RV-10 Annual Finding

Just a heads up on something found during this years annual.

Not sure if these lines are oil return or oil supply, but the rod that holds the baffles against the front and rear cylinders had the plastic slip off and started rubbing a hole in the aluminum.
Here is a shot of this part when I was building the plane.



Zoomed In:


It affected two of the lines that I will have to replace.




This is actually something I check at every oil change because I have been nervous about something like this happening but it always looked great. This happened in the last 50-100 hours. I will wrap the hole rod this time with plastic or tubing of some kind.
Just something to check when that bottom cowling is off.

I would guess it was 1/2 worn through and it made me think how long it would of held oil pressure until all the oil was gone if it wore through. I have read quite a few cases of these lines cracking and they catch it because of oil all over the ground.

Good eye Scott. I will keep this in mind when I get to the engine installation on my -10.

Good eye Scott.

These are oil drain back lines, dont see any pressure to speak of.

I RTV'd the plastic to the oil lines where they touch, to keep it from moving. Not sure how/if that'll hold up, as I'm not flying yet.

-Rob

RV10Rob said:

I RTV'd the plastic to the oil lines where they touch, to keep it from moving. Not sure how/if that'll hold up, as I'm not flying yet.

-Rob

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That's what I do - no problem since I found similar wear early on! Very common Scott.

I may not be seeing this correctly however it looks like the plastic covering the baffle rod is only an inch or so long positioned under the return line. The plastic cover should run the complete length of the rod.

Pat

10 annual

I have two suggestions,

First will the rods slip between the cylinders and the drain back tubes.
If not I used aluminum tubing used for brake lines with safety wire and eliminated the rods altogether

Stripes

Easy Fix

It is an easy fix and just the RTV or silicon would have kept the spacers in place which is how the plans show it.

It was just one of those things I never really liked but for the first 600 hours it looked perfect everytime I checked it.

Many easy fixes, I just posted to bring attention to others out there flying.

ScottSchmidt said:

------ I just posted to bring attention to others out there flying.

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Thanks for doing that, we all benefit from these type of things.

I used a tygon hose to cover up all the rod, I thought tygon was soft enough to not damage the aluminum tubes, I am going to inspect next time the lower cowling is off.

Holes rubbed thru the drain back lines generally only cause an oily mess in the cowl, but could theoretically contribute to a fire if enough oil drips onto a hot exhaust pipe.

Best practice is to simply never allow anything to touch those lines that could rub a hole thru them.

Also nylon zip ties directly on them is a no-no too. If you must zip-tie some wires to them for support of the wires, wrap the drainback tubes with a layer of silicone rubber tape (the kind that sticks to itself like this: http://www.acehardwareoutlet.com/productdetails.aspx?sku=3073533) first.

This is a common problem on Lycoming type engines. I would recomend throwing those away as they look like they are more than 10% worn as per 43.13. As stated above when they break they can cause a fire but also they will empty you oil resevoir. When you install the new ones you will notice they don't fit. You have to bend them to make them fit. Continue bending them till they clear. You might also have to reposition the fitting on the cylinder head. Do the pre fit before you put on the rubber tube.