The brake mean effective pressure differential (BMEPd) can be experimentally calculated if we know the engine power available at the crankshaft (brake horsepower, P) and the measured volumetric flow rate (Qm) of the air entering the engine's intake system:
BMEPd = P/Qm
we know from calculating the stings time over a set course that the engine was run at maximum power not max continous for an extended period of time so we know that BMEP would be higher than normal. Read my post carefully Jabba I did not say that the coarse prop caused the failure, I said the prop was coarsed to take advantage of the extra power and maintain a higher speed brought on by a higher BMEP over time. Yes peak pressures would have increased but as we have not got a dyno run of a rotax I think its a moot point don't you? Are you in a position to infer that any level of change in peak pressure wont affect the operation of a crank especially its harmonics and given we are already at higher than normal BMEP and this engine is running a gearbox?
RE MP gauges Q is a function of MP pressure and therefore gives an indication of BMEP.
Back off mate it doesn't make for a friendly forum
