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


The valve seat is blended into the valve bowl to smooth the step left by the cutter with a carbide cutter.
 You can see that the step is gone here.  The short side radius is also smoothed out.
The head is flipped and the bowl is blended on the other side and the short side radius is contoured here as well.  The valve guide boss on the exhaust side  is also mostly removed and and smoothed into the port.
After the port is roughed out with the carbide cutter, a cartridge roll with 220 grit is used to polish and finish the port.  It is also used to blend and smooth the combustion chamber.
The rough cut port on the left and the stock port on the right.  It was hard to get these images to come out and show what was being done.
The nearly completed ports and combustion chamber.  Note how the valve guide boss has been mostly removed and blended into the port wall.  Look at the opened up valve seats and the smooth radius valve job.  Note how the exhaust seat is a little wider at 1.3mm to promote more cooling of the exhaust valve.

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