they are somewhat rough the way they are cut... Very similar, if not identical to how my newest Sirio's are cut... The GRP sleeve and the Sirio sleeve look as if they were cut using the same machinery.....

The thing is where they are rough will not really affect performance, the key areas of the motor are machined just fine.... Most poeple look at the bottom of the ports and thing smoothing there will create better power, but the top of the port is much more critical, as when the piston first unshrouds the ports its the top of the port that gets opened first, by the time the piston hits BDC the crankcase has lost all its pressure and gas transfer has mostly stopped, most of the intake charge entered the chamber when the port was first opened and crankcase pressure at its highest......... GRP engines do look sloppy at the bottom of the port, but are well designed where it counts...the ports are nicely cut and well directioned, as well they have very good port timing............. Look into the exhaust port of a GRP mill and look how the ports are shaped and directioned, then you will see the real magic of these engines.......