I have been using after run oil but am getting low. Hy LHS no longer sells the type you put in after shut down, the are selling the kind that mixes with the fuel and at a premium price. I have heard that automatic transmission fluid can be used, anyone have any experience with it?

Gary

The best thing to use is air tool oil. Marvel Mystery Air Tool Oil is very popular for this. Some mix with ATF. I just use a generic brand air tool oil, and I use it only when the plane is going away a few months (read winter).

J

I agree -

Marvel Air Tool oil and ATF, I use air tool oil and ATF at a 50/50 mix and I use lots of it, usually about three applications and spin ups after just to make sure that all of the combustion by products of burning methanol & nitromethane are out of there. Like Nitric acid which is very corrosive.

Richard

You can also use automatic transmission fluid as well. Some fuel manufacturers blend an afterrun oil in to their fuel, so you might want check that out. I use Cool Power from Morgan fuels and they add it to all of their fuel blends.

Ken

Personally, I never bother with the stuff.

I recently resurrected an OS 46FX that I bought in the 80's. In the last 20 years this engine has gotten used sporadically but spent most of its time sitting on a shelf, or in an airplane that was not being flown.

It also spent time in two seaplanes where it got dunked more than once.

I just pulled it off the shelf to put in another seaplane which was test-flown this week and it still screams like the day it was broken in.

Thanks for the input. Looks like Marvel oil and At fluid.

Gary

Make sure its Marvel Air tool Oil.. I am told regular Marvel Mystery oil is good, but can still let moisture in. (Could be wrong but thats what i was told, here)

I never bother with the stuff unless the engine is going into long storage or I'm doing A rebuild.
Never ever use it in A YS engine!!

I use Dextron III tranny fluid as my after-run oil . . . and that shows how long a bottle will last - they're up to Dextron IV or better now. I always drive standards so it's all I need it for. ;-D

Automatic transmission fluid works like a charm. Put in about a teaspoon and turn the engine over several times. Then if life unexpectedly gets in the way of your flying the engine will still be good to go for weeks or years.

jess

I'm with Minnflyer on this. I never use it. I have pulled engines out of boxes that were sitting for decades that fired right up with great compression and not a hitch.

Besides, when and if you ever run an engine to the point of destruction.....Hey now you got a reason to go get a new one.

Life is too short to worry about such things.

I'm sure I will catch some heat on this but remember they are just toys. No way, did I really just say that.

While I posted an alternative I am with Minn and Cashpoboy as well. I don't use it in any engine. I do use Morgan fuel that has it blended in, but other than that I don't worry about it. I've had engines on the shelf for 5+ years and opened them up and have had zero rust in them.

Ken

OK, I made the popcorn I'm in the recliner lets start.

First marvel is a great oil, for after run oil. I used it ( in michigan) 20 years ago and put my motors away with out too much attention and now I am getting them out and they are good to go.

a quart of marvel costs about $5 and it takes about four drops at the end of a flying day. Do the math that quart will last as long as you plan to fly your planes ( put it in the will and leave the rest it to the next of kin). If your in a dry area I guess you don't need it, does it hurt anyting ,don't think so, could it help- might. What does a motor cost????

Dry areas have dirt, could the oil help in a dry dirty area, don't know - don't care ( michigan remember ). It all comes down to what do you want to do!!!!!!!!

My experience with Marvel Mystry Oil over long term is that it formed a hard red crud in the engine. I suspect this may have been in combination with castor varnish, but I am not sure. In any case I have never had any problem with Rislone.

[quote]ORIGINAL: Cashpoboy

I'm with Minnflyer on this. I never use it. I have pulled engines out of boxes that were sitting for decades that fired right up with great compression and not a hitch.



I too have run engines that have sat for decades, in a very damp pasement no less, that fired and ran like new. They were lefe due to college, war, marriage, career, kids, all those things that crop up unexpectedly. The engines survived, I am quite sure due to having been run on fuel with castor lube. Despite that experience I now use after run oils.

If one is a gambler, or not particularly concerned about the longevity of an engine I would recommend using it and forgetting it. It is after all a replaceable item. Especially if one subscribes to the throw away societyohilosophy. OTOH for a couple of pennies worth of oil and a few seconds of time the protection of the engine can be assured for years. It is an individual choice, and I am amazed at the thousands of words expended on the subject on the various fora over the years. Like the castor/syn debate it will never reach unanimity of opinion in the lifetime of those posting now.

jess

A counter story. My son had a timer failure and lost His Fox 25 powered free flight at the 1980 Dayton Nats. It landed in a tree and spent the winter there until it blew down the next spring and the people who found it contacted me. The engine had no rust or corrosion. It had been run on all castor fuel. So maybe one doesn't need after run oil after all.

Back in the day when I was listening to my advanced flight/building instructor I had to hear the same argument over and over about the use of after run oil.
His statement was: The alcohlol evaporates almost right away from inside the engine, after that what is left inside??? Oil!!
OK, true statement and to proove A point, I was given A big bunch of old engines by this man last year and these engines were run, shut down, removed from the plane and tossed up on the shelf.
After all these years all I have done when I needed one of these engines is to heat it up with my shrink gun, take it apart and clean up the nasty gunked up Castor oil so it rolls over smoothly and fire it up and tune it. NO rust has ever been found in one of these and all the bearings were in fine shape.
My feelings about it are simple, if it makes you feel better then go ahead and use the stuff, as long as it's not A YS then it isn't really hurting anything. I use it on rebuilds and I clean out my own engines with Alcohol then hit it with some after run oil if I'm not going to use that engine for A couple of years. I don't know if it helps or not but it makes me happy doing it that way.

Jim, that would seem to reinforce the experience I gad with the engines left fordecades in the dank basement after having been run on 100% castor. I might add that some external parts, prop washers, head bolts, etc. were rusted but nothing internal.

For what it may or may not be worth all these engines (Fox, K&B, Johnson, Holland and Holland, Cox, ST) were flown control line or free flight and thus were always run dry, either through running the tank dry or having the fuel cut off by a pinch-off timer.

As a matter of current practice I always run my engines dry after use.

My practice of running dry and use of ARO may do no good, but I have a couple of hundred engines that over the years have never shown any sign of rust, rot, corrosion, or running over at the heels

As running dry and adding a bit of oil requires such a minimal effort and expenditure, with no possible adverse affect I am at a loss yo come up with any reason not to do so unless one simply does not wish to. This being a merely hobby that is reason enough.

jess

I just bought a case of Omega 10% and it says on the bottle "do not to use after run oil with this fuel" and that its already been added to the fuel.
if I do add any lube to my engines for long term storage its air tool oil,it keeps any rubber parts supple and prevents seals from drying out.
as for rust living 3blocks from the beach you would think it might be a problem I have noticed some minor surface rust but nothing internal at all.

it wouldt hurt to still add what was reccomended.........



would 3 in 1 machine oil work?

Hi everybody,

From what I hear at our rc club, afterrun oil is overated for daily or weekly use. Some here swear that it can damage bearings (not quick sure how that is possible). One problem is if you put too much oil in, it is difficult to start the engine next time. One thing that alot of us use at the club is a mixture of 50% lighter fluid (stuff in yellow bottle) and 50% Marvel Mystery oil (or air tool oil). When we are done flying, we squirt it in the carb and start the engine. The engine runs for about 2 seconds. We do this about three times. By doing this, we burn off any fuel (alcohol and nitro) and we lubricate it with the mystery oil at the same time. The important part here is that the engine only runs no more than two seconds. It seems to work really great for us. Any comments?

Happy Flying!

I have used ARO (usually either Rislone or ATF) for over thirty years in at least a hundred engines and have never had ANY ill effect.

jess

If you run the fuel outta your engines at the end of the day, after run oil is at best a bit of insurance. Nothing more. Running the excess methanol/nitro out is the key.

There is one thing you all can do that will ensure badly rusted engines. don't run them dry at the end of the day, and then plug the muffler to keep the drips off the carpet. This traps the methanol/nitro inside, and bearings rust quickly. Especially if the carb is also closed, so the engine si a completely closed unit.

J

Effective insurance at a cheap price.

jess