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Engine basics => Engine set up tips => Topic started by: DanielGelinas on January 31, 2012, 12:06:53 PM

Title: Fuel Mixing
Post by: DanielGelinas on January 31, 2012, 12:06:53 PM

Can anyone help me with fuel mixing?

I have one gallon of 10% nitro, 29% castor.

I would like to mix in some synthetic oil. How much synthetic oil and alcohol do I need to ADD to my gallon to end up with 11% synthetic, 15% castor?

I'm assuming it will lower my nitro content...

Whats the math involved? HB~>

Many thanks!!

-Daniel H^^ H^^

Title: Re: Fuel Mixing
Post by: Bill Adair on January 31, 2012, 01:21:56 PM

Dan,

Try this site, and change the numbers in their work sheet till you get it to the desired level. I even use their formula for mixing diesel fuel, by substituting ingredients. Scroll way down till you see the options to Add oil only, or Add Nitro and oil.

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

Bill

Title: Re: Fuel Mixing
Post by: DanielGelinas on January 31, 2012, 02:22:49 PM

Hi Bill,

I looked into this site already. It only works if you add oil. I do want to add oil (syn) but don't want to end up with more oil content than 25-26% total. Problem is that I'm starting with 29% castor.

I need to add a considerable amount of alcohol to <CUT> the 29% castor before adding 11% syn.  HB~>
 
-Dan

Title: Re: Fuel Mixing
Post by: Tim Wescott on January 31, 2012, 02:30:22 PM

If you have 29% castor now, in one gallon of fuel, you have 0.29 gallons of castor.

If you have 0.29 gallons of castor and you want 15% castor, you want to increase your total volume to

(0.29 gal)/0.15 = 1.933 gallons.

So whatever else you do, you need to add 0.933 gallons total of stuff.

Of that 1.933 gallons that you end up with, you want 11% to be synthetic.  That works out to needing to add

(1.933 gal)(0.11) = 0.213 gallons.

So, of the 0.933 gallons that you're adding, 0.213 are synthetic oil, and you need to make up the rest in methanol.  That works out to

0.933gal - 0.213gal = 0.720gal

So 92 ounces (11 1/2 cups) of methanol,
27 ounces (3 1/4 cups + 2 tablespoons) of synthetic,
and your fuel.

Title: Re: Fuel Mixing
Post by: Steve Hines on January 31, 2012, 09:16:22 PM

You could mix what you have with Bryon fuels, they say is 18% syn and that would give you 9 and 14.5. thats 23.5. I did this with Sig syn plus and caster gave me 10 and 10 It worked good.

Title: Re: Fuel Mixing
Post by: DanielGelinas on February 01, 2012, 08:50:56 PM

Thanks guys! Thats exactly the info I needed. y1 y1
-Daniel H^^

Title: Re: Fuel Mixing
Post by: Paul Smith on February 02, 2012, 02:52:43 AM

Without getting too deep into the math, you will end up with about 40% total oil.  That's some pretty oily fuel without much energy.

Instead of just adding the synthetic oil, maybe you should mix the 29% fuel with some all-synthetic FUEL, not just the lubricant.

Title: Re: Fuel Mixing
Post by: Tim Wescott on February 02, 2012, 08:41:24 AM

Quote from: Paul Smith on February 02, 2012, 02:52:43 AM

Without getting too deep into the math, you will end up with about 40% total oil.

Since when has 11% + 15% added up to 40%?  When I was growing up it was always 11 + 15 = 26.

Granted, 26% is a tad high -- but it's not 40%.