What are the routine items that one should follow for proper care of nitro and gas engines ?

For example, how frequently should after-run oil be used ? Is it something only for long term storage ? How long is "long term" ?

Also in my case i have a SuperTigre GS-40 Dual BB Ringed w/Silent Muffler which has been lying idle for a year..

I will be running it this weekend but would really use some comments before firing it up...

thanks

atul g.

When done with flying run your engine so that the engine is at its operating temprature and then stop by stopping fuel. Remove fuel from tank and if possible disconnect fuel lines (both pressure and feed) so that even fuel vapours do not enter the engine. Drip in adequate preservative oil (even 3 in one or general purpose machine oil is sufficient) and turn over the engine enough to distribute all over. If possible stand the plane on its nose so that oil drips from all other parts and accumulates around the bearings. Applies to all Meth engine where Nitro is used. You can get away without all thse for a long time if you do not use Nitro.  
Others please add on

See that the ring is not gummed up and stuck. If it is you need to free it up, but do this only if you know how to

We use nitro (sort of lavishly!) in our flying, yet I did not have any trouble starting engines (belonging to others) that have not been used for many months (can't remember any that was unused for many years).  As captain said, use of nitro and not taking proper after-run care is a bad combination. So why does it work in general for us ?

The answer is the use of commercial fuel blends.  Most of the well known commercial fuel blends (like Morgan Fuels "Cool Power" brand, which is our regular one) comes with additives that also keeps the engine clean.  In fact, Cool Power cans have written warnings on them saying "do NOT use after-run oil".  I guess all this is what pushes their cost up.

Quote from: flyingboxcar on September 07, 2009, 05:53:23 PM
When done with flying run your engine so that the engine ...

Wonder how many people routinely follow this while using self mixed nitro fuel ?  And this also plays into the comfort factor when it comes to buying used engines.

Quote from: flyingboxcar on September 07, 2009, 05:54:48 PM
See that the ring is not gummed up and stuck. If it is you need to free it up, but do this only if you know how to

What are the usual tricks for releasing gummed up engines ?  What sort of lubricant/cleaning-agents (locally available) can be poured into the engine to help remove the muck ? 

I would strongly recommend a very liberal dose of WD40 thro as many orifices of the engines as possible as the first step to releasing a gummed up engine. then attach a prop and try to turn the engine over. spray even more WD 40 and repeat after 30 mins. usually frees up most engines.

Also Castor oil as lube gums up engines but you never find RUST. so no permanent damage done. The combination of synthetic with nitro will spoil engines unless meticulous care- (burning up residual fuel after run oil etc.) is taken

A word of caution about WD40.  While it is the "son of a gun", it can take out the grease inside bearings, possibly shortening their life. 

Only an issue if you over use it (like clean the inside of the engine routinely with WD40).

Ismail,
Correct me if I am wrong but grease packed bearing in my knowledge are thedomain of high end engines, even for OS engines the bearings do not have internal grease packing and rely solely on lube from fuel for all the lube requirment.
Then WD 40 is only a good treatmeant for engines with no silicone/rubber parts as it will very quickly degrade these parts. Else you are better removing all such parts before hitting it with the WD 40.
Also if you have opened up the engine and taken such part off so that they do not come in contact with cleaning agent you can use liberal dose of  NC thinner to free up and clean the engine.

Doc,
It is always better to take care of your engines meticoulously rather than end up with gummed up engine, BTW even synth mixed with castor are available to ensure that you still get some protection afforded by castor properties, castor is an excellent lube but for its varnish forming properties 

Quote from: flyingboxcar on September 07, 2009, 09:06:42 PM
Ismail,
Correct me if I am wrong but grease packed bearing in my knowledge are thedomain of high end engines, even for OS engines the bearings do not have internal grease packing and rely solely on lube from fuel for all the lube requirment.

I thought lube was for the other moving parts mostly, and bearings did have grease inside them. 

Manish,

That was Anwar's view of using WD40.

I have not used WD40 so far on an engine. So, I am not sure about it..  For all my engine cleaning, I use petrol or kerosene. Of course, the silicone and rubber parts need to be stripped off before the cleaning. I usually, soak the engine in kerosene overnight and use a tooth brush to remove the castor gunk.

Back when I was flying, I never used nitro as it did not make any difference for my flying style. Further, it was very expensive. I used the normal 80/20 brew and it worked very well for all my engines. I would say my engines still have the same compression like when I got them. I would say too much oil has never killed an engine.

Quite recently, I used the detergent cooking method discussed in many forums and it worked flawlessly. However, the shine of the engine is permenantly gone but it came out very clean. If at all anyone is trying this then I would recommend not to clean the piston and cylinder by this method.

-Ismail

Quote from: izmile on September 07, 2009, 10:03:34 PM
That was Anwar's view of using WD40.

So there is no grease packing in the bearings of smaller engines any more (especially OS) ? I mean 46 to 90 size ?

The immediate reference I could find is this : http://www.osengines.com/engines/osmg0890.html ; where they say the bearing is greased.

Many heli fliers end up losing engine bearings often because we push for maximum rpm with high nitro content for 3D (30% nitro is the standard); causing engines to run at some heat all the time.  As a part of engine rebuilds (happen often when push the limits, engines overheat, and the piston gets a hole on top, which needs to replaced, along with the ring), we always tend to apply grease.  In fact, some people I know have switched to other bearings like from www.bocabearings.com and they also recommend greasing the bearings.  If the bearing are too jumpy, then we just replace them.

One a side note, it is common that the bearing refuse to come out, so keeping them in a hot oven for a few minutes (after removing as rubber/plastic parts (mainly the carb, which has O rings etc) is a standard trick.

Quote from: flyingboxcar on September 07, 2009, 09:06:42 PM
Then WD 40 is only a good treatmeant for engines with no silicone/rubber parts as it will very quickly degrade these parts. Else you are better removing all such parts before hitting it with the WD 40.
Also if you have opened up the engine and taken such part off so that they do not come in contact with cleaning agent you can use liberal dose of  NC thinner to free up and clean the engine.

And one more clarification for the sake of everyone.  Other than the O rings etc in the carb, what silicone/rubber parts are usually inside nitro engines ?  (I have never opened a gas engine).

I got the cap 232 3D "subaru style" rite now.. .. Its in perfect condition , just had two flights .

The engine is almost like brand new   covered with castor oil gunk + dirt ..

Cleaned the entire plane with collen spray .. except the engine..

About the engine i think i will go with izmile's way... will take it out and dip it in kerosene or petrol for a night and then try to take out the castor gunk..

So wish me luck..Cheers..

atul g.

I recently discovered that my OS46AX engine (which had not been used for a long time) had the throttle arm stuck... after some WD40 it losenned up.. how can I avoid this again.

Only two that I can think of on small glow engines

1, O rings at the carb base.
2, small rubber ring at the Needle valve

For bigger petrol engines there may be silicone gasket on the backplate. BTW, cleaning petrol engines should be done with great care. The carb of a petrol engine is not as forgiving as a glow engine.

-Ismail

Yep that's I thought. For glow engines, basically if you get the carb out along with the O ring, all your rubber parts are out.  In this stage, WD40 can be used, except for the minor concern about bearings.

Quick question, how do you shut down nitro engines? I have heard that pinching the fuel line completely dries out the fuel in the engine. In that case, is after run oil required?I always shut the engine by pinching the line.

I use little after run oil, but WD40 only on parts like drive shaft, turnbuckles etc which attract rust.

I checked with some long time flyers in Chennai, most dont use after run oil. Another thing was most were using degummed edible caster oil rather than raw to avoid gum build up. I have heard that only raw caster can hold the temperature. Edible oil loses its viscosity fast. I am now using fuel with Klotz lube. Found the engine to be reving better.

Quote from: izmile on September 08, 2009, 12:31:36 AM
Only two that I can think of on small glow engines

1, O rings at the carb base.
2, small rubber ring at the Needle valve

For bigger petrol engines there may be silicone gasket on the backplate. BTW, cleaning petrol engines should be done with great care. The carb of a petrol engine is not as forgiving as a glow engine.

-Ismail

Many a good engines also have an o ring at the low end needle. If you are talking four strokes most will have rubber o rings  on the pushrod housings etc so all these need to be taken into account.  

Quote from: anwar on September 07, 2009, 10:23:44 PM

Quote from: izmile on September 07, 2009, 10:03:34 PM
That was Anwar's view of using WD40.

So there is no grease packing in the bearings of smaller engines any more (especially OS) ? I mean 46 to 90 size ?

The immediate reference I could find is this : http://www.osengines.com/engines/osmg0890.html ; where they say the bearing is greased.

Many heli fliers end up losing engine bearings often because we push for maximum rpm with high nitro content for 3D (30% nitro is the standard); causing engines to run at some heat all the time.  As a part of engine rebuilds (happen often when push the limits, engines overheat, and the piston gets a hole on top, which needs to replaced, along with the ring), we always tend to apply grease.  In fact, some people I know have switched to other bearings like from www.bocabearings.com and they also recommend greasing the bearings.  If the bearing are too jumpy, then we just replace them.

One a side note, it is common that the bearing refuse to come out, so keeping them in a hot oven for a few minutes (after removing as rubber/plastic parts (mainly the carb, which has O rings etc) is a standard trick.

The bearings will be greased if the bearings are sealed otherwise they would overheat and cook up as oil will not reach them. Check out the rear bearings of any/most two stroke engines and you would find them unsealed. Which means that even if they were to be greased the first flow of fuel would ensure it starts washing/burning off. The grease you may notice on new bearings could be preservation grease. Since four strokes have other means of providing oil to bearings and reaching the fuel charge to the combustion chamber they can put in sealed bearings. You will not find mention of sealed bearings on any of the 2T engines.

This is what Boca bearing has to say about sealed ones

Issue 5: ENGINE BEARING SHIELDS & SEALS
If your Front engine bearing has two rubber seals you should not remove them. These bearings have their own grease and can help stop oil leaks. If your bearing has two shields, we recommend you remove one of them. For instructions on removing your shields take a look at this Help Section.

Your Rear engine bearing should be open on both sides to allow as much fuel as possible to pass through and act as a lubricant. You may however want leave one shield on in the rear which would help to protect the rest of the engine from any foreign matter getting through. This should not be done with one seal. If you find your engine is stingy in getting fuel to the rear, you should definitely leave the bearing open.

In our next issue of the Boca Bearings Tips & Advice Newsletter we will show you how to remove your bearing shields.

Yes, my understanding is that the rubber that seals the bearings would get affected by frequent application of WD40 (even though WD40 claims that it is safe for use on rubber). 

So on engines that have sealed bearings, this is a matter of concern in case of frequent usage.

There are some people who just use WD40 instead of after-run oil (because WD40 will take all the water content out and provide a mild layer of lubrication) !

It would not take water out as it is not hygroscopic. What it would do is not allow water molecules to cling to surface of the engine components by forming a barrier film

Ok Guys...

I got the SuperTigre GS-40 Dual BB Ringed w/Silent Muffler out of the plane...

Planning to put the engine with the muffler in kerosene overnight..

any more suggestions..

thanks again

atul g.