abufletcher

Part of the problem is that both UMS and Seidel recommend running the engine with no more than 8% (synthetic) oil in the methanol fuel...and that after break-in that amount should go down to 5%. But, yeah, running it regularly is going to be key.

I let it set for months and month, just occasionally cranking the prop around a few times by hand.

Dick, all the Seidel/UMS engines run on almost pure methanol. No nitro. And only 5% (synthetic oil). I don't recall reading anything about how to "store" the engine. It wasn't the fuel that caused the corrosion but rather the jungle-like climate of my part of Japan. The summer here is particularly hard on machines and devices of all sorts.

otrcman

Hi Don,

If you do some looking for the properties of methanol, you may change your thinking regarding "It wasn't the fuel that caused.....". Here is a quote from the Methanol Institute's Methanol Safe Handling Technical Bulletin:


"Corrosion is another consideration. Methanol is a conductive polar solvent; gasoline is a non-conductive, non-polar solvent. Galvanic and dissimilar metal corrosion in methanol service may be high if incompatible materials are placed in electrical contact with one another. Cathodic protection, and regulator inspection of methanol storage tanks and trim hardware is vitally important to avoid corrosion failure."


In addition to the corrosion properties of methanol itself, remember that it has a very high affinity to water. In a humid atmosphere like where you live, the moisture absorbed into the alcohol forms a highly corrosive combination for any steel or aluminum parts. Additionally, the synthetic oil that is used in your engine does little to inhibit corrosion. The low percentage of oil only makes matters worse.

There are products on the model airplane market called "After Run Oil". It's supposed to be an effective corrosion inhibitor. I have no experience with the product, but have often wondered how it can make it's way into the crankcase section of a four stroke engine. I suppose you just squirt a quantity into the intake and then motor the engine over with a starter to distribute the oil.

In summary, I believe that UMS/Seidel's failure to mention the methanol hazard is an unfortunate shortcoming in their instruction package.

Dick

otrcman

Have you seen this link, Don ? The title is, "UMS Evolution Radial Care And Operation". At post #22 is a discussion corrosion in those engines. The writer describes his methods of injecting a corrosion inhibiting oil into the engine after a day of running.

Dick

http://www.rcuniverse.com/forum/glow...operation.html

geezeraviation

My Feedback: (3)

I think the word is hygroscopic, it absorbs water readily and will rust an engine and its bearings with ruthless efficiency
Doc

abufletcher

Thanks, Dick!

I do have (and sometimes use) after-run oil with my smaller four-strokes. It comes in a tiny bottle and you're suppose to put 4-5 drops in through the breather nipple on the bottom of the crankcase. What I had done (but not done regularly) with the 770 was squirt some of the Technoplate synthetic oil I mix with the methanol into the open carb using a pipette, while cranking the prop by hand...sort of like priming but with oil.

Hmmm..."ruthless efficiency" combined with my usual "lazy complacency" is a bad combination.

otrcman

"Ruthless Efficiency". I like that. It conjures up a terrifying mental image that is entirely appropriate to this discussion of corrosion.

Don, the method you are using to inject after run oil sounds good except that I would not use any methanol with the oil. Note that the fellow in the linked article starts the engine repeatedly to burn out as much residual fuel as possible before injecting oil. Also, remember that synthetic oil isn't a particularly good corrosion inhibitor. That's why they sell after-run oil.

The quote from the Methanol Institute in post #1027 says in part, "Galvanic and dissimilar metal corrosion in methanol service may be high if incompatible materials are placed in electrical contact with one another." Think of a battery. Two different metals and an electrolyte liquid. In your engine steel and aluminum are the two different metals and methanol is the electrolyte. Just like sulphuric acid in your car battery. Think of the methanol as sulphuric acid and you won't be too far wrong.

Dick

abufletcher

I was only injecting the oil. The reason Seidel/I|UMS recommend only synthetic oil (and they are very specific about that) is that they are concerned about "gunking up" the engine with oil residues. Maybe that's more of an issue in Germany than here "in the tropics."

The idea of eliminating as much fuel as possible before putting the engine way also sounds good.

I'm still waiting to hear back from UMS on the financial damages and the options. If an upgrade to the 777 costs $500 (as stated) and the cost for repairing the 770 turns out to be $300-400 then maybe the upgrade makes more sense (assuming I can still mount the Keleo ring on the 777).

TFF

It takes longer for synthetic to start gumming up; thats why it is preferred for the afterun. You almost need two fuels. Flying fuel and then some 80/20 to run through when you put it up. Just injecting oil in will not do much; you will need to turn the engine upside down, side to side, nose up and down while turning the prop to distribute it everywhere. That will be a pain on a 1/4 scale plane. In the glow engine section there is a long thread with the same problem on a Magnum 400 radial. Rebuild thread of the engine.

abufletcher

You're joking, right?

otrcman

Kidding ? No, it'll be good exercise for you.

Dick

foodstick

Yeah thats the bad thing.. after run oiling a single cylinder is one thing.. but a radial makes it a whole new ball game !

TFF

Not when it comes to a $1000+ engine. Yes it is dumb, and yes I dont see another way.

abufletcher

I hate even to think about it. On the maintenance thread Dick mentioned, there was a description of removing one of the rocker rods and some other top parts and squirting oil directly into the cylinder. But what would have to be done on each cylinder...and I'd still need to get oil into the crankshaft.

Anyway, one thing as a time. Once I heard from UMS and get the work done, I'll ask them what they recommend in terms of maintaining the engine in good condition. Actually, that part of India should have weather fairly similar to the summer weather in Japan.

geezeraviation

My Feedback: (3)

In a perfect world, after the last run of the day you should pull the fuel line from the carb while revving the engine up and run out the last of the fuel ( no need to explain how difficult removing the fuel line can be on some models) then inject after run oil ( I use Marvel Mystery air tool oil which has excellent rust inhibitors I it) in the carb and vent and spin the motor with your starter. repeat a time or two. I have very few glow engines these days and find that the easiest way to avoid rusted bearings, lol
Doc

otrcman

[QUOTE=abufletcher;12219201]

"I do have (and sometimes use) after-run oil with my smaller four-strokes. It comes in a tiny bottle and you're suppose to put 4-5 drops in through the breather nipple on the bottom of the crankcase. What I had done (but not done regularly) with the 770 was squirt some of the Technoplate synthetic oil I mix with the methanol into the open carb using a pipette, while cranking the prop by hand...sort of like priming but with oil."


I was just looking at the Seidel / UMS instructions that are posted on the web. Your engine appears to be unique among four strokers in that the fuel-oil mix is drawn through the carburetor and into the crankcase. So when you inject your after run oil into the carburetor, you are doing exactly the right thing. By motoring the engine with the fuel tank empty or fuel line disconnected, hopefully the after run oil will displace the residual methanol on the metal surfaces. I'm not sure you could hand crank the engine fast enough or through enough cycles to do as much good as an electric starter would do.

An alternative way to ensure that the preservative oil displaces the methanol is to run the engine briefly with a non-methanol fuel. We often do this on our antique engines if they have been run on methanol. To do this we drain the fuel tank and then put some gas/oil mix into the tank and do a brief run. The gas/oil mix consists of a 3 to 1 mixture of petroleum fuel (not car gas; it contains too many additives, including alcohol) and ordinary motor oil. Coleman camp fuel, or equivalent, and 30 or 40 weight motor oil work well. You can leave your needle valve adjustment alone and it will result in a fairly rich run on the gas/oil. Running the engine on this mix for 30 seconds to one minute will thoroughly purge the engine of all residual methanol. The remaining petroleum fuel and oil will protect the engine for years.

But what about the Seidel warning that anything other than synthetic oil will thicken in the engine ? I think they are primarily concerned with castor oil, which does congeal in long term storage. I have dismantled old spark ignition engines that have been stored for perhaps 50 years with residual motor oil from their last run. The engines always seems to turn freely and have no corrosion.

Dick

abufletcher

Seidel/UMS recommend AGAINST using a starter motor, saying that that can damage the parts. And one is certainly not needed for starting, since if it is running properly, just a casual flip or two is all that is needed. There's even a warning in the manual about how easy it might be to accidentally start the engine (if the glow is on). Injecting oil into the carb with a pipette after a run on the stand is simple enough. Priming and injecting oil with the engine mounted in the model is a much more complicated affair since the carb is no longer accessible. My solution was to add a 2mm brass tube bent in such a way that the tip points into the carb. I then use a 1mm syringe to squirt the priming fuel into the carb, while hand-cranking the motor.

Given my fairly rural location in a foreign country, "exotic" fuel options are out of the question. I don't believe I've ever seen "white gas" (for example for lanterns) for sale. Regular motor oil is, of course, available.

TFF

Is there not a crank case vent that you could inject oil into, then plug, turn the engine through, then drain? I would want to put at least an ounce of oil in and work around if it was not going to be run within two weeks. You pretty much proven it has to be treated like how much it cost its not a knock around engine. I would not use car oil. It does not mix well with methanol and can cause starting problems until cleared out.

TFF

http://www.sportys.com/pilotshop/cor...FYKBaQodC-MGjg this is what I like for long term storage.

BobH

My Feedback: (2)

I use after run oil. I put it in the crank case by removing one of the cam followers and directly injecting it in the crank case. works fine so far.

otrcman

I don't think I've seen "white gas" for at least 50 year either. That's why most of the Society of Antique Modelers use Coleman fuel. That may not be a common brand in Japan, but I would think that there is something of the same type in a sporting goods store. It's the liquid fuel that people put in camping lanterns and camping stoves. The common chemical name is naptha, which is a fairly low octane petroleum fuel. Works great and is pretty much the same as the old white gas.

TFF, your concern about car oil not mixing well with methanol is correct. If you pour the two together and let the mixture stand, they will separate. But in small ratios, the two oils act as a miscible agent and the mixture works fine. The small amount of residual oil in the engine crankcase easily mixes with the methanol based fuel for the few seconds that the two coexist. And the rotating machinery of the engine keeps them well stirred. SAM flyers routinely put gas/oil mix in a fuel tank that previously held glo fuel. It's all transparent to the engine. Some SAM flyers actually add gasoline to their glo fuel to extend the run time in Texaco fuel economy events.

Regarding injecting oil into the crankcase vent port, it appears that the Seidel doesn't have a vent. Since the carburetor is directly connected to the crankcase, no auxiliary vent is needed. Injecting oil into the carburetor accomplishes the same result.

Dick

abufletcher

Obviously, I'm going to have to learn much more about the part of my engine. I don't even know what a cam follower is...or how to remove one.

Dick, all camping equipment that I've seen here runs on gas canisters.

I wonder if an additional "oil line" could be added to the fuel line so that after running the fuel tube could be clamped off, and external oil "tank" attached to the "oil line" so that rotating the prop would suck oil into the carb. Just brainstorming.

abufletcher

So here's what it's going to cost me for the 770 to be repaired:

Spares Material Cost: $95.87
Service Charges: $50

These are both quite reasonable. However, I will also have to pay:

Freight Charges to Japan: $90
Customs Duties charged by Indian Custom when returning the engine to India (i.e. "importing" into India): $85.

This last cost seems truly bogus and some weird quirk of Indian customs law. In what possible sense is "returning a product for repair (and return)" the same as "importing?" Anyway, the cost for the repair itself seems reasonable given the damages. It's just too bad that the other two amounts more than double the total cost.

geezeraviation

My Feedback: (3)

I agree it seems odd that an individual would be charged an import fee, one would think that was a corporation kind of area related to larger shipments of goods.
Doc

abufletcher

UMS was required to pay this "import" duties before Indian customs would release the engine to them. I was unhappy when they informed me that I would have to reimburse them for this, but then I guess I can't expect for them to have to "eat" these costs anytime an engine is returned for repair.

TFF

Sounds like you lucked out minus the duty.