OK.. Confession time.

John Courte · #1 08-10-2008, 10:32 AM

Last week I bought a mid-time O-360-F1A6. The owner drove it down from WA in the back of a pickup truck, tied down properly, as far as I could tell. I hacked up an engine stand from the directions on mikesplayground.net and it seems to be working great. I'm able to rotate the engine and I've already taken the starter, the vac pump, and the old Cessna baffles off.

But here's the problem: I don't have the first clue as to what to do next. I'm also scared stupid because after pulling the spark plug, there was a nice fur of rust around the bottom of the plug, but a look inside the open exhaust valve shows a shiny, hone-patterened cylinder. What's the process for getting this engine looked at by someone who actually knows what they're doing, and assessing the costs to make it airworthy and preserve it until it's time to hang it?

I'm also a bit lost in the woods because my air compressor is down at the moment and there's not a lot of places I'm currently working on inside the fuse where my cordless drill will fit.

rv72004 · #2 08-10-2008, 10:36 AM

Before you carry on, spray some oil down the cylinders etc. Will inhibit corosion.

Yukon · #3 08-10-2008, 10:44 AM

Hire a licensed aircraft mechanic to compression check it, open the oil filter and dial the crank. (about $100) If it's all good, spray WD-40 in all sparkplug holes, install descecant plugs in the cylinders, put fresh oil in the crankcase, rotate the engine physically upside down so fresh oil will coat the camshaft. Should be good to go in a couple of years.

N395V · #4 08-10-2008, 11:14 AM

Do whatever is necessary to get a look at the cam. If there is rust anywhere that will cause you a big problem down the road it will be on the cams.

Doug Rodrigues · #5 08-10-2008, 02:42 PM

Is this a high time engine, or one of those underwater Katrina engines? On one of those Katrina engines, I asked the seller if he had drained the water out of the engine in the three months since? He said that the thought never occurred to him! I passed.

Check for even a light hint of rust on the cylinders (which would eat up the rings). Use a brass brazing rod with a piece of white cloth pinched to the end of the rod. Insert that into the spark plug hole and rub the cloth against the cylinder wall. If there is any rust, it will plainly be seen on that white piece of cloth. If you find ANY rust, you should pull that engine apart and rebuild it. It doesn't take much to pull a cylinder off. You can check for proper ring gap at that time too. Perhaps even pull one rod off and measure the out-of-round on the rod journal. The maximum service limit wear would be .0005 (a half a thousands). Once you get it apart, you may luck out and find everything within service limits or better. You may be able to just hone the cylinders, install new rings and bearings, new oil pump gears, send the crank out to polished and getting the counterweights rebushed, having the lifters refaced, etc. It only costs a few hundred to get the Cam resurfaced. If the engine was in worse than serivce limits wear, would you want to fly it anyway? Not me. At least you don't have to worry about an RPM prop restriction.

Magnetos are easy to rebuild. Just don't go flipping the mag shaft over to see if you get a spark. Doing that can cause a ruined coil by arcing the spark through the coil's insulation. I did that once with a brand new coil! Also, don't put the magneto shaft down on steel or iron. It will cause a loss of magnetism and the resultant weaker spark. There isn't that much to rebuilding the engine. Just make sure that everything is perfect when it goes back together. It's a good learning experience.

This is coming from a guy who just simply cannot go out and buy a new or rebuilt engine. I'll have to do it on the cheap.

John Courte · #6 08-10-2008, 03:05 PM

It's got 951 SMOH hours on it and was pulled running from a C172 RG back in 2001. The previous owner says that he kept it flooded with oil, but after checking the condition of the spark plugs, I'm not so sure. The cylinders look pretty wet, he says he drained it before bringing it down to L.A. from Camas, WA.

Is there any way to get a look at the camshaft without tearing the engine completely apart? I really don't have any special lyc engine tools either, so I'm not even sure if I can pull a cylinder without the special jug wrenches. How do I check for service limits, do I start calling A&P's and see if they make house calls?

It really is amazing, the coyote-off-a-cliff feeling I've got with this project. I presumed I knew just enough to get by and learn what I didn't know in the process, but I haven't hit a wall like this before.

I do have 8qts of Aeroshell 50 and two quarts of preservative oil, along with dehydrator plugs, but should I repickle the engine before I find out more about it?

AlexPeterson · #7 08-10-2008, 03:09 PM

You sure it is rust on the plugs? Might be brown deposits - just a thought.

RScott · #8 08-10-2008, 05:33 PM

Can't help you with your rust question, but a couple other things come to mind that need to be addressed.

I called Lycoming when I got my engine and they said they had never evaluated whether storing the engine with it hanging horizontally from the prop flange was OK. I was asking because I was concerned about the stresses of all that weight hanging way out there. They preferred that they be stored vertically.

Secondly, I asked about preservation--it was a used engine and didn't have preservation oil. They said to fill it entirely with the cheapest auto oil I could find. It took just under 7 gallons. I was also warned that it would leak a little and it has leaked maybe one tablespoon in 5 months.

John Courte · #9 08-10-2008, 05:51 PM

it's hanging from the dynafocal mounts, not the prop flange.

7 gallons? not quarts? Wow. But I guess that's all the way to the top of the case, which would make sense. And are you storing it upside down as some have suggested?

Doug Rodrigues · #10 08-11-2008, 03:39 AM

Hummm. Sounds like you don't have any engine building experience with automobile or airplane engines. Maybe there is an EAA Chapter near you and someone who can give you good advice on the engine. Really...most small airplane engines are easier to work on than modern automobile engines, but you have to at least know the basics. One basic is to measure tolerances and have the tools to do it. It's all pretty much easy if you just take one section of the engine at a time and know a few basic rules and use common sense. Once you learn, you'll then look back and realize that all it took was for someone to show you how. They teach you, and then you teach someone else.