Adding oil to fuel

caveat - I buy pre-mixed 1/2 A fuel from Brodak - cause they make it easy to buy.
https://brodak.com/fuel/fuel/fuel-qt-15-nitro-11-5-castor-11-5-synthetic-2.html

I prefer SIG, but they seem to be permanently out of stock
Fitz and Ritch's Brew are also good, however, seems to be "see me at a contest, or call me" I wanna click a button and be done.



IF i was mixing? I'd use same as for my 2 stroke motorcycles, this is my oil of choice
https://www.amazon.com/BLENDZALL-CYCLE-460-PT-Blendzall/dp/B000UKIMGE/

Thanks cstatman but I do not want castor in my fuel for use in a Wenmac/Testors engine That has been my understanding

I use a lot of synthetics, I personally would not run full synthetic in that engine. The machining and fits of that engine are pretty archaic. Castor oil is highly recommended especially if it's the first run. However, seeing that your deadset on using synthetics, I would recommend Klotz Super Techniplate. The one problem with adding more oil is that while your raising the oil content, your lowering the other contents such as nitro.

I have the Andy Batts Two Fuel Blender. I took his one quart spreadsheet .xls and re-formulated/re-saved as an eight ounce .xlxs blender.

I tried attaching the .xlxs to this thread, but it is a restricted file type.
PM your email address...I'll email it to you. Get it while it is hot on my frontal lobe!

Admin, if you care to share from the info folder, I can email the original one quart .xls and the modified eight ounce .xlxs. PM if you wish to host it please.

Once you get it, play with it for a bit before asking questions...many apologies to Yabby. I've owed him this one since late last month and just sent it to him.

All good Jim no apologies needed. It hit my mailbox today.

That's a beautiful model Mark..

Thoughts behind use of all synth content fuel was from Testor's Corp. To prevent permanently gumming up the Rotomatic starter with Castor.

However, for our Cox engines, all synth fuel is a no-no.

Greenman38633 wrote:This may sound crazy , at least at first.  I have some 15% nitro fuel with 18% synthetic oil.  I would like to increase the amount of oil in it to about 24% let’s say.  Where can I get some synthetic oil to add to it.  This is to be used on a never started Wen-Mac 049 and I’ll probably also use it in my Testors small Cosmic wind.  I’ll try to post pictures.  It’s a Awesome brand new condition Wen -Mac P-63

Hello Greenman
                        I would add castor oil to the fuel you have as it will help with corrosion. In a lean run the castor oil turns into varnish that protect metal parts, In a lean run synthetic oil will burn in the combustion chamber reducing lubrication. I used to use Cool power 15% all synthetic in my OS engines and they were corroding inside. I started to add castor oil to the fuel and it helped to greatly reduce corrosion. I agree with all the guys that have suggested castor oil. I used to buy castor oil from SIG but now I use Blendzall. Your WEN MAC P-63 looks really great.
                                                                     Juan

Actually what I was saying about all synth fuel use on Testor Rotomatic starter engine is true. Odd recent discovery, discussed maybe a month ago. Words were in black and white in the instructions.

Defies standard wisdom, but the Rotomatic starter is very easily gummed up with Castor and can be rendered permanently unusable.

Bob has successfully freed up a number of bummed up ones, but has also had a few that could not be salvaged. Only solution to Those was leave the spring off and manually flip the prop.

These Testors don't lend themselves to disassembly, easily damaged, why Bob has developed alternative methods to free and clean them up.

It was instructions with the Testor's Fly 'Em series, I believe, but those more familiar can chime in.