|
Hi! Ed
Where is you coolant pressure sender in relation to the water
pump outlet?
My theory is that the initial pressure has nothing to do with
temperature, the 13b coolant passages are small,(those A/C condensers
add to the restriction.) upon startup the water pump is trying to move a
immobile wall of coolant , once the coolant returns to the the pump
inlet the flow resistance drops so does the pressure.
Georges B.-------Original Message-------
Date: 06/27/05
08:18:00
Subject: [FlyRotary]
Re: Engine Rebuild - Coolant Leak Cause
On 6/24/05 3:18 PM, "Ed Anderson"
<eanderson@carolina.rr.com> wrote:
Hi
John,
A couple of things. Tracy and I both discovered that
one ALL the air is out of the coolant system, the coolant pressure may
jump to 21 psi almost immediately upon start up - long before the heat
would cause it to build to that point. At first, I thought
"coolant Leak", however, I could never find any evidence of coolant in
the chambers nor loss of coolant in the system. Talking to Tracy
Crook, he reported the same thing. We came to the conclusion that
without a small cushion of air that the pressure sensor was seeing
hydraulic pressure caused by the pump. With no air cushion even a
small disturbance would likely cause the pressure sensor to indicate
high pressure. As the block and components heated up the coolant volume
got a tiny bit larger due to expansion of parts and the hydraulic
pressure quickly decreased. At least that was the best
theory we could come up with at the time.
During
flight the pressure would quickly decrease until it was below 10 psi and
on cool days would got to zero.
On my
flight back home (some air still in system), the coolant pressure never
got above 12 psi (right after take off when hottest) and most of the
time ran at 8 psi. So if you are seeing a nominal 10 psi and
only seeing the 25 psi on startup, I don't think you have any problem
especially if no evidence of coolant in exhaust stacks.
Ed A
Ed, I
think that maybe it takes few moments for the pump to accelerate the
mass of coolant inside the cooling system. That’s why the pressure at
the pump outlet is high for a while?
Buly
|