Skimming a Z1 head on a mini mill

I had to fly cut a Z1 head last summer for a drag bike build.

All I have at home is this mini mill and I knew it was a bit too small but I also had to fix some exhaust stud holes (drill out at tap for M8) so I needed to make a fixture for that anyways.

Got to thinking I could use the fixture plate to clamp the head to the table as the table is very narrow. A quick measuring with a tape measure showed me I could cut one half of the head at a time then sand the cut transitions flat on a 3/8" piece of glass with some sandpaper glued to it



This is the drilling fixture - It fits both 650/750 and Z1 heads.



Fixing the stud holes



Indicated flat to within .001" when clamped for cutting.



2" fly cutter head



Finish sanding setup



removed .035" to achieve 34cc chambers afterwards (valve seats sunk back)



Final result



37/31 mm - 105 CFM port job on intake side, Jerry Branch style porting enlarged.

Nice job,....the mother of invention.


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