cav551:
A valid point, but London Buses LT or whatever their name was at the time were after all the owners of a vehicle intended for revenue earning service and publicly owned at the time. There would likely have been a few questions asked about the expenditure of taxpayers money for the later advantage of private individuals.There were a reasonably large number of AV 690 powered buses, intended originally experimentally for the RM and taken as an optional fitment along with the Leyland 600. The 690 proved too thirsty in city use and the Leyland just a little bit more time consuming in workshop attention. The extra power available from the 690 proved necessary for the Country area Green Line versions and with full power and revs available for the high speed BEA dedicated London Airport service. These latter vehicles however requiring fully balanced engines to withstand the high revs and a small modification to the front xmember to clear the crankshaft damper.
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Bumping an old thread (tut tut 
) but I’m curious why the RM preservation mob aren’t as avid about refurbing 0.600s as they are AV690s. Or is it the case that 0.600s are even harder to find?