SWORDSN

My Feedback: (13)

I installed Boca bearings which are good quality.

SWORDSN

My Feedback: (13)

Yesterday a friend was flying his F4U with DLE55 and the prop came off during flight. All four prop bolts had sheared off. Anyone else had this happen?

BadAzzMaxx

Seen it happen a lot, First thing to do with a new China made engine is to replace the silver soft metal bolts with some of the black case hardened bolts.

Milton

BarracudaHockey

My Feedback: (11)

And make sure they are torqued correctly

McMaster Carr has the bolts you need, get the 12.9 type

kmeyers

I have seen this two. Loose bolts are the problem, not metalurgy.
Keep it real.

flyboydale54

The difference in oils is the amount of carbon that builds up in the engine. The new Stihl Oil is a real good oil. That is why Stihl increases their warranty to 5 years if you use that new oil Stihl has out. During break-in, the DLE repair center and the manual state to use Pennsoil 2-cycle oil for about 2 gallons, then you can switch to a synthetic. Personally, I think Stihl is the oil to use. I believe the new Stihl oil has to be far better or they would not of extended their warranty to 5 years if used, I believe it come in a grey container. Hey, if it works in a chain saw with that kind of RPM and load on the engine, it will surely make your DLE last longer. There are bearing failures with these DLE engines or they would not have discontinued the parts at Tower Hobbies and replaced quite a few of them with new part numbers, most of which are not even available until the end of August 2016 or into September 2016. I know the Crankshaft, Carburetor, Piston Needle Bearing, Piston, Ring and Reed Assembly have been all changed to newer part numbers for the DLE 55 Engine of which China seems to be dragging their feet on putting the parts out here in the US. That just goes to show you the DLE 55 Engine was junk from the git-go. What we need is manufacturing to come back into the USA where good quality reins. China makes poor quality engineered bearings, not high quality. Personally, I only use 93 Octane with no ethanol in the gas. Pump a gallon into your car first to flush the hose of the ethanol gas, then pump into a gas can you reserve for your model engines. The ethanol does damage to parts. Time your engine with a degree wheel and ignition tester unit. They have had good results backing the advance back to 26 degrees before top dead center. The stock timing which is in the 30's causes excess heat. The cage on the needle bearing on the piston end of the connecting rod on my DLE 55 started to disintegrate of both the inner cage and needles and the engine quit just as I was about to taxi out for takeoff. I had no compression when I flipped the engine over and I heard a clicking sound of the piston striking lightly on the head. Found pieces had struck the top of the piston, seized the ring to the piston due to a strike near the ring of the failed bearing fragments. Luckily it did not score the cylinder. They totally redesigned that needle bearing which you can see the photos of the discontinued vs the new needle bearing on Tower Hobbies web site. Major difference. Personally, I do not think to highly of the quality of bearings coming out of China. I hope I can find a USA made replacement that knows how to heat treat and manufacture superior needle bearings for China Engines.

flyboydale54

I use the Permatex Anaerobic High Temp Flange Sealant (# 51031). I called Permatex support number and asked them if I needed to buy the special accelerator they use on the clean flange surfaces before applying the Flange Sealant and they said no. That only speeds drying and curing to 4 hours. If not used, then the engine must sit for 24 hours for it to fully cure. I told them what I was using it for, sealing my DLE 55 model airplane motor's crankcase halves. He said it works very well on Aluminum. If you look very carefully, you will see DLE has put a very thin bead of a clear green colored sealant around the crankcase half that faces the carburetor between the flange and the protrusion that sticks out and goes inside a groove on the other half. The other key, this product is made for sealing crankcase halves it said on their web site. It was recommended I apply a very thin layer on the entire crankcase flange and to wipe back a little from the inside edge of the flange so it will not squeeze excess into the crankcase cavity and to wipe off the excess on the outside using some Alcohol and a cloth or paper towel before it gets a chance to cure. Support told me it has to be high heat type or it will break down under heat. I would not use the Indian Head Sealer, it is not designed to seal crankcase halves!

flyboydale54

Unfortunately, Frank Bowman closed his business and is touring the world on vacation with his wife and she announced on the voice message on their phone that Frank is no longer manufacturing rings and he is not selling any either.

However, I did find another person that has been in business for years located in the United Kingdom. In less than a week, my 2 rings I ordered from him for my DLE 55 Engine arrived. They cost just a little bit more but he says his metals he uses and the method he uses to manufacture them are very high quality. He has been on eBay and has a store since 2002 I believe it said. It only cost just over $4 US money for shipping and he sent them airmail. That is much faster than China is making them available to Tower Hobbies. I suspect they will possibly end up pushing the date available out and out, as that seems to be the case with parts I ordered. My piston and needle bearing have been pushed out from mid August to September of 2016. I canceled the ring back order and as you can see, I already received it from a manufacturer in the United Kingdom. His name on eBay is ( gaviscool ). He makes rings for a lot of model engines and he sent me the list with my rings. Too bad he does not make pistons and needle bearings, not to my knowledge anyhow.

flyboydale54

That clicking sound is probably the piston very lightly striking the cylinder head. This will fail and cause a lot of damage if you do not tear the DLE 55 down for inspection. You will probably find the upper needle bearing on the piston end of the connecting rod going. Tower Hobbies has a picture of the discontinued no longer available one and the new designed one which is been pushed ahead from mid August 2016 until end of August as of today. It seems to be an issue of Tower Hobbies getting parts for the DLE 55 from the manufacturer in China. I noticed they keep pushing the date available ahead on several parts. I hope they are not going to do with the DLE Engines like they did with the Super Tigre Engines of stopping production of replacement parts as well as the engines.

flyboydale54

Yes and no on special tools. I did find a set of bearing pullers reasonable at Harbor Freight Tools. Sometimes depending on the engine, I heat the outside of the aluminum casting with a torch. Quickly and keep it moving. Do not see how hot you can get it. Use a softwood piece of wood such as a piece of 2x4 and firmly hit the wood with the back of the engine with rear case removed. The bearing usually comes out. Repeat if necessary but not too long on the heat. When installing the bearings, you can put the casting in the oven at around 350 degrees for about 15 or 20 minutes and put the bearings in the freezer. This slightly shrinks the bearing while the oven expands the aluminum and they generally go together without any special tools. Just DO NOT hammer on the new bearing for any reason. Threaded rod or bolts with washers and a couple of nuts will work to pull them in until they bottom out. I have found a few nice videos on "You Tube", some have nice information, with some misinformation. So, it pays to ask or watch several videos and extract knowledge from each of them, noting any discrepancies or missing information and asking on this forum, which is a very good place to search for posts. Again, depending on whether your just doing one engine or your going to keep fixing engines from time to time, whether the special tools are worth the investment from Harbor Freight Tools. At the time, I had a few extra dollars and wanted the tools to have as I plan on using them more and more as time goes on. As an example, on one You Tube video, I saw the person replacing the bearings on a video, yet he was installing them by using a hammer to drive them in. Wood or no wood, he was still beating on the bearing. Never Never Never do this method. Think logically and use a better method. Striking on any bearing will certainly damage it so it catches a little when turned which will result in premature failure. Whatever method you decide to use, make sure it is only resting on the outer race of the bearing and not the center race. With some of the special tools from Harbor Freight Tools, I have carefully used one of their hand operated "Arbor Press", like a vice with gears, to press in bearings. It does not require a lot of force.

flyboydale54

My question regarding the DLE 55 connecting rod is even if you get it apart, where are you going to find the bearing on the crankshaft end of the connecting rod to replace the bad one? I have not seen where this bearing is available separately. You have to buy the crank and rod as an assembly unfortunately. Otherwise, I would press out the pin and replace that bearing while I have my engine apart. The upper needle bearing is available as a separate part.

flyboydale54

It does matter about carbon buildup on the piston. I remember specifically from my Auto Mechanics Instructor at BOCES him telling us carbon buildup can cause pre-ignition. The carbon can heat up to the point it glows and when the piston comes up on the compression stroke, it can fire before the ignition timing allows the spark plug to fire. This can damage an engine, so carbon deposits should always be removed from the head and piston as part of the rebuilding process. I know as I had to clean a lot of heads and pistons to the instructor's satisfaction. Hope this helps you to realize carbon buildup is bad and does matter.