Running an engine after a long sit, AOPA article

[Bartman]

Hi all, with my six month project taking just about two years to the day I went looking for info on what to do with the engine. The article below from AOPA was very helpful and it gave me a little insight before bringing it up with my IA.

https://www.aopa.org/news-and-media/all-news/2019/march/pilot/savvy-aviator-powerplant-resurrection

We pulled one set of plugs to help the engine turn over more easily when trying to bring up the oil for the first time. We also had the pre-heat (oil sump and cylinders) plugged in for a good five or six hours ahead of the first run.

 

[aftCG]

Mike Busch is a somewhat controversial author who has ruffled feathers a few times. I bought his book (manifesto, he calls it) and read it. His section on how the US Army Air Force discovered through analysis that most mechanical difficulties (read: turn backs or worse) in the WW II European theater happened after preventative maintenance.
It makes for a compelling argument to fix what is broken when it breaks and not before.
That flies in the face of the stuffy Bonanza* drivers who believe that an overly obsessed upon aircraft is job one and anyone else should face the music and admit they're too poor to fly planes.

Obviously this article isn't really controversial. A dry engine needs all the help it can get. I've built up several non aircraft engines including a Porsche a few years ago. Assembly lube (more of a grease consistency) is your friend when building one up because it covers for the lack of oil pressurev during that first start up.

But after sitting you don't have the luxury of putting goo everywhere it needs. The oil fogging needs to take place when the plane is first out in storage and probably at intervals after to be effective.

I'm assuming you were successful at getting oil pressure?

One problem with long term storage is that you didn't necessarily realize you needed to do it until your project took too long. Then what?

One of my favorite museums has big signs on some of the planes on display urging that you NOT TURN THE PROP because the engine is full of storage oil. I'm assuming that means FULL of some kind of oil - enough to risk hydrostatic lock and bend things. THAT is long term storage done correctly.

From the first oil change with my Citabria I have either added cam guard or used Aeroshell Plus oil. My mechanic (and others) pointed out that only some Lycoming engines need the additional protection but I think anything which can keep oil clinging to internal surfaces longer is a very good thing.

My own engine had a tear down for an AD on the crank in 2004 (way before I owned it) for corrosion inspection. I've seen the pictures of the crank in the logs. It looked like it had been removed from a rusty farm implement.

Edit: the engine in the T-6 I fly was last overhauled 60 years ago. Compression is very good and oil usage is very low (uh, for a radial). With just over 1000 hours on it, it's safe to say it has spent some time sitting.

*Put down the knife folks I love bonanzas, just using a commonly accepted stereotype to set the stage

 

[Bob Turner]

I pay attention to Busch.

I pressurize a new engine with a hand pump. I then rotate the prop to make sure that each push rod is getting oil flow. Sounds messy, but you only need to see a few drops (my rockers are all drilled). Yeah, I also use assembly lube.

I am appalled at what is happening - small Continentals go into the shop, one cylinder flunks the compression check, and all four come off. They are then rejected by the cylinder shop, and six thousand dollars later your Cub is ready for another year. Not many of us can tolerate more than one six thousand dollar annual on a Cub or Champ.

It breaks ok for me - I get discarded lifters and cylinders - sometimes gears - and my engines go for two thousand hours. I did have some trouble with exhaust valve seats, but 3/4 car gas, 1/4 avgas, and no more exhaust seat problems. I check my compression daily, and wait two weeks before yanking one with low compression. Bonanza owners get compression checks annually.

One of the guys bought a set of cylinders with 35 total hours on them. Sent them to a cylinder shop for inspection. They got a $2000 overhaul. Be careful out there.

 

[Bartman]

But after sitting you don't have the luxury of putting goo everywhere it needs. The oil fogging needs to take place when the plane is first out in storage and probably at intervals after to be effective.

I'm assuming you were successful at getting oil pressure?

One problem with long term storage is that you didn't necessarily realize you needed to do it until your project took too long. Then what?

We did get oil pressure to come up after about three 15 or so second runs with the starter. With the plugs out it was easy to do two or three additional runs of the starter to make sure oil was being moved around the engine.

And, yes, it wasn't expected that the project would take two years (freezing cold winter, unheated garage, two two-month training cycles for work, 8 months of being super junior flying domestic narrow-body schedules, 454 in the Suburban needed new lifters, etc., etc., etc) so the engine didn't get anything in the way of prep for long term storage although I knew to never move the prop once it was shut down for the project.

My IA said to start using Cam-Guard so the oil will get a change after it's had 5 or so hours of time and then Cam-Guard will be standard ops going forward.

 

[Bob Turner]

I parked a 65 upside down in the back of a hangar for ten years - no prep. Then broke a crank in the 85, turnedvthe 65 right side up, mounted it, put a prop on it, and flew it another thousand hours. It is still assembled, and now, after 25 more years, I bet I could fly it. I rebuilt it in the early 1970s using the original cam and lifters, but with micro polished crank and Edelbrock balancing. Hand lapped the valves. I was really poor then. Living on a graduate stipend.

 

[Bill Vickland]

Be cautious when buying an airplane that has been sitting for a long time. I considered buying a nice looking and cheap Cessna 172 that had been parked on the ramp at Atkinson International Airport in Guyana South America. I had considered buying it and flying it home to the US up through the Caribbean Islands. I was cautioned by an experienced pilot not to buy it because the engine had not turned over for more than two years. He noted that one exhaust valve was open during the entire time and that cylinder wall would be rusty. He said that I would run about 25 hours and the engine would self destruct. I'm glad I took his advice. A month later someone copied my plan. He flew north west along the shore line to Venezuela where he would begin following the islands north. The engine failed and he landed on the beach in Venezuela. He reported to friends that the rings in the cylinder that failed were packed with what was probably rust. He replaced the engine and finally flew home to the states.
Bill Vickland