Oxyboxer aviation engine: #4 bearing

[flyguyeddy]

So there is something called the "force one" hub made by great plains for the type 1 vw engine that basically replaces the #4 bearing with anew setup that you must bore the engine case out to fit. New bearing saddle ends up measuring somewhere around 2.3". Anyway, the wasser case has a lip seal bore of 68mm on the front, which is a substantial bit more than what the case would be bored to (were it just like the t1 case). What do you suggest i do to fill the lip seal bore area? Press fit a ring onto the new bearing, or weld half-moon fillers into the wasser case snout to take the place of the lip seal?

[Marc]

Are you committed to direct drive? A redrive would bypass the issue, although I don't know if it might introduce others.

I'm surprised that neither Great Plains or Revmaster makes a #4 bearing for the wasser case - have you contacted them to see if they'd consider producing one? Or maybe selling you one that hasn't been fully machined yet, leaving that end up to you to finish?

Between the two options presented, one could make a case for going either way but I lean towards the idea of pressing a ring over the bearing. Obviously you'd need to be able to resize the I.D. if it were to be constricted by too tight of a fit on the ring, but I don't see that being a problem.

[flyguyeddy]

Redrives add more weight to an already heavier-than-type1 setup, and introduce more heat to the heads from higher rpm. Direct drive just seems like the easiest way to me, plus i like the long front bearing those hubs provide, to keep gyroscopic forces at bay.

[Marc]

I get it. I don't understand, though, why more folks don't just turn the engine around and drive the prop off of the "big end" of the crank as the designers intended. Not as aesthetically pleasing I suppose...or is it more about keeping the frontal area as small as possible?

[flyguyeddy]

It seems easier to do rear-mounted things like flywheels and ignition this way. I realise you can just put a flywheel on the hub end, but then you mount the starter further out from the center of gravity, which can cause issues with balancing

[flyguyeddy]

*flywheel end not hub end