This is one of those trick engineering school problems.  The correct answer:  can't be solved due to lack of sufficient data.  One must assume some things in order to get an approximate answer.

Sounds like you have a can of lube which is 80% synthetic and 20% castor.  You must first balance the syn/castor mix for equal parts.  You have to assume syn and castor are the same specific weight. (they are actually not)  Measure out 1.2 oz of your oil mix and add castor until the scale reads 2 oz.

Measure out 1.1 oz of your new oil mix and add combination of methanol and nitro until the scale reads 10 oz.  The ratio of nitro to methanol is your choice. (this also assumes methanol and nitro have the same weight/volume;  they don't).

(for practical a=mounts, all the above numbers must be multiplied by some constant, depending on how much fuel you want to end up with.)

1%= 1 oz    Yet another assumption which, although not accurate, tends to simplify everything but does not provide precision results  (how much precision do we really need in our fuel mix?)

Just to add more flavor to the brew....

If you purchased an oil that contains 80% by volume of synthetic oil, and 20% by volume of caster oil; and

You want to make a gallon of fuel (128 fl. oz.) with the following percentages by volume:   10% nitro, 22% oil (50/50 synth/castor mix), and 68% methanol; then

In a clean, 1 gallon container add:

   17.60 fl. oz. of your magical mystery oil
   10.56 fl. oz. of caster oil
   12.80 fl. oz. of nitromethane
   87.04 fl. oz. of methanol

If you want to change any of these assumptions, let me know and I will run the numbers again.

Dave


Note--fluid ounces are a measure of volume, not weight. Keep everything in volume units and the percentages will make sense for quoted ratios by modelers. If you get into weights, then the math still works, but you will not recognize the numbers. Since you asked for 22% oil, I assumed you meant by volume, because that is a standard ratio. If you want to better understand the changes to the ratios (and the densities of constituents) then go look for the previous fuel thread where I summarized all this.

Measure out 1.2 oz of your oil mix and add castor until the scale reads 2 oz.

You need to start with 1.25 oz of the oil mix in order to get 1 oz of synthetic oil, as 1.25 x 80% = 1

Frank,
Attached is a Fuel Mix spreadsheet you can use for any blend you want. Only input into the BLACK cells as the ones in Blue are formula cells.

Best,   DennisT