Newbie Question:
The O-360-A1A in my new-to-me RV-6A is equipped with a Sniffle Valve. This part on a carbureted engine seems contrary to the guidance for use. Being new to RV's, are there other useful reasons to have the valve on this engine?
- Chris
It is needed on the injected engines
With one minor exception - those of us that have installed the SDS or EFII systems with electronic injection. Those are positive-stop systems and won't drain fuel on shutdown, hence no need for the sniffle valve.
I believe it's also not needed for the engines with the Airflow Performance bypass valve systems - at least that's my limited experience, nothing substantial coming out of the sniffle valve. Unless of course you leave your aircraft out in the rain, and you fill up the intake with water...
I ran a standard Bendix injection with the AFP purge valve for a few years before installing the SDS. It definitely reduced the amount of boil-out, but you still dump the volume of fuel that is in the divider itself and in the spider lines. That's enough, in my opinion, to warrant the sniffle valve on that setup - at least I left mine in place. YMMV.