Ok so I am getting back to my project and I have the two rotors for my engine here and I can't remember which one is the front or rear rotor... How can I tell which is which? They are stripped of all the seals already...

 

I dont think there's a difference. Aren't the two rotors only supposed to be close enought in weight (2 letters?)?

 

There isn't a difference. The housings have a front and rear marking but even that doesn't matter.

 

However, there is a difference in wear if the rotors are used. It's best to put them back in the same spot. If you can get a good look at the apex seal groove, you may see that it looks like a slight "V". The straight side will be the leading edge, the slanted side will be the trailing edge.