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Keeping water level up to the pump and/or eliminating air up there:
I don't think there can be a problem with air in the rads or pump housing if
the system is filled from the bottom - from a hose going down from the
bottom of a "header" tank (pressurized expansion tank) that is at or above
the level of the top of the pump.
- The liquid will go in the bottom of the entire system and force air
upward as liquid level rises 'from bottom', and assumng that there is a
bleed plug at highest spot in engine or pump (removed) or a peck cock valve
(opened) during filling. (ideal would be to have a permanent bleed line
from that high spot into an 'always-partially-filled header tank that always
keeps the entire system full of liquid - air has to be expelled.
- Given, there may be air traps somewhere in the system, but the liquid
will either bypass them - or purge them as it keeps rising until it comes
out the "high point" (bleed plug hole or pet cock or bleed line connected
there and going into the header/expansion tank).
If you don't have such a header tank, then there should be a way to plumb in
a "fill hose" that is fitted to the bottom of the system (such as a pet cock
with an appendage for putting on a piece of rubber tubing), with "fill hose"
running up to be held above engine with funnel in it - or put top end of
fill hose on bottom of a siphon hose to siphon or pump out of your coutainer
of coolant.
- Fill the system until liquid comes out top of system. Close petcock
at bottom of system. Remove fill hose and put it and your funnel and/or
siphon, or whatever away and then start engine runs to purge any remaining
air and keep topping off the liquid level as air is expelled.
Does this make sense? I'm talking about NOT having what I consider the
ideal system (pressurized expansion tank with fill line going to lowest spot
in system and with air vents from highest point in system into expansion
tank below liquid level). I'm only suggesting that whatever OTHER system
you have, permanently install a fitting (valve or pet cock) at bottom so you
can temporarily install a removable fill line and, holding the top end of
the fill line above the engine & pump, pour in coolant so it goes in at the
bottom until it comes out the high point.
David
If you don't have a
----- Original Message ----- From: "David Leonard" <Daveleonard@cox.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Tuesday, March 30, 2004 9:44 AM
Subject: [FlyRotary] Re: One step forward and .9 steps back.
Bill, I think you have hit the nail on the head. That was also Ed's
thought on my problem.
But first of all, Finn is a genius. The 2-nut trick for removing the
water pump studs worked great and with some difficulty I was able to
remove and replace the water pump without removing the engine.
Findings: It was in perfect working order. The impeller is correct and
turning in the correct direction. The only problem I found was that a
piece of RTV had clogged the priming hole at the top of the housing (see
pic). That was left over from the last time I thought I would have to
remove the engine but just slid it back 1/4 inch and slathered on the
gasket maker (because it was impossible to see if I was getting it in
the right place - I just used extra). Turns out I should have used
Finn's idea the first time. The question is now how much of that stuff
got caught in my rad.
Now it's time to burp burp burp, as lack of good prime the one of the
only explanations left. I am worried about the ability of the pump to
keep a prime when it has to bring up the water from the rad that is so
much lower. Maybe EWP would have been the way to go.
Also included is a pic of my oil cooler intake ducting. Ugly fiberglass
work, but it seem to do the job.
David Leonard
The Rotary Roster:
http://members.aol.com/_ht_a/rotaryroster/index.html
> -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
On
> Behalf Of William
> Sent: Sunday, March 28, 2004 6:10 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: One step forward and .9 steps back.
>
> Dave,
> When I did the water pump tests, I found that a little air in the
vicinity
> of the pump causes it to not work, doesn't take much. As you are
running
> at
> the lower rpm, if there is circulation, then you bump it to a higher
rpm,
> you could displace some air from the rest of the system, andit will
lodge
> in
> the pump, causing it to shut down. If you can pressurize your system
> externally, you might find this minimized.
>
> Otherwise, keep burping the system, and try to ensure no air near the
pump
> impeller.
> Bill Schertz
> KIS Cruiser # 4045
> ----- Original Message -----
> From: "Eric Ruttan" <ericruttan@chartermi.net>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Sunday, March 28, 2004 4:57 PM
> Subject: [FlyRotary] Re: One step forward and .9 steps back.
>
>
> > Dear Dave
> > I suggest that it is the pump. If you can get a flow meter that
will
> really
> > help.
> >
> > I would bet the pump is cavatating at the highter RPM. Without the
> > thermostat it cant build pressure to over come the cavatation
tendancy.
> >
>
>
> >> Homepage: http://www.flyrotary.com/
> >> Archive: http://lancaironline.net/lists/flyrotary/List.html
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