Hey Guys,

Well, I was reading through my OS46 LA manual, pretty much for no reason because I had gone through it many times, (I guess I was bored) and I noticed that it said that "you should not use fuels containing LESS THAN 18% lubricant". I didn't notice this in the manual before![X(] The entire time, even during the break-in process, I have used a 10% nitro fuel that contained 16% lubricant.

The engine seems to run fine with this fuel, but would this potentially damage my engine if it already hasn't? Would a 2% differance really be a problem? And if so, could I add castor oil to the fuel to increase the lubrication content?

I don't think it is a huge problem, but thought I'd check to see what you guys think.

Noah

I've always added a couple cap fulls of Castor to every gallon I buy, one of those things my instrutor showed me years ago and just kept doing it.

Your fine. The oil difference is about 10% (not 2%), i.e. at 16% oil, you are running 10% less oil than the specified 18%, but even so, your still fine. To get from the 16% to the 18%, you'd have to add 1/3 of a cup of oil... a lot more than just a couple of capfuls. Adding a couple of capfuls won't hurt anything, but probably doesn’t really help much either.

EDIT - I just realized the 10% thing may be confusing, so I'll clarify. 16% oil in a gallon would be about 20.5 ounces of oil. At 18% in a gallom that would be 23 ounces of oil. The difference between 23 and 20.5 is about 10%.

Oils cause a bit of controversy over how much and what type/blend. Some engines need more than others and often it comes down to the personal experience of many fliers with a particular engine. You might have noticed from the OS instructions that they say synthetics are "permissible" but give a caution. Just under that there's a table for fuels A and B and that shows 20% castor. This may be specific to the LA series of engines because of the plain bearing crankshaft which really needs castor for long life. Conrods love castor too.

With oils it's near impossible to have too much but you can certainly have too little so I prefer to err on the safe side and never use less than 20%, that being all castor because I don't fully trust synthetics (a personal opinion). With an LA and a synthetic based fuel I'd add castor to get 22% total oil to be on the safe side. Don't use medicinal castor though, get something like Sig castor because it's cheaper and won't have the possibility of sugar added to it.

I add 4 ounces of Castor per gallon to whatever I'm using. Just something I've been doing since my controline days. Some guys think I'm nuts and others feel the added lubrication has benefits. I've never felt that I lacked power. And there is going to be goo cleanup no matter what anyway. Oh and one more thing, I add four drops of original Armor All to help prevent foaming. Sheesh, it sounds like alchemy.

I think you will find that most of the discussion concerning oil percentages vary wildly. Your engine is a plain bearing engine so most consider more oil better for it in the long run. Another view is that the newer synthetic oils give better protection, another matter of strong debate. If you do get some castor be it from Sig or Wally mart it is just a good idea to add some to your fuel to bring up the lube "just in cast". And the supermarket castor is good stuff as long as you read the label and make certain it says no added sugar or other ingredients.

Hey guys,
Thanks for all the info.
I have some "Klotz" brand BeNOL Castor oil I got from Tower Hobbies to use as After-run oil. I just put a 5 to 6 drops in my cylinder after I run the engine. I will probably take your advice and add some to my gallon of fuel. I used about a third of the gallon already, so I will probably add 2.5 to 3 oz of castor oil to the remaining 2/3 gallon I have.

Once again thanks for the reassurance that my engine is OK and also for the tips on adding lubrication to my fuel!

Noah

There's probably no topic sure to ignite a controversy of opinion than oil content and type. You'll hear lots of folks declare they used XYZ fuel and had no problems. The fuel manufacturers will all swear their blend gives the "most power", "cleanest burning" and "longest life" of any fuel.

On the other hand, I know a lot of engine rebuilders who know exactly how quickly any engine can be ruined by running a fuel with insufficient oil or no castor. Ask me how many engines I've bought used which are worthless because someone ran it with "RC Fuel".

I have several OS FP and LA plain bearing engines. All are ABN (aluminum piston, brass cylinder which is nickle plated). Manufacturers used to use ABC (chrome plated) but most went to nickel due to environmental concerns, costs and quicker break-in. For breaking in, I use Sig Champion fuel which has 20% oil which is 50/50 synthetic/castor. Castor provides many benefits and one disadvantage. It cools better, protects better but will eventually cause a varnish buildup. There is no better lubricant for model engines than a high grade of castor. My cast iron/steel Fox 35 Stunt control line engines have to use at least 27% castor fuel.

My engines are broken in using a fuel containing at least some castor and NEVER less than 18%. If in doubt, add a few ounces extra castor - more is better than less.

Use a small prop and don't lean it out more than a 10 second burst.

Add about 2 ounces of castor to a gallon of 16% fuel and you'll be doing yourself a big favor. I've got some engines that are more than 15 years old and still operate perfectly. And that's with a lot of float flying.

Besides, the exhaust smells better!

Ha ha! It's funny, I really like the smell of the exhaust and the castor oil too! [sm=tongue_smile.gif]