[RV10Rob]

After shutting down my engine yesterday, I heard an intermittent "hissing" sound coming from under the cowl. It sounded like compressed air escaping from somewhere. Could this be compressed air around the piston rings (it's a new engine)? I wouldn't think I'd actually be able to hear that from the front. I removed the top cowl, and by then the noise had stopped, and I couldn't see anything amiss. Any ideas?

-Rob

 

[Geico266]

If your engine is fuel injected it is the fuel boiling out of the lines as the engine compartment becomes heat soaked. Normal.

 

[Mike S]

If your engine is fuel injected it is the fuel boiling out of the lines as the engine compartment becomes heat soaked. Normal.

Yep.

Even with the Air Flow Perf system, with the bypass, there is still a bit of fuel boiling off from the spaghetti tubes.

 

[Steve Barnes]

CS prop ?

My IO 540 always makes a kind of hissing sound at shut down. It is oil gurgling through the prop govenor. Another idea too. Could be a snake under the cowl?

 

[RV10Rob]

Thanks for the quick responses, guys. Sometimes it's difficult being new to airplane ownership and new to building at the same time--not that I'm expecting any pity

Given the hissing sound and that my CG is more forward than normal, I've concluded that the most logical explanation is snake under the cowl.

Thanks again...

-Rob

 

[Jerry Cochran]

Just wondering if anyone insulates those "spaghetti lines" and if so, how?

 

[N8RV]

Oh, no ...

SNAKES ON A PLANE!!

 

[rubber314chicken]

SNAKES ON A PLANE!!

Better in the cowl than the cockpit!

 

[Allen Barrett]

Just wondering if anyone insulates those "spaghetti lines" and if so, how?

That's probably not a good idea. If one of them develops a crack you won't be able to detect it.

Allen
BPE, Inc

 

[Greg Arehart]

Oil from the breather dripping onto the exhaust?

greg