A popular mod for flying rotaries is to install a spacer under the oil
bypass valve to disable it.  The piston in the thermal pellet is usually
removed when doing this.

Another popular mod is to install the Racing Beat under drive pulley on the
crank to slow down the waterpump and alternator.

If the spacer was made to fit the stock pulley before changing to the
aftermarket pulley, the bypass valve will be in the incorrect position due
to differences in the pulley.  This results in low oil pressure, similar to
the blown out O-ring in the front cover.

This problem has shown up in at least three engines, Jerry Bass' being the
latest.  If you experience low oil pressure on a newly built engine, check
this as a possibility.

Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com