Hi All,
This is my first time to use the forum and hope there's some expertise out there regarding chafing I have on the oil cooler lines on my 1960 180 SN#1859. Here's the history.
I replaced the original engine with a factory remanufactured one in 1996 and have about 950 hours on it. We also switched from the original hard lines at that time to the insulated, flexilbe, braided Aeroquip type which are quite a bit fatter than the original. But the recommendation to change over from the IA was due to the close spacing of oil line to hot exhaust and because older hard lines can become brittle and crack. The best fit we could achieve was with a 45 degree fitting from the cooler, giving the best spacing.
However, I've had a chafing and wear problem ever since. I've replaced the oil lines once and need to do it again, so this would be the third set. The exhaust pipes vibrate and wear on the lines, so we wrap them with new teflon at annual every year. They also wear against the lower cowl, so that is protected with a stainless patch and more teflon.
Does anyone out there have a similar situation? Or have you fixed a similar situation? I want to find a long term, safe and legal solution.
Thanks all,
Anne O'Brien

Anne,

Welcome to the Forum. There are a number of 180 owners that post here so hopefully someone can give you a hand.

Also, if an answer isn't posted here, the Tech Directors do take private questions and that would be another option. http://www.comancheflyer.com/NS/tq.php

Anne: Its hard to see the way the line is routed by the picture, but sometimes all you need to do is make
the line a little longer and route it away from the hot exhaust pipe. Also a consideration that might come into
play here is your engine isolators, or engine lord mounts. When where they replaced last? Your exhaust should not come into contact with your engine cowl.
If your lord mounts are worn, that would allow extra movement of the engine and sag toward that line.
Have a look around in the engine bay and see if there is a better routing of the oil line than under that exhaust pipe. I am not sure what the legal implications of adding an
elbow joint in that line but that would give you more options, something to ask your AI.
good luck,
Gary

I had a similar problem when I had two new Teflon/fire sleeved hoses made up for my PA24-180. I gave the fabricator the old hoses so they would be the same size. After installation, I noticed they were laying on the cowl about six inches before the oil cooler connection. I cut some silicone baffle seal to partially wrap around the bottom of the hoses and put some small slits near the top edges of the cut baffle seal, I then used zip ties to secure it in place running the zip ties around the hose and through the slits. Later I noticed that the hoses (they were zip tied together about 24 inches before the oil cooler connection) were coming in contact with one of the cam lock receptacles from the cowl nose bowl. I used a double Adel clamp to lift the hoses slightly and attached one of the doubled clamps to the engine mount and the other to one of the hoses. You can’t lift it very much because of the close proximity of the exhaust pipe. I know have about ¼ inch clearance above the cam lock receptacle I then fashioned a very small piece of aluminum to partially wrap around both hoses just above the cam lock receptacle and zip tied it in place similar to the baffle seal, this was to protect the hose if it should come in contact with the cam lock. This is something I check on each preflight to make sure the hoses still have clearance above the cam lock receptacle.
The exhaust is close to my oil lines, but I have never had any contact between the oil line and the exhaust pipe.

Duane

Duane, thanks for the detail, and my IA has done a similar thing. However, this lasts about 5 years until the teflon extra wrap around the braided lines rubs through again. This has been a problem since this engine was installed and the Lord mounts were replaced at that time. They look good now, not saggy. The clearance around the prop and spinner look even and the engine baffles at the top of the engine fit snugly, so it doesn't appear to be a problem with sagging due to old mounts.
It is very tight under the cooler and we seem to have the fittings and cooler lines optimally routed, or at least as best as you can down there. I know what you mean about the rubbing on the lower cowl and we also have aluminum and teflon to prevent wearing through the lower cowl, or conversely wearing through the lines. Sheesh, I don't know how to do this any better, but there must be a better way.
Is your exhaust system original? It seems as though I've seen a right/left system as opposed to the original style cross over design?
Thanks Duane,
Anne

Hi Anne,

I take care of a 180 which has the oil lines routed to the left of the cooler toward the cylinder heads. There are several brackets attached to the rocker cover screws to support the hoses, this keeps them well away from the exhaust manifolds then around the back of the engine to the fittings on the back of the engine. No troubles with burnt hoses.

Clarence

Hi Anne,

My fire sleeved oil lines go directly aft of the oil cooler, under the cylinder heads and above the intake manifolds. They are nowhere near the exhaust. No issues at all.

PatD

Do you have a standard cooler? That sounds very different from mine but I'll look and see if there is an alternative.
Thanks,
Anne

Anne,

Shoot me an email. I have pictures and I think the solution.