Hey fella's. I have several gallons of Wildcat 2 & 4 cycle 15% fuel. It contains 18% total synthetic oil. I would like to add some castor to the blend. If I add 5 ounces of castor to a full gallon it will increase the oil content to 20%. What will the effect be or will it even be noticable in the way the motors run?

hi

yes it will.also depend upon what you intend to use it for.if for brakingin an engine fine.


jimmy

Adding oil very slightly decreases your methanol and nitromethane percentages. So, you might get slightly less power than you'd get running the fuel with nothing added. Also, adding 5 ounces will give over 21% total oil.

So, based on what you are saying, it would be more appropriate to add 3.5 ounces. Right?
Nice chart by the way. Thank you.

If you want 20% oil, yes. I just bought 8 gallons of the same fuel and will be using it with nothing added.

It is not neccesarily the 20% factor that i am after, i just prefer to have a little castor mixed in. Old school maybe ...

....5 ozs. castor will be fine....no worries.

It doesn't really but it seems to because of the way percentages are worked out using the total mix of oil/methanol/nitro. If you look at that table where 5% oil gets added there's 67% methanol and 15% nitro so they're in a ratio of 4.47:1 (which is what the needle valve is tuned to) and after adding extra oil the table says there's 64.48% methanol and 14.44% nitro which is still a ratio of 4.47:1 and all that's needed is a slight "richening" of the needle to account for the extra volume of oil.

An easier way to think about it is if there was a 50/50 mix of methanol and nitro. No matter how much oil you add there's always still a 50/50 mix. Even easier is a fuel with no nitro. With any amount of oil you still tune just for the methanol going into the engine.