Time to start machining this puppy.

I had some imperfections in the bottom of the casting that I needed to weld up. I made a light cleanup pass to make sure I got everything filled.



Next is mapping out the combustion chambers to see exactly where they ended up. Castings shrink when they cool. Although there are formulas to use as guidelines it’s still a bit of a guessing game. All the core sand inside makes it especially hard.


So far so good!

The machining begins…. It’s Mockup time!

Although I was really happy that I got a good casting the first time this meant I had nothing to practice on. I decided to do a plastic mockup so I could test out my valve angles. head bolt locations and intake and exhaust bolt holes

I decided to do the head with a 4Th axis instead of building fixtures. This can save a ton of time when you are prototyping.


I used the original 3D model to carve a single cylinder.


I carved the combustion chamber and drilled the spark plug hole. I then used that hole to locate where the cam towers needed to be mounted.


I then worked off of the rocker shafts to get the valves in the right spot.


As you can see it took a couple of tries to get it right. And that is why I did a mockup. We do it nice cuz we do it twice!

Valves ended up where I needed them to.