wpmcnamara

My Feedback: (9)

That is what I thought. So 1/16" would be bad right.

I'm joking, I know the answer. My next post will have pictures.

wpm

wpmcnamara

My Feedback: (9)

Here is a link to all the pictures I took: http://s211.photobucket.com/albums/b...-111%20autopsy

The photos are in reverse order. Here are a few key ones though.

Crown of the port piston.


Crown of the starboard piston.


Someone had asked where the magnet was at TDC.


Gunk in the rear of the crank. The dirt looking stuff is all metal shavings.


Wear on the back of the crank case. It is smooth, not gouged, but you can definitely see where the crank counter weight rubbed.


The culprit? Notice the gap at the top of the rear bearing between the inner and outer races.


So the inner race on the rear bearing will move about 1/16" in any direction. That is definitely enough to cause the crank to strike the rear of the housing. At idle/low throttle there was likely some movement in the shaft with the ignition impulse. Perhaps even some contact with the housing, but definitely play in the bearing. Hence the "ping" you hear. A bad bearing would definitely make that sad "squeeling" sound too. At full throttle, I expect that one or both of the front bearing gave out and let the crank come into full contact with the rear of the casing. Tomorrow after work, I'll take a closer look at the crankshaft to see if is really bent or just off center due to failed bearings.

wpm

jedijody

My Feedback: (1)

Sorry but that is not an inner bearing race. It's a cage that holds the rollers in place, the end of the crankshaft is the inner race for the bearing. That is the older version of the engines crankcase, crankshaft, and bearing,it's not a bad thing and they weren't a problem but the current production DLE111 uses a sealed ball bearingfor the rear crank bearing. What are the metal pieces from, some pictures of those, the crankshaft, front half of the case,and what ever you think caused the engine to make such an abrupt stop would help, not seeing anything that would cause that here. The prop hub key appears to be intact by the location of the magnet at TDC.

Tired Old Man

My Feedback: (1)

Something that will bring an engine to an abrubt stop that hasn't been voiced yet. Heat. Had a 3mm 53 that shut itself down after a few minutes of idling once. That was one tight engine[X(]

Razor Hobbies

My Feedback: (50)

Yeah at this time just from seeing the pictures to make a better over all determination and to ensure that the engine gets repaired correctly im going to recommend to just mail it back to us.

I can see the shavings and some looks to be shavings in the top of the head of the engine so definitely covered under warranty. We would just like to go over everything to ensure that everything gets repaired that needs to be repaired.

Box it up and go ahead and mail it back and we will get you taken care of.

Unfortunate that this happened.

We will get you taken care of though.

Call us first thing tomorrow morning and we will supply you with a warranty claim number.
832-224-8844

az3d

My Feedback: (59)

Way to go Robert Dunn. That's how to take care of a customer.

av8tor1977

My Feedback: (6)

az3d Hey, Prescott Valley. Used to live up in Groom Creek, Prescott, and then later in Prescott Vallery. I used to fly models both at a field in Prescott Valley, and one at Embry Riddle. I was the shop foreman at Anaco Aircraft Maintenance at Love Field. Used to fly Cessnas, Pipers, Grummans, and Aero Commanders out of Love Field as well. Where do you fly? I see now they have a nice model field out in Chino Valley.

Take care,
AV8TOR

wpmcnamara

My Feedback: (9)

Thanks for the correction Jody. I'll check the rollers just to satisfy my curiosity. I'm going to pack the engine up this evening and send it back to Robert. I'll give the crank shaft and other internals a good inspection when I do and take photos if I find anything obviously amiss. I was, in a weird way, hoping to see massive damage and destruction when I opened it up, but as with many failures, this one seems more subtle and complex.

And as far as support goes, I want to publicly thank Robert. I suspect he understands,, as do several other contributors to this thread that run RC businesses, taking care of your customer is the easiest way to earn return business.

-wpm

az3d

My Feedback: (59)

I fly at Chino Valley Model Aviators. I've been up here for about a year. I used to live in North Phoenix and flew at Sun Valley Fliers for years. The field itself in Chino is OK. There is a lot of nice guys that fly there. They are in the process of finding a contractor to put in a new runway. Our new president is on the ball. When it is done it should be really nice. It is out of the way and noise is not an issue.

captinjohn

Fixed & returned???? (post 79) That Guy should be sent a complete new engine. The seller should fix and sell the returned engine as a used repaired engine.Or seller should be sent a replcement. The consumer bought a new engine...and that is what he should get back...a new engine...not a repaired engine.TheDLEcompany should absorb allcost. Capt,n

Razor Hobbies

My Feedback: (50)

Its not to say he wont get a new engine.

But if its a simple fix and no catastrophic damage has occurred. Then its more beneficial to fix the damaged or defective parts than the replace it out right. I'm not going to send him an engine back lesser than standard thats just wrong.

But he will be taken care of. The important thing is he gets what he paid for and that is a working great engine and the warranty helps to ensure that.

Razor Hobbies

My Feedback: (50)

Anytime that's what we are here for and what warranties are for.

I can understand how it feels when it comes to getting something that you paid for and it malfunctions straight out of the box. It literally sucks.

Super08

My Feedback: (2)

Look at the rollers in the bearing in picture number two. It sure looks like one is at an angle...

Super08

My Feedback: (2)

This sure is a strange one. I can't see anything outstanding that would stop it dead in it's tracks like that.

Razor Hobbies

My Feedback: (50)

When looking at all the pictures its a possibility but to make sure that all problems are addressed we had him send it back to us for further investigation.

Once we look it over and repair it we will post up the findings and full workup on the engine.

jeffEE

My Feedback: (5)

I am gald the owner was not hurt. And I am glad to see the correct attitude of the Razor Hobbies. Sounds like a place I might like to do some shoping with.

Tired Old Man

My Feedback: (1)

I'd rather have a corrected engine. I KNOW that one is right. A new one is starting out from scratch again.

What DLE should or shoul dnot do is of no consequence. I already the the most they will do. So do Jody and Razor.

karl hibbs

My Feedback: (6)

I think the engine will run fine . The prop (flywheel) is almost always required to run, so when the prop came off the engine had no inertia to keep it going. just clean out the shavings and put on a new prop and fire it up. I am sticking with loose prop bolts was the problem.

jedijody

My Feedback: (1)

How would the prop blowing up introduce small broken pieces of metal into the crankcase?

The engine will run smoother and at a lower RPM with a prop installed but it is in no way a requirement to run at all.

willig10

As I stated in an earlier post. I really think the engine seized due to heat. Yes a loose prop may have contributed but only if the engine had a very sudden deceleration or seizure.

I also believe the carb low end needle was too lean. As when the engine was at idle there was no smoke visible at all except after the first start at the beginning of the video.

All engines are gonna make some metal during the initial break in, maybe not as much as was shown on the back of the crankcase plate but will wear in when performing the break in procedure.

Without a micrometer to measure the "choke" of the cylinders, it is impossible for us to determine the root cause if it is heat related. However if the choke was excessive in the cylinders or machined incorrectly a little more idle run in time might have been in order. That said, the buyer owner is not going to know this and will do like anyone else and after a short idle run,go to full power in order to put heat cycles on the engine for break in.

I would sure like to know what the taper/choke in the cylinders is supposed to be. Then again the cylinders may be straight honed.

I am very curious to see what the findings are.

Keep us posted.

Glenn Williams

jedijody

My Feedback: (1)

You're thinking glow engine technology. There is no taper in any gas engine cylinder. This engine ran for just under 1 minute and 40 seconds, there is not enough time to make enough heat toget it mildly warmed up let alone overheated. Look at the pistons, there is no evidence of scoring or even touching anything. If anything got hot it was on the crankshaft.

From what I can see it had either something come apart on the crankshaft or something was in the crankcase that shouldn't have been. The abrupt stop was caused by the crankshaft being stopped, it didn't happen in the top end.

willig10

Understood. I am a gear head and A&P mechanic. Some of the "full" size Lycomings and Continentals have "choked" cylinders. Thanks for enlightening me on the cylinders being straight bore.

This is certainly gonna be a brain scratcher until we know the cause. Inquiring minds want to know. lol

Glenn Williams

Super08

My Feedback: (2)

I am going with something jamming the crank, that one picture I mentioned in my above post has me really suspicious.

chris923

My Feedback: (53)

Jody and Razor,

I thought DLE runs each engine before they are shipped?

Chris923

Super08

My Feedback: (2)

Nope.