Mixing different fuels

[J-S-Q]

If I have two half bottles of different fuel (Optifuel 30% and Wildcat 12%) is there any reason I shouldn't mix them together? I guess the result would be something roughly like 20% nitro.

[robgt]

It might work, it might not...?
Personally I wouldn't do this as the ingredients of fuels differ from manufacturer to manufacturer. Although that said, they can't be a million miles apart, lets face it

If you do it... let us know how you get on!
Cheers,
Rob

[Kwickkwack]

Opticat 20% sounds ok but I would be worried about Wildfuel 20%

[moyesboy]

I mixed half a gallon of magnum30% with half a gallon of Rapicon 30% with no problems - but it was only 1 gallon.
Rapignum or Magnicon?
I beleive it is common to mix different nitros of the same brand to get the nitro% you want (like 15 and 30 to get 20 when its out of stock).

[waveydavey]

We are having a similar conversation at the club that some people can understand and some dont. How does this sound!

If you mix 4ltrs of rapicon 30% and 4 litres of Rapicon 15% you end up with 29% not 20%.

The maths;

Amount of Nitro in 4 ltrs of 30% is 1.2ltrs
Amount of Nitro in 4 ltrs of 15% is 0.6ltrs

Total amount of nitro in 8ltrs of the above mix is 1.8ltrs

This equates to 6.2ltrs of methanol and oil.

As a percentage this works out to be not 20 but 29%.

Anyone got any thoughts on this. We have worked it out to be the difference in the amount of methanol in each respective 4ltrs but surely this is too good to be true!

[debrooker]

unless i'm a spaz but surely its 1.8/8 ltr = 22.5%

[Kwickkwack]

unless i'm a spaz but surely its 1.8/8 ltr = 22.5%

Correct I believe, what he has done is 1.8lts of 6.2ltrs instead of 8lts

It is a percentage of total volume.

[waveydavey]

unless i'm a spaz but surely its 1.8/8 ltr = 22.5%

This is the nub of the conversation and one we don't all agree on. Does the diagram make sense?

[Janek]

I've got a headache, either buy the nitro % you really want, or use it to light your next bonfire !

[unwind-protect]

Er, in your diagram you have one unit of nitro to 4 units total volume. 25%.

If it was nitro to methanol ratio, your first container would be 100%!

[debrooker]

i think the diagram is wrong, the nitro component should still be 25% if the containers are the same..

my brain hurts

[waveydavey]

So does mine. It's a disagreement that has been going on for the last week or so. I don't know one way or the other now thats why I posted it so someone with more than the single brain cell I have can help out.

[GravityKills]

if you get more than 100 %, something is fishy :-)

I'd try something like
(Volume1 * percentage1 + volume2 * percentage2) / (volume1+volume2)

i.e. (0.5 * 30 + 0.5 * 15) / (0.5+0.5) = 22.5

I have mixed 20 and 30 for an OS .50, aiming for 25 %.
I've also had two rear bearings and two piston rings fail within a couple of gallons. Probably that is coincidence, though.

[waveydavey]

Er, in your diagram you have one unit of nitro to 4 units total volume. 25%.

If it was nitro to methanol ratio, your first container would be 100%!

No it's to demonstrate mixing an already mixed percentage of nitro and methanol to a straight methanol mix giving you equal units in each container. I thought I understood it until now.

[DbyMA]

multi viscosity blend of oil

Read this Scott Gray - RC Professional the other day.

Sheds a little more light on the topic, and supports robgt's comment.