Reply to "Stroker engine vibration"

Kristian, two suggestions: first, that crank does not have mallory-metal in the welded balance hole- I hope! Because drilling in from the top and slipping a slug of tungsten alloy in is way-wrong. At high rpms & high heat, the slug will fly out thru the weld (and the engine) like a cannon shell! Several cars and engine have been destroyed by such things. Pro engine balancers ALWAYS drill into a crank longitudinally which is more difficult, but the slugs stay in. That's probably just a drill hole that was then partially corrected with arc weld.
Next, your present 28-inch-oz flywheel should be able to be remachined locally to neutral balance by cutting away the small balance weight on a mill. This will save you shipping flywheels back & forth across the Big Water, and your local balancing shop will be able to correct any tiny errors in milling.