[scsmith]

I bought an overhauled IO-360-A1A (angle valve) and I'm almost ready to mount the prop on. I discovered an odd thing. I wonder what knowledgeable engine folks think about this:

Normally, for fixed pitch prop, you have the front freeze plug in the end of the crank, and the interior of the crank open inside. For constant speed prop, you remove the freeze plug and put a different plug in the back of the interior cavity. The angle valve engines have a provision for the interior plug that is simple, its just a 1/8 npt pipe plug. So, I pulled the front plug out and was ready to install the pipe plug inside.

Anyway, I just found that the overhauled engine came from the builder with BOTH plugs installed! I'm assuming it was run on the test stand in this configuration, and that worries me. The chamber between the two plugs has an oil transfer tube that is to primarily allow oil to move through the prop governor supply tube into and out of this chamber, but I wonder if it also provides oil to the front bearing and seal? Would it be really bad, or no big deal, to run the engine with both plugs installed?

I've written the builder, am waiting for reply, just curious what you guys think?

 

[Mel]

Normally the rear plug is installed for F/P operation and the forward plug is installed to preclude oil drips during shipping.
For F/P, you need to puncture or remove the rear plug and replace the forward plug. For C/S, leave the rear plug installed and remove the forward plug.
To run the engine with both plugs installed will work fine for a time, just not a long time. I've seen them run for over 70 hours this way.

 

[scsmith]

thanks Mel

You make me feel better to hear its probably OK even if it was run that way. I did wonder if they could have put the front plug in after running for shipment, and I asked them about that. We'll see what they say, but you have made me much less concerned.