DLE 55 Connecting Rod Bearing Failure
 

First flight of the day today and about 3 minutes into the flight, engine abruptly quit. Dead stick landing and upon retrieving airplane noticed that ignition light was still on so that was not the cause of the engine quitting. Tried turning over the prop, but met resistance and did not attempt to force it. First thought was that the connecting rod had broken.

I took the plane back to the pits and removed the cowl and muffler. Looking through the exhaust port, pieces of metal could be seen on the top of the piston.

Once home, I took the engine off of the plane and could hear all kinds of nice metal parts shaking about inside of the engine. [:@]

I proceeded to take the engine apart and noted the connecting rod had not broken, but the crankshaft connecting rod bearing had failed and then sent its innards up to do battle with the piston and sleeve.

Looks like I will need the following to fix this engine:

DLE Engines Piston w/Wrist Pin/Needle Bearing DL-55/111 $19.99
DLE Engines Cylinder DL-55/DL-111 $59.99
DLE Engines Crankshaft w/Connecting Rod DL-50/DL-55 $39.99

Here of some pics of the engine after being torn down.

Fuel:93 octane
Oil: Klotz Super Techniplate at 32:1

Good thing every flight is not a $120 flight![8D]

RE: DLE 55 Connecting Rod Bearing Failure
 

Are there any warranty considerations here? How old is the engine? What is its' prior history? Have you always used Klotz in it?

Really curious why this failed. Thanks.

RE: DLE 55 Connecting Rod Bearing Failure
 

Klotz oil huh...tsk, tsk, tsk

Serial #1430, old engine, out of warranty for sure. Easy fix though.

RE: DLE 55 Connecting Rod Bearing Failure
 

No warranty considerations as I bought it off of a RCU member back in June. It was advertised as being a low time engine and I had no reason to suspect otherwise as the piston and sleeve were clean and it turned over smoothly. I have always used the Klotz in it.

At this point, I can only surmise that it was a random parts failure.

RE: DLE 55 Connecting Rod Bearing Failure
 

Thanks Jody! Klotz now getting donated to club string trimmer. LOL!!:D

Live and learn....

RE: DLE 55 Connecting Rod Bearing Failure
 

On another note, should I be concerned about this scoring at the bottom of the rear case? Or should I just dress it with some emery cloth to knock down the high spots?


The dreaded OIL question, what is the preferred oil to use in this engine? I surely don't want a repeat of this in the future and I don't want my 111 to eat a bearing up either.


Thanks!

RE: DLE 55 Connecting Rod Bearing Failure
 

The shaving scars in the case are not an issue. Smooth them off a bit and make certain there are no inbedded particles of bearing in them. Clean everything well with carb cleaner or mineral spirits, rinse with hot water and blow dry. If you don't have an air compressor, put them in the oven on the lowest setting for about 20 minutes, let cool and reassemble.

Several good oils to choose from, MY prefered list includes; Stihl HP Ultra, Red Line Racing, Motul 800, Castrol 2T. Use the same oil from day one to forever @ 32 - 40:1

RE: DLE 55 Connecting Rod Bearing Failure
 

Thanks Jody. I'll get the parts ordered up in the next week or so and locate some of the HP Ultra oil.

RE: DLE 55 Connecting Rod Bearing Failure
 

Jody ...







question .. why the recommendation to use the same oil to forever? Is it unwise to change oil brands after breakin? Why .. for my information.

Bruce

RE: DLE 55 Connecting Rod Bearing Failure
 

There is no reason to change when you have something that is working well. However, if one suddenly runs into difficulties obtaining their usual oil then a change is obviously necessary. When you switch oils it takes rougly an hour of solid run time for the new oil to fully replace the old. You may have to re-tune the engine after changing to a new oil because the viscosities between the two oils may not have been the same, and one may combust while another did not at the same temperatures.

There's not a lot of big negatives in changing from one good oil to another good oil, but why fix what wasn't broken? One oil, one ratio, all your engines, makes things a little easier to deal with. If you fly 20 and 30cc engines while also flying 100cc and up engines, then 32-1 is your likely ratio of choice. If you only fly 50cc and up engines, then 40 or 50-1 works out for all of them. 40cc engines? Depends on who made it. The good ones can run 50-1, the cheap ones probably should be run at 32-1.

RE: DLE 55 Connecting Rod Bearing Failure
 

Being newly associated with a Stihl dealer, I'm a new employee, I'm thinking the Ultra HP is THE OIL to use. I have to do a bunch of on-line training prior to going to Stihl training school to get certified. What I've seen of a 500 hour non stop run using the Ultra HP looks so good it's almost scary!!

Stihl ran BR600 back pack blowers 500 hours non stop against other oils. The Ultra was a clear winner. If I can get permission from Stihl I'll post pictures of those engines at tear down.

I USED to be a fan of Amsoil Dominator, (the only Amsoil product I liked). No more, I'm switching to Ultra HP. Just for what it's worth, I used to race go-carts and most recently my son tried some Motocross. I also wrenched at a power sports dealer so I've seen a few engine failures. I've been a wrench most of my 56 years. Not bragging, just trying to add some credibility to this post.

Ken

RE: DLE 55 Connecting Rod Bearing Failure
 

Jody are you still doing repair

RE: DLE 55 Connecting Rod Bearing Failure
 

Not on purpose. ;)

RE: DLE 55 Connecting Rod Bearing Failure
 

Absolutely nothing wrong with the fuel or oil. I have used the same for years on US, Japanese and German engines. Welcome to China.

RE: DLE 55 Connecting Rod Bearing Failure
 

That's funny.  DLE's website recommends Klotz Oil.
 
<span class="bodybolder"><u>Recommended Products</u>:</span>
<span class="body-small">DLEQ0551 DLE Engines Propeller Drill Guide DLE55
HCAM6351 Hobbico^{<font size="3">®</font>} HydriMax™ Ultra 6V 2000mAh NiMH Pack
KSFP4195 Klotz 2-Cycle Synthetic 32:1 – 50:1 Gas R/C ModeLube
XOAQ2208 Xoar 22x8 PJA Beech Propeller</span>

  Sounds like a high rev with 93 octane sent the bearing into lah lah land.  After all, the DLE enthusiasts swear up and down that the DLE's are perfect.  We know they don't do this!  They CAN'T do this, they're PERFECT, (and all other gas RC engines are not!   Hmmmmm

RE: DLE 55 Connecting Rod Bearing Failure
 

And just to be mean... This leads us right back to the 4.8 volt or 6 volt great debate!

AV8TOR

RE: DLE 55 Connecting Rod Bearing Failure
 

newer RC EXL ignitions are OK with more than 6 v...No debate there....And ny old Husqvarna 390 motocrosser ran fine for years on 1 quart Klotz to 5 gallons of 87 octane, never fouled a plug or stuck a piston...At sometimes 60+ mph in a long sandwash...

RE: DLE 55 Connecting Rod Bearing Failure
 

According to GARP...NOT exactly. Your quote is far from definitive enough to say that. This is a quote from their manual. Guessing whether one's pack puts out 6 volt MAX is a risk who wants to take when it comes to the possibility that one could fry their nice new RCexl ignition system and possibly a very nice plane? NOTI!

<font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman"><p align="left">4.8 and 6v volt</p><p align="left">The Rcexl Ignition ver 2.0 is rated 4.8 to</p><p align="left">6v a max of 7 volts. A 4 cell 4.8v pack and</p><p align="left">5 cell 6v pack with a minimum of 800</p><p align="left">mAh is fine and creates a hot spark. The</p><p align="left">Rcexl ignition ver 2.0 runs most efficiently</p><p align="left">on 4 cell packs and 5 cell 6v pack . Do not</p><p align="left">use an old Pack!! If it&rsquo;s not good enough</p><p align="left">for your receiver, it&rsquo;s not good enough for</p><p align="left">your ignition..</p><p align="left">If Use 4.8v pack the engines not highest</p><p align="left">rotational speed, Also use 6V pack</p><p align="left">II) 6.4 Volt</p><p align="left">2cell</p><p align="left">volts. Nominal 6.6 Volts, use a voltage</p><p align="left">regulator. Or connects one IN4007 diode</p><p align="left">to fall voltage the use.</p><p align="left">If engines not highest rotational speed,</p><p align="left">Also may directly use</p><p align="left">III.) 7.4+ Volt</p><p align="left">We have found that 2cell</p><p align="left">peak charge can be as high as 8 +v. If you</p><p align="left">are going to use a 2 cell</p><p align="left">you must use a voltage regulator. Or</p><p align="left">Serially connects two IN4007 diode to fall</p><p align="left">voltage the use The Rcexl ignition runs</p>

more efficiently on about 4.8-6Volts and</p></font></font></font><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold">NiCd/NiMh </font></font></font><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman">Packs:</font></font></font><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold">Li-Fe(A123) </font></font></font><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman">Packs</font></font></font><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold">Li-Fe(A123) </font></font></font><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman">The Volts Max of 7.2</font></font></font><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold">Li-Poly </font></font></font><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman">Packs.:</font></font></font><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold">Li-Poly </font></font></font><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman">Packs at</font></font></font><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold"><font color="#0000ff" size="2" face="Times-Bold">Li-Poly </font></font></font><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman"><font color="#0000ff" size="2" face="Times-Roman">Packs,</font></font></font>

Quote:

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ORIGINAL: Antique

newer RC EXL ignitions are OK with more than 6 v...No debate there....

---

RE: DLE 55 Connecting Rod Bearing Failure
 

Well, the new C&H ignitions can be made to use 12 Volts if you want to run a car battery in your airplane....;)

RE: DLE 55 Connecting Rod Bearing Failure
 

DLE's website does not recommend any oil brand, 93 octane as recommended in the manual is equal to 87-88 octane fuel in the USA and Canada.

This is DLE's website with links to the REAL factory manuals, http://www.dlpower.net/index.asp

The Hobbico version you visited is full of erroneous information and advertisements to their other products that aren't worth buying.

RE: DLE 55 Connecting Rod Bearing Failure
 

Definitely not a high rev situation. Straight and level flight at 3/4 throttle spinning a 23x8 TBM prop. I'm chalking it up to a crappy bearing that decided to puke its guts out. [8D]

RE: DLE 55 Connecting Rod Bearing Failure
 

I'm just curious as to why the oil is being blamed for this failure.  There seems to be no evidence that this failure was due to lack of lubrication or poor quality lubrication.  I would say that the likely cause of the failure was the bearing itself.

And just for the record I'm not a Klotz user, dealer, reseller, or anything else.

RE: DLE 55 Connecting Rod Bearing Failure
 

Jedijody the oils you mention as perfered oils to use are they all synsytic oils. What is your thought on useing a non synsytic oil like Pennsoil air-cooled oil. I have a RCGF 26cc and a DLE 55cc I have a gallon of 32/1 mix run thru the RCGF engine the DLE has not been run yet..My plan was to use 89 octane pump gas and the Pennsoil at 32/1 in both engines.   

RE: DLE 55 Connecting Rod Bearing Failure
 

Pensoil is fine but doesn't do as well in high heat, keep things cool and it should be fine, it's not MY favorite mineral oil though.

RE: DLE 55 Connecting Rod Bearing Failure
 

Jedijody thank you for your reply to my question re oil. What is your perfered mineral oil?  I am never opposed to a change to another brand of mineral oil.