Y'all know; madness has been getting a head refurb. Elephant adjusters on the list. the rocker arms need to be chamfered so the VW adjusters will have enough room to fit the XS valve geometry.
When the chamfer tools I had wouldn't TOUCH that rocker arm steel and dremel grinding and even diamond bits weren't much better, came up with this hack.
This might not be in the lathe operators handbook
I'm sure my shop teacher is rolling in his grave.
Comparing a typical adjuster setting to the elephant backed off into the recess.
ground off the "decompression tangs" while the rockers were out of the cover.
cleaned up the valve "tulips" too.
been measuring valve stem and guide tolerance. Waiting for some (more) measuring equipment then will dive into the replacing a guide rabbit hole.
Checked about a dozen valve stems. The short version; stems don't wear much in normal use ~8 Millimeter (0.31496") intakes staying at .314140" - .0001 or 2 exhausts .314135 -.0002 or 3 (typically at the head end). the guides end up getting a "vase shape" slightly larger at the ends especially the head end. I think this is mainly from carbon and other contaminates grinding away. My take; a down and dirty "wobble" measure done like this;
The set up; the back of the head with any stud guides removed so it sits flat on a steel surface. a piece of 1/8" stock under the valve end raises the valve off the seat enough to allow the indicator stem to sit against the valve head lip.
Note that I unscrewed the ball end from the indicator tip, the now flat end helps keep a steady reading as a small screw driver push and releases the valve head against it.
A deflection of not more than say .006" will be less than the factory wear limit spec of (.1mm or .004" as measured directly between valve stem and guide) will give a go no go valve/guide use decision.
When the chamfer tools I had wouldn't TOUCH that rocker arm steel and dremel grinding and even diamond bits weren't much better, came up with this hack.
This might not be in the lathe operators handbook
Comparing a typical adjuster setting to the elephant backed off into the recess.
ground off the "decompression tangs" while the rockers were out of the cover.
cleaned up the valve "tulips" too.
been measuring valve stem and guide tolerance. Waiting for some (more) measuring equipment then will dive into the replacing a guide rabbit hole.
Checked about a dozen valve stems. The short version; stems don't wear much in normal use ~8 Millimeter (0.31496") intakes staying at .314140" - .0001 or 2 exhausts .314135 -.0002 or 3 (typically at the head end). the guides end up getting a "vase shape" slightly larger at the ends especially the head end. I think this is mainly from carbon and other contaminates grinding away. My take; a down and dirty "wobble" measure done like this;
The set up; the back of the head with any stud guides removed so it sits flat on a steel surface. a piece of 1/8" stock under the valve end raises the valve off the seat enough to allow the indicator stem to sit against the valve head lip.
Note that I unscrewed the ball end from the indicator tip, the now flat end helps keep a steady reading as a small screw driver push and releases the valve head against it.
A deflection of not more than say .006" will be less than the factory wear limit spec of (.1mm or .004" as measured directly between valve stem and guide) will give a go no go valve/guide use decision.
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