I too have a purge valve from Airflow performance. It is more of a bypass valve that when closed, returns hot fuel from the flow divider back to the tank. What this does is puts cool fuel in the lines above the engine and cools down the lines themselves so you can get started. 100 Octane fuel boils at a very low temp which causes the hot start scenario.
For a hot start, I close the bypass valve and turn on the fuel pump when I am getting in. It runs for a minute or 2 and you can start easily as the fuel and lines are cool. I have sat idling several times whilst my flying compadres have cranked away in the heat trying to get going..
I thought it was a sales pitch to add this to my system, I have since changed my opinion..
Randy
Snarr
235/320
N694RS
"Flight by machines heavier than air is unpractical and insignificant, if not utterly impossible"
-Simon Newcomb, 1902
From: Joseph Czabaranek <joeczabaranek@gmail.com>
To: lml@lancaironline.net
Sent: Monday, August 15, 2011 5:40 AM
Subject: [LML] Re: Purge valve
Ive got one from Airflow Performance. I love it. 60-120 seconds of purging and I can start any time in any temp.
On Sun, Aug 14, 2011 at 8:30 AM, Ronald STEVENS
<Ronald@sdc.com> wrote:
Hello guys
I bet you know this feeling……you are coming into an airport, want to take a break, perhaps a snack, than fuel and then like to continue but…..there is the treat of a hot start lingering over your head.
How many times did you not pray and crank, hopefully it kicks in, tried all the tricks in the book.
Well, I did, and yes until today I was able to crank it, however it took a lot of sweaty hands to do so.
So I did also test flew a Corvallis, and they are having a nice gadget called a purge valve that purges all the fumes out of the fuel system before cranking. So I would love to have this.
Did anybody of you have experience with this? In your 4p or legacy? Would you recommend it?
Thanks — Ronald (42 hours and counting)