Nice chart, but, does it take into consideration; H.P., torque, rpm, temperature, etc., etc???
The mathematics are cool, but go back and listen to the video of his DLE20 in flight, it's screaming as it passes by!

any guess as to what rpm the 12" prop is spinning in the air....12k rpm?

Hey Raptureboy.............Could you possibly post some pictures of your set up ?? My Ryan is coming along and would like to see what your motor set up looks like. Oh yeh, my DLE 20 arrived yesterday starting to figure out the mounting.

Thanks, Don

O. K here are some pictures of my DLE install on my GP Ryan. Mesaflyer you really gave me a scare what you said about forgetting to put the oil in[X(] I emptied out my can and as I got ready to measure the oil out I used a 1oz epoxy cup to measure with and I stopped an thought did I only put in 2oz in last time instead of 4? I emptied the old gas into a clear soda bottle to see what it looked like and compared it to what I just made up and they looked about the same color. Whew So I will try flying both planes tomorrow if it does not rain again and see if the gas is the problem. I've played plenty with the needles and I still may benefit from putting in some baffling to direct the air on the engine and add some kind of device to create positive air flow out the bottom.

Here are some pics for Mr Wad. Let us know how it all turns out,Ive been thinking of redoing the other one I have also. Feel free to PM me if you need any more pics, this engine was made for this plane.

The chart is only showing the load on the engine put by the prop. Nothing to do with the engine parameters. This is the load on any engine. Now you need to work out how much you want to load YOUR engine based on this data. I often use this to calculate the other combination of dia and pitch that may be suitable for an engine, given the best rated prop. For it.
For the DLE20 the best rated prop is the 17x6 but using the above chart you may use 14x12, 15x10, 16x8 also and be within 10% of the ideal load on the engine.
The data above is the volume of air moved by the prop - pitch x dia^2 x constant (pi/4)

Sounds like we are in violent agreement. Of course in the video, it's screaming. It's loaded well below the range specified by the manufacturer just as this shows it would be. I should have shown that his prop would show a load of 317383... a good deal below the recommended range. As far as all the other factors, of course they are there but for the most part they change little and aren't under my control. I just look at the range specified by the manufacturers listed props for THIS engine. Quite correctly, it was pointed out ths is the load on any engine but the range to pay attention to is defined by the recommended props. Finally, while I would agree the 17x6 is a nice match for this engine in terms of putting the engine at a nice compromise between torque and horsepower (it's what I run because it fits the purpose of my RV-4... moderate speed and lots of torque), saying it is best is to miss the point. Best is defined by what you want out of the motor. Most of us like pull/torque but others want more speed and which airframe you install it on and what you want it to do would influence the prop selection. I'm just showing an easy way to figure out if a prop keeps you within the range of loading the manufacturer is pointing you toward and therefore likely to keep your engine "intact" while still giving you flexibility to chose what is best for your application. If I had a P-51 racer I'd opt for picking up something in the 15-10 range or even a 14-11 or 14-12. None of these are listed by the manufacturer but would keep RPMs in the range the manufacturer recommends and give me much more speed than the 17x6. Just trying to give folks some other options... and a way to know they are not likely to damage the engine when doing so. Or at least if they want to go with a 12.5x13 they will have an idea just how much outside the normal range they are likely to be! It's a testament to the DLE that it is holding together when over-revving like that. As we all are finding out, on average these are tough little motors.

jsallade - I hear what you're saying, but if DLE says the max HP for the DLE 20 is 2.5HP at 9,000rpm, I took it to mean that 9,000 is the RPM where this plane will produce it's greatest power. Now that I look closer, the specs do not say which prop was used for that test. Also, does that mean that anything over 9,000 will not produce extra power? Or, if you go smaller diameter \ higher pitch prop you are then trading thrust for speed, i.e., the prop (your transmission) is in a higher "gear'? If that's so, just wondering if mfgs should also include a "max recommended RPM" number. Or maybe that would be asking for trouble, warrantee-wise. Just wondering now how many RPM's these DLE's can turn before they start to tear themselves apart or wear out prematurely. (not that I'm looking to do that - I"m happy with my 16x8 for now).

GSNut
You CAN make your 7C idle down - like the 8FG. Mix throttle to throttle, and put its activation on a switch. I flew 'idle down' on my 7C for a long time before I upgraded to the 8FG.

OK. I had a bit of a rough landing the other weekend, Had a Eflite electrict retract fold on me. To make a long stroy short my Zero noised over, In the process the muffler outlet dug into the ground picking up some dirt. When I put the plane on the stand to remove the wings the dirt fell inside the engine.( I noticed the dirt as I was flipping the plane over). When I got home I took the engine apart and used a parts washer to flush all the dirt out of the engine and relubed with 2 cycle oil. I had to replace the base gasket as it was destroyed in the process.

 Now that i have the engine back to gether with all new gaskets, and picked up a Jtech wrap around for it and a Tach. I installed it into my test bench and nothing. I can see the fuel being drawn into the carb and the plug is wet, but there is NO spark. I tried a new plug and still no spark.
I am using NGK CM-6. The engine was running fine when I took it apart. 
 
I took extra care not to get varsol on the sensor and removed the carb and the reed cage when cleaning.

I guess my question is, how do I test the sensor and the CDI to make sure the problem is not there?

Thanks in advance

wjcalhoun

Thanks wjcalhoun !

Will get back to my 7 C asap. Just ordered new Sanyo's (2000mah) all the way around including the Tx's and double packs for the planes. Should be here about Monday or so, then b. pack building time. I don't trust my Old Walmart $ 1.00 per each nicad after 6 years of use. Some packs are starting to show flat cells.

Now just find a suitable IBEC ?

Cheers

OK, took the hall sensor off my DLE 30 and the 20 fired up. guess that is the answer.  is there any way to test the sensor or just scrap and get a new one?

Anyone tried a canister muffler on this engine yet? Any performance gains to be had?

I know this is kind of obvious, but check it for broken wires. The white wire on mine broke right at the edge of the plastic housing. It was real hard to see. I have a "how to check" page that Jody sent me. I can't seem to upload on here. You should be able to search here, or PM me your e-mail and I will send it to you.

Spinnerrow - I don't know about performance gaines, but that cannister muffler is AWEFUL pretty.

Estang - Why not just test the DLE 20's hall sensor with the DLE 30. (since it worked the other way around...)

Here it is http://www.rcuniverse.com/forum/m_88...tm.htm#9851597

Mesaflyer, Thanks for your post.
I did not use a servo wire but a small wire to short the pins, same results. I put witness marks on the case where the edge of the sensor was before I took it off, so I could put it back in the same place.  With a MAS 16-8, I am getting 8500 rpm and 1700 idle with a clean mid range, no 4 stroking anywhere unless I come off the gas fast.
One thing that bothers me, My low speed is out 1 turn and it is a bit sluggish from idle it is snap the throtle quick after sitting a few seconds.I am not using a servo on my test stand, only a wire, so this might just be the engine spooling up.  If i trun the low speed leaner (1/16 turn) it will die out as I snap the throtle. 1/16 richer and it really lags untill it is past 1/2 way mark. I am using Still oil mixed at 32:1 but am seeing a lot of black gunk out of the pipe. Is this normal?

Estang,

Try adjusting half as much.....1/32.
Some of these are a wee bit touchy in adjusting.
Be CERTAIN all such adjusting is with the eng warmed up.

You'll get some black goo residue for about 1-2 gallons of fuel,
but it'll become less & less as the eng breaks-in.

Estang,
Your welcome. And yea, what he said. Just keep it on the rich side.

As for the rpm, 8500 is a bit more than what I believe you should be running WOT. It will unload in the air. I try to keep mine closer to 8000. I'm running a XOAR 17 x 6 at 8100 rpm.

O.K back again, I dumped the old gas out and mixed up a new batch with 4 oz's of oil this time for sure and now my baby is humming along sweet only now I've discovered that the crank on my Stearmans engine is bent[:@][:@] I've never hit the prop on the ground or nosed over hard at anytime. I use an electric starter sometimes and I'm wondering is it possible to bend a crank using the starter? Someone tell me, why am in this hobby again?[&:] Oh yeh because it's totally cool when it all works Any thought on a bent crank from starter use?

Well, I have never heard of bent crank from using a starter. I would say no way. How did you determine that it's bent? Do you have a lot of vibration?

I've bent crank shafts from crashing nose first and hitting trees, but never from a starter. does not sounds possible. Unless you swung the starter sideways, like a bat.

is your spanner fitted properly? Its not off centre as this can create the illusion of a bent crank and the vibration

You could have your spinner bolt to tight. That will cause it to distort making you think that the crank is bent. I cannot see any reason that a starter would bend it.

Is the 16x8 too small for this engine? I figure if the 17x6 is ideal, the 16x8 should also be ok

Ameyam