Question about Factory Inverted Oil installation

[Bradc16]

Does anyone have photos they can share of their oil sump and the connections to it for a 70's era IO-320?
My mechanic is wondering if he is looking at something that Bellanca did or if it is someone else's creation.

Specifically it is the oil line connections to the sump that are in question.

 

[Bartman]

Hi Brad

There was an early version that Bellanca designed and then the Christen system that is now sold by Lycoming. If you have a large whitish tank in the upper right area of the firewall it's probably the Christen system. The Christen system also has a shuttle valve that uses a ball to block off the oil return paths depending on if the plane is upright or inverted. If you have a smaller aluminum oil tank and scavenge pump, then it's the earlier Bellanca system. Have any photos you can post?

 

[Bartman]

here's a diagram of the basic Christen inverted system

 

[Bob Turner]

The Christen system has a weak point.
The pump sucks not from the sump directly, but from the ball check valve assembly. In order for that to work, there is a plug in the sump that blocks the suction. The plug has a single O-ring. It should have had two.
You will note the failure when you roll inverted and oil pressure drops to zero and stays there.
Mine has failed twice in 18 years. O-ring is maybe eight bucks - shipping and handling can drive that north of $40 if you do not carefully select your supplier.

 

[Bob Turner]

Oh - the maintenance manual describes both systems. Study that while you are looking at the hoses. If it is Christen, you are in luck.

 

[Bradc16]

Thanks for the replies! Yes our plane has the Christen inverted oil system, I should have mentioned that but I didn't realize there were other options.


This fitting welded into the sump seems odd and is specifically what is in question. There is also the cap over the tap just above it in the accessory case that seems odd.

Our mechanic pressure tested it today and it doesn't leak so this is really just an academic question at this point.

 

[Bartman]

Thanks for the replies! Yes our plane has the Christen inverted oil system, I should have mentioned that but I didn't realize there were other options.
View attachment 4334

This fitting welded into the sump seems odd and is specifically what is in question. There is also the cap over the tap just above it in the accessory case that seems odd.

Our mechanic pressure tested it today and it doesn't leak so this is really just an academic question at this point.

what year is the plane?

 

[Bradc16]

It’s a 1974 150HP CS

 

[Bartman]

@Bradc16

I think you might have a Bellanca system oil sump and that a previous owner might have switched the engine over to the Christen system without really thinking through the conversion beyond removing the old and hooking up the new.

It's a bit of a stab in the dark but you might want to investigate that possibility. I'm pretty sure the '74 models still had the Bellanca system.

 

[Bradc16]

Thank you again for the replies.

 

[champ guy]

I am kind of late reading this post. My 76 150 CS has a Christen system. This airplane has been sitting for ten years inside. Are there things to check out other than the "o" ring on this system?
Also, I am looking to has a new set of Teflon hoses made for this engine and fuel system. It has a Harrison oil cooler and a Style "J" emergency fuel pump. Does anyone have a part number list that I could get to Aircraft Spruce to build those hoses? Chad at ACA was going to look them up but has not got back to me yet. Thanks

 

[Big Ed]

I am kind of late reading this post. My 76 150 CS has a Christen system. This airplane has been sitting for ten years inside. Are there things to check out other than the "o" ring on this system?
Also, I am looking to has a new set of Teflon hoses made for this engine and fuel system. It has a Harrison oil cooler and a Style "J" emergency fuel pump. Does anyone have a part number list that I could get to Aircraft Spruce to build those hoses? Chad at ACA was going to look them up but has not got back to me yet. Thanks

I'm told the best way to work with the Spruce hose vendor is to box up your old hoses and send to them. They will send you matching new ones in return.

 

[champ guy]

That makes sense, thank you.