Lycoming "Piddle" valve

sf3543 · #1 12-07-2005, 10:21 AM

I have always had carbeurated engines in the past, but now I have the ECI Titan IO360 with the vertical induction system.
I was told I need to install a "piddle" valve in the the plugged hole on the bottom of the sump.
Apparently this is not the official term for the device.
Can anyone shed some light as to what this is, where I can get one and what it's function is? (I think it has something to do with keeping from flooding the induction system with fuel, but.....)

sf3543 · #2 12-07-2005, 10:24 AM

Correction on my previous question...the sump is a HORIZONTAL induction with the forward facing servo!!

Davepar · #3 12-07-2005, 10:32 AM

I think it's called a sniffle valve. And I'm not sure what its purpose is either.

flyeyes · #4 12-07-2005, 10:34 AM

Ooh, I know this one.

The part you want is a Lycoming sniffle valve, part number 75444.

It allows excess fuel to drain out of the induction manifold, e.g. on a flooded start. It has a flapper valve that shuts so it doesn't become an induction leak when manifold pressure is less than ambient.

If it doesn't work properly, it can cause a rough, surging idle (go ahead, ask me how I know...).

James

Allen Barrett · #5 12-07-2005, 10:43 AM

You can also get one from Airflow Performance, or I stock them as well. Definitly need one

sf3543 · #6 12-07-2005, 10:46 AM

Thanks for the quick responses.
After I posted I thought...why not call the engine dealer where I got the kit and ask them...so I did.
Same answer as you guys, but he called it a Wiffle valve. Go figure.
When the engine is off, sitting idle, the valve is open and allows stuff, like moisture or excess fuel, to drain out. When the engine is started, the vacuum in the induction system pulls the valve closed.
He said that 90% of the FI engines out there do not have it, but it wouldn't be a bad idea to install one. (Another part to go bad!)
So, I now have the part on the way. Why not!!