how much oil?

[avbrando]

picked up some 40 % byrons car fuel, (11% oil) and would like to run it in my 67 green head, can anyone give me an idea on how mutch oil to get close to 20% oil? i will be using klotz techniplate for nitro. when the bottle says 20% oil, is that actually 20% of the gallon or is it measured a different way?

 

[misshydro]

If it say 20% oil in a gallon or quart its 20% oil in it. If thats like traxxas car racing fuel it will have 12% oil in it.? I'd put 3oz to one quart of fuel to get about 18-19% oil.

 

[Sean Bowf]

128 ounces to a gallon. Fuel already has 12% oil in it... so you need to add 6% more to get to 18%..

x/128 = 6/100

100x = 768

x = 7.68 ounces to the gallon to add 6% to a gallon.

If you add 3 ounces to a quart of oil...

3/32 = x/100

300 = 32x

x = 9.375% oil to it.. add that to 12% and you are over 21% oil.

Sean

 

[avbrando]

thanks alot guys, i will try the new mix tomorrow.

 

[steve wood]

18% oil is way too much. we run 15%,and have for years. there is more power in alcohol than in oil

 

[Chris Wood]

yep.

gonna try out some 12% this weekend.

you get a whole new look at it when you mix it yourself.. i looked at our standard mix and thought WOW this is overkill.

chris

 

[misshydro]

man the way I was told ,you mush have 16-18% oil in your fuels. you guys are running less the 15?? Man no wonder why you guys burn out your motor quickly!!beside running hight nitro to that also help burns that motor out quickly too.

 

[steve wood]

man the way I was told ,you mush have 16-18% oil in your fuels. you guys are running less the 15?? Man no wonder why you guys burn out your motor quickly!!beside running hight nitro to that also help burns that motor out quickly too.

don't know who you are, but if you know us you should know we don't burn up motors. matter of fact iv'e never seen anyone "burn up" a motor. don't know who told you you had to run 16 to 18%. you don't need that much. our 67 greenhead's about 3 years old. us1 last year. 1st at hydro masters last year. same p/l, same bearings then and now. 14%+1% castor. still runs perfect, and looks new inside

 

[Sean Bowf]

Steve...why the 1% castor and not all synth??

Sean

 

[Charles Perdue]

man the way I was told ,you mush have 16-18% oil in your fuels. you guys are running less the 15?? Man no wonder why you guys burn out your motor quickly!!beside running hight nitro to that also help burns that motor out quickly too.

An old Indian once told me that running too much oil in the fuel lowered the octane, causing the engine too detonate excessively and could make the internal engine temperature be too high.

 

[steve wood]

Steve...why the 1% castor and not all synth??
Sean

just my piece of mind. i may drop it in the little motors, but will continue using it in the needle bearing ones

 

[Don Ferrette]

man the way I was told ,you mush have 16-18% oil in your fuels. you guys are running less the 15?? Man no wonder why you guys burn out your motor quickly!!beside running hight nitro to that also help burns that motor out quickly too.

I run 70% with 12% oil in the 21's & 60/15% in everything else (all synthetic oil). Higher nitro does not "burn out" a motor, it requires requires a richer mixture not to mention too much oil causes bearings to skid rather than roll in the races. Also a little 21 does not need to be slogging it's way thru 18- 20% oil, you're actually working it harder that way. B)

 

[Preston_Hall]

128 ounces to a gallon. Fuel already has 12% oil in it... so you need to add 6% more to get to 18%..
x/128 = 6/100

100x = 768

x = 7.68 ounces to the gallon to add 6% to a gallon.

If you add 3 ounces to a quart of oil...

3/32 = x/100

300 = 32x

x = 9.375% oil to it.. add that to 12% and you are over 21% oil.

Sean

But you don't end up with 128oz so the percentage is not 18%. Closer to 17%. ((.12 x 128) + 7.68)/(128+7.68)

starting out you have

40%N = 51.2 oz

11%oil = 14.08 oz

49%M = 62.72 oz

asume X = total volume and Y = oz of oil added

eq #1 51.2 + 62.72 + (14.08 +Y) = X

also, (14.08 +Y) = .18 (18% oil)

solve for X,

eq#2 X= (14.08 + Y)/.18

substitute that for X in the first equation and

Y = 7.35oz of oil to be added for a total volume X of 135.35oz

20% oil

38% Nitro

46% Meth

 

[Sean Bowf]

128 ounces to a gallon. Fuel already has 12% oil in it... so you need to add 6% more to get to 18%..
x/128 = 6/100

100x = 768

x = 7.68 ounces to the gallon to add 6% to a gallon.

If you add 3 ounces to a quart of oil...

3/32 = x/100

300 = 32x

x = 9.375% oil to it.. add that to 12% and you are over 21% oil.

Sean

But you don't end up with 128oz so the percentage is not 18%. Closer to 17%. ((.12 x 128) + 7.68)/(128+7.68)

starting out you have

40%N = 51.2 oz

11%oil = 14.08 oz

49%M = 62.72 oz

asume X = total volume and Y = oz of oil added

eq #1 51.2 + 62.72 + (14.08 +Y) = X

also, (14.08 +Y) = .18 (18% oil)

solve for X,

eq#2 X= (14.08 + Y)/.18

substitute that for X in the first equation and

Y = 7.35oz of oil to be added for a total volume X of 135.35oz

20% oil

38% Nitro

46% Meth

Some of your numbers are off (you wound up with 104% with your final numbers and adding 7.35 ounces to a gallon of 11% will not get you 18%)...but yes, you are correct, you will wind up with more than 128 ounces...

12% of 128 ounces is 15.36 ounces. 15.36 + 7.68 = 23.04

x / 100 = 23.04 / 135.68

135.68x = 2304

x = 16.98% total oil with my earlier calculations...I think I can live with that...heh.

Thanks,

Sean

PS

When starting with 12% and adding your 7.35 ounces of oil

7.35 + 15.36 = 22.71 ounces of oil total after adding 7.35 ounces

128 + 7.35 = 135.35 ounces total volume of fuel mixture after adding 7.35 ounces of oil.

x / 100 = 22.71 / 135.35

135.35x = 2271

x = 16.778% oil when using your 7.35 ounces of oil to 12% oil fuel...unless I am messing the numbers up some place...

For starting with 11% and adding your 7.35 ounces of oil...

7.35 + 14.08 = 21.43 ounces of oil total after adding 7.35 ounces

128 + 7.35 = 135.35 ounces total volume of fuel mixture after adding 7.35 ounces of oil.

x / 100 = 21.43 / 135.35

135.35x = 2143

X = 15.83% oil if adding 7.35 ounces to a gallon of 11% oil fuel

Nitro = x/100 = 51.2/135.35 oz

135.35x = 5120

x = 37.88%

Meth = x/100 = 62.72/135.35

135.35x = 6272

x = 46.34%

Oil = 15.83%

Meth = 46.34%

Nitro = 37.88%

My brain hurts...

 

[Sean Bowf]

Ok...

12% of 128 ounces is 15.36 ounces of oil in it now...but we want 18%...

15.36+x / 128+x = 18/100

1536 + 100x = 2304 + 18x

82x = 768

X = 9.36

Checking the math backwards...

9.36 + 15.36 = 24.72 total oil content in the jug

128 + 9.36 = 137.36 Total fuel content in the jug

24.72 / 137.36 = x / 100

137.36x = 2472

x = 18%

So the formula would be

 

Y + x / 128 + x = P / 100

 

Where:

X is how much oil to add in ounces

Y is how much oil is in the fuel to start with in ounces

and

P is the percentage we want to wind up with...

So if we have 11% and want 15%...we need to solve for Y first...

.11 x 128 = 14.08 ounces of oil to start with

14.08 + x / 128 + x = 15 / 100

1408 + 100x = 1920 + 15x

85x = 512

x = 6.02 ounces of oil to add to 11% oil content fuel to get to 15%

Checking the math backwards

6.02 + 14.08 = 20.1 Ounce of oil total

6.02 + 128 = 134.02 ounces total fuel

20.1 / 134.02 = P / 100

P = 15%

 

[misshydro]

man the way I was told ,you mush have 16-18% oil in your fuels. you guys are running less the 15?? Man no wonder why you guys burn out your motor quickly!!beside running hight nitro to that also help burns that motor out quickly too.

I run 70% with 12% oil in the 21's & 60/15% in everything else (all synthetic oil). Higher nitro does not "burn out" a motor, it requires requires a richer mixture not to mention too much oil causes bearings to skid rather than roll in the races. Also a little 21 does not need to be slogging it's way thru 18- 20% oil, you're actually working it harder that way. B)

Then why has everyone been telling some of us that you need 15-18%oil in the .15-.21 because there under alot of loads on a boat and you need the exrta oil to lub the bearings. Around here the hobbyshops dont carry boats fuels. So I'd been running traxxas racing car fuels in my boats. They have 12%oil in them,So I was told to add 2-3oz of castor oil. I've been using SIG castor oil. another question for you guys?? what motor will last before you have to change the pistion&cyclender set?? The one that runs on 30%nitro or the40-70% nitro? With most of these pistion&cyclender sets in these motors arent cheap to replace eather.There almost the half the cost of a new motor. I got a CMB.21RS Redhead that was moded and was given to me as a gift and I dont want to wear that motor out quickly eather.The only thing I hate about it,its very touchie on the needle and can be very tempermental,But when the needle is on its a screamer.

 

[Don Ferrette]

Then why has everyone been telling some of us that you need 15-18%oil in the .15-.21.....

Who's "everyone"? h34r:

 

[Sean Bowf]

I think it goes back to when they used all castor oil... I was told that you can use less synthetic than castor...but who knows...

I think with Red Max...if you don't tell them you want a custom blend, they put 20% oil in boat fuel.

Sean

 

[avbrando]

i added 8oz of oil to the car fuel and it ran great! i know 8oz is a little more than your formula but i was able to achieve 74.4 mph in a 36" sprint cat with a 67 green head. thank's alot sean.

 

[Preston_Hall]

Ok...
12% of 128 ounces is 15.36 ounces of oil in it now...but we want 18%...

15.36+x / 128+x = 18/100

1536 + 100x = 2304 + 18x

82x = 768

X = 9.36

Checking the math backwards...

9.36 + 15.36 = 24.72 total oil content in the jug

128 + 9.36 = 137.36 Total fuel content in the jug

24.72 / 137.36 = x / 100

137.36x = 2472

x = 18%

So the formula would be

 

Y + x / 128 + x = P / 100

 

Where:

X is how much oil to add in ounces

Y is how much oil is in the fuel to start with in ounces

and

P is the percentage we want to wind up with...

So if we have 11% and want 15%...we need to solve for Y first...

.11 x 128 = 14.08 ounces of oil to start with

14.08 + x / 128 + x = 15 / 100

1408 + 100x = 1920 + 15x

85x = 512

x = 6.02 ounces of oil to add to 11% oil content fuel to get to 15%

Checking the math backwards

6.02 + 14.08 = 20.1 Ounce of oil total

6.02 + 128 = 134.02 ounces total fuel

20.1 / 134.02 = P / 100

P = 15%

What was I smoking?

Anyway we really have not answered the original question which was to go fromm 11% to 20%.

After thinking, there are way too many numbers and I still don't know what I was thinking before.

But now,

X= amount of oil to add

(14.08+X)/(128+X)=.20 or whatever percentage

so X=14.4oz, total volume = 142.4oz

Check that and thanks for keeping me on my toes.