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How to Fix Chatter or a Really Poor Finish on the Valve
The following will resolve a valve finish issue and is also a good part of the process of setting up a new Kwik-Way SVS II Deluxe Valve Refacer.
Chatter or a Poor Finish
on an engine valve after grinding is almost always the result of vibration somewhere. There are other things that can cause it too, but the most common is vibration. There are little adjustments that can be made to try and clean things up. Slow the valve spin, dress the stone more aggressively or less aggressively. Maybe even try a different grinding wheel. Those can all affect the finish of a valve. But if it's a really bad finish, chances are you have a vibration somewhere.
Fixing the Chatter Causing Vibration
The Kwik-Way Model SVSII Deluxe machine is a High-Performance machine. The cast iron base and special treatments to parts and sections of the machine make it the most accurate and long lasting machine of it's kind. But even so, when it gets out of calibration it will happily produce a bad finish. To prevent this the technician must be diligent with maintenance and cleaning. Afterall you are producing fine particles of metal and stone from two spinning objects. Even though you are using a liquid to help capture this debris it's still getting around.
Start with the Big Motor
Start by making sure your machine is turned off and unplugged. While standing in front of the Valve Refacer, move the traverse arm to a vertical position. Then place both hands on the two aluminum end caps of the main motor housing. Now attempt to move the housing away from you and towards you. Does it move? If it does you likely have found the reason for your bad valve finish.
Adjusting the Gibs
Leave the traverse lever in the verticle position. Go around behind the machine and locate the three Allen head screws just under the black housing cover. Start with the screw that is near the large grinding stone. Tighten until the traverse lever won't move anymore. Now slowly back off the screw while trying to move the handle until you are able to move the handle its full range with a noticeable amount of smooth drag. Put the traverse lever vertical again and repeat the same process on the screw on the other end.
Now move back to the front of the machine and check to see that the rocking movement you felt earlier is now gone. If not you'll need to repeat the process above or you may have a warn or damaged gib. But if the movement is gone you can finish by repeating the same steps we did to the outer two screws on the middle screw. While this will likely have solved your bad valve finish problem I would recommend you check all the other possible adjustments I'm going to give you.
Switch Sides
Over on the Chuck side of the machine, there are several different areas that need to be looked at to ensure everything is correct. Let's start with the easy things to check. The belt that drives the chuck is a ribbed belt for a reason. This belt needs to be as loose as possible without slipping. This is to prevent any motor vibration from transferring to the back end of the chuck. Vibration back here would be amplified at the other end of the chuck where your valve is grinding.
Next, you need to check the chuck for lateral movement. Grab the valve end and the other end of the chuck and see if you can move it side to side or front to back would be a better way of saying it. There should be no movement from front to back. If you have movement then you need to loosen the set screw on the spline pully on the back of the chuck and while pushing the valve end of the chuck toward the back slide the spline pully up until it just touches the side of the rear saddle mount of the chuck. Then tighten the setscrew back up.
Chuck Gibs
Similar to how the grinding motor side had gibs to be adjusted the chuck also has a set of gibs that can become out of adjustment. To check this you first lock your chuck degree adjustment and then try and move the valve feed hand wheel side to side while looking were the cast plate the chuck is mounted to meets the other cast plate that has the degree markings. IF you see a very small bead of oil moving where those two plates meet then you probably need to adjust your chuck gibs.
These are adjusted one at a time until they are tight then back them off slightly. When you think you have it, do the test again to be sure.
Adjusting the Chuck Saddles
The last item to investigate is the chuck saddles. These have the capped oilers on them and should be oiled on a regular basis. Over time the chuck shaft and these saddles will become worn and need to be adjusted. Remove the chuck belt to make these adjustments. Start with the saddle closest to the chuck. While turning the chuck with one hand tighten the saddle bolt until you feel resistance and back off ever so slightly until no resistance is felt. Move to the rear of the chuck and do the same. Finish by repeating the first operation.
After All These Adjustments
If you still have a finish problem it could be a dirty or worn out Chuck. Do a full disassembly of your Chuck and clean it with denatured alcohol then reassemble using ATF as a lubricant. Which, by the way, is the only thing you should ever use to lubricate your Chuck ball area. Instructions to disassemble your Chuck can be found in the manual and a current manual is available on the Kwik-Way website as a free download.
After cleaning, check the runout of your Chuck. Use a known straight shaft like the pilot for seat grinding and place it in the chuck. Set a dial indicator about 1 inch from the face of the Chuck and check your runout. Excessive runout at this point would indicate the need to replace the Chuck.
If your runout is good, then it might be your stone and/or the way you are dressing your stone. The stone should match the type of metal you are grinding and the machine manual will tell you the proper way to dress the stone for the type of cut you are attempting.
Still having a problem even after doing all the steps above? Then you should call Irontite Tech Services for more help. But in most cases, the above guide will solve your poor valve finish issues.