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Engine basics => Engine set up tips => Topic started by: wwwarbird on September 20, 2010, 07:07:46 PM
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If I want to increase castor content by 5%, how much do I add to a fresh gallon?
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6.4 ounces
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Actually my bad I didn't take into account the displaced fuel make it 6.1 ounces.
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6.4 ounces
Casual, "good as it needs to be" answer: close enough.
Strictly: Nope. That is, indeed, 5% of 1 gallon (128oz). But it's only 4.8% of 134.4 oz, which is what you have after you add castor.
Doesn't make much difference if you're only increasing by 5%. But if you want to go up 20% it makes a marked difference (25.6oz of castor would bring a gallon of fuel up by only 16.7%).
If you're not afraid of calculators, and you want to increase the castor (or nitro) content of fuel by 'p' percent, then you need to add
v_a = v_s * p / (100% - p)
where v_s is the amount you started with and v_a is the amount to add.
So if you want to add 5% castor to a gallon, p = 5%, v_s = 128 oz, and v_a (by calculation) is 6.7oz.
Just chuck 8oz in there -- it's close enough, and it's a nice round number!
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Thanks guys, 8 ounces it is. H^^
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I just use this ...
http://www.nitrorc.com/default2.asp?Introduction=http://www.nitrorc.com/fuelws/oilonly.asp
Hope it works ,
Rob K.
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That's really slick Rob, Thanks! y1
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Yes it is itbeats me trying to figure out how much fuel needs to be reomved from the gallon jug and then figureing out how much oil to add to that to get my percentages correct. Sorry I messed you up there I went the wrong way with the correction for fuel removed my bad.