krayzc-RCU

My Feedback: (31)

yeah i see it needs a curve sort of on or off if not

flyin two low

My Feedback: (44)

if i am not mistaken, i saw a .52 gas engine from magnum engines, that is approx 8cc if i figure right. by the way i got my DLE 20 FROM TH TODAY AND CRANKED IT UP, SWEET AND SMOOTH.

Phoenex

My Feedback: (1)

You guys might be interested in seeing the Revolver 70 with a DLE-20 video. Part of his comments on Youtube are quoted below.




[link=http://www.youtube.com/watch?v=BllA1VnwsSg&feature=related]DLE20cc and Revolver 70[/link]

NM2K

My Feedback: (14)

It is very hard to argue with success. I'll get over it.


Ed Cregger

NM2K

My Feedback: (14)

Thanks for the tip. That Revolver sure is pretty and the engine runs like a watch. It even sounds like a sporty glow engine.


Ed Cregger

a1pcfixer

My Feedback: (7)

Without a curve, 1/3rd stick movement=60% throttle movement.
I tried altering geometry, but had it worse.

I'll fine tune the curve after several flights.

Regardless, this is a very spirited 20cc engine!!!

guinnb

My Feedback: (2)

I've been working on getting the DLE 20 and Syssa 30cc engines tuned where I like. The Syssa was nearly perfect out of the box and, in fact, I didn't even have to change the short throttle arm out to get more throttle resolution.

The DLE 20 is another beast. It has what I'm told is a normal on/off lower throttle range where the throttle is very sensitive at the low end. I've changed the throttle arm out to a 3/4" long arm from WrongWayRC and that helped. I've tuned the lower end and have been playing with throttle curves as well to help this. The throttle curves have helped the most and I still have a lot more that i can adjust here (this coming weekend I hope). I will also change over to Redline synthetic oil the next flights at the recommended ratios (30:1 for the DLE 20, 40:1 or 50:1 for the Syssa). I know a bit of this can be prop related as well and I continue to try new props.

My question is why are two-stroke gassers, in general, sensitive on the low end throttle range? Something to do with the carbs, reed valves, timing? Are there any solutions such as intake manifolds, velocity stacks, etc. that can resolve this w/o the use of throttle curves (many radios still don't have TC's)?

captinjohn

<hr />I doubt very much your Syssa engine is or was perfect out of the box. If it was , maybe you should stay with that brand. There are a lot of things that will help with the problem.....they have been posted here already. You are just going to have to search for them. As much as I like helping people....I cannot do the looking up for everyone....got many things to do myself. Regards capt,n

guinnb

My Feedback: (2)

Thanks for nothing Capt'n. Why don't you just not respond? Sad ppl act this way....

tkg

My Feedback: (1)

The carb sensitivity is simple, to much carb. Its a matter of how much air an engine needs at any RPM. With a large carb the % of air flow change is huge at very small throttle openings.
Its all based on the mfg's having to playing the numbers (HP) game of power at WOT, mines bigger than yours, so they can sell more engines.
On several engine I've gone to a smaller carb, lost a 100 rpm or so at WOT, but gained a much more linear response

guinnb

My Feedback: (2)

Thanks Tkg. Makes sense. I also got the following response which helps me understand this a bit better:

"It really has to do with the archaic carbs that we are using. The carbs are designed to run balls out. Lower throttle response is touchy because the cross sectional area of the throat opening of a butterfly valve has the most change per angle of rotation at the initial opening, and conversely the least change at the high end.

For a linear response we need the exact opposite.

You can do a little mechanical expo in the system to fix this, by setting up the servo arm so that it has the least linear movement on the low throttle area and maximum movement at the high end."

So, I guess we are limited by the butterfly valve type carbs used on these engines. I'll keep working on the linkage and throttle curves.....

JoeAirPort

My Feedback: (41)

Check out his diagram that shows servo and throttle motion using your idea.

Truckracer

My Feedback: (19)

To add just a bit to what TKG said .... and he is dead on, I recently had an experience with a DLE30 and a Syssa 180. My Syssa was always throttle happy at the bottom end of the travel range .... sort of an all or nothing throttle or as I have come to call it on some gassers "a toggle switch" throttle. Given the port timing on the Syssa and the large carb, the situation was a given. The DLE30 was just the opposite, very linear throttle and much happier overall throughout the throttle range. Now I have always set up my gassers with some mechanical differential on the throttle linkage to reduce the sensitivity on the bottom end of the range so that was not the issue on the Syssa. The Syssa uses a larger carb than the DLE30 and I blamed this for most of the problems but it also has more radical port timing than the DLE and the above combined with using lightly loaded props and possibly an ignition that provided advance (removed the retard) at just the wrong time, the throttle was overly sensitive.

Good engines all .... you just have to understand them. Had I kept the Syssa, I was considering using a smaller carb to make it run more to my liking, The DLE came along, runs the way I want it to run out of the box so I never looked back.

guinnb

My Feedback: (2)

Joe,

Tx for the diagram. That explains why the Syssa was so much smoother and linear on the throttle than my DLE 20cc...it's in the linkages. The Syssa setup has the throttle in a different place and the linkages are much more like the diagram. I'll rework the DLE and get it better!

av8tor1977

My Feedback: (6)

Yes, that is a nice diagram and should explain the geometry of throttle setup quite effectively for a lot of people. Good post!

AV8TOR
P.S. However, one time I made a throttle arm that was .8940" long instead of the .8939", and it didn't work well at all. (Just kidding. .8939"?)

JoeAirPort

My Feedback: (41)

LOL...I was waiting for someone to ask about that. I just made a line in AutoCad and never looked at the length. It just ended up that way. It's funny how the number turned out,. In hindsight I should have made it 1.0000.

av8tor1977

My Feedback: (6)

AV8TOR

ghoffman

My Feedback: (3)

Getting close to flying it, weather permitting:



It weighs 4-5 oz less than the RCGF 20cc, even with the aluminum engine mounts.

Johnny_Zero

My Feedback: (44)

Hey guys.....Looking for some advice. I have a Goldberg Ultimate 120 ARF and am considering the DLE 20cc for this plane. It should weigh around 9 to 9.5 plounds when finished. I fly at 5500 ft altitude. My last Ultimate was powered with a YS 120 FS and weighed 10.5 pounds (Heavy I know, but it was real strong). I have seen the videos of the DLE 20 flying a 10 pound plane and it looked good. Just not sure what altitude they were flying at. I am looking for input from people that have flown with this engine. The local flyers here think that the DLE 20 won't have enough power but there isn't anyone using this engine here yet. Any input would be great.

Thanks in advance.

jedijody

My Feedback: (1)

If you want to fly 3D, you willneed the DLE30 at your altitude for the 10-1/2 pound plane.

Johnny_Zero

My Feedback: (44)

Thanks for the quick response. Not really looking for 3D, but want it to be fast and smooth.

Johnny_Zero

My Feedback: (44)

Forgot to ask........What prop would you recommend for the 5500 ft altitude?

Thanks again

jedijody

My Feedback: (1)

If you want fast you would be better off with a mono wing airframe. For the 20 I would start with an APC 16x7 or 8, for the 30 a Xoar 17x10 or 18x8, maybe 18x10.

Johnny_Zero

My Feedback: (44)

That's the prop I was thinking of trying. If the DLE 20 will fly an Untimate 120 like a YS 120 FS I will be happy. I haven't flown planes for about 3 years, been playing with helis. I want to get back to planes and the Ultimate is the airframe that I have. It is framed up and ready for an engine.

Thanks so much for your help.

NM2K

My Feedback: (14)

You expect an equal displacement (1.20) gas engine to produce the same power as a YS 1.20? Nope, it doesn't work that way. Gasoline/petrol as a fuel produces less energy than alcohol/nitro fuel. That is why Jody recommends the 30cc engine over the 20cc engine.


Ed Cregger