentioned my vapor lock issue to my mechanic the other day and he told me to put clothes pins on the fuel line. I asked him what they did and he had no idea. he was just repeating the old wives' (or husbands') tale. The internet probably helps spread stories quicker than word of mouth did in the old days.

They had to do something back in the day and hey, wood is an insulator isn't it. The more added the more the line was protected. Today, clothes pins add that air of mystery and visual interest to the engine compartment.

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I agree Howard, I'm quite sure that there are kids nowadays who have never seen a clothespin thanks to the invention of the clothes dryer and working moms...so yeah, they would be mystified by the appearance of a clothespin as much as they would by penny candy, nickel cokes and Oh Henry! candy bars in a mom and pop gocery store.

I heard the practice of clothes pins on the fuel line was from the days before vehicles had fuel pumps and relied on gravity feed. This makes sense as none of the fuel system was pressurized and the clothes pins may have helped somewhat in dissipating heat and mitigating vapor locking. Don't know, but it sounds right.

(o{}o)

I have a pygmy voodoo witch doctor I keep in the glovebox. When I mention vapor lock he dances around inside the glovebox and shakes a container of clothespins carved out of the rare balsa bush. Seems to work just as well.

I just bought one of Ross' heat shields. Fits perfect, looks good, has the attachment that goes from the heat shield to the bolt on the fuel pump.

Randy,

Interesting approach. Here in southeastern Arizona, El Cucui (also spelled El Kookooee) is similarly called upon. My 400 suffered chugging some weeks back when I had her out one evening after sunset. I managed to get home and actually understood I was on very "thin ice" given as our ethanol percentage and oppressive ambient temperatures. A confidential informant later advised that El Cucui was packing up and preparing to leave for points north just as my fuel pump was sputtering. I wasn't aware El Cucui had purchased non- refundable airline tickets. Given that, the 400 is currently in repose in the garage, I'm enjoying cabernet sauvignon watching preseason football and El Cucui is somewhere in a cooler locale. We await his return because car shows begin in earnest here in October. October also enables me to drive without benefit of air conditioning through April. Lastly, here in the desert we use vigas or octillo branches as opposed to balsa bush. Seems to work just as well. The movement of the sun plays a role somehow too.

Finally someone gave me a good technical reason how/why clothspins might work to prevent vapor lock. I always saw pictures of a few clothspins on a fuel line and could never figure out why this would do anything. What I never saw was the fuel line totally covered with clothspins!

The old clothspins were wood and wood is a good insulator. If you put many, many clothspins on the fuel line right next to each other the metal line would be insulated from exhaust manifold heat. Any insulation would also do (such as wrapping the fuel line with asbestos tape). It's just that wooden clothspins were very common and cheap in the old days and very easy to install.

In modern times the wooden clothspins are rare and asbestos has been replaced with safer material such as glass fiber. Today an equivalent fix is the insulating tape or exhaust blanket material found in performance stores such as Off Road Warehouse. Wrap the fuel line with the insulating blanket and tie it on with hose clamps or safety wire. The insulation is more effective if it has a shiny outside surface. This cuts down on heat transfer due to radiation from the exhaust.

Also find/buy a heat shield that Packard used between the exhaust manifold and the fuel pump. This is a radiation shield, so it also works better if the surface facing the manifold is shiny (chromed?)