PhatheadRacing
Honda CR250 2005-2007 Phathead cylinder head kit
Honda CR250 Phathead cylinder head kit 2005-2007
Chamber selection:
H30 21.8cc Stock
H31 20.6cc 95+ octane
H32 19.7cc 100+ octane
H33 18.5cc 105+ octane
H34 17.4cc 110+ octane
Phathead Kits include a head shell with one combustion chamber, two sets of o-rings, cylinder head nuts, copper washers, some stickers for your bike and tool box and installation instructions..
Phathead cylinder heads are made of 6061 T6 billet aluminum. The material is stronger and transfers heat better than cast aluminum. The two piece design allows an increase in coolant flow as well as surface area which improves cooling for better consistency and performance.
The O-ring design eliminates the need to use a gasket. You can swap chambers without the cost of replacing gaskets.