Report: BME-110 & 500 flights

[KrisW]

I just wanted to pass along a bit of long-term usage information about my BME-110 w/canister exhaust that I have been running for 3 Years now.

First off, this is the original BME-110 I received from BME back in 2003, that was bolted to my 40% 3m CA-330, and has been on the plane ever since. It uses a semi-optimized exhaust using the PEFA "LL" canisters, and 3" headers (90 degree bend, right into the canisters). Since break-in, after 5 gallons of 50:1 ratio regular oil, I've used nothing but the Amsoil 100:1 ratio oil products in this engine. . be it the old style Amsoil, or the newer Saber. Gas octane has been Premium, since about 4 months into the engines life (when i started detecting a bit of a "rattle" uncer load using 89 octane).

There are well over 500 flights on the engine now, but the power took a 200-300 rpm drop recently, for no apparent reason, so I decided to pull the jugs off and do an internal inspection to see if anything was amiss. Right off the bat I found a pretty good sized score mark in one cylinder, between the "finger ports" of the piston, that was .003-.004" deep, and ran the length of the cylinder, and had also damaged both rings and the ring lands. Obviously a pretty good sized chunk of debris had passed through the engine, giving a place for combustion gasses to pass by, contaminating the intake charge and reducing power.

The other cylinder looked very good, with no obvious heavy scoremarks or damage, so all it will need is a light honing and new set of rings when I do the "Top out" rebuild.

But .. what is interesting is the overall state of the engine itself. Note, in the pictures, the LACK of carbon buildup on the piston crown, and the mild amount of carbon in the combustion chamber. The piston was lightly wiped off with a dry rag, no scrubbing involved, to just remove the light layer of surface soot. It reveals almost NO carbon buildup. Also, the ring lands and sides of the piston crown show a similar lack of carbon. . attesting to the Amsoil Sabre's ability to prevent carbon buildup in 2-stroke engines.

Note that, except for the score mark, the piston and cylinder bore appear to be properly worn, with no evidence of galling, scoring or other damage,and that the crownof the piston appears smooth and virtually unblemished, attesting to lack of detonation or overheating.

As of now, the crank and rod bearings are very tight and slop free. . there are no discernible leaks from any seals or gaskets, and as soon as I replace the scored cylinder, hone the other, and install a set of new rings, it will be back together and ready for at least another 500+ flights.

Contrary to some statements in opther threads about the Amsoil Sabre, I find the overall condition of the engine, and lack of carbon buildup, to be direct evidence of the Amoil products superior overall performance in our engines.

I use the Amsoil Sabre at an 80-85:1 ratio. . Premium 93 octane gas.

Power is a consistent 6800-8900 rpm using the Mejzlik 28-10 prop, and 6400-6500 using the Biela 28-10 or Mejzlik 29-10.

Here's hoping YOUR oil does as good a job, and that YOU get as good a life out of your engines as I do.

[Tired Old Man]

Kris,

Although you've had some pretty good success with the oil you're using, and without attempting to start an oil war, you could substantially redue the carbon build up by changing over to a 50-1 mix of Bel Ray. Cylinder scoring will also be reduced. In doing so the the already super lifespan and performance that you have experienced will be extended even further.

Testing performed over a few thousand flight hours in a very harsh enviornment has proven the BelRay to be superior by quite a large margin over the Amsoil.

[KrisW]

	Quote: Originally Posted by silversurfer
	Kris, Although you've had some pretty good success with the oil you're using, and without attempting to start an oil war, you could substantially redue the carbon build up by changing over to a 50-1 mix of Bel Ray. Cylinder scoring will also be reduced. In doing so the the already super lifespan and performance that you have experienced will be extended even further. Testing performed over a few thousand flight hours in a very harsh enviornment has proven the BelRay to be superior by quite a large margin over the Amsoil.

The only "scoring" is due to particle contamination, Surfer. See attached Pic.

Bel Ray had, when I started using synthetics . .a very BAD reputation for carbon buildup and heavy residue on airframes. Local guys used to complain constantly about these problems. I've never. . not ONCE. .heard a complaint from an Amsoil user, about heavy carbon buildup or lack of lubrication.

Other testing, as seen on several sites, has shown me that Bel Ray STILL has undue carbon buildup compared to the Amsoil Sabre, especially in heavy usage environments. The pictures shown speak for themselves. Sabre, run at 50:1, still has less carbon buildup than the Bel-ray, under the same test environments. All you have to do is look at the pictures, to see the difference.

My 110 is probably worked harder than 99% of the engiensout there, simply because it's on a very large aircraft, and I USE that engine constantly. It's a constant stress test of everythign associated with the engine . . be it oil, exhaust, prop, or the internal parts.

Consider this. . Imagine a DA-150 on a Composite-Arf 3.3m Yak. . for 500 flights. . .imagine what the engine would look like.

That's 125 HOURS .. at least.

This looks absolutely pristine compared to the vast majority of engines I see.

[Tired Old Man]

For comparison purposes only.

Imagine a 24 or 28cc gasser pushing, not pulling, a 40 pound airframe 10 to 14 continuous hours a day, 7 days a week, for 100 hours before a check up, with a rebuild taking place at 300 total hours in service. Do this on a minimum of 4 airframes everyday. Each location provides 1,200 flight hours or more a month.

We do manage to develop a little performance data in relatively short order. We manage to reach your engines' total running time in less than 9 days with any given engine. Tried the Amsoil, along with some others, and they didn't work out. We also found that the BelRay contributes better cooling properties.

Total flight hours to date is in the tens of thousands of hours. Sorry I can't be more specific.

[OverTemp]

I love my BelRay too.

[KrisW]

	Quote: Originally Posted by Bunky F. Knuckle
	Thats ALOT of carbon!!! My 3W doesn't look that bad at 60:1 mix!!!!

What is WITH you guys??? All I'm doing is reporting on the engines condition and you ATTACK the oil????

Get OVER it!!

If you can't be positive and say NICE things. . ..then don't respond. .

Geesh I am so tired of this sort of crap.

One more response like this and I'm deleting the thread

[Tired Old Man]

Kris,

I actually was saying nice things.

You've done extremely well with the engine. My only intent was only to illustrate another path that may provide you better performance and longevity in the future. Sorry if you misunderstood. I will refrain from offering constructive experience or suggestions to you in the future. Again my my apologies.

BTW, you have the best avatar I've ever seen. I laugh my a-- off everytime I watch it.

Pat

[SleepyC]

Guys... BOYS.... this was informative thread on the longevity of the motor.
Lets not get into the age old oil argument...
Everyone has their favorite, and thats great.
But we really don't need a oil battle...

I also understand that nothing was taken to a level where the thread should be closed or edited,
but I just want to stay focused here, and make sure we don't go there!


so please KRIS back to your LONG TERM BME review...
I did find the thread pretty informative...

THANKS!

[KrisW]

A comparison of the pistons, and any carbon that might have accumulated ..

Note that the FRONT piston has slightly less carbon, due to the front cylinder usually running a little bit leaner on a flat twin. Single cylinder engines are easier to optimize for perfect mixture, which usually means they show less carbon buildup over the long haul.

Where the carbon accumulates on these pistons is a direct result of where the intake mixture washes the pistons during the intake portion of the 2-cycle event. Manufacturers try very hard to achieve 100% coverage and burn of the mixture, but an area of carbon indicates burnt mixture left behind, or not self-cleaned during the combustion/intake/exhaust.

The same is true on the combustion chambers, with areas of bare metal indicating where the metal is "washed" during each firing cycle, and areas of heavier carbon buildup indicating leftover combustion material between the firing cycles.

I took a rag to the combustion chambers, with no solvents, just the dry rag. A bit of light rubbing removed about 50% of the soot, and any ash left on top of the carbon. In 10 seconds per cylinder, all the excess is removed, and you can now take a good look and see the extent of real carbon buildup, which is very minor.

If you can see metal, it's not carbon buildup.

A close look at the piston skirts reveals zero adverse wear (except for that ONE gouge mark. . . yuck), and normal thrust wear. Again, the piston rings are very shiny along their entire periphery, indicating very good ring seal, and there is minimal-zero carbon buildup on the sides and tops of the pistons.

All indications are that the engine is probably being a tad on the rich side (plugs are a little darker than I like. . but it keeps the engine alive), oil content is probably a little bit more than perfect (rated at 100:1. . actually mixed at 80-85:1. . again. . it keeps the engine alive), no evidence of detonation or pre-ignition, and overall the basic engine design shows a good fit, lack of excessive side loads and resulting thrust wear, and superior flow characteristics of the intake and exhaust mixtures.

[rcign]

Give up, Pat, Kris^ ALWAYS gets the last word

[RTK]

For some reason mine usually impacts the earth long before that many hours
I hope the new 115 does as well.

[Tired Old Man]

I did. It's that old horse and water thing.

[bodywerks]

Is that the oil you use in the UAV's, Silversurfer?
Thanks for the info Kris. It is informative!

[Tired Old Man]

Yes sir.

[paffy]

Kris,

I think you should clean all the carbon, switch to Bel-Ray and report after another 500 flights

P.