SOD has it.
Its for measuring crankshaft deflection when the engine is solidly coupled to what ever it is driving. The gauge is usually fitted between the webs of the crank throw nearest to the load, "the drive end". Then shims are fitted under the engine or the load until the deflection is within the specified limits. Still a very relevant piece of measuring equipment.
Used on larger engines as you need to be able to get inside the crankcase through the crankcase doors.
Neil
Edited By Neil A on 29/05/2021 17:40:15
Edited By Neil A on 29/05/2021 17:47:50