Abstract: A system and method for sampling fluid from a top land piston crevice of a reciprocating piston engine. Access into the crevice is via a length of tubing inserted into a bore through the piston wall. Two valves, first a relief valve and then a piloted check valve, operate together to capture a sample of fluid from the crevice at a time just before TDC of the piston on its compression stroke. The sampled fluid flows from the check valve into a sample container. The valves further cooperate to close fluid communication from the crevice after a sample is taken, which allows the engine to operate normally.

Abstract: A system and method for sampling fluid from a top land piston crevice of a reciprocating piston engine. Access into the crevice is via a length of tubing inserted into a bore through the piston wall. Two valves, first a relief valve and then a piloted check valve, operate together to capture a sample of fluid from the crevice at a time just before TDC of the piston on its compression stroke. The sampled fluid flows from the check valve into a sample container. The valves further cooperate to close fluid communication from the crevice after a sample is taken, which allows the engine to operate normally.

Abstract: Disclosed is an engine valve port including a valve opening, a first portion, and a separate second portion. The first portion and the second portion are separately connected to the valve opening, and the first portion and the second portion merge together at a location spaced from the valve opening. The valve port has a bifurcated, porpoise-like shape. The first portion and the second portion are generally arcuate in shape, and the first portion and the second portion have a generally semicircular cross-section. Also disclosed is an engine including such a valve port. A valve associated with the valve port may be an outwardly-opening valve.

Abstract: A method for reducing pulsation effects associated with the compressor nozzle of a positive displacement compressor system. A pulsation absorber, having a design like that of a side branch absorber, is installed on the cylinder valve cap or on the cylinder nozzle. The acoustic dimensions and placement of the pulsation absorber are designed to reduce the amplitude of the pulsations associated with the peak resonant frequency of the compressor nozzle response.