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IMHO you're holding your engine by the wrong end... the plug, pierced or not, plugged or not, present or not, is to be looked at from the propeller flange side, the front of the engine as seen when it'll be pulling your craft, which by coincidence is the place your carton paper rag gently rests.
Will you be using a constant speed prop or a fixed pitch. That is the first and foremost question. Normally, you remove the front plug for a Constant Speed prop but leave the rear plug in. For a fixed pitch, the normal way is to remove the front plug. Punch a hole in the rear plug, then install a new front plug in the crankshaft. However, if using a fixed pitch, but planning a CS in the future, there is another method that does not require doing anything to either plug. This assumes that the CS prop governor mounts at the rear of the engine, not the front. DM me for all the details. The post above this one, is referring to the same method I mention.
These photos show fittings in the back and front for a constant speed prop and a stainless steel line for a constant speed prop. Only way to know what you have is to remove the front plug and check to see if there is a rear plug. Rear plug needs removed, pierced, or the allen plug in it removed. IF the rear plug is not installed, you will still need to reinstall a new front plug.
There is a govenor cover plate with a bypass machined into the face to relieve oil pressure from the propeller hub for FP installations,
That is not correct. Leaving the governor line in place with the Proper governor cover plate is an ALTERNATIVE to piercing the aft plug as described by Mahlon and others. It greatly simplifies possible future installation of constant speed prop. In this case no need to check the rear plug at the front main bearing. For a fixed pitch in the OP configuration it does not matter if the aft plug is solid.
Same here
Have a CS prop.
It's fine to use a hollow crankshaft swinging a FP prop, but can I ask why you didn't go with a IO-360-M2B (solid crankshaft) engine unless you plan on upgrading to a CS prop in the future? There's no crankshaft inspection required for the -M2B (solid crankshaft) engine swinging a FP prop. I have a solid crankshaft O-320-D2A (i.e. D2A) swinging an all metal Sensenich FP prop. A solid crankshaft swinging a FP prop avoids Lycoming Service Bulletin No. 505B.
Great reference. Mahlon works for Mattituck, now part of Continental. If Mahlon says it, bank it! Since the engine was shipped with a rear governor mounting pad and the tube running from that pad to the right/front of the crankcases, nothing needs to be done when using a fixed pitch prop. Remove the front plug if using a Constant Speed prop as shown in the drawing below.
Wasn’t an option through vans
I got my engine from Aero Sport Power, and they had both crankshaft types. If I recall on a previous engine install we did for an O-360-A1A (A1A hollow crankshaft), we didn't have to do anything because it already came with the front plug in place. But, to be certain, I would contact Vans Tech Support to verify -- Lycoming might have changed that configuration.
Can you post a photo of the very front of your crankshaft? It's covered-up in your other photos.
That is wrong. It is not about stagnating oil. Oil makes it way into that cavity via the clearance in the nose bearing, even when oil is not being fed their by a gov. That oil is at 80-100 psi. If you don’t provide a path to drain that oil, it will blow out the front plug and ruin your day. As others have said, a properly set up system with oil supply line, that will act as a drain.
Have you read and understand SB 505B using a FP prop? There were crankshaft failures due to this where the prop departed the airplane, and that's what I'm talking about here. If the drain back line, rear cover plate and forward crankshaft plug is installed, why would that cause a problem?
I understand the corrosion issue. You asked why you need to pierce the plate. I explained that some type of drain is required to avoid blowing out the front cap and that is why we pierce the rear cap. And,yes, I explained that a properly setup line will also do that. Also, that is not a drain back line. It is the line that lets the gov “supply” oil to the cavity, thought it will also drain when the gov allows it to do so.
So, without a prop governor installed to supply pressure, and the proper plumbing line installed, then essentially you only have drain-back in a FP prop setup -- right?
No, there is ALWAYS oil migrating into the cavity. I am not going to Take the time to explain the entire oil circuit. However, oil is always moving across the bearing clearance area and gets to the cavity. This is why the SB applies to all hollow cranks, not just those with CS props installed. If you do not provide some way to drain this oil that collects in the cavity, It will eventually build up pressure and create issues.
Not so simple to replace that rear plug! BTW -- SB 505B primarily applies to fixed pitch prop setups (i.e. the one's that have experienced broken crankshafts from internal corrosion) -- I remember when they occurred, starting with a Piper Warrior at Aspen Colorado that lost a FP prop. Heading out for another long cross-country at the moment, so we can do some "real RV flying" instead of armchair RVing.
Catch you later lr172.
