castor as afterrun oil
 

is medicinal castor oil to use as an after run oil?

castor as afterrun oil
 

ok to use , sorry :o

NO
 

Castor will get gummy. 50-50 blend of Marvel Air Tool oil and Automatic Transmission Fluid works well.

castor as afterrun oil
 

It depends on how long you expect not to use the engine. Castor gets a bit sticky after maybe 6 months but a bit of fuel soon frees it up. After maybe a couple of years it can get very gummy and can be hard to get out of the bearings and the con rod wrist pin end. That's for normal castor like Castrol M but I'm not sure about medicinal castor. If you're thinking about putting it away over winter (isn't that most of the year in Melbourne? :D )then a bit of castor in the fuel and running the engine completely dry of fuel is all you really need. If it still worries you then put some ATF in it.

castor as afterrun oil
 

Marvel Mystery Oil works great for an after run, and very cheap too.
Joe

Any preference ?
 

Vinnie, any type of Automatic Transmission oil ?

any kind
 

yep, cheapest kind. :)

castor as afterrun oil
 

Marvel Mystry oil is not the best, use Marvel Mystry Air Tool oil (or any air tool oil) instead. The ATF's are good also, so is Rislone which is probably the least expensive of them all.

castor as afterrun oil
 

Actually, almost any light weight machine oil works well. I typically don't even use after run oil unless I won't be starting the engine for a while. (Weeks.)

But I ALWAYS run my engines dry. Our fuels are hygroscopic, meaning that they pull moisture from the air. Leaving fuel in the engine will cause the internal components to rust or corrode.

It's also why you should not leave fuel in your tank, or your fuel jug uncapped.
Dennis-

castor as afterrun oil
 

Hate to say it, but I feel you are doing more damage running the engine dry than just leaving the fuel in. I have never run them dry, and have never had to replace a bearing. I have friends that run them dry and oil them after every flight and they are always changing bearings. Would you drain the oil in your car, and then start it to make sure it is all out?

I leave the fuel in, and have never had an engine rust. Been using some for 25 years. I do use marvel if I am going to store it though.

castor as afterrun oil
 

I don't use Nitro in my car - if i DID I might think about clearing it out of the engine. My local hobby store told me that nitro is corrosive and that is the reason to clean it out of the engine and treat with some after run oil. However - you have years of practical experience behind you so now im more than a little double minded as to whether i should or should not run dry and use after run oil :confused:

castor as afterrun oil
 

The nitro is said to attract water, but your hot engine will evaporate the nitro in it pretty darn fast, and all that is left is oil. If you are in a really humid climate, I would consider putting Marvel tool oil in it after use, but if it is dry, I wouldn't waste the time. Running all the fuel out of it runs the oil out as well. I don't know if it is right or not, but I have been told by people that know more about it than myself that the engine will do more damage in that short few seconds of heating up as it quits than leaving the fuel in it. All I know is I have never had an engine go bad not running it out, and friends that run it out and use after run oil religiously change a lot of bearings. One guy that has always run it out and oiled afterwards listened to what I had to say and doesn't run it out any more. I will have to ask the next time I see him when the last time he changed a bearing was. I think i already know the answer though.

Re: any kind
 

Hi Vinnie,

Just a thought ..

That avatar of yours is the Tiger Moth with the words Sussex Flying School , or something on the side isn't it?

I was born in Shoreham-by-Sea, Sussex, on the south coast of England and used to belong to the flying club at Shoreham airport that became the club mentioned on the side of that aircraft. They used to have 2 Tiger Moths, and, I couldn't swear to it, but that particular model might even be a model of one of them!

The other one was involved in a bizarre accident many years ago, when the pilot got it into a flat spin (and once in one of those, it's impossible to get it out again) and the aircraft spun all the way to the ground. The pilot was OK though, and only the undercarriage was damaged, as the Tiger Moth has a vertical speed of only about 30 mph in a flat spin!

There! Thought that might bore you to death!

:rolleyes:

-David C.

castor as afterrun oil
 

Flyboy, are you sure all the oil is burned off as well? have you ever looked inside an engine after its been ran dry?

Just curious as I haven't either, but it would make since to me that the oil would remain.

Blackie

castor as afterrun oil
 

It doesn't burn off the oil, but from the way it was explained to me, it goes extremely lean and there is a short temp spike. That is what he said does the damage. There is always residual oil in it, but the temp spike from it going lean is what he said does the damage. The oil was also used as an example because you shut the flow of fuel off, you also shut the flow of oil off. It has some, but not what it requires at a full flow, also causing the heat spike. I am not an expert, and can only relate what has been said to me by people who know better and from experience.

If you are unsure, afer run oil will never hurt, but from what I have seen, running it and shutting off the fuel when you are done to clear the engine of everything in it does more damage than not. I will continue to do it the way I have for over 27 years. Go with what you feel is best. I don't know of a proven test done either way. Probably is one somewhere though.

castor as afterrun oil
 

I know my cowled engines I don't put after run because I can't, except for one and that is my satio 100, which has a drain nipple that I use to eject oil into, but I never run it dry. Maybe as long as you get some oil in there you may not truly need to run it dry.

Someone else like me !!
 

Flyboy,
That's my kind of flying, minimum maintenance and ground cleaning. I leave fuel in my engine, never fuss with too mcuh stuff and save the time for the air. In the fall I leave the plane in the garage and pick it up in the spring after a simply battery cycle. Never had a problem, like em tough. I panty polish the Saito Golden knight, just because it's slick.

castor as afterrun oil
 

Flyboy,
I haven't been in this hobby for 25 years, but I do have an OS 40FP that was in my trainer and a lot of planes since. Have always run the fuel out at the end of the day, and can still start the engine with one flip. I believe it has more power now than it did 8 years ago, so I don't think the 1 second lean run has hurt it. ;)

I guess we just do what works for us. :D
Dennis-

castor as afterrun oil
 

FLYBOY (and others who may be curious)...

For the last 50 to 60 years every CL engine runs dry at full throttle at the end of each and every flight. Maintenance is generally zero other than maybe wrapping a rag around it to keep dust out. After run oil is never used mainly because fuel with castor is normal and rusted bearings are virtually unknown even with engines that have been used for an incredible number of hours. What I'm talking about here is literally thousands of flights on one engine that stops every time completely dry.

As for nitro being hygroscopic, it'll only absorb 2.5% water whereas methanol will absorb 100%.

castor as afterrun oil
 

It is not necessarily the water that causes the damage, most of it is from the nitric acid (the result of nitromethane and water mixing) that does most of the damage. As an aside, while after run oil has never hurt anything, not using has caused allowed damage; take your pick. After run oil may not be needed in some cases but it has never hurt anything to my knowledge.

castor as afterrun oil
 

downunder, sounds like you have good reliable tests showing running the fuel out won't hurt either. Thats cool. I wonder why my friend that does it keeps running bearings out. Strange. Good to know that running the fuel out won't hurt it. I don't do it often, but I know a lot of people that do. From my old control line days thinking back, those all ran out of fuel ever time too and never hurt them. Good point you brought up.