I think I remember one member posting that his non dampened gauge was banging against the top pin. I think his lift pump pressure was also low when he switched to a glycerin gauge. Not near zero just low.

The non dampened gauge should have tended to hit the lower pin even easier as well. Maybe it did. I cannot remember or find the post. If it was not in my opinion it would indicate those pulses are there.

The only easily obtained proof I can think of that they were the reverse pulse charges. From from the elements fill ports as they were closing off. Is testing.

Most if not all piston/cylinder type injection pumps have the reverse discharges I think. Just the last bit before the port closes. Intense high pressure spikes are produced. The pressure has to be quite a lot higher than the lift pump provides. Or the element ports would not discharge back into the base.

As the lift pump pressure is incrementally increased that may also be a way we are getting a little better element loading profile as far as quantity goes.
The return pulse is defeated a small amount.

Reduce the feed pressure at idle to zero. Hook up a mechanical non dampened gauge. If it is still hammering it's stop or stops we know. As a poster recently mentioned it is time for some assorted tests.

This may also in some fashion answer how the injection pump can function with zero injection base pressure or close to it. What is filling the elements specifically then? There is not enough time for a very good gravity feed. A small portion of what remains of the reflected pulse residues.?

Some pumps apparently provide harder discharge shields to eliminate errosion problems of the injection casting they are so intense.

Cervan pulled the relief valve spring and lost it. Litterally and figaritivly I imagine at that moment . Car still ran. Pressure from the lift pump had to be low as proven by the gentleman again with the valve in the return line. He reads zero with his return port open and no spring. For some reason the various tests to establish things are not being conducted.

Again since the reverse pulses may contain a small amount more fuel in the discharge as basically the loading pressure has been reduced. .Or even less fuel as the elements did not fill properly.. This in combination perhaps could cause other effects.

No hammering gauge no element pulse discharges. The non dampened gauge may be even under reacting if the frequency is high enough. At seven hundred rpm is it 1400 pulses per minute? Or about 23 pulses per second on a 616 injection pump?

The best test might be at cranking rpms other than at the slower speed the pulses may be much smaller in amplitude. I have to wonder if the reflecting pressure waves experience any delay adaquate enough to be helping the elements in any way at very low supply pressure? If the relief valve is closed. These are events of very short duration. Information in this area is very sporatic.

You know this is pretty complicated for a simple guy like me. Simple tests would allow me to understand things better and perhaps others if done and posted.

Then we might move on to methology of increasing milage on these old indirect direction diesels. It of course is basically simple in concept.

A way to increase efficiency that does not involve the injection pump. I have a pretty good ideal I believe with a chance if we all contribute. Need this base pressure thing out of the way first.

What I call the effect for want of a simple term is already present in another indirect diesel engine. I had known of it for years but thought it could not be developed because of certain limitations. I found a way around them if what I believe is true.

It should be looked at for the entertainment value alone. I believe there would be some opinions and a few disscusions. Anyone want to get the injection pumps base pressure tests done and out of the way?