Subjective Cylinder Comparison ? Lycoming vs. ECI

Ironflight · #1 07-09-2012, 12:46 PM

Let me be clear - I have been a huge ECI fan ever since they began making replacement parts that challenged the design technology and quality of the Lycoming monopoly. Way back in the days before ECI and Superior, you bought your parts from Lycoming, and that was that ? and many of us complained about poor cylinder and valve cooling due to lousy parts finishing and antique metallurgy. With the advent of competition came, well?competition! And quality on all counts improved. Let?s forget, BTW, that they have ALL had AD?s, SB?s, recalls, and failures?.yes, they all have those?.).

Because I was an ECI fan, I was pleased when Mattituck built my RV-8 engine from ECI components, and the Cerminil Cylinders were, in my mind, a big plus due to their non-corrosive properties. Of course, I never dreamed I?d be flying the airplane five days a week so that corrosion just wasn?t going to be an issue, but I liked the idea. Mattituck did their usual excellent job of matching the various components for the engine, and it was a very smooth runner, even LOP (with a carb!). I was never, however, very satisfied with the oil consumption on the jugs ? the best ever was about 8.5 hours/quart, and I averaged about 5 - 6 hours per quart. I talked with Mattituck frequently over the years, and was told this was well within spec, and that we could re-ring and hone, but might very well end up at the same place.

Well time went on, and I kept using oil ? eventually, it got to a quart in four, just about the time I had 1400 hours on the engine, and I decided it was time to do the top. I have recounted this here earlier this year, so let?s just say that I went with Lycomings this time due to a number of reports of problems honing nickel cylinders, and customer service mis-steps on ECI?s part. The four new Lycoming (standard nitride) cylinders came from A.E.R.O. and have broken in nicely. With fifty hours on them, I can draw a few interesting (and somewhat subjective) observations between the old and the new:

1. Oil Consumption: Clearly, even though it is still stabilizing, the Lycomings are doing far better ? on the order of a quart in 9 or 10 hours right now.

2. Balance: The four ?random? jugs and pistons from Lycoming don?t seem to have changed the dynamic balance by any perceptible amount ? the engine is wonderfully smooth (except when I get it excessively lean and jugs start mis-firing of course).

3. CHT?s: The Lycomings are running about 20 degrees WARMER all the way around, and seem to heat up and cool down more quickly than the ECI?s. All are within normal limits, and the baffling is identical. (I had no cracks or damage to the baffling in 1400 hours ? simply amazing!)

4. Leaning: The carefully matched ECI?s from Mattituck did better than the random replacements from Lycoming. The four EGT?s don?t come together as nicely as I lean, and the engine won?t run quite as smooth when I get to peak or beyond ? therefore, I am not able to get as low of fuel flow numbers - probably on the order of .5 gph average at lower altitudes (better up high).

5. Oil temperatures: Seem to be running just a little bit cooler with the new jugs, now that the initial break-in has occurred.

Overall, I am happy with the new jugs, but a little sad to lose that beautiful smooth LOP capability ? we?re still getting LOP (as evidenced by the significant drop in CHT?s when you go over peak), just not as deep. I am curious to see how the engine will do on its first long cross-country to Oshkosh and back in a couple of weeks. I expect to see the oil consumption improve a little bit more, but we?ll see.

Paul

rocketbob · #2 07-09-2012, 01:09 PM

Oil consumption really has very little to do with how the engine is broken in and more to do with how the honing process is done at the factory. The RV-6 I fly has about 100 hours on ECI cylinders and it goes about 30 hours before a quart needs to be added. Lycoming and most engine shops use only one grit of honing stones for roughing and finishing which in my opinion is pretty stupid. No other engines have cylinders that are honed in this fashion anymore.

rv6ejguy · #3 07-09-2012, 01:33 PM

Very interesting comparison Paul!

DEWATSON · #4 07-09-2012, 02:07 PM

Rocketbob has hit the nail square on the head. Sometimes I just don't understand why things have to drag along in the aviation world.

LotusSeven · #5 07-09-2012, 02:43 PM

Excellent info for comparison but it seems that the differences are two fold, different companies, and different cylinder finishes. I would be interested to see the comparison between different companies for similar cylinders (ECI vs Superior w/through hardened steel) or the same company with different cylinders (Through hardened steel vs Cermanil from ECI). Thanks for providing the data!

Guy Prevost · #6 07-09-2012, 04:21 PM

Very interesting! I wonder what all of the factors are in oil consumption. My Mattituck built ECI engine (delivered late 2007) uses about 1 qt in 30 hours. That value has been unchanged since break in. I've got about 350 hours on it now.

Ironflight · #7 07-09-2012, 04:47 PM

One thing that I forgot to include in this post is that it turns out I had delaminating rings - it was an issue that ECI knew about, but it apparently wasn't well publicized. When we took the jugs off, it was apparent that about half the ring/cylinder contact areas had delaminated, and I blame that for the high oil consumption over the years. What I find interesting is that the ECI's ran cooler CHT's than the Lycomings - consistently. All are within limits, just ... different.

David Paule · #8 07-09-2012, 04:51 PM

Can you comment on the relative quality of the fins?

Dave

aerhed · #9 07-09-2012, 04:52 PM

Makes sense. More heat transferred to the oil yielding lower CHT and higher OAT than the new jugs which may be shedding more heat through the head and less into the oil. If so, that should be kinder to your oil.

Ironflight · #10 07-09-2012, 05:50 PM

Quote:

Originally Posted by David Paule

Can you comment on the relative quality of the fins?

Dave

The fin quality was good on both - it was something I checked as soon as I got the Lycomings because the reason I went with ECI "way back when " was Lycoming's reputation for lots of flashing between the fins around the spark plugs. Clearly, competition forced them to clean up their act - they are far better than what I had on my old Lycoming-powered Grumman in the late 90's.

Paul