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Engine oil analysis help

Lemos

Active Member
I have a beautiful RV14A in pre buy right now (3rd time!! First two aircraft had too many problems). From a build standpoint the airplane sailed through the inspection. But we have a bit of a problem (I think) with the oil analysis.

This RV14A is unique because it is powered by a fixed pitch prop and an IO-360. The motor has 200 hours on it in the last ten years, and it was installed in this RV14A four years ago. Prior to this inspection, the airplane was not on oil analysis.

Anyhow, without further ado on Friday I received the results of the oil analysis. The results were high oil, copper, nickel, aluminum, and tin. Results:

Aluminum 11 ppm
Iron 66 ppm
Copper 20 ppm
Tin 8 ppm
Nickel 12 ppm

So the numbers above do not mean much to me. Talking to the lab, they suspect possible corrosion due to flying only 200 hours in 10 years.

What is the collective wisdom of this group, are those numbers concerning, or is the oil lab covering their butts by flagging those numbers?

The owner admits to the airplane burning a quart of oil every 8 hours. That seems reasonable to me.

If you were in my shoes, would the numbers I have typed above be enough for you to end the deal? What would you do about those numbers, if not?
 
The -14A that you are considering is a bit of an oddball with the IO-360 and FP prop. That in itself in my opinion reduces the value and resale of the aircraft as most builders are opting for the more desirable 390 engine and CS prop. Considering the inactivity, at the very least I would plan on figuring in an engine teardown/inspection into the purchase price. It is hard to judge the condition of the engine by a single oil analysis since they rely more on trends, however the high metal content should raise a red flag. 1 quart in 8 hours is acceptable, but certainly not optimum for a healthy IO-360.
Good luck!
 
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O.A. misses a lot and overstates a lot.

Pull a jug and cam gaze.

1 qt in 8 is high if he has an air-oil sep or runs 6 qts or less in a normal 8 qt sump. Easier to find and fix.


Ten years and 200 hrs can be fine for another 10 years and 2000 hours but not another 200..

Any engine can have faults.

Even fixed pitch, 200 hp, that will be a nice performer.
 
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Likely the simplest place to start would be with a borescope run by somebody who really knows how to use it?
 
I would be looking to see how much cross hatch is left. Cylinders may not make it to TBO, but they should be "good enough". Oil consumption could stabilze at 8 if you run it more.

I would cut open the filter. Biggest concern is lifter spalling and you will usually find small, finger nail shaped pieces of ferrous metal if that is happening. If it is, the engine needs to come apart for a bottom end.

Larry
 
O.A. misses a lot and overstates a lot.

Pull a jug and cam gaze.

1 qt in 8 is high if he has an air-oil sep or runs 6 qts or less in a normal 8 qt sump. Easier to find and fix.


Ten years and 200 hrs can be fine for another 10 years and 2000 hours but not another 200..

Any engine can have faults.

Even fixed pitch, 200 hp, that will be a nice performer.

I would be surprised if the seller allows you to pull a jug, but if so go for it. A teardown, cylinder work and reassembly with no major issues will run around 8K. Depending on engine model, consider Lycoming SB-505B pertaining to corrosion/pitting on the crankshaft. That can get expensive.
 
Just another Data Point

Just got my analysis back yesterday. This at 480 Tach hours in just over 3 years. ~150/yr.
Aluminum 6
Iron 29
Copper. 21
Tin. 2
Nickel. 1
8 hrs per QT seems hi. I use 1 QT per 20+.
Fairly consistent thruought it’s life.
 
I have an o320- attached is my report below for reference.
 

Attachments

  • N457DH-200729 OA.pdf
    23.5 KB · Views: 315
The -14A that you are considering is a bit of an oddball with the IO-360 and FP prop. That in itself in my opinion reduces the value and resale of the aircraft as most builders are opting for the more desirable 390 engine and CS prop. Considering the inactivity, at the very least I would plan on figuring in an engine teardown/inspection into the purchase price. It is hard to judge the condition of the engine by a single oil analysis since they rely more on trends, however the high metal content should raise a red flag. 1 quart in 8 hours is acceptable, but certainly not optimum for a healthy IO-360.
Good luck!

I echo Jake's comment here, also pay close attention to the W&B, RV14A likes/needs a bit more weight up front.

As for the engine's health goes, I agree with others that further investigation is warranted pending how much the owner will be willing to cooperate.
 
Copper & Tin...

I have a beautiful RV14A in pre buy right now (3rd time!! First two aircraft had too many problems). From a build standpoint the airplane sailed through the inspection. But we have a bit of a problem (I think) with the oil analysis.

This RV14A is unique because it is powered by a fixed pitch prop and an IO-360. The motor has 200 hours on it in the last ten years, and it was installed in this RV14A four years ago. Prior to this inspection, the airplane was not on oil analysis.

Anyhow, without further ado on Friday I received the results of the oil analysis. The results were high oil, copper, nickel, aluminum, and tin. Results:

Aluminum 11 ppm
Iron 66 ppm
Copper 20 ppm
Tin 8 ppm
Nickel 12 ppm

So the numbers above do not mean much to me. Talking to the lab, they suspect possible corrosion due to flying only 200 hours in 10 years.

Where does the lab think the Copper and Tin are coming from? My guess is those are bearing metals. Elevated wear in the bearings in not a good sign at all, and wouldn't be just corrosion... no Tin in cylinders, rings, pistons...

I'd check out Savvy's pre-buy program. Some experts that are on your side at a price that is far less than cost to pull a jug and look.
 
Thanks all.

I spoke to the A&P this morning. Boroscope has revealed corrosion in the cylinders. Next he is going to pull off a cylinder and see what the camshaft looks like.

An option I am debating is making a low offer on the plane and allowing enough money to buy a new IO-390.

Please keep the suggestions flowing!
 
Thanks all.

I spoke to the A&P this morning. Boroscope has revealed corrosion in the cylinders. Next he is going to pull off a cylinder and see what the camshaft looks like.

An option I am debating is making a low offer on the plane and allowing enough money to buy a new IO-390.

Please keep the suggestions flowing!

Sounds like a reasonable action, Al, Fe, were high. Lots of wear going on. Copper, . . .well, I got high copper when I switched to 15w-50 aeroshell. Oh-Ni seems way high too. You will find more with a jug off. Or just low offer for OH, sell the core and install the 390. Decisions decisions, good luck.
 
Sounds like a reasonable action, Al, Fe, were high. Lots of wear going on. Copper, . . .well, I got high copper when I switched to 15w-50 aeroshell. Oh-Ni seems way high too. You will find more with a jug off. Or just low offer for OH, sell the core and install the 390. Decisions decisions, good luck.

Well, and install that CS prop at the same time. Let me make a wild guess... $50K plus labor? Boy that's going to be a real low ball offer.
 
High Copper is Peculiar to the Shell

Sounds like a reasonable action, Al, Fe, were high. Lots of wear going on. Copper, . . .well, I got high copper when I switched to 15w-50 aeroshell. Oh-Ni seems way high too. You will find more with a jug off. Or just low offer for OH, sell the core and install the 390. Decisions decisions, good luck.
.
Had the same issue when I started using Aeroshell years ago. Discussion with a metallurgist at Lycoming lead us to find than an additive in the oil was stripping the copper flashing off of the cam shaft- the flashing or light plating was used to inhibit case penetration on non-bearing surfaces during heat treatment of the camshaft.
Terry, CFI
RV9A N323TP
 
A cylinder was removed today, and the cam has corrosion. Really sad to see in a motor with 200 hours on it, but I guess that’s what to little use does.

I have ordered plans from Vans and as soon as they arrive I will be reviewing what I’d need to do to convert this airplane to a 390 motor with a constant speed prop. Once I have the plans I’ll total up the cost and make an appropriate offer to buy the airplane as is.

I feel for the owner, because now he knows what he has on his hands. Even if we cannot come to terms, he’s going to have to do something to sell the airplane since the cat is out of the bag. I’m not sure if he’s better to repair what he has, or to sell it as is at a significant discount.
 
Assuming bottom end is OK, what would be the typical cost of a top end overhaul?
 
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Assuming bottom end is OK, what would be the typical cost of a top end overhaul?

Depends on what you call a top overhaul. To most, that means replacing all the jugs - price four jugs, and you’ve got the parts costs.
 
Another thing you can look into is the fact that the builder installed a used engine, you may be able to purchase a new motor from Van's.... and maybe a CS prop..
 
.
Had the same issue when I started using Aeroshell years ago. Discussion with a metallurgist at Lycoming lead us to find than an additive in the oil was stripping the copper flashing off of the cam shaft- the flashing or light plating was used to inhibit case penetration on non-bearing surfaces during heat treatment of the camshaft.
Terry, CFI
RV9A N323TP

This was my thought, but not sure if this is a really bad thing. What did the Lyc guy say about the final effect??
 
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