I have a 2011 mcs that I'm 99% sure has a bad or multiple bad valve seals or guids. I'm going to pull the head and have them replaced. I do have a stage 2 RPM tune on the car and would eventually like to go up in power. I know I'll need to eventually build the motor for that but for now what kinda upgrades are there for the n18 head? I know there isn't any aftermarket cams for it due to the variable valve timing. I have seen some supertech springs but they seem to be a factory replacement but was told are stronger? What about going to a larger valve? I know stock valves can work for higher HP but is it better to replace them and go big valve since it will be stronger? Any input as to what I can do to the head while it be off would be great.

 

Well I'm new to the mini world but a good port and polish is always a good thing. If you can find some upgrade springs that will help eliminate valve float if you run a higher redline.

 

Consider going with Iconel exhaust valves and stainless intakes, for future high power / temperature durability. Probably not worth going oversize --- already pretty big. Without hi-lift cams, there's no real need for new springs or keepers, unless you intend to do a lot of high RPM driving. Definitely get it ported and maybe even match exhaust ports to manifold and gasket.

For future upgrades, consider bigger dia exhaust, like 2 ¾" or 3", and definitely a good WMI system.

 

yeah port and polish will deff be done, just trying to see if larger valves is a must for strength and better flow

 

iconel? Is that a brand or what exactly is that?

 

Iconel is what the valve is made of --- used in hi-temp applications, and resists breakage.

 

Inconel is a high-temperature super alloy. Helps avoid melted/burned valves. https://en.wikipedia.org/wiki/Inconel

 

If you're going for higher power than stage two, and already will have your head out for work, then you should also look to upgrade the rod/pistons. Those are the weakest links on this motor. I regret not doing mine when I rebuilt the head due to a burnt valve. Now I'm stuck at RPM stage 2 and wouldn't dare to go up for more power.

 

FYI the supertec valve springs are about 30% stronger, the guy who did my head checked them vs the stock valve springs, they are cheap I think its good insurance especially if your going to autocross or track your car