Originally posted by carbikebus:
There's a certain limit of speed during running-in of new or just overhaul engines,Be it Motorcycles,Cars,Buses or Trucks
yes precisely. This running RPM during the run in in period should be observed in order to prevent damage to the engine parts. Never ever believe anyone who says hard run in is good or he has some dyno testing run in which he design himself. Do not even trust that person even when he says his self design hard run in method can give more power. Those who're well versed in engine constructions will never dare to say that. I have seen quite a few 'engine-nears' claimed they have some great way of running in engines and swear by it. And kept arguing and flaming over these matters. I only have one word to say - foolish empty vessels.
The tolerance of the combustion chamber/piston rings, how many piston rings, piston size, gundgeon pin, bearing for crankshaft to con rod etc etc all has a tolerance. The oil pump pressure, cooling capacity all affects the engine future performance after running in. Only with a proper manufacturer who has the correct values, correct trial test results can be qualified to give the recommendations. Even in CDGE, the engines are run in according to the proper specifications before giving to SBST for consumption. Also during running in periods, since the amount of 3 body wear metal is more than usual, oil change will be much faster.
I have previously consulted Dr Teo Swee Hin (NUS) regarding material engineering on a ZF PTO project. He explained that the worst form of wear is caused by 3 body wear. That is why oil filter and oil must be changed regularly. All automotive technical personnel knows that oil and oil filter must be changed periodically else it will cause unwanted wear in the engine. But few knows about this 3 body wear matter.
I am now administering the overhaul of MB0405 air compressors which tap the rotary powers from the MB0405 engine directly. Air compressors also need to run in actually. But since the overhauled compressors only replaces piston rings (2 air 1 oil), running in is not so critical. At the same time, if it is new compressor fixed to a new engine, since the rotary power is tapped from the engine, running in the engine = running the air compressors also. Since they run on the same RPM.