How good is the M50 for sustained runs over 5k rpm like at an autox or track day? Is it durable or will I have shit breaking all the time? My Porsche winds over 5k all day long and all she wants at the end of the day is some mobil1. how would the M50 compare to the S50 in terms of high stress runs? I know BMW inline sixes like to rev, but what are the limits? Thanks.

5K? The only time mine ever saw below 5K was at a stopsign.

You'll have no problems whatsoever banging off the stock rev limiter all day long. If you want to go more than 7K, you'll need to look into solid lifters...but it takes an internal buildup and a very aggressive cam to move the power band that far up anyway.

I agree with mr. its, the motor should be fine as long as you keep it moving with those rpms. IE - sitting in neutral would not be a good thing at 5k, you need some air going through that radiator.


I believe the of the M50 and S50 internals are the same except for displacment and the S50 uses titanium oil pan bolts. :D

Originally posted by themadhatter
IE - sitting in neutral would not be a good thing at 5k, you need some air going through that radiator.

The worry is not so much overheating, as much as making sure you have a load on the engine. Revving it constantly without a load is never a good idea.

sees constant 7K RPM to 7200 (w/TMS chip) at the track during 100+ deg. in the summer....no problems! 5K - 7200 is where the car stays for hours at a time for 2 to 3 days in a row at least twice a month for an entire season....these motors were meant to rev and run the piss out off...I am also running Amsoil 0-30 Synthetic motor oil with change intervals between 7000 miles and 14000 miles depending on usage and time of year.:)

Sunir

thanks guys!