Ttalk Tech

More Ideas on Emergency Fuel Pumps. Small images are thumbnails, click to enlarge.

Primary information is from Stuart Locke's paper. See LockePump

A word of caution. Even at these low pressures, i.e., 1 to 2 psi, the fumes that are present when you open the release valve of the sphygmomanometer bulb are highly flammable. Please be careful.

Under Construction to show things like component sources and modifications, such as

Deluxe version with gauge.

On March 6 I went up the garage to find out how usable the Emergency Pump really is.  I was curious as to how long it would take to pump in an adequate volume of air to obtain a reasonable fuel pressure, i.e., greater than 1 psi.  To know where I was starting from I shoved my fuel measuring stick into the tank: It showed about 8 gallons remaining.  I then shoved the stopper into the tank opening, checked my watch and starting pumping.  Must admit that I wasn't expecting any dramatic results and just hoped that my hand would hold up long enough to see some results.

Sonuvagun -- the gauge started moving after just a few dozen pumps.  I was flabbergasted at the results.  I pumped for 60 seconds and read the gauge -- 76 mm Hg, about 1.5 psi.  Took a 30 second break and went back at it.  After a second 60 seconds of pumping the needle on the gauge registered 134 mm Hg, about 2.6 psi!!  Wow.

One of the folks on the UK MGBBS, Dallas, mentioned the possibility of utilizing the air in the spare tire as a source.  Intriguing!! I did some measurements of Lazarus' spare tire and computed its volume to be about 1820 cu. in. This is at about 25 psi.  There's a law of physics that equates pressure and volume by something like PV=NRT.  That should allow us to get an idea of what the air in the tire could do for our emergency fuel pump.

If we take the capacity of the fuel tank to be 15 US gallons, that would equate to about 3,465 cubic inches.  A quick look at the numbers says that, if the spare were connected directly to the fuel tank, there would still be about 8 psi left after all of a full tank of petrol had been used up.  If, as was suggested, a 2 psi regulator were inserted into the air hose there would be enough air to go through about 4 tanks full of petrol!!

Stay tuned --- more to come.

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Created March 6, 2009