SUNNEN CRG-750 FIXTURE TUNE UP
I just used a set of LS main caps to shim the fixed surface plate (opposite the clamp) on our cap grinder. LS caps are normally cut very square to the sides, but first I verified these with a machinist’s square. I use dye chem on the bottoms and just barely touch off on a known square cap. If it’s not touching off square you can use thin shim stock behind the surface plate on either the top or the bottom. If the cap isn’t square, but your plate is, you can use shim stock to get it square, again using dye chem to check contact before grinding. Someday we’ll upgrade to the wide 2 post clamp so I don’t have to shim. With the wide clamp you can just grind the sides square, then go back and grind the bottoms. The CRG-750 uses a center post clamp that is in the way, so you can’t grind the sides square. It really doesn’t take much longer to shim them square with enough practice. We keep a set of feeler gauges next to the grinder just for that. If you change the angle of the bottom of the cap you’ll not only have a hard time getting the bore back to straight, but you’ll also beat the heck out of your rod or line hone stones and guide shoes.

Jake Sampson
Sampson Race Engines
Inver Grove Heights, MN
January, 2020