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Ellison TB

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robert ruggles

Active Member
I bought a 0-320E2A to put in my 6A, it's 150hp and I'm thinking of going with the Ellison throttle body.
Has anybody had any bad experiences with the Ellison?
Thanks
Robert Ruggles
Surprise AZ
 
robert ruggles said:
I bought a 0-320E2A to put in my 6A, it's 150hp and I'm thinking of going with the Ellison throttle body.
Has anybody had any bad experiences with the Ellison?
Thanks
Robert Ruggles
Surprise AZ
Click to expand...
The following article was written in Van's August 1996 RVator Page 08.

THE ELLISON REVISITED...AGAIN by Richard VanGrunsven

Over the years, I have written several times commenting on my experience with the Ellison Throttle Body Injector (TBI). This is an interesting, simple unit based on motorcycle technology, but designed expressly for aircraft use. Primarily it was intended to provide a simple, lightweight, low cost means of providing induction for inverted flight. It has also been promoted as being more efficient than the Marvel Carbs (for 0-320 & 0-360 Lycs.) because of better fuel atomization.

My experience with the Ellison TBI has been positive overall, but with a few reservations.

1. Inverted flight has worked just fine.

2. Idle speed is a bit difficult to set accurately; sensitive to engine temperature variations: We have been able to live with this OK.

3. Idle mixture is sensitive and difficult to set exactly right: Again, easy enough to live with.

4. In-flight mixture control is difficult at some throttle settings: Mixture changes with throttle setting.

Even with the Filtered Air Box now standard with RV cowls, my experience is that full throttle fuel distribution is poor. We must use full throttle cruise mixtures that are richer than optimum to satisfy the leanest cylinder. This of course works counter to the claimed superior fuel economy. On my Ellison equipped RV-4, I have found it necessary to reduce the power at least 1 inch manifold pressure to improve the distribution and have a positive effect on leaning procedure. Overall, I never felt that fuel economy was noticeably better than for a carburetor.

However, I am happy to report that we have made some progress.

A new induction flow straightener from Ellison has improved full throttle induction distribution.

I became aware of this through Wes Shireman who had written of his before-and-after testing of it on his RV-4. Wes had kept good records of CHT and EGT which validated his cockpit impressions. Improvements included a smoother running engine at full throttle and smoother operation when leaning.

After Wes reported his favorable experience to me, I contacted Ellison and was sent one of the honeycomb flow straighteners. We installed this and the difference was immediately noticeable. Full throttle leaning could now be done easily. Engine operation just seemed smoother overall. However, when we had more time to experiment during the trip to Oshkosh, we found that full throttle cruise was still not perfect. The EGTs were closer than before, but the same ?skip? or hesitation every thirty seconds or so that had annoyed us before the straightener installation was still there. Just as before we could eliminate it by either a richer mixture or a retarded throttle. Perhaps this skip is caused by another, as yet undiagnosed, problem.
 
Hi Robert,

I had an Ellison on my original RV-8, and it worked quite well. I installed it along with the inverted oil system, as an alternative to fuel injection. I found that I could indeed lean farther than I had been able to with the carb, and that was without any of the flow straighteners.

If you decide you want one, I have an EFS-4 that came off an O-320 powered RV-4. I was told that it was used about 40 hours, and then the plane was upgraded to an O-360, making this too small. I bought it for a single rotor engine project that I'm working on, but have decided to stick with EFI. Email me off-list if you are (or anyone else is) intrested.

Cheers,
Rusty
13brv3 (at) bellsouth.net
 
Ellison

I've used an Ellison on my RV-4 specifically for aerobatics. The advice on their website should be followed, I took a few iterations to get there! At 75% cruise I could lean further and save 1litre/hr over my carb set up. Search for ellison and you will dig up all the past comments.
 
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