From: tel@cbnews.cb.att.com (thomas.e.lester)
Newsgroups: rec.aviation.homebuilt
Subject: Re: VW engine conversion (by HAPI) & a few questions
Date: 16 Oct 92 15:07:35 GMT
Article-I.D.: cbnews.1992Oct16.150735.22598
Organization: AT&T

In article <Bw6M8D.FEz@waterloo.hp.com> enns@waterloo.hp.com (Roger Enns) writes:
>Filip M. Gieszczykiewicz (fmgst+@pitt.edu) (karol+@pitt.edu) wrote:
>: 
>: 	Greetings. Went out on a limb and bought a Jeanie's Teenie I.
>
>: 	I also got a VW 1500 engine with it. It has 50 hours on it and
>: 	comes with a HAPI (Homebuilt Aircraft Products International)
>...........
>: 	About the same time as the front landing gear got CRUNCHED
>: 	during a wind gust, the carburator was reduced to ashes ;-)
>: 	Does anyone know what carb I can use with this engine. I will
>
>You can use any of a number of carbs on your engine.  Two basic
>varieties are the throttle body injector type, or constant
>velocity carb, and the regular venturi type carb.  If your intake
>is set up as per std. VW aero practise, with the carb below the
>engine, then carb ice is a very real concern.  The intake and
>carb can collect ice very easily, so be sure to set up a very
>ample source of carb heat.

    Probably good advice, but most VW powered craft I know of have no
    carb heat and do alright.  I only have a few inches of exhaust in the
    cowl and so would be hard pressed to add carb heat.  Also, no air filter.
    (using a modified POSA)


>Using a CV carb will minimize carb icing problems, but not
>eliminate them (I had an incident of carb ice on my Ellison 2
>weeks ago).  If you are flying in areas where carb ice is not
>generally a concern (Arizona, for instance), a venturi carb would
>do the trick for you.  If you plan to fly in areas prone to carb
>ice, then I strongly recommend a CV type carb, as a safety
>precaution only.
>
>CV carbs for VW's come in two major types: 1) POSA and variants,
>2) Ellison TBI.
>They both operate on the same principle, with
>the Ellison being the 'Cadillac' IMHO, and the POSA being a
>somewhat crude but workable alternative.  You could probably get
>a used POSA for 50-100 bucks, Ellison new is ~$400.         
>
>
>Fuel pressure requirements vary from carb to carb.  I believe the
>POSA requires a fuel pump and regulator.  I am running an Ellison


    No.  The POSA is a gravity feed system and floods out under
    the pressures of a fuel pump.

    If anyone can tell me how to add a fuel pump to a POSA, I would
    like to do so for inverted flight possibilities.

>(filter changes, gascolator checks, etc).  As long as the
>compression is set to some wildly high value, you should be able

	I think you meant "NOT set to wildly high" ??

>to keep the prop windmilling without trouble.  A friend did some
>power-out glide tests in his Dragonfly, and said that the prop
>stops at about 80mph, but it takes 140mph to get it spinning
>again!

    I have not yet had the courage to test the restart capability,
    but I did do a dead stick landing on second flight when my 
    throttle cable broke   8-{  .

    And I can tell you the prop came to a very decisive stop with no
    hint of even wanting to windmill at 90 mph indicated.  Of course this
    is a new 2180 cc engine and is still very tight.
    8 to 1 compression.

>
>Also, Great Plains is another VW conversion company, sorry no
>address on hand for this one.


	Great plains aircraft supply Steve Bennett 708-464-4178
	PO box 304 St Charles Ill.  60174

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