Good day all,

Good idea actually calling Klotz, information right from the horses mouth and all that.

I checked my castor/kerosene mix this morning and the castor was indeed in solution with the kerosene. Seems the little "bubbles" I was seeing last were indeed little bubbles.

So, I repeated Andy's experiment of putting the mix in the freezer. It didn't take very long nor much of a temperature change before the Castor and kersoene began to separate. The castor oil wouldn not go back into solution until the mix had warmed up to room temperature.

I seems regular Sig Baker AA castor will so into solution with kerosene but only reliably at warmish summer time room temperatures.

I spent some time poking about the net on the subject of Castor oil. Interesting stuff; been around for more than 4000 years. I stumbled across many references to medicinal grade castor and degummed castor oil. Clarenece Lee and many others recommended using only degummed castor oil in our engines but there where some posts on threads on RCU stating that there was no such thing as degummed castor oil but the manufacturers clearly describe some of their grades of castor oil as degummed and Andy made reference to his chat with a gentleman at Klotz who also described their oil as highly degummed.

Perhaps in the early days of model engines and diesels in particular the grade of castor oil commonly used was not as degummed as our more modern oils and that was the reason for the start of the old wives tale that castor oil will not go into solution with kerosene.

In any respect it seems that castor oil and kerosene will mix - Myth Busted! but with certain caveats; keep it warm and it seems that Klotz Benol works a bit better in this than ordinary castor oil.

I couldn't just let Andy be the only one running some tests so I got off my duff and did some running today.

I have messed about with model engines since I was a wee lad. Unlike Andy I have never been so concerned about idling and good throttle response. While those topics are of interest, most of my engine use has and is in control line and climb and glide (1/2A Texaco and Texaco) type of models so throttle and idel have been of little consequence.

I have also gone 30 years without buying a starter but that has all changed. I believed the old Wives Tales about not using a starter with diesels but after ready Andy's and other posts on using starters with diesels I took the plunge and got one and boy an glad I did.

Don't use Starters with Diesels - Myth Busted!!! - again with certain caveats; be careful and think about what you are doing, these leasons from Andy and other users.

I put together a .049 diesel from Cox reedy parts using the RJL diesel head and Davis heavy duty crankshaft, and various other bits and pieces I had laying about. I put a phenolic washer tween the prop drive washer and crankcase so that I could use a starter on this engine.

After a bit of messing around and a couple of tear downs to replace the internal fuel line and fix a leaky tank I got the engine to the point where it would start and run well. Some of my initial problems were caused by it running very over compressed caused the RJL not having enough adjustment to reduce the compression; I added 3 head washers and now is much better.

Initial test's where done initially with my standard mix of fuel 35% ether, 40% kerosene, 25% castor oil, 5% marvel mystery oil, and 2% Amsoil Cetane boost. (I know it doesn't add up to 100% but replace the % with ml and makes it easy to mix)

Starting with the starter was dead easy. After I got the compression and needle valve set I didn't even need to prime. Just fill the tank and put the starter to the engine; a coupe of tries and it was drawing it's own prime/fuel and would start. A short warm up and it would be on peak. Consitent runs at about 11,000 rpm on a Master Airscrew 7x3 prop. Repeat a dozen times just to be sure this all wasn't a fluke.

To carry on the no ether fuel tests, I then tried running this engine on 25% castor oil and 75% kerosene and 2% Amsoil Cetane boost. And, I was able to get it running. It took a bit more trying to get it going using the technique I described above, was very touchy to compression and needle setting and ran noticeably hotter than before. On a hot day like today (hot and muggy) no or low ether fuel will certainly work but I don't think I would have had much luck getting this going on a cool crips Autumn day.

I will have to try low ether and more Cetane boost in various combinations. Awaiting more results of Andy's tests and I will certainly pass on more of my tests as they happen.

Andy, thanks for getting us off our duff's and challanging some of these old Myths and Wives Tales.

cheers, Graham in Embrun near Ottawa Canada