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English term (edited): 6000 hours of engine rigs

engine rigs = more than one engine rig was used for testing - all the engines considered together were running 6000 hours in total.

each engine was mounted on a rig - a supporting frame.

as the engines were standalone and stationary, the testing is quantified by the total time the engines were running. As opposed to the testing done with the engines mounted in a vehicle, where the extent of the testing is measured by the total travelled distance - 200,000 km.

Engine Rigs (Petrol)
Self contained, fully operational Petrol Engine Rigs.

Complete with start, charge, fuel, air-intake, cooling and exhaust system. The petrol engine rig offers an enhanced training resource, hands-on training with real components, greater understanding for the student without the constraints of the modern motor vehicle.

http://agblock.co.uk/catalogue/engine-rigs-petrol

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Note added at 1 day 20 hrs (2019-08-23 20:32:20 GMT)
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