Builders,
While MA3-SPA’s and Strombergs are on the majority of Corvair powered planes, there are a number of Corvair powered planes that are equipped with Ellison EFS-3A carbs, including Phil Maxson’s and Lynn Dingfelders 601XL’s, Mark Langford’s KR-2S, and even some new planes just getting to the flight line like Jim Tomaszewski’s JAG-2 twin: JAG-2 Corvair Twin, running on film.
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In my manual, the Ellison is #3602-C. The Ellison is a very high quality, made in America, noted for efficient operation, no float, resistance to icing, and the ability to work at any angle, including inverted. It was designed decades ago by Ben Ellison. Although it is shaped like some other carbs, internally it is a very sophisticated, and it’s design details are matched by no other carb in it’s class.
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After many years of running Ellison Fluid systems, Ben Ellison announced his retirement. This caused a bit of a stir about his carbs, because there was no public announcement on who would take over new sales and service for the existing fleet of them. Privately it was said that Ben Ellison was deaf to large financial offers, he was willing to wait to find the right person who was willing to continue his design with the same standards he had. While there was a list of people who wanted to buy the design, Steve Glover, our local host for the Chino Corvair College, made an extended personal trip to meet with Ben and be trained by him on the Carbs. After months of lining up high end machine shops in the LA area to machine the parts, and setting up his own FAA level fuel system repair station and live test equipment, Steve is now getting the carbs in the hands of builders.
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When I was in California last week prepping for the College, Steve gave me a full tour of his Ellison operations, including visiting the CNC shop and watching as an EFS-3A body was being machined on a Haas 5 axis mill. The Ellison isn’t a carb design that would tolerate being slapped together with hastily made parts. It has taken some time for Steve to get the right shops and people, but he is there now. Steve sent me a short video yesterday of Corvair/Panther builder Paul Salter’s EFS-3A running in testing in California. It is being shipped to Paul today.
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If you are interested in these carbs, I have a section on them in group 3600 in the manual. We make specific intake manifolds to mate them to Zenith aircraft. ( Other airframes using an Ellison use our standard manifold. ) These carbs are not cheap, they run about $1,200, but they are new, and made in America. This is actually about the same price as an overhauled MA3-SPA, and hundreds less than a new MA3-SPA. You can also look at Steve’s website: http://www.nvaero.com/ or contacting him directly at: Email: info@nvaero.com Phone: 1-800-515-4811.
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Grace and Steve Glover, photographed at CC #28.
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-ww.
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What is the principle of operation, and in comparison to MA3-SPA ? Is this type of carburetor the same as the one offered by Sonex for it’s VW based engine?
Mike,
A Sonex Aerocarb is also a floatless flat slide carb, but the Ellison had a lot more elements inside to fine tune the operation. The metering on the Ellison is controlled by the diaphragm built into it, and it has a metering tube with a very fine series of #80 holes in it which controls the mixture. An Aerocarb is the answer to “How simple can it be made?” an Ellison is an answer to “How accurately cam we get it to meter fuel?” -ww.
William,
I think that you need to talk to whoever provided the photo for this post. I seem to recall one of your posts a couple of years ago specifically advising against mounting a slide carb sideways on the manifold. The reason being that under partial throttle operations, one side of the engine would get a richer fuel mixture than the other. Orienting the slide so that it ran fore and aft eliminated the problem… or am I nitpicking?
Dave,
It is preferable to mount it the other way, but in most Ellison applications, including Zeniths with tricycle gear, it must be mounted this way for space reasons. The mixture distribution is slightly better with the slide for and aft at part throttle. The flat slide carbs most sensitive to this are Aero-carbs and simple models, the Ellisons are less affected by this. -ww.