new pistons require rotational rebalancing?

[Bearmw]

I'm considering a M30/B35 rebuild with Max-Sil pistons which are lighter than stock (waiting for that specific info). I'm running a lighter weight 533i flywheel. Is it necessary to have my entire rotating asembly or crank rebalanced to make up for lighter pistons? I'm not looking for a blanket "of course rebalance them" but more detailed info on when it is needed and noticeably beneficial as opposed to simply desirable.

Thanks

[Myster-E]

No you don't have to. Each part gets balanced individually such as the crank from BMW. Rods should be very close in weight (couple grams or less) and brand new pistons are supposed out of the box. If you wanted though you could bolt up your pressure plate to your flywheel after resurfacing it (no clutch)and get it balanced

[whodwho]

Changing piston weight on a straight six is not an issue like is is on v6.

[LJ851]

There is no balance factor on an inline 6 engine. As long as all your new pistons weigh the same as each other your engine will remain balanced.

[nando]

while it's not neccesary to rebalance the rotating assembly, it doesn't mean it isn't a good idea or that there aren't benefits to doing so. it just depends - if it's a race motor and you want every last HP, then it's a no brainer. On a daily driver it will be just fine without.

[Bearmw]

Thanks y'all. Its a street motor so I'm just balancing the flywheel and pp.