225 /6 at 250HP?

That bolt appears to be in the piston, but, it's not...

I machined a cylinder-size (less .010") piece if eighth-inch-thick aluminum to catch the shavings when I cut the O-Rings, so that when I was done cutting, I could just pull the aluminum piece out the top of the bore, and, the shavings would be lifted out, leaving a relatively-clean bore. Easy clean-up.... The (very short) bolt ran through the top of that aluminum disk and was just something to grasp with pliers, to lift the disk out.

That's about as "high-tech" as this engine gets... LOL!

My dad (who gets smarter in my memory as I get older,) once told me, "If there's a hard job, give it a lazy guy; he'll figure out the easiest way to do it."