lycoming question

[JimWoo50]

I have a disassembled 0-320-B3B in the basement and am finally at the point of putting it all together. I noticed that the case halves were assembled and looked into the overhaul manual and saw that a special plate like tool is used to seperate them. The description of this tool is somewhat vague as is the use of it. Does anyone have any further info on this tool and how to use it?

[Shine'r]

Jim, just completed putting my 320-B back together so I might be able to help a little. You only need the tool if you have the narrow case (you can tell its a narrow case if the cylinders are held on with heavy plates and the cylinder nuts are like allen heads.) What the tool does is tighten down on the studs pushing the through bolts out along with spliting the case. You cannot get the case apart without some type of spliter. You can make one yourself if you have the tools. I'm not sure but Lycoming may have a loan/rental program where you could get it from them. If you look at the case and determine which are the studs and which are the through bolts you will understand what I'm saying and what the tool does. DO NOT TRY AND USE A SCREW DRIVER OR ANY TYPE OF TOOL TO DRIVE BETWEEN THE CASE HALVES, YOU'LL END UP BUYING A NEW CASE. If you have more questions e-mail me at jasperg@nationwide.com.

[JimWoo50]

I do have the narrow case and will need the tool i guess. It appears to me that the tool fastens to the studs on one side and pushes the through bolts out of holes in the plate on the other side when tightened?

[Shine'r]

Thats about how it works. But the tool fastens on one side and pushes the through bolts on the same side. The part your having a problem with is you have to extend the studs long enough to get the tool on top of the through bolts to push them out. You only need to push the bolts about an inch or so. You can make your own tool if you can't find one, like I said, once you understand what your trying to do.
Shine'r (Sunny, Warm, Pittsburgh, Pa.)

[JimWoo50]

I'm wondering if I could put nuts on the threaded end of the through bolts and tap on them with a rubber or rawhide mallet and loosen the bolts enough to pull them out and thereby split the case? Or just tap them out without the nuts?

[Rivethead]

You would be better off by making yourself the tool you need. A plate of steel and careful measuring would work well. If memory serves me correctly you will need to use it to draw the case halves together. Using the tool allows you to tension all the studs and evenly push the case apart. Pounding the studs in order to push the case apart sounds like a recipe for disaster.

[rgbewley]

The collars on the narrow deck collars are really tight. Best to rent the tool from Mahlon. It really won't budge without the splitters, especially. You can make the splitters, but don't frustrate yourself and risk damaging the cases and/or crankshaft by trying it without.

[Shine'r]

Jim the short and long answer in "NO." You cannot pound them apart without breaking something. The case has dowels on one side that press fit into the other side. You need some kind of tool to push, pull or spread them apart.
Shine'r (Sunny, Warm, clear air, Pittsburgh, Pa.)

[JimWoo50]

and the tech pounded the through bolts with a plastic mallet thereby pushing the case halfs apart. He looked at my case and said he has never seen a case like it. I thought I was buying a 0-320 b3b but now am unsure. He noted the breather was on the front of the engine; something he says he has never seen and also the oil pickup was on the opposite side of what he was used to seeing. He said my case was possible from a ground power unit. I am having a hard time accepting his diagnosis. How about a little help? How can I positively identify my case?

[Mark Burns]

Originally Posted by JimWoo50

How can I positively identify my case?

Just give Lycoming a call. Of course you will need the serial number of the case.

570-323-6181 from 8 AM to 5 PM (Eastern Time) Monday - Friday.

They have always been super nice and helpful to me.

Mark