[agirard7a]

I have an 0320 that has been sitting for about
Five years. When I purchased, it did not seem to be pickeld.
I am thinking about pulling off at least one cylinder
To see if it is badly pitted. An Ap did a boroscope
And said there was rust at the cylinder tops.
Is there a preferred jug to remove to also get a look at the cam?
One AP said just run it. Another said I should remove
To inspect. Hone if needed and replace the rings.
Another AP said if I run with rust it could lead to an expensive
Problem or worse, upside down in a feild some where.
I also thought to remove all four to inspect.
Any thoughts?

 

[aerhed]

#2 & #3 will give you best view of the cam & followers.

 

[krw5927]

This is a great question and I will be watching the answers in eager anticipation. I have an O-320 E2D in the same general condition that was higher time (1900 hours or so) but running well and came off a Skyhawk a few years ago for an upgrade to 180HP.

I pulled cylinders 1 and 4 on mine, and only pulled #4 because I couldn't see past the center bearing to check out the aft half with #1 off. Between those two it seemed I could see all the cam lobes and tappets pretty easily, but I don't know if there's a "preferred" or "best" way to do it. And when I had the jugs off I looked up inside at the condition of the head. No rust to speak of, good wear patterns on the exhaust valves indicating no leaks, machining still visible on the shiny cylinder walls, and nothing to catch a fingernail on the cam lobes or tappets. I put some new cheap auto engine oil in an oil can and coated the cam, tappets, and crank with it, just to make myself feel good about maybe an extra layer of corrosion protection. Then buttoned it back up and installed dessicant plugs while covering all other openings into the case and cylinders.

My plan is to go ahead and install this engine when my 9A is ready, then fire it up when it's time. I'll run it a few times on taxi tests and so forth before I take a compression test. Oil will be changed again right before first flight if everything looks and runs ok.

Hoping to get lucky and get a year or so off the engine before I tear it down. Of course at any time luck could change and I'd have to start budgeting for an overhaul before first flight.

 

[krw5927]

#2 & #3 will give you best view of the cam & followers.

Dang it, I did it wrong. So what do we miss by pulling 1 and 4 instead?

 

[aerhed]

You didn't miss much. That mostly applies if you're only pulling one jug.

 

[agirard7a]

pulled a jug today

Ok, I went for it today and pulled #1. I talked to an AP about first getting the piston at the top before pulling so no tension would be on either valve.
I simply used a coat hanger in one of the plug holes to determine when the piston was at the top. It came off very easily and was sure not to let the piston and connecting rod drop so not to damage the flange on the case.
I was happy to inspect that there was no rust on the cylinder walls as well as no visible rust on the cam. I cleaned off the carbon ridge at the top of the cylinder with 120 grit paper and used a cross hatch pattern to sand.
I then applied a liberal coating of oil on the piston and cylinder, compressed the rings and made sure the gaps where opposing and reinstalled the jug being very careful to tighten the bolts in a sequence. They are now just hand tight and I will have an AP instruct me on how to re-torque the nuts.

Can anyone tell me if it is ok to wire brush off the piston top to remove any carbon deposits?

Any other recomondations on this procedure? precautions?

thanks, al