Project EJ Honda Civic – Fixing a Leaky Head for more Power!


 The final step is to cut the 45 degree valve seat high on the radius.  The seat width is held to 1.1 mm.
The narrow band that is shiny near the top of the valve seat is the 45 degree seating surface that the valve seals on.  Look how unobstructed the flow on either side of the seat is.  Just the valve job when done the way Portflow does it gives significant power.  You get valve unshrouding and opening up of the seat all in one step.
 Another view of the completed seat showing the unshrouding to the side of the chamber.
The stock seat with its thick single angle valve job.  Even intuitively you can see how this hampers flow. Porflow’s valve job opens up the seat 2mm to increase flow area considerably..
The Serdi’s air floating head allows quick and repeatable cuts to be made on seats.
The next step is blending the unshrouding cut into the combustion chamber and the bottom of the radius cut to the port.  The short side radius of the ports are also cleaned up at this point.  Portflow uses electric die grinders and carbide cutters to perform this operation.

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