|
|
Bob-
Thanks for catching that, I misread the label. It is indeed 35 GPH.
35 GPM *would* tend to overload the return, wouldn't it?
What are you barbecuing?
I think this has been suggested before but I'm thinking about using an ON [low]-OFF-(MOM) [high] switch for the boost with a separate guarded ON-OFF switch wired in parallel for the high side marked something like "Emergency Boost". Now to see if I could remember that five years from now when I get to that point...
The Lancair circuit includes a primer solenoid that's energized at high boost. The TCM schematic shows a primer that diverts flow from the spider to a primer nozzle, and includes an oil pressure switch to disable the primer circuit when the engine is running. Is this the same setup that Lancair uses?
Thanks- Bill Wade
----- Original Message ----- From: "bob mackey" <n103md@yahoo.com>
To: <lml@lancaironline.net>
Sent: Thursday, June 14, 2007 10:53 PM
Subject: [LML] Re: Boost Pump
I'm looking at a Dukes pump that's rated 11.0 PSI low and 25 PSI
on high. Flow rate is 35 GPM @ 21.0 PSI. I don't know how this
compares to the pumps being used in Lancair installations, but
wouldn't seem that the Dukes could overload the system, especially
if the engine-driven pump was inoperative.
If you were idling and hit the high boost, yes. At full TO power it should
be less than the engine-driven output. My question is: could the output of
the two pumps combine and overwhelm the return line causing pressure and
thus fuel flow to go out of limits?
Bill:
You might want to check those specs... you wrote that the
Dukes pump is rated at 35 GPM (gallons per MINUTE)
while the engine uses 32-36 GPH (gallons per HOUR).
If you can really fill a 5 gallon can from the Dukes pump
in 8.57 seconds, it can probably flood an IO-550.
I use a system that flows 35 GPM liquid propane at about 200 psi.
That generates a flame about 100 feet high. That kind of flow
might be excessive even in an Lancair IV.
--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html
|
|