I need the formula

How many ounces of castor do I need to add to a gallon of Powermaster that is already 18% oil to make it 22% oil?
How much to make it 29%?

1.28 ounces of oil per every 1% increase of oil percentage. Starting at 18% oil, add 5 1/8 ounces to get 22% oil. Starting at 18% oil, add 14.08 ounces to get to 29% oil.

Greg L. Bahrman

Clint and Greg: I am getting 6.56 ounces.

Here is the algebra involved...

23.04 + X = .22 (128 + x)

Clint: The way you asked the question was for oil addition, not subtraction of x amount of fuel, and substitution of oil. So that is the way I approached this question. You will therefore need a container larger than a gallon.

The 23.04 represents the existing amt of oil in ounces in your gallon of fuel, at 18%. You are adding an unknown (x) amt of oil. You wish to get 22% in your new total amt of fuel, which of course is a gallon (128 ounces), plus that mystery amt of oil (x) you are adding.

Solve for x: 0.78x = 5.12

x = 6.56 ounces. This is by volume, not by wt.

Currell

You beat me to it. Add 19.8 oz for 29%.


Howard Rush

Good info Greg, I know this gets old after awhile but I went to the drug store and bought a 250 ml plastic graduate. Using the table of 1.3 oz. to raise the oil content 1% of a gallon. (1 oz equals 29.5 ml) So then 40 ml. of castor oil will raise a gallon of fuel 1%, only before the oil is added you must subtract the same amout of fuel from the container, then add the castor oil. This formula may lower the Nitro just a little. I Thank You.

Thanks guys. Thats what I needed to know. I'm not removing any fuel to add oil. Just splitting the gallon in half to make a 1/2 gal of each. And yes, I'm smart enough to cut your measurements in half

I use this link.
At the bottom of the page are two buttons one for adding oil and one for adding Nitro.

http://www.nitrorc.com/default2.asp?Introduction=http://www.nitrorc.com/fuelws/

Terry

http://www.dustersrcclub.com/

I bookmarked that site. It's interesting that their starting percentage of oil is only 12%.