Hangar Flying

Hangar Flying => Hangar Flying => Topic started by: alleycat on March 30, 2010, 10:46:46 AM

Title: 0-200 with ellison tb
Post by: alleycat on March 30, 2010, 10:46:46 AM
Greetings, I was wondering if anyone out there is running a VE 0-200 with a Ellison throttle body. If so could you give me some input about the performance differences of the ETB vs carb and any additional considerations that may sway my decision  toward the Ellison. Thanks for the input. Allan
Title: Re: 0-200 with ellison tb
Post by: A. Bruce Hughes on March 31, 2010, 10:39:02 PM
Hi Allan

I don't have a Varieze but my Longeze has an Ellison.   I do not have any
flight experience.   I am convinced that the Ellison is far better than the
ancient carburator device.   It, of course, is not as good as fuel injection
but it is far less costly.

Bruce Hughes   :)
Title: Re: 0-200 with ellison tb
Post by: Joe Person on April 01, 2010, 03:21:35 PM
And the O-200-equipped VariEze, having a gravity feed fuel system, differs from a Long-EZ (the Long-EZ fuel system is a pumped system).  You'll have to find someone with an O-200 VariEze, running an Ellison TBI, to get useful information here.  There may be VarieEzes out there with an O-200 and running an Ellison unit, but make sure you get ALL the pertinent details associated with such a configuration, AND make sure any "positive" responses are from those with actual, and sufficient operational time with their configuration (i.e. avoid any non-flying "theorists" here).

-Joe Person
VariEze N79JN
Bothell, WA  (KPAE)
Title: Re: 0-200 with ellison tb
Post by: Bill James on April 01, 2010, 08:50:40 PM
Howdy Alan-
I should just say "Yeah, what Joe Person said."
But with the usual caveat of being a late starter and now finding myself somehow in the middle of the gaggle, I will offer a few details of my fairly stringent perusal of the Ellison up to the point of actually trying to obtain one, and then choosing instead to lengthen the carb induction on my current 0-290. My observations are worth what you are paying for them  :)
First, the facts as I see them:
A. Some really fast guys use the Ellison throttle body. Some really fast folks use a carb, and fly a lot rather than tinker.
B. Several years ago I saw the letter from Ellison where the company denies any benefit to the 0-235 Lyc, which was my VariEze engine at the time. I gave this factor proper weight, keeping up the Ellison chase, but lowering the amount I was willing to pay for ‘nothing’ according to them, and expanding my pursuit, looking sideways at other forks in the yellow brick road to efficiency.
Second, Physics. The following details have been explained to me by some very patient people. I believe they are true:
A. The carb has a jet spraying to one side.
B. The Lyc carb induction system has a hard hill to climb from the get-go because of being located on the oil sump with only about 3 inches of flow before the split. That is a very short run, especially combined with the jet spraying more fuel to one side than the other. Not a big deal when I was putting around in a Cessna 120 at 70 mph where you never think of such things, but a very significant factor when thinking of lean of peak ops in a highly-refined steed. The Lyc sump design and its immediate fuel distribution imbalance became a sore spot for me.
B. The Ellison advantage would seem to come from using a spray bar rather than a carb jet, immediately being a step ahead of the carb in expanded fuel distribution. My imaginary vision of the spray bar was probably somewhat accurate and it intrigued and beguiled me for a long time. It still does, but I am easily distracted by more shapely curves, especially on intake tubes, so that hunt increased.
C. I heard that the Ellison advantage requires the equivalent of a straight, undisturbed two-foot run (probably less) into the inlet, or there is no benefit. I heard of a couple of things that folks had done to approximate this and made notes in my book of tricks, with visions of a two-foot inlet going through the firewall and up under the belly. Or not. Standing around at fly-ins invisibly listening in, it wasn’t hard to hear a story or two of an Ellison installed and finally replaced with a carb.
D. After many hours of listening to very knowledgeable people, I began to realize that this is kinda like the “law of thermodynamics” that I saw explained recently: “You never win, you always lose, and you have to play.” No free lunch. One step forward and two steps back.
As I saw it, if you have an intake that is long enough to enable equal fuel mixing, there is going to be some fuel pooling. Oh great. It occurred to me that it wouldn’t hurt for this longer intake that I was becoming more inclined toward to have some twists and turns to keep the mixture non-liquid to the greatest extent possible. So some turns and zigs and zags in the induction tube might not be all bad.

With several years of use and benefit now from the 0-290 extended intake tube,  a recent observation  made sense: Some folks were documenting fuel mixture characteristics looking through clear tubes, and observed that the fuel was not totally vaporized, but besides the vaporized fuel, some was liquified and flowing through the tubes like pencil-sized strings wriggling toward the carb. I can’t vouch for the veracity of that, but it makes as much or more sense as anything else I have observed and experienced.
The surprise for me was that my extended intake tube works, that there is no throttle delay or hesitation, and that takeoff power improved with the better fuel balance, as well as comfortable  higher altitude lean of peak operation. If you haven't seen them there are pics here on ez.org at Featured Canards.

At the end I was at a place where the lengthened induction tube had become a solid element of my desired design. From what I had learned it would work as well with either a carb or throttle body, and provide what I wanted - even distribution. The chase ended, thankfully, as a boater-friend and I were blowing a couple of decades of settled dirt off of his old Evinrude outboard mini-carbs, holding them against the underside of the Lyc cylinder head intake ports.

All to say, my point of arrival with the Ellison hunt was that I wasn’t going have a perfect enough installation to allow the Ellison to truly do its thing. The over-riding fact is that many of the fast guys and gals have combined numerous meticulous elements that blend to enable their magical performance.
My journey is quite satisfying with the extended intake tube and carb. No issues. It is also true that from my study I have nothing negative to say about the Ellison throttle body, and would offer only positive comments and congratulation to successful users, with any negative issues being related the limits of the installation.
I would suppose that about half of what I have said here holds water. Thankfully my intent is to fly, not stand around holding water. Good luck with your project.
Next time I see you, you owe me $.02.
Title: Re: 0-200 with ellison tb
Post by: Bill James on April 05, 2010, 08:18:03 PM
Lots of other things i could have mentioned above, in particular, that one of the best things i did was in fact flying the VariEze with a stock 0-235, with the carb on the oil sump. Specifically, the plane was prepared for first flight using a stringent list of things ONLY that kept me out of the air. Thus i flew about 8 years earlier than feared. The engine came off a Long EZ with 150 hours. So a simple airframe and proven engine. The engine setup i fly now was thought through for several years, years while i was already flying a simple airplane.
Other than a 7 amp battery to run the elec fuel boost pump for engine priming, the plane had no electrical system. It also had no paint, but rather white primer that had been done so well by buddy Jerry McAdams that everyone thought it was final paint. The wheel pants and other niceties were figured out during the 40 hour restricted period, which i planned to fly off in 4 days but actually took 3 months. Three very good months to fly, come back and sit and reflect. And end up not doing a lot of (heavy) things on my other lists.
The upholstery was a camping mat and a sheepskin from my mom.  The handeld com and GPS got me everywhere i wanted to go, including Terry Yake's Kansas City GIG, Oshkosh, Jackpot, Kanab and Rough River. I flew non-stop 1400 miles from Ft Worth to Reno with that carb on the oil sump, 31 gallons at 3.8 gph at 175 mph average against the wind.
I still use the same GPS. It hangs from the canopy lip and is right in line with the altimeter, and my flight path out ahead. The GPS pointer arrow and altimeter needle tell me all i need. The engine gauges are right below the airspeed indicator.
While i agree that it is important to win the race to lunch and back at RR, a big part of that is getting the plane there in the first place. By default, you have beat dozens, maybe hundreds, that arent' there yet.
While i dont think there is a wrong way to do this stuff, including using an Ellison, as long as you do it right, point is, my intent with the above comment was to encourage you to get the plane in the air, not to give you more things to deliberate  :)
Title: Re: 0-200 with ellison tb
Post by: Joe Person on April 08, 2010, 10:42:11 AM
I should just say "Yeah, what Bill James said."  Inasmuch as I won't even attempt to put a "Jamsean" work of prose & philosophy to keyboard & screen (I'll not render anything near as good & palatable as what Guillermo the Master writes), I'll second Bill's final point by citing the Great Philosopher himself, Larry the Cable Guy - "Git 'er DONE!"
Title: Re: 0-200 with ellison tb
Post by: easyrider on April 08, 2010, 06:43:35 PM
I always compare cost to increase performance and I think I have a winner for the O-235 L2C.
The Sparrowhawk conversion which is basically 9.75:1 pistons and advancing the Mags. to 25Deg.
I did get increased oil temps 220+ on climb out which would drop to 200 in level flight.I changed the oil lines to the cooler from 6 to 8AN.This gave me 10 Deg so it was a step in the right direction, my next move is a 13 row cooler from 7 row.The conversion has an STC and for a Cessna 152 it includes a baffle change and a different prop.The fuel computer shows 128 HP on full throttle climb out.
The set of pistons for the conversion is around $1,000.
Here's a link to the STC

Title: Re: 0-200 with ellison tb
Post by: dorr on April 11, 2010, 03:16:01 PM
Never had an Ellison - was there when people discussed need for carb heat, however. 

The rumor, early on, was that Ellison gave about 1 gph better performance for same speed...but in 3000 canard hrs I've never bothered, so figure I lost at least 3000 gallons in that time.  Klaus is talking electronic fuel injection next, I'd wait.