Mini diesel engine.

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Steamchick

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Sorry, Min. Somewhere in a text book, but I have been too busy to research it. There are 2 basic formulae, one for a pin fitted in the con-rod and rotating at the piston bearings (diagram 4. SIMPLE BEAM- UNIFORM LOAD PARTIALLY DISTRIBUTED ) , one for the pin fitted in the piston and rotating at the con-rod small-end bearing (diagram16. BEAM FIXED AT BOTH ENDS- CONCENTRATED LOAD AT CENTER).
See: http://www-classes.usc.edu/engr/ce/457/moment_table.pdf
For Fatigue I would use max calculated stress must be below 0.1% of the proof stress for the pin material.
Of course the bearing loads are relatively easy to calculate.
or:

Getting the ratio of piston bearing width to con-rod small-end bearing width is very important for optimum design.
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GreenTwin

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I remember looking at Find's website a long time ago, and as I recall, there were photos of his true injector build.

If my memory is correct, Find said that the injector has to be designed such that the pressure within the engine cylinder forces the injector closed, and the pump pressure forces the injector open.

This situation is similar to a valve on any standard 4-stroke engine, where the valve opens into the cylinder when lifted by the cam, and then closes with the cylinder pressure pushing against it.

I assume that Find uses a light spring to keep the injector valve seated, and the tiny (I guess mushroom-head) valve lifts off it seat when the pump reaches sufficient pressure.

I think this is one of the secrets of making a miniature injector work.

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