Warbird Information Exchange

Continental W670a engine - MADE 1942. Engine oil analysis shows a fair amount of ferrous inclusions, very very fine, they pass through the filter, but we think that the laboratory is checking to 2011 Standards and not to 1942 Standards. We see that the oil appears to "stick" to a magnet. No-one else here in France does an analysis, they just don't bother. We have grounded the aircraft, Morane-Saulnier 317. Are we worrying too much ? Is there an oil analysis laboratory in the States ( or in the UK ) that do regular oil checks on radials, to 1942 standards ? Appreciate your help.

Is this an overhauled engine? How many hours on it? If someone in the US has done an oil analysis on a W670 there should be a baseline, but there shouldn't be any reason this engine should have more metal in the oil than any 6 cylinder Cessna or Piper unless something is wrong.

There is no filter on the engine, just an oil screen to keep really large metal chips from going through the oil pump.

Bonjoiur to BDK.
Thanks for the reply.
Yes, overhauled, new front thrust bearing, new piston rings, new crankshaft pin.
We added a standard oil filter to the aircraft's circuit - quality as on any modern Lycoming or Continental - when we broke it open after 5 hours there was nothing inside, no dust, no chips.
But when we sent the oil away to be analysed, they found a lot of ferrous material.
The engine has not flown since overhaul, only two lots of five hours of ground runs.
It is as though ..... the oil has absorbed an iron powder ..... thin enough to go through the aviation quality filter, but enough to show up on the analysis.
Do we know of a company in the US who check radial engines on a regular basis ?
Frustrating, I do not know where to turn next.

With only 10 hours since overhaul, the Fe particles are just the piston rings seating. Perfectly normal.

I might be concerned if you saw elevated amounts of Cu or Sn as that would be bearings.

_________________
Lest Hero-worship raise it's head and cloud our vision, remember that World War II was fought and won by the same sort of twenty-something punks we wouldn't let our daughters date.

That explanation makes sense to me. You should find the contamination level going down at each oil analysis until it stabilizes. If you can't see metallic particles in the paper element filter (or sparkling on your finger under a strong flashlight) you should be OK.

Hard to diagnose over the internet of course. Send me a round trip ticket and I'll be glad to have a look!

Checkout Blackstone Laboratories:

http://www.blackstone-labs.com/

They've been analyzing the oil from our R-1340 and M14P.

Drew

I'd like to say "Thank you" to all of you who have replied to my questions. But the guy who has the power, refuses to sign the paperwork. So we have ourselves a "Hangar Queen". BDK, sorry, I cannot offfer you a round trip ticket, would that I could, but I can offer you an invitation, if you are ever on the Atlantic coast of France, please call into the airfield at La Baule, be glad to see you.
Thanks again to you all.

You had also asked about rust and corrosion prevention before. It's possible that the elevated Fe is the result of that as well.

We've found that the best method of preventing that is frequent and vigorous use of the airplane. We have a customer, a flight school, that have (legally) extended their TBO from 2000hrs to 2800hrs. They use the airplanes 10-12 hours each day. When we get the engines for overhaul they have often have less than normal wear, and almost nothing related to corrosion.
Conversely, we've had engines come back to us with every steel piece orange with rust, and the customer complaining that it only had 15 hours on it - over three years - and only five flights.

I don't know if this would be practical, but a long weekend spent fast taxiing and almost flying a la pingouin combined with another oil and filter change may seat the rings and knock off enough rust to make your oil analysis happy.

Just a guess, The guy who needs to sign this off works on turbines as his day job, n'est pas?

_________________
Lest Hero-worship raise it's head and cloud our vision, remember that World War II was fought and won by the same sort of twenty-something punks we wouldn't let our daughters date.

In my experience, that level of wear on a newly overhauled engine was normal, regardless of whether it is a radial or flat engine. When I was maintenance controller for a flight school, we pretty much ignored the first oil sample, the levels were that abnormal, up to about 50 hours.
Another question; how long had the engine been in storage before being fitted, and had it been properly preserved? If it has been lying around, or not stored properly, there could be a lot of corrosion built up inside the engine.
Shrike's advice is sound, give it some more ground running, at as high a power setting as possible. The last thing you want to do now is to glaze the inside of the cylinders up and not have the pistons bed in properly.

I don't know about radials but in most horizontal recips the only way to be sure of having the pressures and temperature to seat the rings is to fly the aircraft. Ground running even at full power tied down does not ensure the proper air flow through the cooling fins and baffles etc and may not get the oil hot enough to boil off the acid carrying moisture in the oil.

_________________
"I can't understand it, I cut it twice and it's still too short!" Robert F. Dupre' 1923-2010 Go With God.

I have been reading the post and replys on this and might be able to help.
I have been doing oil analysis checks on my engine overhauls since 1983. I have a fairly large data base of engines both V-12's and radials. If you could e-mail the report to me I will review it and if you need I can send copies of other reports for your inspectors review.
mike
[url]vintageradials2008@att.net[/url]