[RICE RACING]

This is just a question:
Why is the rotor land machined/ground? it looks like in the pictures that there is no land to tip clearance? the lands are never machined, even in engines I have built that do 12,000rpm, however the area between the tips to the oil control rings is clearance down 0.15mm under the std clearance.

I pulled apart a motor from a self professed expert here who is known in the circuit racing realm and they looked just like these, they were ground inc the lands and there was ZERO clearance, the end result was the tips crashed into the side plates!!!!

The idea many builders get wrong is you take NOTHING off the lands as they are fine stock std, they need to act as a 'bearing' surface and act as a support to stop the tips from hitting the side plates.

Please excuse if yours are machined correctly, but I still don't get why the lands are machined either way.