Project Ruckus part 4, Building the ultimate Honda GET engine

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The valves after getting reworked by DPR.  The stems are reduced under the valve head for less weight and more flow, the seat surface is narrowed and back cut for more flow.  Then the entire valve is polished.  This is an entirely different looking and performing valve from the stock part!

The valve job is one of the most critical areas in the production of power and Dan did amazing work here.  Usually more than half the power unlocked by headwork is due to the valve job. Dan first turned down the valve stems of the valves in the area of the valve head.  This does two things, lightening the valve and yielding more flow area in this most restrictive part of any port.  Then Dan backcut the valves until the seating surface was a less than one mm band around the bottom of the valve.  This gives a more streamlined line of flow from the valve to the port of the combustion chamber as the valve starts to open greatly improving low lift flow.  Then Dan blended the cut angles together and polished the valve faces to maximize flow.

The stock intake and exhaust valve contours vs our DPR modified ones. The gold coating is Embee's thermo barrier coating that protects the valve from heat.  Note the smooth contours of our modded valves.

Next Dan cut the 45 degree valve seat deeper to make its outer diameter as big as possible, and then machined the 30 degree chamber and the 70 degree port throat unshrouding cuts on either side of the seat, constituting a 3 angle valve job.  With the valve seat at its maximum useable diameter, Dan opened up the valve seats and the port bowls to this larger size.  This made for a huge improvement in flow.

The cut down, shortened and polished spring retainers are 30% lighter than stock.  This cuts down the chances of valve float at high RPM.