I know some have used special gauges that measure bore diameter through the spark plug hole but only if the head is a center plug design and all plugs are straight shot accessible. But for those that are not, is it OK to use a cubic inch tester common and trusted in the car world for many years?
Speedway, Comp Cams, and P&G are examples.
Of course the valvetrain would have to be disabled for it to work(keeping both valves closed for the length of stroke). But beyond that, is there a logistical reason this would not be used for motorcycle engines? I’ve been told that anyone can supply their own method for testing displacement as long as it can be proven to be accurate and repeatable.
George