K&K Performance

 Porting and Polishing, Boring and Honing and Valve Jobs

The reason you port and polish heads is to align the torque curve with the intake and camshaft specifications.  Taking all of the possible metal out of a port does not make it better.  If that was true there would be no reason to place them on a flow bench.  We flow bench all of our work.

Porting and polishing when done properly will increase horsepower and place the torque in the proper RPM range dictated by the intake and camshaft specifications.  One of the reasons for porting and polishing is to increase the air flow. Doing this you will flatten and lengthen the torque curve of the engine.  However if you get the port too big then you move the torque curve so far up in the rpm range that you lose bottom end power. There is no advantage to give you a set of heads that start working good at seven thousand rpm if the cam and intake are peaked at six thousand rpm.

Our years of experience with many successes proven daily with the work from our shop.

Boring and Honing:  Many people pull their engines apart and take a look at the cylinders and say, "There isn't any ring groove, so I don't need to bore this engine".  It is true with today's ring technology there is less wear in the cylinders due to ring tension.  However there is only one way to be sure that the cylinder is still in specification and that is to test with a dial bore.   What may not look like much wear to the naked eye will often be proven wrong with a dial bore gauge.   If the cylinder has taper or is out of round, it will need to be bored.  An out of round cylinder will not allow the rings to seal properly and a tapered cylinder will have to much end gap at the top of the cylinder and cause blow by.  When you bore the engine you are making the cylinder straight and round again and setting the proper clearance between the piston and cylinder wall.  This is what the factory did when the engine was built new.  The honing process is used to create the crosshatch pattern that is required for proper ring seal. This pattern is what helps the ring to lap itself into the cylinder.  It also removes the micro tears in the cylinder wall created by the boring bar.  Let us check the piston to wall clearance and taper so you can take the guess work out of the process, and have an engine that will last for a long time.

 Valve Jobs:  This is a subject that is often debated. Most people take their heads to a machine shop and tell them they want a high performance three angle valve job.  The shops "say well that will cost extra if you want three angles".  The truth is that all cylinder heads have a three angle valve job from the factory. This is required because it is what positions the valve seat on the face of the valve. A three angle valve job is just making it to factory specs.  An actual high performance valve job is usually four or five angles on the seat along with back cutting the valve and radiused  margins.  These extra angles and cuts will aid the low lift flow and in essence make the engine think it has a bigger cam, since it can breathe better because of the extra work.  Sometimes a plunge cut on the combustion chamber to DE shroud the valve is essential also for clearance around the valve to aid the upper lift flow.  Does the extra work cost a little extra?  Yes but you are not getting charged extra for a factory valve job.  Call us and we can discuss what will work best for your engine build combination.

Still have questions? Please contact us anytime!  We look forward to hearing from you.

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