A few tach numbers from the BME 110 and 55cc prototypes.

55- menz-s 24-8 @ 6200
Mejzlik 22-10 @ 7800
Bolly 19-8 @ 10,250 ! ! ! !

Seems the Bolly was a test to see of a rod or crank would let go. . .Apparently the engine is going to be turbine-safety certified.

ON a side note, the ASPCA has requested that future mega-rpm tests be done in an an-echoic chamber to prevent eardrum damage and psychological distress for all dogs within a 5-mile radius.

Final weight for the 55, without ignition or muffler, is now set in stone at 2 lbs 1 ounce, and the crankshaft balance parameters are finalized so production can now carry forward.

On the 110, the projected cylinder/piston production schedule is on track, and should arrive in the latter half of the month.

Power figures are now consistent on the prototypes with the engines spinning a Menz-s 28-10 at 6300 after warmup and the Mejzlik 28-10 in excess of 6700 (these figures are HOT engines). Power figures with tuned cansiter exhausts would improve 300-400 rpm depending on prop loading and design.

An evaluation of the current CH ignitions showed an inconsistency in timing retard at lower rpms, leading to development of a more consistent advance logarithm embedded in the timing chips. This should improve low-rpm smoothness and give the BME an even smoother transition than before.

I have 2 of the Xtremes on order. . would make a nice 4th of July fireworks display to fire both of them up on the back deck at the same time.

Hey Kris...We're REALLY impressed with your knowledge strokes, and ignitions in particular..

Advance logarithm ???


Logartithm..n. The exponent expressing the power to which a fixed number must be raised in order to produce a given number..

ALGORITHM..n. A predetermined set of instructions for solving a specific problem in a limited number of steps...

If you can't dazzle 'em with brilliance, baffle 'em with BS.......

Keep up the good work..........

Is anyone but me tired of Kris blowing his horn around RC Universe. Geeeeze!!!! A wealth of misinformation, it seems to me.

You are not alone :stupid:

Just so I understand this correctly...

Somebody posts some information on an engine that is of great interest to lots of people who read these forums, but that is not currently available. Then he gets lambasted by several people because of the semantics of his post. Nice job, fellas. So much for "fun" in the hobby.

semantics - (n) the study of meanings (see, I have a dictionary, too).

Ken

Notwithstanding that you are factually incorrect (as evidenced by tests both here and at CH Ignitions), where and when did you personally perform the tests on the BME 110 that led to your assertion?

It is true that we are working with Keith to develop a timing map for that specific engine, however, there is no inconsistancy in the retard timing.

If you install an ignition with the 20 degree map selected and another with a 26 degree map selected there will be obvious differences, but no inconsistancy.

Ed Vollmer
M-E Technical, LLP

Ed,

When do you expect the new 110 Syncro Spark/ignition module to be completed and how soon after that can it go into production?

Brian

Brian, I prefer to let Keith make any announcements of this kind. He is the person doing the work - we are simply trying to assist.

Or.............perhaps Kris^ knows.

Ed, not to refute what you are saying, but I've seen it in my own engines that 'mysteriously" don't hold the proper timing at lower rpms sometimes. This "inconsistency" is most evident in the 1100-1300 rpm range, where sometimes the timing will be more advanced than others, usually on the scale of 5-6 degrees. This condition is always accompanied by roughness and the engine seeming to "hit" harder with each power stroke.

According to Keith, and I believe it from my own readings, the timing chips in the CH ignitions can start advancing the timing as low as 1200-1300 rpm, and if so this would account for timing differential at the "borderline" point for timing advance (or lack of retard) to occur. A simple thing like a tiny change in magnetic field from the permanent magnet, due to heating up or a small change in air-gap because of temperature changes, COULD be enough to affect the "dwell" time seen by the processor. After all, the processor senses the magnets speed and position as it passes the pickup, does it not? And then does a comparative search based on how many times per second/minute this is occuring to determine actual rpm and position of the crankshaft, THEN institutes the proper retard/ignition point from the programmed timing curve. Correct?

You had better believe I would not put it out on this list unless I had that sort of information directly from the source. The fact that you are helping out with this timing hassle is to be aplauded, Ed. I for one, really hope you guys get it straightened out.

As for logarithm vs. Algorithm. . I stand corrected. . .Oopsie, gee golly, I made a goof up. somebody please crucify me for making a mistake at OH-dark-thirty when my brain was only firing on 3 cylinders.

One thing to remember, Ed, Keith is not allowed to make announcements of that sort on this forum (didn't we just have a poll that said people didn't want manufacturers using RCU as a Sales Bazaar???) And if, in all the discussions I have entered in this forum I make one or two mistakes, I'm sure it's very few and far between. Excuse me for being only human, . . it happens sometimes.

Have any of you tried a different brand of ignition on the BME (100, 102...1??) to see if they get smoother at idle? Seems easy enough to try. Falkon, DA, or the dreaded 3W?

Helping out ? Ed is the manufacturer of the syncro spark chip...the ignition on a DA, 3W, ZDZ, RCS, etc.. is NOT controlled by a syncro spark chip..The ONLY ignitions that use this chip are C&H, RC, and Silent spark....
The low speed needle setting will affect the timing..If it's too rich the timing, controlled by the crank rotation, will not advance as fast if the low needle is too rich....
The ONLY timing that is completely controlled by the throttle is a C&H or an RC or a Silent Spark with mechanical advance connected directly to the throttle......
If you have an engine with C&H and you think the timing is inconsistent you would have to run it with a timing light and a degree wheel...Have you done this ?? Where does the timing begin to advance ? How many degrees at what rpm ? Anything else is pure speculation....
Only ignition in recent memory that had a "step" in the advance curve was the early Reichmuth...It would change rpm somewhere in the 1500-2500 range, from a few degrees to the final setting, around 28 degrees...a small change of 5 or 6 degrees at 1200 rpm would be barely noticeable in the running of the engine, if at all....If you doubt this, get a mechanical advance engine and try different settings..I have been making my own ignitions and mechanical advance units for 16 years, maybe I don't know enough about it yet....

Since those other "foreign" ignitions don't use the synchro chip, substituting one of those ignitions onto the problem motor would quickly tell you if it was an ignition problem or not. If the engine ran the same with the foreign ignition, one could conclude that the problem lies within the engine and not within the mysterious workings of the synchro chip.

It would have to be a blind test...Problem being, the other ignitions don't use a Hall sensor, so it's not a matter of just plugging in the different ignitions to the same sensor....
It's possible that Keith has already tested a 3w or DA ignition already, anyway.....

Falkon (ZDZ) uses a Hall sensor, but you're right on the DA and 3W.

AS a matter of fact I have, RCIgn. Not with a degree wheel, but with timing marks scribed on the hub/crankcase for reference. Yes, the engine advances, and yes, sometimes it's dead nuts on "zero" reference at idle (1100 rpm) but come up a hair off that and it advances, and it does not always do it at the same point, nor always drop off the timing as the rpm comes down. I don't mind that it does this. . I'm not using that part of the power band to begin with, and it probably helps the motor stay running in the air during long low-throttle glides.

Personally, to me, the timing curve of the ignition is fine, and down at the bottom it's not worth worrying about. Heck, I would never have checked it if Keith had not mentioned it to me in the first place. But, it seems a difficulty was perceived at idle rpm, where the engine seemed to be "hitting" too hard, and causing the characteristic "BME SHAKE" that a lot of people find bothersome. IF Keith, Ed and others are taking steps to smooth this out, GREAT!!. . it can only improve the end product.

Now, if you'll excuse me, I have to go work with some logarithms and algorithms. . . .

Before this gets out of hand let me say that we have been very satisfied with the C&H ignition and the Syncro Spark chip that Ed Vollmer produces. I have done some testing of the ignition and its processor. I have found that on our twins they would benifit from a different amount of timing at idle. Ed was kind enough to furnish me with some new chips with programs I requested. I will test them soon and let you know if they work as we expect them to. This is to assure the new engine idles as smooth as any other brand engine.

rcplanefan,
All this technical jargon is just so much drivel to 99.9% of us who enjoy this hobby. If your engine doesn't run properly or the ignition doesn't work properly you get it fixed. What's the use of all the technical mumbo jumbo and who really needs the information? Thousands of these engines have been sold with little problem, so again, what's the point? I've read many of the posts and quite frankly, a lot of the information given is incorrect and biased to say the least. I'm sure all the TOC guys are not reading any of this because they know better. What gets me is the fact that so many TOC wanna be's are here reading this stuff as if it's come down from the burning bush. It just ain't so and is misleading to those who don't know any better.

fancman - I agree. But rather than go through all the drivel, I wait for Mr. Vollmer, RCign, and Mr. Baker, and a few others to pop up and tell it like it really is - every now and then a little gem of knowledge pops out. Believe it or not, guys like Kris actually help bring the Manufacturers out of the woodwork when they would otherwise just lurk.

Speaking of pulling guys out of the woodwork, Mr. Baker, how long until the 110 hits the streets and Kris really rants?

RCign: I'm still hunting down that Motorcycle engine, its not going well, either its prohibitively expensive, or the dealer doesnt want to work with me... I'm going to junk yards now...

Roger

I don't call it "ranting" DesertRat, I call it a "Frothing, mind-crazed, hyperzealous, pathologically-depraved discussion". . it could be worse. . I could drink my coffee first. Then it would be ranting. . .

Kris^

I have really enjoyed all the BME Extreme stuff floating around all these postings over the last what is 18-months or so. I have owned 2 BME engines by the way. But really I think this new Hot Rod lite weight will come to be. And as soon as it does Keith will offer some updated cylinder spacers and your New 110 can be a new 112. And if that dont shake your tailfeathers wait 2 more years and the new EVO-EXTREME MAX 118 will really knock these DA guys down. Lets see 118X2= 236cc's of 4 cylinder rock & roll. Man oh man I cant wait. I think Im mind crazed and frothing.

The word from our cylinder manufacturer is they will ship June 15th. If this holds true we will begin to ship engines around the end of June. We have around 400 people on the waiting list so if anyone here not on the list wants one they should give us a call or e-mail us soon. Our first production run is almost sold out.


Thank you
Keith
BME

What if...

we provide the timing circuitry with the pulse width from the throttle channel. I do see the ability to use the throttle curve manipulation from our transmitter to fine tune the throttle band to an individual's taste/setup.

The throttle servo moves in proportions with the width of the pulse (1.5ms +/- 0.5ms), which would simultaneously be fed into the timing circuit. Both the servo and the timing 'know' what we want, i.e., idle, midrange, etc. I do not know how many points currently are available from the transmitter that heli guys play with. With a minimum of two points (in addition to 1ms and 2ms) we should be able flatten or steepen the part of the curve where it matters most to each engine/setup.

Such an ignition could be plugged into the receiver with an extra port into which we plug in our throttle servo. This would allow the servo to be placed close to where we mount the ignition unit.

What if... (cont'd)

we plug our 'new' ignition into a separate channel. We can manipulate the advance/retard independently of the position of the throttle valve.

Bob,

That sounds like a great idea. Just install a fiber optic cable to eliminate the noise. This could be the way of the future.

Brian

My ball bearing "Model T" mechanical advance ignition is looking better all the time....Linear advance from about 4 BTDC to 28 BTDC at wide open...The K.I.S.S principle...
All this timing stuff is vastly overrated relative to engine performance..My .02