Transducer location

[dustman]

Hello all, hopefully a simple question. Is there a problem mounting the oil press sending unit and gas preasure sending units directly to the engine as opposed to connecting them thru piping of some sort?

[Pat Hatch]

Originally Posted by dustman

Hello all, hopefully a simple question. Is there a problem mounting the oil press sending unit and gas preasure sending units directly to the engine as opposed to connecting them thru piping of some sort?

Yes, this is a common mistake and can cause a real problem. The vibration will eventually break the pipe fitting connection on the sending unit causing a major oil leak. Thus the reason for mounting it remotely!

[elippse]

I have mine mounted directly to the engine through some pipe fittings but I have a bracket that holds it securely to the engine.

[RKellogg]

We have seen a high functional failure (won't work) but no leaks with transducers mounted directly to engines... something about the vibration fatiguing the diaphram, maybe. There may be a way to make it work, just a question of how experimental you want to be. The hoses, brackets and fittings for a remote mounted transducer certainly adds potential failure modes, and several feet of firesleeve. Easier to run wires than hoses. There must be a pezioelectric transducer that would laugh at the shaking that Lycoming / Rotax gives it... - Roger Kellogg

[MontanaMike]

Just went through this with Electronics International, whose installation instructions clearly state... do not mount their pressure transducers directly to the engine, or to a manifold, but remotely, using flexible hoses. I consider the manifold prohibition unresolved, however.

I will add that restrictor fittings located on the engine have been long been recommended on this site for the engine hose feeds to the transducers, reducing the risk of catastrophic failure if the hose or transducer fails in flight.

Montanamike
RV6 N918MB Phase II