----- Original Message -----
From: "Jim Sower" <canarder@frontiernet.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Friday, March 05, 2004 12:52 AM
Subject: [FlyRotary] Re: Ideal Cooling System Plumbing (was
Re:[FlyRotary]Re: overflow connections


> <... there is one failure mode ... where sensing the coolant level ...
will not
> help ... Blowby from
> compression and/or combustion gasses forcing air into the coolant system
...>
>
> How long would it take a coolant pressure gauge to pick up on that one??
>
>
>
 A pressure gauge will show up combustion gas blow-by immediately.  Most of
the time what you will see is an immediate pressurization of the coolant
system on startup -  long before the engine temperature rise would cause the
coolant to pressurize.  Then the pressure would remain high and would
probably exceed your radiator cap capacity thus ending us blowing coolant
into your overflow tank and out its drain.  Another indication is
indications of oil film and bubbles in your coolant header tank.

Personally, whatever other type of instrument or indicator one might use to
indicator a potential cooling system problem I think a pressure guage is one
of the basics.  But, obiviously, you need to integrate the indication of all
your sensors to monitor engine operational status.

Ed Anderson