Engine Tear Down

Following a Thursday night meeting tech session with a discussion about engines and overhauls, the chapter
members gathered in president Jeff Scott's hangar to tear down the O-290 engine that the chapter inherited
from Arlene Walsh.  Under the tutelage of A&P Jeff Scott and machinist Doug Reid, the engine was torn down
for inspection, then sold to one of the chapter members once some gauling was discovered on a cam follower.

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The victim (O-290) and the executioners.

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O-290 on the stand with cylinder wrenches ready to go.

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Jeff explains the plan of attack..

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Yes, we had some young observers with a critical eye.

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The silverware trays laid out to collect and sort the parts.

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Jeff demonstrates how to slip the piston pin out.

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George takes his turn with the Cylinder base wrench.

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This engine appears to have brand new pistons and rings.

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Travis gets hands on with the cylinder wrenches.

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Doug inspects the rings with lots of observers.

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Brian wrenching on one of the front cylinders.

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Hmm.  Apparently not all of the pistons were new.  As it turns out, this piston wasn't even the same compression
ratio as the other three.  This engine would have been a real shaker had it ever been started.

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The left bank apparently had all new pistons.

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Thomas gets the feel of the cylinder wrenches.

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Thomas seems to really be getting into this engine work...

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Jeff working the wrist pin out of a piston.

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Finally, an empty hole we can look in!

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Jeff starts loosening the rod bolts.

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Jeff starts loosening the rod bolts.

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One rod out.

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And the rod bearing out of the cap.

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The rod bolts had to be gently tapped out with a brass drift.

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Inspecting the cam and cam followers.

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There it is.  A small amount of gauling on the lower cam follower.  The gauling was caused by a mal-adjusted
valve that kept the cam follower pinched against the cam, preventing the cam follower from rotating.  Consequently,
it wore in one spot rather than rotating, which prevents wear.

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Doug brought his valve removal tool and demonstrated how to remove valve keepers and what he looks
for when he inspects valves and guides.

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Doug measures the valve stem.

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And points out some important facts about this valve.

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