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Do you have anyone on the list who has instrumented a vehicle? Sure would
be great starting point. I would expect the car would periodically see
these numbers and higher(oil). Nothing better than gathering some facts
and perspective from applications that have hundreds of thousands of
hours. You can use any car, doesn't need to be rotary (rotary best
though). Just shoot the oil pan with infrared thermometer. Shoot black
radiator (more difficult to get accurate numbers with silver radiator).
Comparing your numbers to mine strongly suggests you can easily improve
your airflow during climb. I notice Joe Hull has same basic cooling sys I
do, so I would expect he sees temp drop during climb too. You are flying
Cozy, right? Btw Joe, what an excellent install you've done.
One of the most severe tests you can do is heat soak as you describe.
Sitting on ramp after shut down, heat is radiated to all the surfaces
adjacent to the engine. Little rejected to atmosphere due to lack of air
flow. Of course it would be worse if oat were higher. Since you have good
cruise numbers, it's pretty clear it's caused by some air flow issue. Do
you have those vortex generators on airbrake? I found without them it
took time for air to flow thru NACA. In fact, it flowed backwards for a
while. Ended up with symptoms same as you describe.
Congrats on the good cruise numbers.
-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
On Mon, 10 Jul 2006 11:10:37 -0700 (PDT) Steve Brooks
<prvt_pilot@yahoo.com> writes:
> Ed,
> While you're on the subject of cooling, I have a
> question.
>
> What are you temps on takeoff when you are starting
> with a hot engine ?
>
> This weekend, I flew and the OAT on takeoff was about
> 75 F. Climbing up about 1500 AGL my coolant was at
> 200 and oil about 180. Both stabilized at about 190
> in level flight.
>
> I landed to check thing out and temps on shut down
> were about 160. Cooled off some on decent.
>
> After sitting for 20 minutes or so, start up showed
> about 185 and taxing to the runway. coolant was about
> 200 when starting the takeoff roll. Climb to about
> 1000 AGL had the coolant up to 220, and oil about 200.
> I reduced power and continued a slow cruise climb
> (about 200 fpm). The temps came down withing 2-3
> minutes to below 200, and stabilized to about 190
> after 5 minutes or so.
>
> Does this seem reasonable, or are my temps running a
> bit high ? I have always seemed to have temperature
> problems when starting out with a hot engine.
>
> Just wondering about what is normal.
>
> Steve Brooks
>
>
> --- Ed Anderson <eanderson@carolina.rr.com> wrote:
>
> >
> > ----- Original Message -----
> > From: James Maher
> > To: Rotary motors in aircraft
> > Sent: Monday, July 10, 2006 1:28 PM
> > Subject: [FlyRotary] Temperature control
> >
> >
> > The setup:
> > · Engine/Model/Year: 13B 6 port NA mixed
> > · Source Condition: David Atkins Rebuilt
> > for Aviation Application
> > · Modifications: Ported intakes and cooling
> > for 180HP
> > · Intake: Atkins short manifold w/TWM 48mm
> > Throttle body
> > · Exhaust: 321 SS tangential muffler
> > · Engine Control: RWS EC2
> > · Fuel Control: 4 Mazda 460cc Injectors,
> > pri. in block & sec in manifold
> > · Fuel Pumps: RWS
> > · Cooling System: 2 - 9"x13"GM evaporator
> > cores with 0.75" auto hose, stock water pump with
> > 180F deg.-thermostat, 50/50 glycol\water mix.
> > · Oil System: stock 1986 oil cooler
> > · Installation: conventional - self built
> > mount
> > · PSRU/Re-Drive: Ross 2.85:1
> > · Prop: IVO Magnum 74" 45-105"pitch
> > in-flight adjustable
> > · Power: 180HP?
> >
> > The issue:
> > On the ground, cooling stabilizes at 180-190F deg
> > and oil is usually 10 degrees below the cooling with
> > an OAT of 65-70F deg.
> > When running with higher OAT (75-85F deg) after
> > about 0.5 hours of moderate taxi runs (up to
> > 4300RPM) the cooling temps reach 212Fdeg with the
> > oil about 200F deg.
> >
> > The question:
> > Can something be done to get lower operating
> > temperatures without redesigning the system?
> > Would switching to pure water help and if so by
> > how much?
> > Would removing the thermostat help and if so by
> > how much?
> > How much change should I expect if I were to do
> > both?
> > You guys down south should have a good idea of how
> > best to enhance cooling.
> > What are your suggestions?
> > Thanks,
> > Jim Maher(Dyke Delta)
> >
> >
> > Hi James,
> >
> > Welcome to the club, cooling appears to always be
> > the first item of business. I can not quantify the
> > differences those changes you propose would make.
> >
> > However, a 50/50 coolant mixture has a 40% lower
> > specific heat than pure water alone. Meaning it
> > will not carry as much heat away at the same coolant
> > temperature. Would pure water give you 40% more
> > cooling - I personally doubt it, would it help, I
> > believe it certainly would.
> >
> > I fly without a thermostat and my normal (60-70 F
> > OAT) temps are 160F for coolant and oil at cruise.
> > On a hot day, right after take off, I may hit 200F
> > on the oil and 220F on the coolant for a short
> > duration. With a thermostat, your coolant temps
> > are going to go right up to the thermostat limits
> > shortly after starting your engine - after all that
> > is what a thermostat does. But, still at moderate
> > rpm of 4300 on a 60-70F day, I would like for the
> > coolant and oil not to exceed 200F.
> >
> > I fly without a thermostat to remove any flow
> > restriction as well as permitting my temps to stay
> > below any thermostat limit if conditions permit.
> > Since I get acceptable temperatures when flying I am
> > satisfied without a thermostat. In winter, the
> > temps do run a bit cool, but then I can tape off a
> > bit of the core and get higher temps.
> >
> > Ed
> >
> >
> > That's my 0.02 worth
> >
> > Ed
> >
> >
>
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/
>
>
-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
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