S3 Cylinder advantages...
 

I?m curious about the cylinder, not so much about the head. Is the S3 cylinder ported differently? I noticed they have it advertised as a race cylinder. I just slid one on my 2012 EC 300 Race. My original cylinder is still good. I just got this S3 cylinder as a big package deal and I was opening everything up anyway to check how all was wearing. I?ll be finishing up the build tomorrow, but I haven?t ridden the bike in almost a year, so I?m not sure if I would notice a real difference, or if I?ll just be caught up on the old power but feel like it?s more cause how long it?s been. Know what I mean?

You'd have to compare it to your OEM to be sure.

I used an S3 race ported cylinder on a 2010. The porting was nothing out there. Mostly the exhaust port had just been moved up a bit to favour top end peak power. Obviously all the ports were nicely dressed with no casting flaws evident.

You may find using a thinner base gasket with the S3 will keep similar port timings.

you could measure up the height of the exhaust port, as stated before.
also visual, you might notice? bigger ports? flowed ports?
if it's been a year since you took your bike out, theni doubt you'll feel a difference. (nt saying ther isn't, just your reference is gone too far)

When the S3 cylinders first became readily available for gassy?s I compared one to stock and found no difference in port dimensions at all. The only perceptible difference was the cleaning up of the usual casting flash and port matching.
Apparently the quality of their playing is of a much higher standard.