CorvAircraft> Fuel injection for Corvairs

[Dave Morris "BigD"]

I'm no engine engineer, I just play them on TV.  I too was taught 
that whenever your hand goes to the throttle and starts to pull, it 
first sidesteps to the carb heat knob and pulls that one.  In my 
Cessna flying days, I always and religiously turned on carb heat 
whenever I was reducing power.

The MA-4 carb on my Lycoming is bolted directly to the block, so as 
the block heats up, so does the carb.  I believe that must be the secret.
http://www.davemorris.com/Photos/Mooney%20N6030X%20Guts%20-%20Firewall%20Fwd/IMG_2138.jpg

The intake air going into the carb comes from a regular air box just 
like we've all seen, so it isn't preheated unless you pull the carb 
heat knob.  I do have a carb heat control, which I test dutifully 
during runup, and that would probably be the first thing I yank if 
the engine ever sputtered at low power settings.

I don't know that I have heard any stories at all of engine failure 
during takeoff due to carb ice.  I think you're confusing that with 
the landing phase, where the throttle is partially closed and the 
temperature drops quickly inside the throat.  Pat Panzera has some 
really nice photos of carb ice on Corvair test stand.

I'm not qualified to design anything, I'm just sharing some data from 
the TC world.

Dave Morris

At 12:43 PM 4/9/2007, you wrote:
>Dave Said:
>
>
>Carb
>1. If the carb is installed in such a way that it gets direct heat
>from the engine block, the ability for carb ice to form is so
>drastically reduced that the need for carb heat is virtually
>eliminated.  My CFI with 4000 hours in Mooneys instrumented his carb
>with a temp gauge for years, and told me not to use carb heat the way
>
>Dave,
>
>I would like to hear more about configuring my corvair so I would be 
>less suseptable to carb ice.
>
>Carburated planes use carb heat and I know many pilots who are 
>almost paranoid about using carb heat--I remember once I was PIC 
>with a pilot friend in the right seat who got very upset with me 
>because he felt I did not ingage the carb heat as soon as he thought 
>I should on our approach to an airport.  His routine was to hit the 
>carb heat on the decent to pattern alt, and mine was to engage it as 
>a part of my initial CGUMPS routine.  From his reaction, you would 
>have thought I had put the plane in a 
>skidding-tail-spin-death-spiral.  If he had a chute on, I'm sure he 
>would have departed the aircraft.
>
>And none of the injected planes I have ever flown have 'carb heat' 
>-- or 'injector servo heat' or what ever you might call it.
>
>We have all heard stories of an airplane losing an engine shortly 
>after takeoff due to carb ice formation.
>
>Any recommendations on fitting the corvair with a system similar to 
>your CFI's mooney?
>
>Greg
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