IO-540 Metal in oil screen.

[Ian]

Original engine from 1985 1000 hrs never overhauled. Found several bits of metal in oil screen and finer material in filter element. All magnetic. Compression in mid seventies . Would like to do field repair/overhaul. There is a shop at my airport KASH Nashua NH as well as friend who is IA. Any advice. From what I have learned so far this could likely be the cam or lifters or both. Do I repair just what is wrong or go further and overhaul engine . I have had the air servo , flow divider overhauled by Mattituck 2 yrs ago and the prop is new. Also newstarter ,mags,harness, and hoses. Cost is a factor.

Ian

[210TC]

It's up to you and your pocket book. Many many ways to skin a cat.
What if you zero time and loose another cam?
My opinion,
With as low of hours you have, zero time the lower end as in the case, crank, rods, cam and lifters along with the gears. All should pass with and inspection except for rod bushings, engine bearings and of course the failed parts you have. I would pull the cylinders out just enough to remove the wrist pin, not allowing the rings to pop out of the cylinder, then reinstall as long as the compression is very good without repair, save your money.
A valid argument exist to send the cylinders out for overhaul. However, they may last another 10 years. Do a real compression test before you tear down and see if they are close in compression. A differential compression test only test at top dead center and does not give any indication of the true condition over the complete compression cycle. Note: a flat cam lobe can effect a true compression test.

[YELLOWMAULE]

Having just faced this with a different engine and diferent circumstances, I would suggest that there's not a real good "budget" outcome ahead of you.
Because there's metal in the oil, your prop govenor will have to O/H'd. Same with the oil cooler. In my mind the why is as important as the how.
My engine was 200 hours beyond TBO. I had a trace of aluminum in the oil. My compressions were terrifc, oil consumption was also well within tolerance.
You've got twenty years on this engine and in my mind, that carries more weight than the actual time on the engine. In fact, with the Lyc's, that may be more of a determination. TCM states 12 years or TBO. I believe these 540's are far more subjective to corrosion than others due to the internal orientation of the components. Hence the cam/lifters going away.
Sorry no answers other than stressing finding the why. It can only help avoiding it in the future.
I don't know what your climate is like where you're at but I have a tremendous change in climate in a year's time and fly year round. I was pleased to find upon tear down that there was virtually no corrosion during tear down. My metal was from the piston pins (It appears there was only one) so it seems that it was due to a buid up of "stuff" naturally accumulated in the wrist pins forcing the buttons against the cylinders.
It's going to hurt (the overhaul) but if you have an IA that will let you go through the engine with him, there's a lot you may be able to learn. There's a silver lining to these some times, UP-M5 had his wrecked last year and through a lot of hard work, it has become one of the nicest Maules out there. I hope to be back in the air in the next month although being land bound during the summer is killing me, I look forward to having a new engine. There are very few of us that don't have to make this flying thing a major consideration in the family budget.
Good luck, I hope it works out for you. Keep us up to speed with your progress.

[a64pilot]

It's 23 years old, almost twice TBO. Your going to spend 75% of the money an overhaul will cost to repair it, but not reset the clock. You would be crazy not to overhaul it in my opinion. If you can possibly swing an overhaul, do so. Your cylinders may check out fine.

[Green Hornet]

I went through the same thing about 9 months ago. One thing I found that you may want to take a look at is the CAM shaft STC from firewall forward. They drill holes in the shaft to allow better oil flow to the lifters , tappet valves, etc.It makes the shaft cost a little more but if there are gaps of time that it is not possible to fly it should extend the life. My thinking was what another 600.00 bucks when I am spending thousands.
http://www.firewallforward.com/

[Green Hornet]

BTW my cylinders were Ok and the crank shaft was polished but I did have to overhaul the oil cooler, flush the prop, new bearings, bottom line everything @ 11.5K $$
Put a trickle charge on your battery because after 45-60days the acid will eat the cells and you'll need a new one.

[a64pilot]

If I were overhauling again, I would find out if Lycomings roller cam can be used. It couldn't a couple of years ago, but maybe it's available now.
If not then you have to decide if you are going to replace your cam or have the old one re-ground. Lycomings position is that most of the problems come from re-ground cams. Maybe they have a point, who knows?

[Ian]

THanks for all the responses.

Here is what we found and what we are doing. I have removed the engine and completely torn it down .The crank shows no signs of metal in bearings and my mechinc feels good about the rod bearings so we are leaving them attached. We left the pistons in the cylinders . The rear double cam lobe was shot and the associated lifters are spalled. There were signs of impending failure on the other lobes as well but it had not progressed as far as the bad lobe. My mechanic ,who I trust , is letting me do the work under his watchful eye. We are going to replace the cam and lifters , main bearings, oil pum gears as one is aluminum, flush the oil cooler and governor the reassemble with all new gaskets and hardware. I have thoroughly cleaned flushed crank case parts and painted. I spoke with a couple of engine mechanics on the field both with decades of experience and there response was that they both had done similar repairs frequently in the past.

The total parts bill is 2500.00 . I had already replced or overhauled every component on engine in the last 2 years. Prop is new as well. Since I am doing the lions share of the work the labor cost is minimal.

I will keep you posted.

[Ian]

Just an added point regarding the planes history. It lived in Long Island outside so as far as corrosion it is not surprising. It still lives outside in Nashua NH but I run it regularly at least 90 mins a week.

[a64pilot]

Ian, is it an IO-540W1A5D ? If so be double sure you get the right oil pump gears, the (D) at the end of the engine nomenclature complicates things if it is. If it's not a (D), then unless I'm wrong there was an AD on that aluminum gear.
The (D) is the one with one big mag, not two seperate mags.

[Ian]

Hi

It is a d , ie one gig mag-What a boner of an idea that is - defeat the purpose of dual ignition. I have the one aluminum gear. What is complicated about the oil pump?

[a64pilot]

I think the gears in the (D) are different from other 540's. It's been a few years since I overhauled mine, but a couple of different people sent me the wrong gears a couple of different times. Don't just buy gears and set them aside and then grab them when it's time or you will likely add some time to you overhaul while the right ones are sourced
And that darn dual mag cost more to have overhauled than an exchange one would. I want to think it has an AD due every 500 hours, it may only be a SB, but people that would know tell me to have the mag overhauled every 500 hours and I will save money in the long run.
If it helps, if any of the gears in the acc. case break, your losing both mags whether they are in the same case of not.

[UP-M5]

the dual mag lycomings do have completely different oil pumps than the standard lycs. no more complicated or hard to get than the standard mag engines. just make sure you order parts for your model and suffix engine, and you are golden.

the lycoming roller cams are only available by having your engine factory overhauled. they are not allowing them to be installed by anyone else. there is some machining that has to be done to the case.

i second the recommendation for the firewall forward centri-lube cam. since you are replacing it anyway. i put one in mine, as it sounds like good insurance.