External Oil Line on TMX IO-360

I have a TMX IO-360 Engine that is fitted with both a hollow crank and an external oil line that goes from the nose of the engine to the prop governor pad on the aft end of the engine.

In my case, I am hanging a Catto (fixed pitch) prop on the engine. It has been suggested that I need to remove this external oil line and cap it off in a fixed pitch application.

This is the first that I have heard of this.

What have others in this situation done.

Dale
DAR scheduled for Friday.

I paid Mattituck extra when I ordered my IO-360 just for this setup. If someone buys the plane in the future -- or if I decide to spend the rest of the money i was going to leave my kids when I die -- switching to a CS prop will be a little easier. Nothing needs to get capped and the line doesn't need to be removed.

I believe that for a fixed pitch propeller, it is necessary to pierce a 1/8" to 3/16" hole in the plug behind the oil return tube, and to install an expansion plug in the front of the crankshaft, but I don't believe that's what you're talking about here..

Dale,

Don't pierce anything!!

If you are using a fixed pitch prop you will have to insert a bung in the front of the crankshaft to prevent oil spilling out. That oil must go somewhere - and down the external line is the best place. Ask the engine builder to confirm that the engine is fitted with a governor pad cover plate that allows oil to flow in (in a constant speed set up it normally flows out).

Using this set up will mean it is straight forward to convert to constant speed if you ever want to go down that route in the future.

If you don't use the external line to route the oil back to the sump it is necessary to pierce the rear crankshaft bung - but that is difficult to install so is a one way trip. If you ever wanted to go c/s then you would likely be in for an engine strip and rebuild to insert a new rear bung.

Pete

penguin said:

Using this set up will mean it is straight forward to convert to constant speed if you ever want to go down that route in the future.
If you don't use the external line to route the oil back to the sump it is necessary to pierce the rear crankshaft bung - but that is difficult to install so is a one way trip. If you ever wanted to go c/s then you would likely be in for an engine strip and rebuild to insert a new rear bung.
Pete

Click to expand...

While I agree that this is the best practice, the "piercing" of the rear plug is NOT a "one way trip". It's not that difficult to replace the rear plug when necessary.

If you told Mattituck that the engine was to be a CS engine but set up for FP then you should be all set. However if you told us you wanted Constant speed then you will need to either replace the governor pad or pierce the rear crank plug. Disconnecting the line and trying to blow in both directions into it will tell you if you are set up for FP. There should be a fairly unrestricted path for your breath in one direction or the other depending in which way the nose bore of the crankshaft was vented. Free flow towards the crank means the rear plug is missing or vented and free throw toward the gov. pad means the cover plate is the trick.
Good Luck,
Mahlon