Over filling a unit such as this will not harm it, other than possibly spitting oil out the vent.
But what it does is rob hp from your driveline.
You're floating all the parts in the BB in oil and not light oil at that. There is a LOT of drag and you only need "enough" oil to keep the parts lubed and cooled.
Why do you think motor builders use windage trays under the crank, to keep the oil from the pan getting on the crank throws and costing precious power.
When we ship gearboxes out on our equipment, they're filled to the manufacturer's specs and usually there is a "fill level" hole about 1/3 the way up the case. This amount of oil is more than sufficient to lube and even our gearboxes get hot enough that they are hot to the touch.
Again, if the BB quiets down with over filling them and they don't puke out the oil, you're probably not going to notice any lost hp with your seat of the pants dyno.
Good luck to all on the BB lube issues.
Have a great weekend to all!!!
Great points Dan...I also felt the difference in height between the two "fill holes" was negligible, so I'm not too worried.
In regard to silence on this issue, sadly I suspect the real concern is legal liability...
