Hi all

I read in many post that most of the BCMA SPE26cc rpm seems to be very much higher than my SPE26 direct from factory. As per what BCMA said, they toss the original carb as its venturi of 8mm is too limiting for the engine.

I have run the SPE26 on almost 3 gallon and its rpm just weak compare to my G26 Magneto.

The SPE26 only hit 7300 for APC17x8, the G26 hit 7800 on APC18x8 and as high as 8500 on 17x8 albeit the G26 is using Abell muffler which will gain usually 2-300rpm. However the G26 on stock still outpull the SPE26.

On reading many folks getting great performance from their BCMA SPE, it seems that Adam mentioned that the stock carb venturi is too small at 8mm where as BCMA SPE hit as high as 12.7mm venturi.

So if I just swap the carb, retune and it should give much better power?

The carb is part of the equation, the other part is the ignition. The ignition that Adam sells gives a stronger spark. The carb will probably have the biggest impact, though.

Andy

Great performance is relative to what you're hearing from new users that have tried nothing else and believe everything they read on the net... An SPE is not as strong as a G26 ? EVERYONE has been told a Zenoah is a heavy underpowered boat anchor
Spark intensity has very little to do with rpm, if it sparks at the right place and doesn't miss a stronger spark makes no difference...
Try a larger carb...Carbs are about $20 wholesale..For what they pay for the engine, anyone who sells a Chinese 26cc engine can well afford to use a carb that works better....

Hi Ralph

The SPE26 is definitely not as strong as G26, period! Even though my G26 is magneto, it kicks butt! APC 18x8 at about 7800rpm, it haul my 14lbs Super Stearman really well, more than enough scale power. The SPE26 does not come close.

The SPE26 (from factory, not from BCMA) is no where near what a 26 cc should be. In fact it is weaker than my Zenoah G20EI. The G20 able to spin 16x8 at about 8500rpm. 17x8 should hit at least 7800-8000. The SPE26 just can't go above 7400. The G20EI is still on stock ignition and stock muffler and less than 1 gallon flight time. The SPE26 is used a lot more longer so its well run in, but just does not cut it. On flight with H9 SHowtime, the G20EI have very strong vertical more than OS91FX, where as the SPE26 seems like OS91FX power, poor vertical.

On the other thread of securing the higher flow carb, the SPE26 is just sitting on the shelf and I thought if a different carb will indeed generate more power another 500 rpm will be nice, rather than gathering dust.

The G20 here turns my 18-6 Mejzlik about 8000 rpm, very close to a G23...You'll see
It has a sensor mount like the G26 conversions, timed at 28 BTDC, extra casting lugs cut off, different carb mount, stock carb, spool type prop hub from a G23....
Conversions run the same as stock magneto, just lighter...

I have owned and run both and the G26 is definitely stronger, even with a large bore carb on the SPE26.

The desirability of the SPE engines is not so much the power but the power to weight ratio. I don't think anyone ever said the SPE engines were more powerful than the Zenoah's. There is better than a 1 lb weight difference between the G26 and the SPE or BCMA 40CC engines. If you have a plane that needs a lot of nose weight, then the G26 would likely be the way to go. The SPE 40 opened up 3D possibilities for lite airframes. On some aircraft, the airframe just would not handle an engine the size of the Zenoah, but it would handle the SPE 26 size. I wouldn't read any more into it than that.

just my 2 cents....I can 3d my light airframe with a G26, no problem

edit***and this is with an inefficient prop, I can only imagine the Mezjlik on it.

Yeah, I know. Some will argue that you can't 3D a gasser under 50CC. Most of it has to do with wing loading. People will do almost anything to keep that wingloading down. I am no 3D expert, just recounting what I have heard.

Andy

arobatx: What plane do you have the G26 on? It looks nice! Capt,n

Yeah, a G26 with EI like the other 26s is a full pound heavier...That means the other 26s weigh 1 lb 4 oz...Show me one

Why the sarcasm Ralph??? Go to the source: http://www.horizonhobby.com/Products...ProdID=ZENE26A Check the specified weight yourself.

And nothing was said about EI on a G26. Only you.

Sarcasm ? How about Facts ?
How come everyone compares magneto ignition Zenoah engines to electronic ignition engines ?
I've been listening to this stuff for about 20 years, ever since the G62 was one of the only large scale engines sold...Looks really good for the other engine when compared to a magneto system..

Electronic ignition Zenoah engines compare very well to the others equipped the same...
nothing was said about an EI G26 because it makes the other engines look better if they use the magneto engine weight...
Same with any Zenoah, whateve size...

Here is why. We were discussing Stock G26 to Stock SPE26.

I guess stock means different things to different people...Stock to me means mechanically unmodified...Source of the spark makes no difference. A properly timed engine runs the same with EI as it does with a magneto ignition...
FWIW, there are some factory EI Zenoah engines shown on the Toni Clark website..Are they stock ?

captn,

that is a funtanaX100

As for the rest...I recall no comment ever made that conversion to EI adds performance. Like Ralph said, properly timed, you will see the same performance between the Mag and EI versions, I converted my 26 for two reasons, neither were performance...weight and physical size/shape.

I wanted to convert mine with one goal in mind: to replace a YS1.40 glow engine with a gas alternative in the same plane, sacrifice no weight and no flight performance. Well, I did it, and got a few hundred more RPM while I was at it. So in my case did I increase performance, yup....cuz of EI...nope.

We can compare performance, or weight. Since we all want to compare both, we have to equip the compared engines the same...weight without muffler, but with ignition, properly timed, same prop, same day, same gas/oil, and run em without muffler at all to get data. Everyone uses different exhausts, different batteries, switches...etc. So leave all that out. This is why Ralph and others of us speak up during these comparisons...just making the comparison useful. I've never seen anyone convert a top brand EI engine to mag, in order to compare it to the performance and weight of a Zenoah....hmmmm

In my case, and I am assuming in the case of many of the readers, I am talking about the way you would buy it from Horizon. Once you add the EI, the price goes from $299.00 to ??? considerably more money. What does it cost to convert one of the G26's??? Anyway, without the conversion, a weight conscious person would likely consider the SPE 26, with a given loss of power.

I believe I gave accurate answers, based on the information given in the thread starters opening comments. I believe the scenario I gave, why someone would want an SPE 26 over an unmodified G26 was accurate. Now, I am supposed to be the bad guy, because you guy's are changing the ground rules without telling anyone. The person that started the thread did not make comments on an engine with EI, or any other modifications. He specified that it had a magnito. If you wanted to say, "now, if you really want a sweet engine, convert it to EI and get rid of all that unnecessary weight", now that would be different. Your information is good, but the presentation confuses the opening of the thread, in my opinion. Sorry if this ruffles anyone's feathers. I am not a bad guy!

Oh dear, let me clarify.

I bought the SPE26 because it was dirt cheap over here.(this is not the BCMA version) at about US220. Now it is even cheaper, like US185. I already fly the G26 on my Super Stearman and it was priced the same as SPE26 then. But the Zenoah dealer got greedy and price shot to US270+.

Since I'm just into gasser I want to learn and tinker without too much of initial investment. Seeing how great my G26 perform, I have same expectation that it will at least perform similar but my finger was cross because SPE26 was very new then and being a chinese gasser at that. Granted that its much lighter, something like at least 1++ lbs lighter, I thought even if its not as good as G26 power, if the weigh reduction able to compensate the lowered power, why not.

I also bought the Zenoah G20 EI at the same time. Weight wise it was heavier than SPE26 by a few oz and 6cc lesser too. So I thought the G20 is a waste buy so I started to prep the SPE26 first on my showtime and I almost sold off the G20EI (lucky I did not, I will explain later). Flown the SPE26 at least 7-8 liters(2 gallons?). It was ok but rpm just too low. APC17x8 at max 7400rpm. I ask the Chinese factory and given the nice video they demo on hovering, they say their pilot also on 17x8 at 7400.

So then I help my buddy to setup his G20 and did some bench test.

The nos was ....SUPERB, SWEET! Right out of box, barely 10 mins run, we got APC 16x8 hitting up to 8500 and 16x6 at 8800. The response was crisp and starting was super easy. 2-3 flips it start. Once warm, just a flip. The SPE26 required almost 10 flips before I can any. Its actually worst than my magneto G26 on starting. Maybe its just my SPE26.

So I swap the G20EI into the Showtime, immediately it show the power it has despite a 4oz heavier than SPE26 and requiring a much heavier pack at 2450mah for longer flight where I was using 1400mah for SPE26. I did use an 8oz tank vs 10oz for SPE26. All in all, I do have more AUW with G20, but the power it generated was AWESOME. The vertical is almost unlimited. This is 2 flight after 1 tank run in on ground. Factory say just flight, no ground run needed. It was reliable and superb transition. I was a very very very happy man!

The SPE26 is gathering dust today. The power to weight ratio claim did not cut it. even at 6cc more and lighter, its power/weight ratio is not there.

Lots of folk knock on the Zenoah engine without even testing and run them adequate to see how its perform. If zenoah can make the G20EI, its a matter of time, they make the rest as EI. Only in US, Zen is expensive. Go to Hong Kong (land of free tax) you will can get almost all zenoah at US100 cheaper.

Bottomline, I bought it because it was cheap and I get what I paid for. Lesson learnt.

Though I have not tested, if I were to put a stock G26 magneto on a same plane as SPE26 stock, my money is on the G26. It may be heavier but the power generated will surpass the power to weigh ratio claim of the SPE26. Why I say so? Its obvious isn't it. If the G20 is more powerful and heavier than SPE26 and yet smaller in cc, you can only imagine where G26 is even with the heavier magneto.

BCMA insisted that their SPE26 is substantially more powerful than G20 etc due to some internal work they enhance on and a different bigger venturi carb. So I thought why not inquire about the carb because if another 30-40bucks spent can get another 4-500rpm on that 17x8, then I would go for it otherwise the SPE26 is just gathering dust.

On picture wise, my SPE looks exactly like what BCMA have on their Version III minus the ignition.

I talked to Adam at bcma engines, he sells a single Bowman ring that replaces the 2 stock rings, 200 rpm increase and lowers engine temp 40 degrees less friction, 15.00 for the ring. He also told me he is working on a higher compression head, 13:1 to be exact. I have rings ordered 4 mine 3 spe 26.s, so I cant say how well they work.

So what Magna really needs is some body with a SPE 26 is to run a big and little carb back to back and see what the RPM change is. Who cares about G26s, (in this thread anyway)
P.S. Love my G20 too

Put the G26 carb on the SPE...Run with the same prop...A G26 with an 11mm carb willl turn almost the same as with the larger one, within 100 rpm....Larger carbs are not always the answer....

When a person says 11mm bore....is that the bore of the throttle plate area or where it chokes down some at the venturi? Thanks Capt,n

tKG, [sm=thumbup.gif]

But I still care about my G26 hehehheh and I love them and the G20.... yeeehaa!

Same inquiries as captjohn...