Restarting piston engine after a long AOG

[Ultranomad]

Hello colleagues, I'm after some collective wisdom. I need to bring several piston engines back into operation after a year or more AOG without proper preservation. I see the process as follows:

1. remove the spark plugs,
2. spray some oil into cylinders,
3. preheat the engine well above room temperature,
4. drain the old oil, if any,
5. replace the filter, inspect the old one,
6. fill with new 80W oil (also preheated to e.g. 80°C),
7. crank the engine a few turns by hand,
8. check the crankshaft for smooth rotation (if not, tough luck),
9. crank the engine with a starter, check for normal cranking speed and at least some oil pressure,
10. if no oil pressure, check for oil flow out of pressure gauge union,
11. if no flow, check if the engine oil pump is properly primed,
12. if not, prime manually, check again,
13. if OK, check cylinder compression,
14. if the results are sensible, attempt a restart.

Is this reasonable? Any additions, corrections or helpful tricks will be greatly appreciated.

[wrenchalot]

It is, but if you want compression (item 13), you'll need to re-install the spark plugs...; had to mention it LOL

[Octane]

quick looksy with a borescope?

[Mr Bizzle]

I actually popped onto here to ask another question but I saw this thread and thought i'd respond as i'm about to do the same thing.
I'm currently in the process of bringing a pair of TSIO360's back into service after being stood for about 10 years. The aircraft they're off needs to go for an airworthiness inspection so I had to get formal advice from an Airworthiness Surveyor and also Continental.

Basically I agreed the following (which seems like common sense to me)
- Remove each cylinder & piston.
- Inspect, very lightly hone and re-seat the valves
- Clean up the pistons with fresh rings
- Inspect the lifters and cam for corrosion. Service Information Directive SID-051B has all the information required for continental engines re acceptable levels of cam and lifter corrosion.
- Reassemble with fresh gaskets and o-rings.
- Remove and reseal the sump + clean out any debris & change all filters, plugs, leads etc
- Replace any flexible hose.

Then a 500h inspection on all other engine items including the mags.

- pre-oil as per M-0 manual prior to start.
- Run it up to temperature. Change the oil and screens
- Fast taxi and full power runs. Change the oil and screens/cut the filters.





This of course assumes the engine is otherwise free turning.

[NutLoose]

I would whip the rocker covers off as well and give them a good dose of oil, also drain the old fuel from the carb, this might help show points that need lube

https://www.lycoming.com/sites/default/files/SI1059E%20Pre-Lube%20of%20Parts%20Before%20Assembly.pdf

also read

https://www.lycoming.com/sites/default/files/Engine%20Preservation%20for%20Active%20and%20Stored%20Aircra ft.pdf


I forgot to add, if you spray oil in the cylinders and let it soak in for a while, remember to take the lower plugs out and turn the engine over by hand to drain them, you do not want a hydraulic lock