Hollow crank shaft

[Simon Hitchen]

I've recently converted a constant speed engine to a fixed pitch. The service instruction dictates that the rear crank shaft plug is pierced, that an expansion plug is inserted into the front end and obviously the governor and oil line is removed and blanked. The tech at ECI told me that this cavity would now fill, from the rear with oil at the engine oil pressure. I just can't see how this could be the case?? The engine case isn't full of pressurised oil thereby forcing oil into through the pierced rear plug into the hollow crank??

Am I missing something here?

[Bicyclops]

The cavity is where the oil that is pumped under pressure to the front main bearings winds up as it comes out past the ends of the bearings. The piercing will allow this oil to drain back to the sump. It would only be under engine oil pressure if there was no escape path for the oil.

Ed Holyoke

[jrs14855]

If you don't pierce the rear plug the oil will likely blow out the front plug.