27/07/2026
For those of you lucky enough to spend time on a fuel flow bench I am sure you are aware how it is that some Enderle Dash 6 poppets do not always completely shut off and when they don’t they let a little bit of fuel flow back to the tank which does affect the flow rate to the engine. Part of the problem is that each time the system pressure goes up as the engine rpm goes up the poppet opens just like it is supposed to then after the shift when the rpm drops back the system pressure drops back and in some cases the poppet is supposed to close. The challenge you have now is that did it close all the way or is there still a bit of leakage past the poppet and if so is it the same amount of leakage as it was the time before.
Let’s say you have a 40 pound poppet and as the RPM goes up past the 40-pound pressure point it opens but when you shift gears the pressure drops back to 35 psi the poppet is supposed to close. On the flow bench, when I am flowing your system, I can see that poppet does not close fully so I spend time working on the poppet making sure the poppet sets against the seat correctly. Because it does not always return to the same spot on the seat each time the little dribble of fuel going back to the tank will be different. On a DYO car that will change your performance from run to run and you seem to not know why. Check your poppets, call me if you need help.
Some of the challenges are that the bore on the inside of the check valve is supposed to be concentric with the hole in the other end, some are better than others, some are downright awful but you never know unless you get to see it on the flow bench. You can check yours by removing the poppet from the system and use your mouth and draw a suction on the poppet valve to see if will hold a vacuum.
I have been dealing with this little annoying problem since I first started doing fuel systems in the mid 1970’s but over the weekend the light bulb over my head flashed brightly and I had an idea which I spent time on the flow bench today making up a replacement valve assembly by adding one small component to the valve to insure that the poppet valve will push against a floating valve that will always find the center of the hole on the inlet end of the poppet valve body. I am a bit ashamed to think it took me over fifty years to figure this out but at least no one else in the industry has done it yet. Most of the new production valves will have to have a slightly longer body to accommodate the additional components. I think the new valves will be the same cost as the standard valves. You can choose which valve you want, the old style or the new one.
It is too early for photos, but damn it is so cool.
Now on to my next challenge, getting oil to the rocker gear assembly on an Arias Hemi Chevy engine. Very squeezy.
