gas pressure

Home Page Forums Engine gas pressure

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
  • #390337

    lately the gas pressure guage on my series 36 touring is indicating 4 pounds when it should turn off at approx. 2 pounds. if i forget to let the pressure off when i am done driving it will force gas through the carb a little until the pressure comes down. how do i regulate the system? am i causing any damage at 4 pounds as the car operates well there?

    george quay


    You can put a pop off valve in the tank area. They are available from supply houses that sell to scientific labs. Order one made of brass, not plastic. They are available in 1/2 pound increments. The gas today has a much lower boiling point and expansion ratio, and when the tank gets heated in the sun, pressure can rise. Also look at the air pump, cars run higher rpm today due to faster road conditions. I have seen this problem on my 14 Caddy. Too much pressure is VERY DANGEROUS! Youwant to run the system with as little pressure as possible and not have any running problems.


    The pressure pump for the gasoline tank, located on the lower left side of the engine crankcase, has a small square head screw on the top which is held in place by a hex jam nut. Loosen the jam nut, turn the screw in to decrease pressure and out to increase pressure. However, it appears that there is a problem with the needle valve in the float chamber leaking. It should not leak even at six pounds pressure. Take some fine compound such as jeweler’s rouge and re-seat the needle and also check the float level at the notch in the pin at the sight hole in the side of the carburetor float chamber.


    thank you both for the quick response. the same problem was occuring on dianne gallets-ehmanns EDL at the rochester meet. hope to see you at gillmore next week

Viewing 4 posts - 1 through 4 (of 4 total)
  • You must be logged in to reply to this topic.