Bruce is correct in that the front stack is where so many rebuilds go
down the drain. So the rear counterweight goes on first. Also once you do this
a few times it can be just a personal choice. If the front bolt is not torqued
down on a completed (correctly) front stack, rotating the engine through
horizontal often allows that pesky spacer sleeve to move foreword just a
bit and then the rear thrust bearing drops down behind the spacer. Now
when you torque up the front bolt, you crush that bearing. Then you have zero
end play and pieces of bearing
adrift in your new engine.
Do not use the front counterweight to hold the crank still while you
torque anything. The keys are soft and can be deformed. The counterweight can
warp a bit and upset the surface where the bearing washer sits.
When checking end play,with the front of the engine still pointing
up on the stand, just push up with your hand on the rear counterweight.
Do not pry up on the front counterweight with a screw driver. The thrust plate
is flexible and you may see a totally bogus measurement on your dial
indicator, when part of your measurement is plate flex.
In racing engines I used double lip seals on the rear counterweight
installation. A stock looking rear main seal with a spring loaded lip facing
the engine and a non spring loaded lip facing aft or, away from the engine to
keep dirt away from the inner seal.
In any case a bit of lube oil on that seal lip gives it a head
start on a long life. Just a bit, as oil attracts dirt, the reason for the
rear facing seal lip. Not needed on airplane stuff.
Piece of cake.......................Lynn E. Hanover
In a message dated 2/21/2017 6:42:20 P.M. Eastern Standard Time,
flyrotary@lancaironline.net writes:
That's what I though, although Bruce says to tighten the rear nut (and
admonishes you to not invert the engine) before the end-play testing.
I actually made a counterweight holder of a piece of steel which also
includes a removable counter torque angle.
thanks
Rich