From: "Stephen Izett stephen.izett@gmail.com" <flyrotary@lancaironline.net>
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Subject: Re: [FlyRotary] Cooling Issues
Date: Fri, 29 Dec 2017 15:42:29 +0800
References: <list-10483773@logan.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
In-Reply-To: <list-10483773@logan.com>
Message-Id: <C9E80A01-A467-4C0F-B1CF-C0DA7E97EEBD@gmail.com>

Hi Lynn
Current testing is stationary.

I have had it on the apron doing figure 8=E2=80=99s and it seemed to not =
overheat.=20
Still to hot though.

Once its moving it seems to help with airflow.

I=E2=80=99m not going to give up on our setup just yet.
I=E2=80=99ve got a few ideas and a bunch of testing and then maybe fly =
it and see what it does with some wind in its face.

What delta T=E2=80=99s should I expect from the oiling water coolers?
Sounds like 15F on the water and a fair bit more on the oil?

Cheers

Steve Izett

=20

> On 29 Dec 2017, at 10:07 am, Subscriber Lehanover@aol.com =
<flyrotary@lancaironline.net> wrote:
>=20
> Are these cooling tests being done at speed, say 60 to 70 MPH? Or, =
stationary?  It only needs to cool long enough to get to the runway. Put =
some tufts on wires right behind the prop and long enough to get into =
the ducting. I bet almost nothing flows into the ducting. Mount a =
pancake fan behind the radiator to cool on the ground. Some of the =
spiral flow from the prop will defeat the straight sides of the ducting. =
Ram air at flying speed is completely different. Most added temperature =
shows up in the oil with high power settings. The racer cooling at low =
speed is just not adequate. But once you hit the first straight and go =
over 100 MPH
> (top speed 146) the cooling is great. Make one change at a time. Make =
it a big change. Record the instruments on video. Just like running the =
dyno. Run a bit rich on the ground. Say 1600 degrees or less EGT. This =
will help a bit.
> Lynn E. Hanover
> =20
> In a message dated 12/28/2017 7:55:29 P.M. Eastern Standard Time, =
flyrotary@lancaironline.net writes:
> Steve
>=20
> I suspect it=E2=80=99s #2. Steve B=E2=80=99s email has a wealth of =
information and points to airflow. To prove it layup a quick but =
reasonable shaped duct and test it with the cowl off. I would start with =
a 28 sq or large inlet. 30% of the core face would be a good place to =
start testing.=20
>=20
> I=E2=80=99ve only seen Tracy takeoff in the RV8 once. But he was not =
using anywhere near full throttle. He did a lot of work on the inlets =
but I=E2=80=99m not sure he can use all 300HP in the summer. =20
>=20
> Bobby
>=20
>=20
>=20
> Sent from my iPad
>=20
> > On Dec 28, 2017, at 5:13 PM, Stephen Izett stephen.izett@gmail.com =
<flyrotary@lancaironline.net> wrote:
> >=20
> > Hi Guys
> >=20
> > Thanks for the replies
> >=20
> > Our water inlet is small (Standard Glasair) - modelled of Tracy=E2=80=99=
s RV8 20b=20
> > I understood he had a round right cheek inlet of 5.25=E2=80=9D =
giving him 22 in^2 to his water rad for 300hp in Florida temps.=20
> > For the two rotor -> 2/3rd of 22 is <15. We have >16 for <200hp
> >=20
> > My concern is the delta T=E2=80=99s.
> > Yesterday at 1800rpm I was seeing 12F across oil and 6F across the =
water. Previously I=E2=80=99d seen this as high as 18F and 9F not sure =
why so low yesterday.
> > What do others see on the ground at idle?
> > Does anyone have good pressure data on the ground. Idle and power =
settings?
> >=20
> > Are these low due to:
> > 1. Water flow due to cooling system design or air trapped.
> > 2. Air flow due to small inlet, compounded by a prop that doesn=E2=80=99=
t have much blade near the spinner.=20
> >=20
> > I=E2=80=99ll look at some further baffling of the Rad to exit but =
cant see this helping at idle air speeds unless I duct the exit low =
pressure direct to the back of the core.
> >=20
> > I=E2=80=99ll send further photos
> > Thanks
> > Steve
> >=20
> > Steve<3.JPG>
> > <Cowl exit.jpg>
>=20
> --
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