Low Time Engine ?

danhagan

En-Route
Joined
May 7, 2009
Messages
2,674
Location
El Paso, TX
Display Name

Display name:
danhagan
Aircraft has 217 total hours on engine since 2008. From 2015-through now it has only operated a total of <18 hours and is located in Florida. What are the odds for cylinder/cam corrosion?
 
I’d feel safe putting my money on yes.
 
High probability but...maybe not. Hard to say. ;)

Only way to really know is to run it for 7-10 hrs and check the filter for metal and debris.
 
What are the odds? Well, if there is actually corrosion, the odds are 100%, and if there is no corrosion, the odds are 0%.

I'd say you can't give odds... instead have it inspected, then you know whether it is 100 or 0. By the way, my current aircraft was used 50 hours in 7 years before I bought it. I've now put 200 hours on it in 2 years. It has an O-320, which is known for both cam system corrosion and a difficult to get to cam. We inspected what we could, and took a chance on the cam...I got lucky, but I knew the risk.
 
I am looking at similar aircraft right now.
Coastal. 25hrs in last 4 years
Coastal. 17 hrs in last 2 years.
50mi from coast. 4 hrs in last 2 years.

I tell them I have to price the aircraft budgeting for an overhaul. They don't like that, sellers think their engines are like new.

You can possibly mitigate risk by:
-buy them an oil and filter change, you get the oil for testing, and the filter for examination.
-taking an oil sample with a long red rubber catheter and syringe through the oil filler port (some won't allow you to open sump for a sample or change their oil/filter) Don't drop that damn catheter!
-permission to pull a jug understanding that you are responsible for putting things back to the way they were.
-run your borescope into the case through the oil filler neck and maybe the oil sump drain hole to look at as much internals as are available (I can see a few cam lobes and follower faces on my IO-520. Of course do each cylinder too.
 
Aircraft has 217 total hours on engine since 2008. From 2015-through now it has only operated a total of <18 hours and is located in Florida. What are the odds for cylinder/cam corrosion?

This is like reading tea leaves.

Could go ether way, only way you'll know regardless of hours or location is to check it out, remember if airplanes sitting was actually bad most of the fleet would be turned into soda cans, since any plane that was built prior to 1990 that doesn't have over 10,000hrs has been sitting, and yet people don't want to buy GA planes with over 10k hours ether.
 
Interestingly, I am about to sell a similar engine. So I will see both sides.

I have borescoped it, comp tested it, put in new oil and filter. I am going to fly it for 10 hours and repeat all that plus oil analysis and filter exam with photos - for any buyer that might show up. I am going to do it like I am going to retain the airplane (short of pulling a jug).
 
Aircraft has 217 total hours on engine since 2008. From 2015-through now it has only operated a total of <18 hours and is located in Florida. What are the odds for cylinder/cam corrosion?

...
Only way to really know is to run it for 7-10 hrs and check the filter for metal and debris.

This would be the ideal solution, but could be difficult to do in practice, with someone else's airplane with other buyers likely in the wings. I had a similar situation on my last airplane purchase. As someone else suggested, you could check the logs to see when the last oil change was and get permission to remove and examine the oil filter (assuming it has one), then pay for a fresh oil/filter change. But there is no way to be certain that the oil/filter wasn't changed recently.

It also makes a difference if it is a Lycoming or a Continental.
The OP was looking for an RV-7, I believe. So it will be a Lycoming.
 
Each engine is it's own little science project. Scope it and if the cylinders are rust free the cam ought to be OK. A few years ago I bought a NEW Lycoming IO-360 that sat in the factory box in FL for 17 years. I paid a price reflecting my cost to tear it down and do whatever it needed. Upon receipt of the engine We pulled two cylinders and had a look before disassembling it. Amazingly it was shiny and new. No long term preservation and no rust. Sold it and made a lot of money. Charlie Melot X Zephyr Engines owner
 
Back
Top