Ellison EBTI Help

While we are investigating viable alternatives for the Ellison Bottle Throttle Injector (company is gone, no more support) for our O-360 A2F, could I ask for some help and advice, please?

* if anyone has a pdf manual, please drop me a copy ([email protected]).

* I believe our mixture is generally too rich:

1. at full throttle and full rich, the engine suddenly stuttered on climbout #6 in pattern work at 300'. scary. fortunately, pulling back the throttle immediately eliminated the stutter.

2. we had fouled plugs recently, just 3-5 flying hours after the annual (which had checked that we had cleaned plugs). we mostly fly patterns, though. we rarely run the engine for a long time at high speed.

3. even on a 110F day, the CHT never gets above 600 degrees.

our indicated fuel flow on the Dynon reached 18gph on climbout at sea level. does this seem high? I don't know.

other oddities of our EBTI is a general unwillingness to shut down even at full idle mixture.

I know remote diagnosis is difficult, but any advice would be helpful.

also, is there a mechanic in the Los Angeles area who is very experienced with the EBTI?

600 degrees for the CHT is way too hot, do you mean EGT?

Sent you an email with some old documentation. Not sure if it will be helpful, but it is pretty detailed information on the theory of operation and such.

yes, of course. sorry...

The cool EGTs and fouled pugs indicate a rich condition to me. I have an IO-320 engine in my RV6, on takeoff I see about 16 GPH, I see you have an 0-360, 18 GPH seems about right though.

I recently adjusted mine. the Ellison TBI only has two external adjustments, the idle speed and the idle mixture. The allen screw on the top of the regulator is the idle mixture. Adjustment is simple. Turn the screw clockwise for learner and CCW for richer. Adjust (with engine warm) so that you see a 25-50 rpm rise when you pull your mixture control to idle cutoff. Adjustment is sensitive, only go about 1/8 turn at a time. If you open the throttle rapidly and get an engine stumble, you are probably too lean.
You may need to tweak the idle speed screw after adjusting the mixture, to achieve the idle speed you want.
As for shutdown, the Ellison will often dribble enough fuel out of the metering tube so that the engine won't stop cleanly. This is normal. You can also just shut off the mags to stop the engine.
I will check my hangar in the next few days as I think I may have a PDF copy of the Ellison manual. If so, I'll email it to you.
Good luck,
Jim

iaw4 said:

1. at full throttle and full rich, the engine suddenly stuttered on climbout #6 in pattern work at 300'. scary. fortunately, pulling back the throttle immediately eliminated the stutter.

2. we had fouled plugs recently, just 3-5 flying hours after the annual (which had checked that we had cleaned plugs). we mostly fly patterns, though. we rarely run the engine for a long time at high speed.

3. even on a 110F day, the CHT never gets above 600 degrees.

our indicated fuel flow on the Dynon reached 18gph on climbout at sea level. does this seem high? I don't know.

other oddities of our EBTI is a general unwillingness to shut down even at full idle mixture.

Click to expand...

1. I have never known my Ellisons (2 airplanes) to cause engine stutter at WOT. I find on takeoff I have to retard the throttle slightly to get max RPM, though.
2. An Ellison can be leaned far more than a traditional carb. I lean almost to cutoff on the ground and way, way back at lower RPMs.
3. You don't mean "600 degree CHT".
4. 18 gph at climbout at sea level is reasonable
5. Your shutdown is characteristic. I have to use the mag switches

Examine your exhaust pipes after some lean running. If they appear black you might not be leaning enough. Do this on the ground

My experience is with the Rotec. Rotec is bascially a copy of the Ellison so it has the same problems the Ellison does at wide open throttle (too rich.). There are too many holes at the rich end so the pressure differential inside the metering tube drops off at full throttle, which causes fuel to not flow properly. Some in the past have simply mechanically prevented the throttle plate from opening fully by adjusting the cable throw. I myself have soldered these holes closed and appropriately enlarged the holes from mid throttle to full. This worked well.

Shutoff is a little different with these TBIs. The best way to get a proper shutoff is to advance the throttle to 1000 rpm or so and pull the mixture.

Despite their quirks once one gets them running well, they atomize fuel extremely well with a significant reduction in fuel flow for a given power setting.