Translation;
Hi! I got mine from Valley View R/C and it was a few dollars less
only 1 down tube (muffler)

All, Has anyone done or seen any tuned pipe prop/thrust data on our little beauty?  Bob</p>

I haven't seen any tuned pipe data but someone has done a mousse can muffler with good results.

I have a header and ES Composites pipe that I plan to put on my next DLE 20.

Thanks Jim I was in fast mode !!!! I hope more people under stand !!! R/L
Good looking pipe from VVRC!!!
do you know anything about the inserts that T BM sell I wonder how thay work for the Muff. DB. R/L

Thanks.  Going flying w/ my 20 on a pattern plane.  Bob

OK, that sounds like fun. Which plane? Piped? Prop size? Please spill the details!

Per the TH site the DLE 20 is rated for 87-93 octane gas, but the DLE 30 and DLE 55 states only 87 octane. Just spoke to a TH rep who said 87 octane is the recommended fuel for the DLE 20, also. I"ve been using 93 octane, due to the range stated on the site. Does anyone know if 93 octane could \ would cause any damage to the engine over the short or long term? Any advantages of using 93? I'm going to move to 87, since I use the same tank for both the DLE 20 and 30 - just wondering if I'm giving up any performance (like a higher percentage of Nitro), or are these engines designed for 87 and nothing higher? Thanks.

Within the recommended range they are not octane sensitive at all, all three grades of regular pump gas work fine. There is no performance advantage to one over the other.

http://www.rcuniverse.com/forum/fb.asp?m=10630851

The octane rating of gasoline refers to the resistance of the fuel to preignition and has nothing to do with the energy of the fuel. High compression motors such as race cars are more prone to this which is why they need the higher octane. It doesn't hurt to use the higher octane, but if you car ( or plane ) doesn't "knock" with the 87 octane, anything higher is only a waste of money.

ahicks, It's a KMP Arrestti III, this is a DLE20 using an APC 17x6 with a header and a cannister muffler from Mile High. It fit with no body modifications. I was shooting for ~101/2 lbs but ended up a smidge over 11 lbs. The engine only has about 20 minutes of run time and it certainly pulls hard on the ground and really hauls in the air. Looks like vertical is unlimited ( I was afraid to hold full tilt for more than 10 seconds with the engine on such little time). It originally started quite easily once the gas got to the carb. The only problem is with the idle. It will idle nicely at a low idle but seems to jump from being slightly too fast to the low. I would like to hit somewhere inbetween. Seems like I read about this earlier in this thread. The muffler is supprisingly quiet and the header was easily modified.Will post a picture and some prop data shortly. I just don't want to stress the engine too much. My intention is to try beginner class this fall when the weather get a bit towards fall. This plane is about the smooth and most stable plane that I ever flown. Bob

+1

Hi

I have a question .

If the compression ratio , is higher than say : 10: 1 or 11:1 , should we use a higher octane ?

Michel

thanks for the info. Ihave a smaller Pitts Python 54" and im really contiplating to install a DLE 20 on it. Icurrently have an electic setup on it.

Yes. Once you get above 10.8:1 then you need to be considering RON 98

Only & IF the engine mfg recommends premium.
The vast majority of our gas engines we use for rc run fine on regular & don't require premium gas.

Jody &/or Ralph can probably tell ya which DO require premium, and won't have to take their socks off to count that high.

C/R and H.P. claims are more marketing/sales than actual fact.....along with bragging rights.

WOW  what a great motor

Just got my DLE 20cc installed in my fleet biplane (10lbs 3 ozs) and started her up based on the reccomended hi and low carb settings, and she ran great!

After a break in tank - took up the plane and ran and flew great!!!!!  no problems great transititons from low to high and back down again!

I ran a 17x6 xoar prop, lots of power not great speed - but not a great speed, but scale speed for the biplane.  I was thinking of trying a 16x6 or 16x8 prop to see what happens!

GREAT Engine!!

a1pcfixer - I understand that hp specs may be more for marketing than factual, but would hp numbers be RELATIVELY significant and consistent between mfgs, i.e., if the DLE 55 says 5.5 hp and another make of 50cc engine says 5.0 hp, at the same RPM, would the DLE produce 10% more power at that RPM?

Within what a mfg produces.....maybe.
Between mfg's.....nope.

They don't all uniformly state their HP numbers at the same rpm's, so often you can't compare that way.

Do you really think ANY Chinese gas eng mfg puts their eng on a dyno to actually check the HP figures?
If they did, wouldn't we be able to find their data sheets and graphs somewhere?

Might be enlightening if someone started a new msg thread; Which mfg's actually dyno test their claimed HP figures?
Doubtful any but the top dollar/top quality ones get listed.....and that leaves out the clones & copies of clones.

I'm flying an APC 16X8 on my DLE 20 in my Sig 110 Rascal and it really zips along.......

APC props seems to work well. I was told not to use a plastic prop on my DLE20 but it appears many folks are having a lot of fun with the performance these offer.
ANy reasons to not run a plastic prop on the DLE20?


a1pcfixer, for a small two stroke I doubt the compression ratio is going to get to 10.8:1, so using premium gasoline is really bragging rights I agree. The DLE 20 comes close depending on which spec sheet you read. Most of the samll two stroke gassers are undersquare in geometry so have low swept volumes. To get to higher compression ratio's they wouold need to have over head valves.
I've often wondered why the Saito gassers seem to produce such poor power when they can achieve higher compression ratio with the design.

Loss of thrust ring any bells?

Look at one from the side while running and rev it up.
See the tips flex?

Here are a couple of shots of my engine mounted in my Arrestti. Hope they are viewable. Bob

That's not a very good plan. I'll save you the trouble. They flex. Just like most props do.

APC's are popular 'cuz they have an EXELLENT reputation regarding durability (think low ground clearance, grass and or rough filelds), 'cuz they are available in enough different sizes/styles that allow your airframe/engine/flying style to flat work well together, 'cuz they are reasonably priced, and 'cuz they are easy to get.

Is there a better prop available? Sure, but you aren't likely going to see one priced competitively - or with grass stained tips? That's my opinion though.

I love my grass-stained tips.