stunthanger.com
Building Tips and technical articles. => 1/2 A building. => Topic started by: Mike Scholtes on March 07, 2018, 10:35:27 AM
-
Not exactly "half A" but this seems like a good place to ask. I have an OK .099 that appears to be in excellent condition. Never run by me. What fuel do these motors want, in terms of oil type and content? Any reason not to run modern 10-10-10 fuel used in larger engines? Or does it want to boatload of castor?
I also have a new-to-me McCoy .09, same question. Also appears to be little used.
-
Mike, I have run them on Sig fuel which I believe is 20% oil 50/50 blend. I have used Sig Champion all castor in addition. Bottom line is that even though my success with 20% has been well received by my engines, I've been upping the castor slightly. On the Mccoy .098, I would run that on all castor in the 25-29% range. I'm a fan of both as they're just cool little engines.
-
Thanks Kenneth. Planning to put the OK into a Wee Duper Zilch, the motor it was designed around. Or maybe the McCoy .098.
-
Cubs love Nitro. They have low compression ratio and can handle it.
The problem with the WD Zilch is how to get a big enough tank in. It is on my bucket list and I have a kit. I have thought of using a Cub .074 diesel so a small tank would be enough.
-
I have 25% and 35% half-A free flight fuel that I run in oldies like Holland Hornet and TeeDee 049s plus newer stuff like Cyclon 049. That should be plenty of nitro! Also have 15% nitro Sig Champion, that might be good if add more castor to bring oil up to 25% or more.
-
They like the 25 percent range for castor oil
Ted Brebeck of Ok engines said they ran better on Cox half a
then his own
Bruce
-
I found I have an unopened quart of K&B 1000, which the infallible internet says is 20% oil (type not so clear) and 20% nitro. Probably 30 years old. My thinking is to add some Sig castor to make it 25%. Anybody have any reliable info on type of oil in K&B 1000?
-
From old memory....questionable, the K&B 1000 was 25% nitro and 20% oil---- all castor
you thought to up the oil is advised... I would be tempted to use synthetic but that is me
Sig and Tower have very good 1/2a blends in quarts once you use up the old K&B stuff
-
Thanks Fred, I will look for some more recent small-bore fuel. I even have a pint can of red-label Cox Racing Fuel, which I think is 40% nitro! I have Aerodyne 25% and 35% half-A fuel, several quarts, which is probably literally a lifetime supply, but it too is at least 20 years old.
Speaking of which, how MUCH fuel does an OK .099 and/or McCoy .098 require to run for 4 minutes in CL use? I may be using these motors as an Old Time Stunt entry in the Wee Duper Zilch. Got the full size plans and am ready to cut balsa.