Rob,

 

It ends, really!

 

If I remember correctly, an oil operated prop will have a line from the accessory mounted governor (nothing more than a oil pump that increases the oil pressure under regulation) to a point on the case just aft of the forward prop seal (unless the governor is mounted on the forward case itself).  As the crankshaft rotates there is a port that would allow oil to enter the forward part of the crankshaft.  Aft of that port is a step in the interior of the crankshaft and a plug (the shape of a bottle cap) that is force fit with the cap edges aft into the step so the oil pressure would help keep the cap in place and the rest of the oil (under pressure) would go forward to regulate the prop.  In other words, do not remove the plug that is about 4" deep in the shaft.  If this were a crank for a fixed pitch prop, it would be solid or there may be a different plug for a constant speed crank used in a fixed pitch environment.  So, where is the plug or what kind is it? 

 

If you have the fixed pitch one at the very front of the crank, see a mechanic that actually knows something and do not listen to me (I played a mechanic on TV and stayed at a Holiday Inn Express).

 

If the plug is the one I mentioned, also make sure the sealing o-ring is in the prop part that slips over the crankshaft.  Run the engine and exercise the prop (the first time may take a while to get rid of the air in it).  If it doesn't work right (eventually go to coarse pitch), something is wrong. When you are through fooling around, remove the prop whilst over a 5-gal bucket as oil will want to come out - then empty the prop into the bucket and rest it on the bucket (or garbage barrel).  Stuff a rag into the crankshaft, take off the cowl, wrap the engine compartment in plastic, and get the dang thing painted.  Oh yeah, don't touch nutt'n until it cools...........

 

Grayhawk

 

PS, to remove the plug, drill a hole in it to get something behind it to pull on....... Don't plan on reusing it as they are cheap.

 

Guys -

I'm planning on running my Lycoming IO-360-B1F engine for the first time this summer, then sometime later removing the propeller and trailering the aircraft for painting.  With my trailer setup, it is better if the prop is not installed because the air causes the prop to rotate.  Plus, rocks could ding it up on the road.

According to a Lycoming Service Instruction (number 1435, dated 1986) there is an expansion plug at the front of the crankshaft which must be removed in order to get oil into the constant speed prop.  Apparently the plug stays in place if using a fixed pitch prop.  I have an MT 3-bladed oil controlled constant speed prop.  My engine already has the prop governor oil line installed.  In fact, the governor is mounted as well.

Two questions:

1)  Must the expansion plug be removed if the engine is only going to be idled at 1000 RPM for one minute and no attempt will be made to cycle the prop?  (In other words, will the prop be damaged if it is not supplied with oil?)  If so, how do I remove it -- short of poking it with a screwdriver and prying it out?

2)  If I do need to remove the plug to run the engine, can I just put it back in when I remove the prop?  Do I need a new one in order for it to seal properly?  (Obviously, if I poke it out with a screwdriver I'll need a new plug anyway...)

Thanks in advance.

- Rob Wolf

p.s.  I thought I was very close to running the engine until I made a list of everything I need to do first.  It's three pages, single spaced.  Sigh.  It never ends....

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