So I'm trying to get the B18 to be all it can be. Just adjusted the valves (.016-.018) and am starting on the carburetors.

I've been trying to learn how to tune SU's. I have rebuilt two-bolt SU's on a 1965 B18B 122. (If anyone has info on how to verify block/heads via casting numbers that would be great)

Installed Grose Jets to try to keep the fires inside the cylinders. However during the tuning process I have had several overflows. A pucker-inducing event if any of you have had the pleasure of witnessing "SU Falls" in action.

I've set the floats to 5/32" as opposed to the recommended 1/8" and am considering going to 3/16". Wondering if different float levels are better with Grose Jets. The Grose Jets do hold vacuum if tested with a Mighty Vac. But I'm wondering why they intermittently aren't shutting off the fuel supply and allowing overflows.

Really don't want this happening under a closed hood while driving.

Also, I've seen some posts that recommend adjusting the opposite carb when doing the "piston lift" tuning method. A little confused about this as lifting the piston should create a lean condition on that carb. How that carb reacts to a lean condition should tell you about the jetting on that carb, not the opposite one it seems.

Anyone have thoughts on SU tuning before I go buy a Colortune or an exhaust analyzer?

Thanks,

-Mario E.

Portland, OR