SpinnerRow

Well, I guess the little guy was spinning pretty good then!

a1pcfixer

My Feedback: (7)

Probably both!

Compared to a new roller cage, yours looks a wee bit toasted;

jedijody

My Feedback: (1)

The bearing definitely show signs of localized high heat, bands of blue on the rollers.

ahicks

My Feedback: (2)

Seems like a lean run would show on the sides of the piston? That one doesn't look too bad.

Agreed the bearing looks like it's been heated up pretty good, but the much softer rod appears to be in pretty good shape? I would guess from the appearance of the rod, the oil would have to have been doing a pretty good job to keep the rod from frying due to the heat from the needle bearing?

That leaves only one other option?

a1pcfixer

My Feedback: (7)

And that localized high heat left little if any lube to cool & protect that heat treated pin,
so it eventually let go.

I'm not a big fan of high rpm's out a DLE20.

jedijody

My Feedback: (1)

Neither is the DLE20.

aerobear

My Feedback: (4)

From a longevity standpoint it's probably wise to avoid high rpm but it is fun to see what the design is capable of. From my limited experience with the 20 it looks like it has the potential for impressive power in the 9-10k range. As it is, the 20 is great choice for average sport flying but I think there is plenty more as long as the engine can be made to hold together.

a1pcfixer

My Feedback: (7)

I must have missed that memo on it being fun to blow $269.00 eng & possibly crash your model doing so. Looks like SpinnerRow missed it too.

The DLE20 produces it's peak torque around abouts 8400-8600 rpm. An occasional blip into the low 9000rpm range is ok.
But start actually running them consistantly in that upper range and we see what happens.[sm=thumbs_down.gif]
That upper range does nothing to produce usable power, but it does increase the heat generated internally, resulting in decreased lubrication, and a damaged engine.

My first DLE20 is 1 year old and has 6 gallons of gas through it, and spins a Vess 17 x 6 prop.
Second one is about 8 months old and has almost 5 gallons of gas through it, and spins a Xoar 16 x 6 prop.
Both use a top notch lube @ 30:1....both still running great!

TimBle

Did you by any chance try a different prop without retuning the engine?

SpinnerRow

No, I've been running this prop all season.

When I put the bearing back on the pin and the pin/bearing into the rod, it rolls smoothly.

SpinnerRow

I like the speed that I'm getting out of the APC 15x10 but I may have to put a Master Airscrew Classic 15x10 on it to put more of a load on the motor. I've tried an APC 15x11 and it lugged the motor down below 8000

tevans55

cerralvo-

I have been using a silver jewelers screw driver to adjust my DLE 20's on my B-25 without any problems. A larger screw driver would vibrate off the screws but the jewelers screw driver allows me to adjust the engines while they are running at idle and full throttle. Please fasten your plane firmly to the ground and move slowly and carefully around the prop!!!

a1pcfixer

My Feedback: (7)

That -or- a 3 blade prop, and increase the oil mix ratio to 25:1 if you often run up in the higher 9000+ range.

The cyl walls/piston skirt have a larger area for oil to get splashed onto, so they looked OK.
The pin on the other hand, is a case hardened part (ie, cheap heat treated), and increased friction in that area
changes the surface hardness where that bearing rides. Eventually, extended stress causes a few to bail out.

Hopefully you'll find a better combo of prop, lube mix ratio, flying style, so that your next one lasts longer.

jedijody

My Feedback: (1)

At 32:1 fuel/oil ratio there is only 1/4 ounce of oil in an 8 ounce tank of fuel. Running at those RPM is asking a lot from that little bit of oil.

SpinnerRow

Flying style won't change (WOT or Bust!) so I need to change something else.

SpinnerRow

.

Joespeeder

Hey RBean,

MAS Prop emailed me a follow up today on our inquiry to the 16x8x3 redesign question.

Here is the email copy and pasted to this post.


"Joe,

Ok, it sounds to me like the 16x8 3-blade with the "4020T" is a prior production model, and the 41 versus 40 refers to diameter in centimeters. We felt for safety sake the high torque gas engines needed a beefed up transition area. We have to balance safety and performance, as you can understand. That said, the 16x8 3-blade generally does well with the DLE20. An alternative is a 16x10.

Another change with the new 16x8x3 was strictly for pitch measurement. Because of our design, the back of the prop blade doesn't sit flat a prop gauge and people thought we were underpitched because of is. We had a slight re-design so that the pitch could be accurately read.

I hope this gives you the info you need. "


I thanked Teresa for her followup and insight. However, your test results suggest a definite change in the way the 16x8x3 performs on the DLE-20.

I think I still have an older MAS 16x8x3. I will have to dig it out and protect it till needed.

A few options in the 16 inch 3 blade variety can be found here.

http://www.valleyviewrc.com/estore/x...ller-16x8.html

http://www.v-eastonline.com/categori...e-blade-props/

http://magnumrc.com/3-blade-wwii-war...6x8-p-245.html

http://www.menz-prop.de/english.htm

Joe

microdon2

My Feedback: (47)

SpinnerRow - do you really run WOT? I rarely do - usually run about 2/3, then might go WOT for a speed pass, but then back off. Which is another reason I was surprised mine broke, like yours did. Maybe I was running too lean, or maybe this is just a defective part, and you and I were some of the unlucky ones. Either way, TH replaced the engine and I haven't had that problem again.

SpinnerRow

It's a P-51 - I run WOT and might drop it "some" to land. [8D]

I also have a DLE 20 in a GP PT-17 with a Vess 17x6. It putts around on way less than half throttle for 20 minutes. An occasional WOT on an upline to do a roll, split S or hammerhead. I'm too afraid the plane would come apart on a WOT flat and level run.

RBean

Joespeeder,

Thanks for forwarding the e-mail re M/A prop. Does not really answer my concerns. Next good weather I'll put the new 16-8-3 in a DLE 20 which is broken in and see what the result is in the air. I'll report here. All the other props you listed are good but expensive compaired to Master Airscrew.

gazzazh

Hi All,

I am having a lot of issues with my 30cc dle engine and EMI...
I am using an AR7000 RX and Dx7 .. I am getting major interference.. my servos are moving on their own..
how many ferret rings do i need.. or what should i look for to get this problem solved.

Cheers and thanks a million

Happy Landings..

karolh

If you are running the engine with the stock spark plug replace it with an NGK CM-6 plug, as the stock plugs are known to sometimes give interference and or running problems. Also ensure that the spark plug cap is pushed all the way down on the plug and over the hex section. HTH.

Karol

gazzazh

Thanks.. will change plug, and will also wrap ignition in tin foil, shiny side facing in as well as place some ferret rings.. will keep u updated ,,cheers

karolh

Try my suggestions first before using the foil or f/rings.

Karol

TimBle

I tried a APC 168 on my DLE20 in the Spot On today.
WINNER excellent vertical performance for pattern

Much better than the Xoar 16x8.
Still waiting for some VEss17x6 props to arrive.
I may try the APC 17x6 in the mean time.