View Full Version : Been thinking again----oil measuring pump

06-17-2003, 06:01 PM
My first idea was to pump oil into a measuring cup, switch a valve and pump that oil into the gas tank. Well looking through a catalog has simplified that.
I originaly wanted to use a peristaltic pump, those things chemists use that smooshes a length of tubing with a roller. Real simple but super expensive.

Then this new catalog showed a manualy powered pump and that was it!
Still too expensive but these pumps are sooooo extremely simple.
I'm building one now that will pump exactly 4 oz. of oil per revolution of the pump handle. On the handle will be a disc with 10 posts. To finish it a counter. The first digit reads in 1/10 th of a gallon and the 2nd reads in gallons.

Pump in say 11.7 gallons of gas and all that needs to be done is rotate the handle 11.7 or 11.8 times, the counter makes it so you don't have to count or forget to count. This is 32:1 ratio.

I don't like the diaper wipe, rag stuffed in the cup and oily hands scene.

A 3/4" tubing wrapped in a U inside a 5.2 inches diameter will produce the 4 oz. per rev. Inside the circle is a bar with 2 rollers. The rollers squish the tube as they pass it- 180* circle to make calculations easy.
.44 square inches per 3/4 hose X 16.34" length for 7.22 cubic inches which equals 4 oz. Only half the length is actually used but it's pumping twice per rev. 2 lobes. More lobes only reduce pulsing and isn't important for this.
The circle can be reduce to half-2.6 by using 2 hoses in parrallal or cranking twice as much. Other hose sizes can be used but have to calculate for the volume for them.

I'm casting this out of aluminum but it could just as easily be made from fiberglass. A cup shape holder for the hose and some bearing supportfor the crank and rotor, and the rotor with 2 rollers. Look at a picture of one of these to see how dirt simple they are. It's a crime they ask over a $100 for just the heads.
Project # 182
BTW this is plumbed directly into the tank and with my "smart" fuel gauge I can pump it in while or before the gas. The gauge tells me how many gallons to fill the tank.