which is better?
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which is better?
I'm considering a 70cc twin for my 1/3 cub and was wondering which engine is better, and has more power? The roto 70 or the da 70? I notice the carb location on the da would be easier installation, where as the roto is rotary valve which is a plus for me. Also could anyone posts rpm's and props used from each engine thanks.
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I've got a Proctor 1/3 Cub in a stolen German paint scheme, you may have seen it, anyway, its powered with a Zenoah GT-80 swinging a Xoar Sabre 24X10 scale prop. Its more than enough power.
#5
This looks like a good option. I've not seen the 70 but the 60 single I have. Mile High's service is great.
http://www.milehighrc.com/EME70CC.html
Jim
http://www.milehighrc.com/EME70CC.html
Jim
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thanks for the reply's! Right now I haven't made up my mind as of yet, but now I'm looking at the roto 85 fs boxer. The plane had a dle85 which I gave away because of the clink and clank that engine made, so I'm going away from all the Chinese made engines. Don't get me wrong that engine ran beautifully, I'm just wanting a high quality engine for the long haul.
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thanks for the reply's! Right now I haven't made up my mind as of yet, but now I'm looking at the roto 85 fs boxer. The plane had a dle85 which I gave away because of the clink and clank that engine made, so I'm going away from all the Chinese made engines. Don't get me wrong that engine ran beautifully, I'm just wanting a high quality engine for the long haul.
#9
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I just sold a GT-80 that had very low time. Great engine but not one I would use on a CUB because it wouldn't effectively pull the sizes of props I would prefer. As speedracer says, these engines like to turn up and I don't think that would match the personality of a big CUB.
I'd be very interested to hear some reports about the Roto line of engines. I have never seen one in person.
I'd be very interested to hear some reports about the Roto line of engines. I have never seen one in person.
#10
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You guys are nuts debating the power band charisteristics on the gt 80 for a cub. Same prop about the same rpm from both the the da 70 and the gt 80. If you put a little teeny race pitch prop the gt 80 will spin up reliably much faster. But this isnt a race it is a cub.. I would avoid the roto as i have never seen one. Phave you? What does that tell you? The gt80 is more than the da70????( *** come on horizon? What are you trying to do- get everybody to buy your china made evolutions?) the da 70 fits a little better on a cub, the top carb on the gt80 can cause issues if you arent careful with the cowling installation. Da is proven and has da service.. Hmmm. No brainer...
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It appears your mind is made up at to which engine you want, so get one and you can tell us all about the roto 85 who knows you may even get another one or two tried out with your report.
#13
Hi Barry, is that plane the one that our Balsa Eater tree reached up and grabbed at the warbirds event in Thornburg, Va a couple of years ago? Missed you last year. Sincerely, Richard
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Nope, that was my Balsa USA 1/4 scale with the PTE36R engine. My 1/3 Scale 140" w/s is a Proctor with the Super cowl completely covering a Zenoah GT-80 swinging a Xoar 24X10 Sabre propeller painted in German markings. This plane was also at Warbirds Over Fredericksburg and flown by Rob and myself.
#15
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The thing that sticks in my mind here is that the OP has told us that the airplane has flown with a DLE 85. This tells me that the airplanes CG was correct with that engine. Some of the suggestions here and including the OP thinking of going with the Roto 85 4s are much heavier then the DLE. Obviously this is going to lead to more work getting the CG back to where it was with the original engine.
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The thing that sticks in my mind here is that the OP has told us that the airplane has flown with a DLE 85. This tells me that the airplanes CG was correct with that engine. Some of the suggestions here and including the OP thinking of going with the Roto 85 4s are much heavier then the DLE. Obviously this is going to lead to more work getting the CG back to where it was with the original engine.
#19
My Feedback: (29)
Barry, I'm glad you are so happy with your GT80. I do agree it's a nice running engine. Just some food for thought, the GT weighs 2.5 lbs more then the DLE, I don't think relocating the RX battery is going to compensate. Personally I have not used a separate ignition battery for 4 years now so it really is not required however we do not know if the OP was running one or not..
Last edited by speedracerntrixie; 11-23-2014 at 04:23 PM.
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I agree with you 100% on the 170 it looks so sweet. I have a 1/4 hangar 9 with the os 320 ff pegusas which everyone said was too much for the airplane, and we all found out it was a match made in heaven, and it even looked scale. Problem with the 170 is the prop clearance on the 38.5 pd 1/3 cub. When I had a 26x10 on my dle85 and if you landed slightly hard it would hit the prop. I KNOW the 170 would be overkill since the dle85 was unlimited vertical but it would be cool to have the 170 on the 1/3 and the Pegasus on the 1/4...I'M real loyal to my four strokes!
#23
I own a BUSA 1:3 scale Super Cub.
Itīs powered by a GT-80 which fits nicely in the cowl with the exeption of the plug caps. They extend about 5mm from the cowl.
The propeller I normally use is a Fiala 26x10 since the engine would rip the original Fiala 28x8, cut down to 27". Way too much noise.
The 26x10 spins about 6200 rpm and provides a good bit more than scale power for the 46 lbs Super Cub.
Donīt have direct experience with either the ROTO 70 or the DA-70, but from reading several reports on the net, I seems that the ROTO is not very powerful. About the same, or maybe even slightly less, than a G-62 on a non tuned exhaust.
The DA on the other hand is reported to be quite powerful. Not that itīs really needed for a Cub though. :-)
Itīs powered by a GT-80 which fits nicely in the cowl with the exeption of the plug caps. They extend about 5mm from the cowl.
The propeller I normally use is a Fiala 26x10 since the engine would rip the original Fiala 28x8, cut down to 27". Way too much noise.
The 26x10 spins about 6200 rpm and provides a good bit more than scale power for the 46 lbs Super Cub.
Donīt have direct experience with either the ROTO 70 or the DA-70, but from reading several reports on the net, I seems that the ROTO is not very powerful. About the same, or maybe even slightly less, than a G-62 on a non tuned exhaust.
The DA on the other hand is reported to be quite powerful. Not that itīs really needed for a Cub though. :-)