Cool Head

[matusdkw]

I WAS WONDERING IF IT JUSTIFY TO BUY ONE FOR MY R
THERE IS SOME GAIN OR IS JUST TO KEEP IT COOL?

THANKS.
MATIAS. :)

[Motofool250r]

it provides two things. changeable domes for compression ratio. and it provides more cooling. and it is shiney

[All250R]

The real benefit to losing the stock head is a better combustion chamber shape. The stock shape is horrible for high rpm performance. The stock shape is supposed to be a very safe, easy going design - and it is. To take full advantage of a higher performance dome shape though, you need to have the cylinder decked to bring the head closer to the piston. The stock clearance is so wide it's a question whether the squish band is even functioning.

Of course a better heat exchange to the coolant is nice but it's probably more applicable if you're running a bigger bore or higher compression, timing... Changeable domes are convenient if you're running a variety of conditions. In that case you probably want an o-ring'd head so you're not burning money in head gaskets every time you change the dome.