Advise sought on E2A crankcase bearing

gorbak · #1 08-28-2006, 10:59 AM

We are looking for advise/information on keeping the front, long bearing in place while closing the E2A case. Any trade secrets?
This bearing is split with two pins holding it in place (in the split of all places).

As you can guess. We overhauled this O-320 E2A, including a "new" yellow tagged crankcase and bearings. We put the engine back together, hung it on the plane, got the prop delivered and......it hand turned too hard to be correct.

After trying to determine what went wrong, we loosened the two thru bolts on the front of the case and...walla...prop turns like it should.

So we spent this weekend taking the engine off the plane and tearing the engine back down to the crank and found that the bearing had slipped when we put the case together, ruining the bearing (new one ordered).
We will accept all information on how we can avoid this costly error (6 hours of time too) with many thanks in advance.

Pat Garboden
Ozark, MO
RV9-A 942PT (reserved)

gorbak · #2 08-28-2006, 09:35 PM

Still looking for advise from an A&P or engine shop with experience with the Lycoming O-320 E2A model. Specifically on how to align and maintain the front long bearing on the pins while enclosing the case.

Thanks,

Patrick N. Garboden
Ozark, MO
RV9-A 942PT (reserved)

pierre smith · #3 08-29-2006, 05:26 AM

No sweat guys, we did it too. I'm assuming that you tried to assemble the case halves with the crank vertical, as per the book. The hard, wrong way to do it.

The engine shop told us to lay one case half down (on a cardboard box or equivalent) and insert the bearing, engaging the locating pin. Next, take a soft lead pencil and make a mark down the length of one of the bearing halves where the edge of the case is, on both sides. This is to determine if the bearing moved as you complete the next step I've listed here.

Next, take hold of two rods and suspend the crankshaft by them while the other two rods hang down in their proper positions and slowly and carefully lower the assembly (two guys works best) while engaging the bearing half that's laying in the case. It should settle snugly and you can double-check the bearing by trying to slide it fore and aft and also try to rotate it. If it's "bedded" properly, you'll know it quite easily.

Place the lifters in their respective spots, all lubed up and lay the cam in place (It'll be timed later).

Remember to place the silk thread on the case that's lying down. We used two threads-one inside the case bolt holes, the other on the outside of those holes.

Lay the other front crank bearing in place, well lubed and mating the crank and first bearing half. Now lower the top case half and evenly, fore and aft and laterally tap it into place, watching the front bearing half for any motion until the case halves meet. Before you put any stud nuts on, the crank can be slightly rotated to check for binding. If you're happy with what you have, start the nuts on and snug up in Lyc's recommended sequence, constantly checking for free crank rotation.

We had "pinched" the bearing on our first attempt with the crank vertical, bolted flange down to our steel work table but hey, bearings are cheap...congratulations for your own overhaul.....take your time and double-check torque values and each other.
Regards,

pierre smith · #4 08-29-2006, 08:53 AM

Brain fade.
If your bearing's split is not in line with the case i.e. 90 degrees to it, place both bearing shells in the case that has the pin in it while it's laying on its side. Mark a pencil line along both bearings at the case split and another line perpendicular to that one on the bearings and the case flat. The long line will help you align the bearings as you lower the crank/rod assembly down while your buddy holds the two bearing shells on the crank and aligns the pencil marks as you lower it. With the two pencil lines its easy to align the bearings fore and aft and align the notch with the pin in the case.
Regards,

gorbak · #5 08-29-2006, 11:42 AM

You are correct that we did try to assemble according to the lycoming book...on the upright engine stand.
The new bearing gets here today and we plan on having this enclosed and back on the plane this week, thanks to your answer to assist the process.

This is a great forum. Very beneficial when we stand in the shop for two hours scratching our chin trying to figure how to accomplish a task. Experience and knowledge is valuable.

Patrick N. Garboden
Ozark, MO
RV9-A 942PT (reserved)