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-   -   spe-26 in big stick (https://www.rcuniverse.com/forum/gas-engines-142/8899546-spe-26-big-stick.html)

geeter 07-01-2009 09:46 PM

spe-26 in big stick
 
want to use my spe 26-cc in a 60 size big stick. weight about 6-7 pounds. the spe runs ok ,but ain't much power there for any sport plane. or anything over 8-9 ponds either. turning a 16-8 prop. what do you think..................RON

Bill Rademacher 07-01-2009 10:36 PM

RE: spe-26 in big stick
 
I'd try an 18 X 6. I have an SPE 26 in a seagul YAK. It didn't do much until I gave it more blade. I started with a 16 X 8.

Not the most power, but definitely more than with the 16 inch prop.

billrad

soarrich 07-02-2009 05:32 AM

RE: spe-26 in big stick
 


ORIGINAL: geeter

want to use my spe 26-cc in a 60 size big stick. weight about 6-7 pounds. the spe runs ok ,but ain't much power there for any sport plane. or anything over 8-9 ponds either. turning a 16-8 prop. what do you think..................RON

Ron

Did you ever take rpm readings?

GeraldRosebery 07-02-2009 06:36 AM

RE: spe-26 in big stick
 
Have you checked the timing on your SPE? Mine was set to 45 BTDC and it ran like crap. It run much better when it was reduced to the STANDARD of 28-30 deg BTDC. The ignition by Melody is also not the best unit out there. If you have problems, change it out for one made by RXEL, available through CH Ignitions (and others). It is currently the gold standard of Chinese ignitions.

That said, I agree, increase the prop (ground clearance permitting) to an 18x6. If ground clearance is an issue, try a 16x12. My SPE (not yet run in) is turning an 18x6 Xoar at 7000 even (altitude 300 feet above sea level). Because these Chinese engines are still so poorly fit together I have found that running the heck out of them on the bench is a good idea. I run a gallon or so of 32:1 ashless oil/gasoline through the engine at full throttle. It takes about 3 hours and afterwards they are much smoother, have better compression and no longer squeak and groan when you turn them over by hand.

Gerry Rosebery

geeter 07-02-2009 06:58 AM

RE: spe-26 in big stick
 
my spe has been run about two hours off and on. it,s building compression very nice. it doesn't have the power for a sport plane as i can see, so i guess it's better off suited to a floater type plane like a stik type. the engine ain't much heavyer than a 91 2 stroke, maybe 8 0z, that ain't alot with a plane with almost 1000 sq, inches of wing. just a thought..................RON

togatoga 07-02-2009 07:16 AM

RE: spe-26 in big stick
 
Even with a 61 two stroke , the plane tends to be nose heavy. i would advise converting to a taildragger, relocating the rudder and elevator servos behind and beefing up the frontend. Karol has a zenoah G20 in it and flies well. The spe26 is definitely not a powerhouse-I've junked mine.At best i could only get 7400 on a 17x8 on rcexl ignition which should be more than sufficient for the big stik. This engine shakes a lot at idle so I'd go over the weak spots with glue especially the tailplane where at idle, the tail shake can be scary.

GeraldRosebery 07-02-2009 07:30 AM

RE: spe-26 in big stick
 
I have to admit that the SPE 26 is fundamentally junk. I also have switched to the RXEL ignition and pitched the unreliable Melody unit that came with it. I agree that it is especially badly balanced and shakes like the devil at idle. It is clearly a cheaply made industrial engine. It vibrates a lot at 7000 rpm too and will cause airframe failure at some point. I had mine in my beautiful Aeroworks 73" Yak 54 (wonderful airplane BTW). It is a travesty to power it with the SPE.

soarrich 07-02-2009 07:37 AM

RE: spe-26 in big stick
 
Take a look at the FTL26cc, mine is super smooth running. I may test fly mine today.

karolh 07-02-2009 07:38 AM

RE: spe-26 in big stick
 
Though not known for it's power the fairly light SPE engine should do quite well in the Big Stick. Relocate the elevator and rudder servos to the rear, position the fuel tank, Tx and battery under the wing, locate the ignition module and battery in the original tank compartment and of course use the tail dragger arrangement and it should balance okay. I had to use a taller alum l/gear for additional ground clearance to accomodate the 16-17 " dia props. As Togatoga suggested beef up the front end and make sure the horiz. stab is well secured to the body as it can vibrate like crazy at idle.

Karol

WCB 07-02-2009 08:45 AM

RE: spe-26 in big stick
 
About the vibration of the SPE... mine was so bad it literally tore apart the Funtana X100 I had it on. One of the fliers at my field is a retired industrial machinist. He volunteered to take the engine to his shop, tear it down and find the problem. He took the crank out and put it on a lathe and using a dial indicator found the crank to be slightly bent. The engine had never been crashed or dropped. Somehow he fixed the bent crank to within enough tolerance that he said it would be ok. I ran the engine on a test stand and it is much smoother now. It still has a little vibration to be expected, but nothing at all like it was.

wcb

GeraldRosebery 07-02-2009 09:48 AM

RE: spe-26 in big stick
 


ORIGINAL: WCB

About the vibration of the SPE... mine was so bad it literally tore apart the Funtana X100 I had it on. One of the fliers at my field is a retired industrial machinist. He volunteered to take the engine to his shop, tear it down and find the problem. He took the crank out and put it on a lathe and using a dial indicator found the crank to be slightly bent. The engine had never been crashed or dropped. Somehow he fixed the bent crank to within enough tolerance that he said it would be ok. I ran the engine on a test stand and it is much smoother now. It still has a little vibration to be expected, but nothing at all like it was.

wcb
Very interesting observation. Further proof that the engine is fundamentally junk put together with bent (??????) parts. What are they thinking, that ALL Americans are stupid? Since I bought one I guess I am, anyway!

Gerry Rosebery

SRimer 07-02-2009 02:03 PM

RE: spe-26 in big stick
 
I'm happy with my SPE 26, i swapped the carb with a 11.1mm one and it runs very good, I get 8200-8300 with 16/8 or 17/6, it is not the strongest 26 , but it is very light and very easy to use. it would be a good choice for 90 size ugly stick in my opinion.


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