Cobra CX50 Phathead cylinder head kit Chamber selection: CX50 Stock 90+ octane CX51 Mid 100+ octane CX52 High 105+ 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. One of the main benefits of the product is the replaceable combustion chamber which are available in a range of compression options. Suggestions : Swap chambers to adjust performance for a variety of riding conditions and track types or keep a spare in case of engine failure.
CX50 Stock 90+ octane, CX51 Mid 100+ octane, CX52 High 105+ octane