REFLECTOR:INTAKE COMBUSTION AIR

[Scott]

Ronnie,

We gotta get you dialed into LOP operations....  Less gas, cooler running, longer lasting.

Scott


On Sun, 14 Sep 2003 09:10:38 -0400, Ronnie Brown wrote:
> We asked Duane about the open baffling on the cooling shrouds on
> the factory XL Continental (shrouds don't wrap under the bottoms of
> the cylinders).  He said the angle valve Lycoming and Continentals
> with their larger cooling fins don't need the tight shrouds. 
>
> However, I did wrap the cylinders all the way to the bottom of my
> IO 360 C1C - 200HP and only have about a 1.5 to 2" opening at the
> bottom of my cylinders.  My engine runs cool with the NACA down
> draft cooling - 350 - 360 degrees while leaned out to 100 degrees
> rich of peak.  I have never seen 400 degrees on my heads, even on
> 90 degree days and during a long climb out.  Even taxiing at
> Oshkosh only produced 300-320 degrees. 
>
> And, I am only running one oil cooler.  My A&P/IA friend says one
> cooler and those long oil lines should be plenty of oil cooling IF
> the engine is cooled adequately.  After 85 hours of mostly summer
> flying, I agree.
>
> I worried a lot about a hot running rear mounted engine while I was
> building and watched the reflector and VV's for any information for
> improving cooling.  Now I am happy to say, this has been a non
> issue for my Velocity.  I LOVE IT!!!
>
> Ronnie
>
>
> ----- Original Message -----
> From:  SlvEgl99@aol.com
> To: reflector@tvbf.org
> Sent: Sunday, September 14, 2003 8:18  AM
> Subject: Re: REFLECTOR:INTAKE COMBUSTION  AIR
>
>
> I have an XL FG with Lycoming IO540, two oil  coolers.
>
>
> I have always had a bit of a cooling issue. Not so much that  temps
> are high, but that they are uneven between cylinders. The center
> two  (3&4) are significantly cooler than the end four. Thisa is
> sometimes 70  degrees or more.
>
>
> After a lot of time trying to get diverters in the  ducting to move
> a greater amount of air to the ends of the plenum, I took a  hard
> look at how Lycoming has the air flow controlled between the
> cylinders  and noted that they have baffles between the cylinders
> that force the cooling  air to stay within the cylinder fins nearly
> to the bottom of the cylinder. On  the other hand, the XL plenum
> stops half way down the front and rear  cylinders, allowing the air
> to "escape" from the cylinder fins at this  point.
>
>
> I also took a look at a a long EZ and how that engine is  baffled.
> I saw that the baffling has the air confined to the cylinders with
> just a small (2.5") opening for the air to exit the fins.
>
>
> By  coincidence just this week I decided to extend the ends of the
> plenum to near  the bottom of the cylinders, cutting them off at
> the approximate length of the  Lycoming  baffles.
>
>
> How does it work? I don't know yet as I have  just completed the
> job and have not had a chance to fly it yet.
>
>
> The  other heat issue I have is that the front oil cooler puts too
> much heat into  the nose., and then into the cockpit. I have a
> piece of foam above the canard  inside the hatch cover to block the
> heat from the nose and insulated it as  well as I can by adding
> insulation around the body of the cooler and  insulating the oil
> lines. I point out that I have a FG, thus no nose gear door  to
> allow air into the nose. I have toyed with the idea of adding a
> small vent  to bring in cool air to this area.
>
>
> Any thoughts or ideas or  concerns?
>
>
> Bob Wood
> N658SE
> XL FG Bob II