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Oil Pressure Sender

E

echowhiskey

Member
I bought my 6 with pressure sensor mounted to end of a short copper tube very small ID, maybe 1/8.

Someone mentioned to me that this will work harden and fail over time. The plane is a quality build with engine overhauled 400 hours ago.

Is this something I should worry about or is this common on other lycomings?
 
Yes, you should be worried. Thin wall copper tube can work harden and crack due to constant vibration and the flexing that it can cause. This is very non-standard and should be replaced with some type of braided rubber or PTFE hose.

A broken OP sensor line can result in a complete loss of oil and engine seizure.

Larry
 
Common aviation practice is to have flexible (braided) lines from the engine to remotely mounted sensors, for both oil and fuel pressure senders. Vans has a manifold (VA168) that mounts to the firewall where senders can be mounted. Also most engine instrument mfgrs suggest in their installation manuals not to mount pressure senders directly to the engine.
 
I am just trying to wrap my head around this. Automotive and marine engines have sensors directly mounted to engines. What makes it an issue with aviation?
 
Restrictor

And make sure there's a restrictor in line in case of failure, it restricts the flow.


Automotive and marine engines normally don't leave the earth... :rolleyes: but there's probably a better reason that our oil pressure sensors are not directly attached to engine... :D
 
Sorry to say I m recovering from a Prostatectomy. Happy to say the prognosis is good. But man I feel old. Anyhow, can't get down to the bird but want to get the parts'

I found a restrictor at Spruce, its 1/8 npt to an4 , sound right? what are most using for the line out to the sender from there?
 
Why is aviation different?

echowhiskey said:
I am just trying to wrap my head around this. Automotive and marine engines have sensors directly mounted to engines. What makes it an issue with aviation?
Click to expand...

Because when an engine fails in a boat or car, the vehicle is reusable afterwards? I had a car with a brass fitting mounting a sender to the engine, and it broke as I was driving down the freeway. Pulled off, no damage done.

I've got the restrictor (VA-128), the Van's manifold (VA-168), and the Van's braided "aeroquip" hose (VA-133) from the restrictor to the manifold.
 
Hoses

I didn't build my plane. This thread has me worried. My sensors are mounted to the engine mount and I have the copper tube to both. Does anyone know where I could get the braided hoses? Good quality of course.
 
Tooch,

Certainly. I would go with lifetime teflon-lined hoses from TS Flightlines, fellow VAF'er Tom Swearengen. Superb quality and excellent customer service. He can walk you through it if it's your first hose gig. You will be very pleased.

https://www.tsflightlines.com/
 
Its pretty easy actually. Just take the original copper tube, measure it --if you are happy with the location of the sender-- and replace the tube and the appropriate adapters with a hose.
Not a huge deal. Probably the best thing to do is use the VA168 and locate all the senders there.

Tom
 
Finished product
 

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echowhiskey said:
I am just trying to wrap my head around this. Automotive and marine engines have sensors directly mounted to engines. What makes it an issue with aviation?
Click to expand...
Mounted directly to the engine, the sender has some moment of inertia that's hanging off there by the nipple, and the high vibration of our aviation engines can cause it to resonate and snap off resulting in loss of engine oil.

I know of at least one accident as a result of that. Just completed Questair Venture (who remembers those?) on a ferry flight to it's new owner. Fortunately the builder-pilot survived the crash-landing. But the plane, not so much.
 
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