custom valve seats galore!

Once in a while, we have to machine up valve seats for knuckleheads. The seat on the left is a blank, and the one on the right is one that my dad cut the od and id down on. This is a good fix, but you have to remember to check to make sure that the bore that it presses into is concentric, other wise it will drop out when the head gets hot!


After we make each valve seat to spec, we throw them in the freezer for a couple of hours. I found a dead mouse in the freezer, which is really bizzare. I think that Mara put it in there. I am not sure though.

Fixing knucklehead head repairs

This is what a knucklehead that has been converted to run pan head cylinders looks like. This was a popular deal back in the seventies. Chopper guys and girls used to have a hard time finding low bore knuckle cylinders, so they would use pan head cylinders. Four of the bolt holes in pan head cylinders are the same as a knucklehead, but one of them is in a different spot, so they would screw a head bolt into the hole, and drill and tap a different one.


The first step in changing the heads back to stock is drilling out the head bolt hole.



Then you put a bolt in the hole that was previously used for the pan cylinders.




Next step is to drill hole for the knuckle head bolt pattern, then tap it for a helicoil.





Here is the almost finished product. we still have to face the head bolt surface, but you get the idea. This is a good fix and will last a long time.