Paul Cataldo

My Feedback: (10)

Fellas,
I have discussed the new 110 Extreme with many other members of the forum, and a few of the guys think that the engine will be prone to overheating, or other problems, due to it's small, lightweight size.
Of course, this is strictly speculation, as the engine has not been out for very long.
I just wanted to get some feedback on this engine. I need some good feedback from fellow modelers to justify the cost (over-priced) of this engine. I really would appreciate any comments from guys that have experience with this engine.
Also, IS this engine readily available at this time? Who would have one in stock NOW? Thanks fellas.

blkbird68

My Feedback: (19)

over-priced?? you must be thinking of 3w's


besides you seem to have made a post intended only to start an argument since the availablitly etc. has already been covered on this forum...

Paul Cataldo

My Feedback: (10)

Well blkbird,
I ALMOST went ahead and posted a "disclaimer" for all you nitpickers out there, that I DO NOT BELIEVE that BME is the ONLY overpriced engine. Guess I should have gone the extra mile. Hell, ALL of them are overpriced. No? I thought that was obvious....
As for posting with the intention to start an argument? Perhaps one should re-evaluate the above two posts, and re-think as to WHO is REALLY trying to (and I quote) "start an argument".
I am FULLY aware of the previous posts about the engine's availability. That is EXACTLY why I was asking about the availability, as I have not seen the topic discussed here lately. I also heard they may be readily available here soon.
I'm sorry a simple question brought out hypocricy from within yourself.
You will NEVER find me trying start an argument on RCU for arguments sake. I've got better things to do with my time than that.
NOW,
If anyone else has some feedback on this engine and it's performance, I would greatly appreciate some up to date info. Thanks fellas.

blkbird68

My Feedback: (19)

they are currently out of crankcases...again...prior to that they were filling back orders at a rate of approx. 15 to 20 a week.

Diablo-RCU

My Feedback: (1)

And they're $50 more than a DA-100 or a 3W-106 and $75 more than a ZDZ-100.

CAPtain232

My Feedback: (40)

Paul,

I DO NOT have experience with the engine, but if you ever believe published info about a product,

Keith had his test pilot fly around with on of the engines with NO DUCTING to test the heat issue....SUPPOSEDLY even without ducting, BECAUSE OF THE THINNER FINS, the engine ran cooler than his other engines.........

This makes some sense.....the thinner fins would absorb heat really fast and as long as there is adequate airflow, they will cool FASTER as well

Let me throw this analogy out to you......

I do a lot of metal work and can relate to it this way.........If you take some steel sheet stock, let's say 1/8" and 1/2" (just to show what I am saying), put a rosebud to it and start heating, the 1/8 will heat up faster than the 1/2....Remove the heat once both parts are cherry red and the 1/2" will stay hot longer......This is what an engine does....it applies heat when combustion occurs and that's it. HEAT AND COOL.....HEAT AND COOL. the fins are really going to absorb the heat and then they will cool even faster than a "STANDARD" fin

rmh

This is not to throw cold water on your comments --
cylinder fin technology -on air cooled engines - is very old -
The standard for years has been to use lots of fins -which "radiate" the heat.
Also most of these large engine setups used steel fins - lots of em -close together and inportantly, a close fitting duct work which insures that the air passes thru the fins --not around the fins .
Many new model engine designs have reduced fin count- and on the engine you mentioned - shorter fins in reduced count.
should it work?
of course - as aluminum has very fast heat transfer -
But you have to have moving air flow for any setup - not the tight ductwork on the early on steel fins - that close spacing , created a heated air layer which effectively insulated the barrel and the cool air -if not forced thru the fins -simply passed on by-----
On current tech engines, as long as the plug and upper head get good flow - and the fuel mix is right -- the aluminum jug /gas engines will not go into thermal overload.
I think the last of the steel finned model engines were some industrial conversions. Kioritz I think was one
The wide fin spacing used on current designs (most ) ,allows the air flow between the "fins" and that is why the technology works, without close fitting ducts.
(you already knew that stuf tho --)
There is a fair bit of "Danger Will Robison!" warnings on 3D flying - , suggesting duct work is required to cool twins, due to low air flow-
One real reason is that constant hovering puts a higher load on the engine -and if you lean the mix - you may get free smoke -

Kris^

My Feedback: (1)

I've been running both the 110 and 106 (102 w/110 jugs) for about 6 months now. During the heat of the Summer, hauling around a 40% plane, NEVER an indication of a heating problem. Of course, I am prudent about ensuring airflow is directed over the engine, and I NEVER lean the engine to peak, but have it about 1/8 turn rich of that little area on the needle where there is no rpm change, basically slowly closing the needle till the speed just stops increasing, then backing off 1/16 turn. That needle adjustment, for me, has worked flawlessly no matter what the temperature or humidity are. I came to the conclusion a long time ago that if you HAVE to lean the motor for an extra 50 rpm, you need a bigger motor or a lighter plane. Using this adjustment on t he ground, whtn the motor unloads you have a little extra mixture to ensure against leanout in the air. So far the spark plugs read just rich of neutral, a slightly medium brown color, with just a hint of carbon on the top of the pistons.

Now, some other precautions, that would help ANY engine, I run my oil mix a little fat, using Amsoil 100:1 at an 80:1 ratio, or one 8 ounce bottle to 5 gallons of PREMIUM gas. I've found that with the canister setups you tend to get just a little more cylinder pressure, so using 89 octane is not the best idea and the occasional "rattle" can be heard. 93 octane solved this dilemma. I also make SURE that all the air coming in the front of the cowl has to pass over the engiens cooling fins, and put small holes in the bottom of the cowl so that the carburetor can breath fresh air.

The last thing is that I don't over-prop my 110 or 106, but let them spin above 6400 on the ground. That's the break-point for me on these engines, as I feel that lugging the engine down to 6000-6200 with a larger prop makes you have to run more throttle all the time and never gives the engine a break, so it stays hotter than an engine that is not loaded as heavily. Right now I'm using the BME 28-10 and turning right at 6400-6450 HOT on the ground. A Menz-s 28-10 is about 50-100 rpm stronger, as is the Mejzlik 29-10.

The biggest consideration IMHO are: Keep the airflow over the engine, keep the oil mix just a tad fat, don;t lean the motor for absolute max rpm, and don;t load the motor with a stupidly oversized prop. This works for any engine. I've had this 40% plane/BME110 setup hovering for over a minute several times. . .overheating, you got to be kidding, right?

As for the cooling fins on the Xtreme, it's been covered both here and in other threads. They WORK, let a lot of air get in between them for better sloughing off of the heat, and really let the heat out of the engine. (they also save weight )

Hope this anwers all pertinent questions.

Diablo-RCU

My Feedback: (1)

I won't dispute the effectiveness of the BME cooling fin design. But, while we're on the subject of cooling, for the fin design the most important factor is the total surface area of the fins. More fin area makes the motor run cooler.

Kris^

My Feedback: (1)

Okay, has anyone ever considered that the cooling fin designs of the OTHER guys are outdated, obsolete, and inefficient?

Here you have these thick, heavy, closely spaced fins that do not allow air to get between them unless it is forced to do so. By merely reducing the thickness of the fins by 50% you would gain greater cooling for the engine becausemore air would be able to get between the fins. Hmmm. . so, if you get more heat transfer because there is more air passing between the fins, perhaps the fins can be made smaller? Seems like that is what BME did, and now everyone else is scratching their heads and wondering why THEY didn't think of that. . .

rmh

Kris -others did reduce fins in spacing and thickness -also as noted earlier - the " old designs were iron/steel sleeved . then finned etc.. It is all evolutionary - very small fins is NOT revolutionary- many old c/l speed engines were setup in similar fashion.
The setup use by gas contemporary engines is basically the wider spaced /all aluminum /coated sleeve setup.
The intake ports also add to cooling -as does the incoming charge . The total radiated area - selected by each ofthe others , was likely based on lots of feed back from users -intentional or simply from burned up stuff .
The other guys are hardly obsolete / outdated etc.
they have their good points and you have your own favorites - -
If your choice was the "perfect choice" - everyone would promptly buy only the one brand .
A very unlikely scenario.
Have a cup of "nog" and unwind - -

Diablo-RCU

My Feedback: (1)

The heat transfer equations and best engineering practices haven't changed for over 70 years. You can't fool physics. Thinner fins is not anywhere near as important as total surface area. Look at the radiator on your car, the fins are thin to increase the total surface area by using more fins. Thinner and leaving out half the fins is of no advantage to cooling. And yes, aluminum cylinders with plated bores are much more efficient at transfering heat than a steel sleeve. Thermal conductivity of aluminum is much higher than iron. Thermal conductivity closely parallels electrical conductivity. Copper is a better thermal conductor than aluminum which are much better than iron.

To be certain, I know of no cooling problems with the BME - no experience with it.

Kris^

My Feedback: (1)

Cmon Dick, sounds like you've already been into the 'nog a bit too much. . .

Here we have smaller, lighter cylinders that displace more CC's yet have no overheating issues compared to the competitors cylinders (some of which have a deserved reputation for running HOT). The competitors items are at least 50% heavier/piece, make no more power, and radiate off about the same amount of BTU's (Maybe). So, somewhere inside all of this is proof that smaller, thinner, lighter, and more radiant works just as well, if not better than, "conventional" designs. Now, Dick, we all know how much you like knocking things off pedestals (as stated several times) but you're aiming just a bit low here. You might try learning from this example of a different design working just as well, if not better, than the "other guys", instead of holding the line on "your way is the only way". There's no pedestal to knock things off of this time, just a better way of doing things. I'd think you'd at least grant that instead of digging in your heels and braying.

The design works, it works VERY well, and there are NO overheating issues with it. I was out blasting around today with a pair of new cylinders on my 106cc motor, just having a ball and it never sagged one time. Less than an hours run time on it and I showed it NO mercy. I even had to lean the bottom end a little bit because it was a tad too rich. I even managed to get in a 1-minute TR (Okay, I'm no TOC jock). Did it burble, bobble, sag, or get weak? Nope.

Case closed, the cylinders work just fine on the BME Xtreme's. Now, flip the prop and fly!

rmh

Kris - at least you are consistant------------
I meant - have some nog - it may help relax you.

WRK

My Feedback: (2)

I would not recommend lugging a BME 110 down below 6000 RPM at wide open throttle it will get quite warm, 6200 minimum is preferred.

Optimum fin spacing is dependent on how much air pressure is available to push the cooling air between the fins.

flierbk

stomper

My Feedback: (20)