Shot of Test Plate I had friend make. It is bolted on in place of the
I made a bunch of mistakes on the test. First I didn't have any help.
I didn't tighten the bolts that hold the plate enough. So when I was
warming the engine I could not see the plate. Oil everywhere. I did put
a flare fitting at the gauge port and ran tubing up above and installed
gauge where I could see it from the cockpit. The 100 psi gauge rapped out
against the stop indicating way over 100 psi. Bought from Grainger and it is
a 100 psi.
Warmed oil to 110 degrees and all cylinders just over 300. But after
shut down and cleaning all the mess up found second mess up. I should
have removed the plug for the prop circuit and installed the female side
of quick connector for the test gauges. Soooo, but the time I FINALLY
connected the gauges and added air, the engine had cooled a good bit.
When I first applied the 40 psi, the gauge on the prop circuit when up to
almost 40 psi while it was pushing oil out of the transfer line and other
areas. It then settled down around 30 psi which indicates a good test.
Lycoming said it should be between 6 and 35 psi.
Still not sure why pressure on gauge was so high if true.
BUT...as I just left the air running, over time of about 20 minutes
the pressure on the prop circuit declined to below 6 psi. If I moved the
prop around, it would go back above 6 psi then go back down. Lycoming
does not give a time factor on the test. I assume the air cooling down
the bearings etc reduced the back pressure...right?
So today, if I can beat the coming storms, going to go back and
1. Check plate for tight once more.
2. Leave quick connect installed with hose removed. Can't think of any
reason not to do this since there should be no pressure on that circuit.
3. Install another cheap gauge but 0-200 psi this time, just to see.
4. Warm to 110 degrees oil temp.
Then immediately on shut down hook up gauges and apply 40 psi to
prop circuit. AND see what new gauge shows for oil pressure.