From: "Neil Kruiswyk" <neilak@rogers.com>
To: "'Rotary motors in aircraft'" <flyrotary@lancaironline.net>
Subject: RE: [FlyRotary] Re: Dave's pump problems and Rotor Poll
Date: Sat, 17 Apr 2004 07:48:36 -0400
Message-ID: <000b01c42471$eaf69730$6402a8c0@CR754193A>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit
Importance: Normal
In-Reply-To: <list-3175120@logan.com>

David,

	It's a matter of flow rate.  The vent line is something small
(in my case, 1/4" AL) going into a relatively large tank.  The
coolant/air separates in the tank.  

	The flow is slow enough in the tank that the air will rise and
remain at the top of the tank.  This assumes that the only flow going
through the tank is from the vent line.

	As you increase the size of the vent line and/or reduce the size
of the tank, eventually the flow rate of coolant will overcome the force
of bubbles rising in the coolant and they will be swept away with the
coolant. 

Neil K


-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of David Carter
Sent: April 17, 2004 12:09 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Dave's pump problems and Rotor Poll

Speaking of the "vent from high point in the engine and/or pump":  That
"vent line" may be asusmed to initially have air at the vent fitting,
which
"should" flow to some tank; with the space the air occupied being
replaced
by liquid coolant.  Thereafter, won't there be continuous coolant flow
from/through that vent line back to whatever named tank it is plumbed
to?
If that tank is pressurized and is part of the total pressurized system,
and
if the bottom of that tank "drains down"/flows down (as air is expelled
at
start) to the radiator outlet/pump inlet side of the system, then there
will
be "lowest pressure" in that tank, so that the vent line, being after
the
pump and at higher pressure, will always flow coolant back to the tank
and
probablay continuously down thru the bottom hose and into the low
pressure
area into the pump, etc, etc.

If the vent line just goes to some "tank" that is not plumbed,
eventually,
to the low pressure (pump inlet) area, then, as others have said, it
isn't
the kind of vent that will do the job we need done.

David

----- Original Message ----- 
From: "Ken Welter" <rotary.coot@verizon.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Friday, April 16, 2004 12:09 PM
Subject: [FlyRotary] Re: Dave's pump problems and Rotor Poll


>   I have had to deal many systems with high points like you have
> mentioned and I have tried to bleed them out but they always develop
> an air pocket in that high point and the only way to stop it is to
> make that high point your pressure relief point.
>   To do this I have  made a remote pressure relief cap assembly and
> tapped off that high point, note that the cap you now have on the
> fill point must be replaced with a with a non vent cap to seal it and
> force the venting to take place at the high point.
>   In the case that there are two high points I bring a line from each
> point to the remote pressure cap.
>
>   Ken
>
>
>
> >
> >
> >Thanks for the input.  I made that drawing for (un)clarity.  But in
> >reality my system is just as you have indicated.  there is a straight
> >uphill path from the upper part of the rad to the pump housing.  I
have
> >an air outlet screw on the high point of the water pump to bleed out
the
> >last little bits of air.
> >
> >Thanks,
> >Dave Leonard
> >
> >
> >>>   Homepage:  http://www.flyrotary.com/
> >>>   Archive:   http://lancaironline.net/lists/flyrotary/List.html
>
>
> >>  Homepage:  http://www.flyrotary.com/
> >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>


>>  Homepage:  http://www.flyrotary.com/
>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html