- Mar 8, 2019
- Reaction score
- Charlottesville, VA
Hmmmm. That is an interesting solution. Letting the large spring drive the piston and control the maximum pressure, too. No matter what, It seems that getting the spring forces correct is always difficult and requires trial and error and often winding a spring by hand. Having a supply of various diameter check balls and very light springs could be helpful.Here is the better solution. The spring is pumping the fuel into the injection pump, if pressure is enough then the spring is feeding the fuel before the cam is pushing the lever to suck more fuel. The spring is maintained to keep the continuous fuel feeding. The pump piston diameter must be large enough, but not to inject the fuel into the combustion chamber, injection pump only.
View attachment 149187
Minh Thanh's pump could incorporate a similar scheme by breaking the single long pressure piston into 2 shorter pistons with a spring in between the two pieces to maintain continuous force on the fuel and to also limit the max pressure. Again, finding the correct springs by experimentation would be time consuming. Minh's solution does show an easy adjustment for the pressure relief valve.
Many solutions to the same problem/pump.