Abstract: The invention presented herein makes it possible to construct and operate an engine monitoring apparatus that calculates the engine speed, the engine load and/or engine monitoring quantities basically only from the measurement of an angular velocity curve at the gear rim of an internal combustion engine (optionally, from a plurality of angular velocity curves). The basis is thus simultaneously created for monitoring all other measured quantities within narrow limits that are dependent on load and speed. The invention can also be utilized for control purposes or for measuring power.

Abstract: A test stand for testing multiple engines which may be liquid cooled or air cooled including apparatus for preheating a liquid coolant to preheat the engine prior to testing, apparatus for heating lubricant for preheating the engine prior to testing, apparatus for conserving the heat through heat exchangers to heat the coolant and the lubricant for a supply of coolant and lubricant for testing a successive engine; a brake and drag for the engine arranged for generating electricity to obtain electrical energy from the testing forces. For an air cooled engine, a throttle arrangement is added to block the air for a fast heating of the engine prior to testing. In one form, lubricant is bypassed from the sump up to the head of the engine and heated in the bypass such as by a heat exchanger energized by heat from the coolant from testing a previous engine.

Abstract: For single-cylinder evaluation of an internal combustion engine, the respective angular velocity is measured--for respectively defined crank angle positions--at at least one component part of the internal combustion engine, the respective overall moment of inertia is calculated from the design data of the internal combustion engine and, while operating the overall moment of inertia with the angular velocity, the respective overall energy of the internal combustion engine is calculated. A single-cylinder evaluation can then be implemented from the comparison of these overall energies in cylinder-associated crank angle ranges.

Abstract: Three impulse transmitters are provided of which one co-acts with an impu mark on the flywheel, another with an impulse mark on the camshaft drive wheel and a third with the teeth of the ring gear on the flywheel of the engine. The impulse mark on the flywheel enables a precise determination of a reference angle position of the crank drive and the impulse mark on the camshaft pinion by triggering a window enables correct association within the working cycle which covers 720.degree. of crank-angle. The time spacing and amplitude of the triggered window are controlled by the tooth sequence on the ring gear.

Abstract: An extraneously driven piston engine is fitted in the region of its valve ar with solid-borne vibration pick-ups which are connected to a processor unit. An angle-mark transmitter on the crank assembly controls a gate circuit which within specified zones of crank angle, feeds the vibration signals into a limit-value circuit which, by a comparison of levels, provides a "good/bad" information read-out.

Abstract: A loading mechanism which may be moved relative to a free belt strand is provided with a measuring roller which is driven by the belt upon contact and furnished with pulse markers, and which, together with a pulse transducer sets to zero a device measuring the distance travelled by the loading mechanism, as soon as the measuring roller begins to rotate. The distance measured after a given period of contact of the loading mechanism acting with a known force is used as a measure for the belt tension.