rageman

I have a gallon of Odonnell 20% nitro "CAR" racing fuel part number ODOP3220 and BeNOL racing castor oil. How much BeNOL should I add to the gallon of Odonnell 20% for a boat engine? The BeNOL bottle says to mix at 15% to 18% for two cycle glow plug engines.
This fuel is to break in a new engine (Dynamite .32 in a Thunder Cat 31 RTR).

jetpack

My Feedback: (1)

You'll have to find out how much oil percent is in your O'Donnell fuel, then use this calculator:

[link=http://www.nitrorc.com/default2.asp?Introduction=http://www.nitrorc.com/fuelws]Fuel Mix Calculator[/link]

I would suggest 20% to 25% oil for break-in.

What does your manual provide for information?

misshydro

Ok on traxxas car/truck/buggy racing fuel.. They only have 12%oil in them.. I buy my traxxas 33% by quarts.. I add 2oz of oil to one quart of fuel..Had a old timer boat racer calulated it out to 1-2oz of oil in a quart of fuel..So you can add 8oz to one gallon of fuel. ODonnell makes boat fuels too.

rageman

Odonnell does tell what their oil % is. It is a secret. I found an old post that incuded a website that had a chart listing the oil content of a bunch of fuels that said Odonnells was 14%. It did not say which Odonnell fuel and noted that it would no longer be updated. No date on the chart so hard to hang ones hat on the data. The manual just recommends their in house fuel and not a % oil. I want to run 20% but need someone to tell me how much to add to the Odonell fuel noted to get to taht level.

rageman

Nitro boating is not big in my area so LHS do not carry boat fuel or I would buy it. The LHS said that the car fuel would work....right. I guess I will just have to add a ton of oil to the car fuel to make sure I have enough uless someone knows teh answer to my question. Thanks.

Dan S

I did a search and found an old thread dating back to 2006 asking about fuel.

One of the members contacted O'Donnell and was told that ALL of their fuel had oil equivalent to 18%.

Dan.

rageman

Dan,

Would you post the URL to that thread?

Thanks,

Bill

Dan S

right here: http://www.rcuniverse.com/forum/m_47...tm.htm#4747872

Post #9 and 13.

Dan.

rageman

Thanks Dan.

I guess this statement versus the Odonnell fuel offerings leaves me confused. If all Odonnell fuel contain either a 18% oil "equivalrent" [which implies that the actual oil percent is different than that but Odonnell believes that the pecent oil that they do use performs "like" there was 18% oil in the fuel or "equivalent"] or an actual 18% oil then what is the difference between an Odonnell packaged, let us say, 30% nitro fuel for "Cars" or for "Boats" or for "Aeroplanes" or for "Helocopters"?. What is then the difference between the different Odonnell fuels other than the lable, the Odonnell part number, the price and what? I guess one could hypothosize that each different fuel uses different oils in the 18% oil formulation. Other than that there is only methanol and nitro.

rageman

I learned that there are contract fuel test labs. I sent inquiries to a few to see if they would determine % oil of a nitro methane model engine fuel. TBC

rageman

Well it can be done but pricey. You have to send two fuel samples for each to be tested in a gas chromatograph. One sample to be a baseline of nitro methane with zero oil and the other sample containing the unknown % oil. By compareing the results the % oil content can be determined. The lab I talked to said $100 per test x 2 = $200.

f16man

Put 8 oz in graduated cup or measuring cup let the meth and nitro evaporate measure the oil that is left and do the math, castor goes a long way especialy in premixed fuels , 4 to 6 oz per gallon should be plenty.

rageman

Thanks for the info/suggestion.

I had the same thought and ordered a graduated cylinder yesterday. I checked and the boiling point of nitro methane is 217F so I may speed it along and prevent the hygoscopic nature of the fuel from absorbing water and thereby distorting the results by puitting the cylinder in boiling water (outside with plenty of ventilation and using a hot plate with no open flame heating a pot of water to set the cylinder in.

AQUAMAN69

BlueThunder sport uses 16% oil if im not mistaken. I'm not sure what the big difference between boat and car nitro motors are as far as breaking them in but on my car i'm on my 12 gallon of this fuel and my motor still runs like a champ. Its hard for me to believe that this extra oil is gonna make that big of a difference after its broken in correctly. If you can run 12% oil with more than 40% nitro why would 16% oil in any nitro content not be enough to break in a marine motor. Your not reving it to kingdom come when breaking it in. Can someone plese explain why its so important to have 20% oil when breaking in a marine engine? I'm new to the whole marine thing but not to Nitro engines. I'm not doubting any ones advice i'm just trying to learn more of the difference between marine and, car engine break in.

Dan S

It is the first time I hear that you need to breakin an engine with 20% oil or more.

Myself (and majority of people) I breakin my engines with the fuel I use, no switching around.

I remember when I was doing the search for the fuel I saw another thread or post from Grim saying that O'Donnell was very good fuel.
if all O'Donnell fuel have an oil mixture equivalent to 18%, adding 8oz to the gallon will bring the oil content to 23% and the Nitro content will drop from 20 to 18.8%.

Dan.

AQUAMAN69

I definately agree with not changing fuels . Ive always been under the impression that you should run what you broke the motor in with for its life span as well. My whole thing is with this having to use 20% oil to break the motor in with. Im aware that these marine engines are under more stress than a car engine but again if 12% oil is good enough for a marine engine to run a full throttle; why is 16% oil not enough to break a marine engine in at part throttle? Unless someone can convince me that you HAVE to use 20% oil to break in a marine engine i'm just gonna continue to run the best fuel i've ever used and, take my chances with the break in on 16% oil. If anyone can explain why you must use 20% oil content to break in a motor please explain it to me and all who would read up on the subject. Im not attacking you Dan S. i'm just trying to understand this concept of using 20%oil content for break-in. Maybe someone will set the record straight.

Dan S

no worries Aqua, I don't feel attacked.

Like I said, no need to have to use 20% oil for break in.

The fuel I use is the same I run and has 18% oil (95% synth, 5% degummed racing castor - thats how it comes).

I have seen, heard and read that some run 14%, so I would think that 16% would be plenty. if anyone wants to be a bit safer and go up to 18% oil all they need to do is add 3oz to 1 gallon.

Dan.

AQUAMAN69

O.K., So its more of a piece of mind decision than a must do thing. I can go with that. My apology for getting all excited over it.

rageman

So what is "degum racing castor"?

What fuel do you run?

jetpack

My Feedback: (1)

The extra oil helps carry metal particles away from the engine, and forces you to run a richer setting to get it to run.

What your actually trying to accomplish is flushing the engine with a higher percent oil mix at a higher consumption rate, and using the right oil. Castor has protection qualities synthetic really cant provide with a new engine.

Using 14% all syn oil at 30% nitro sounds pretty dry on a new sleeve and piston.

I would add a head shim and castor to reach at least 20% and try not to over-prop or run mid to lean with the carb.

This is all my own 2cents how I would go about the first batch of fuel on a new engine.

Something you should take advice about however the more nitro you run the more oil you should add. Nitro has the effect of "washing" down an engine or "drying" a fuel mix sort-of-speak.

I posted a Webra fuel mix table to help draw a better picture. Even though Webras are high compression and low to no nitro fuel (0-15%) due to their combustion shapes, the table shows a picture on how oil percentages and types are suggested to be used during break-in and in normal running.

Dan S

rageman,

I use Wildcat Promix 35% Nitro and 18% oil, here is a Quote from Wildcat about their oil:

"Wildcat uses only Klotz lubrication packages. Wildcat's lubrication packages were designed in cooperation with Klotz and are proprietary. We use only the highest grade pressed and degummed racing castor. Any castor that is not degummed does not have the same superior properties as BeNol. While other companies settle for lower grade AA castor, we use Klotz BeNol. BeNol has a 25% greater film strength, higher load capacity, and reduced varnishing properties".

Dan

rageman

Dan S,

Thanks

rageman

See attached picture. I filled a 50 ml Borosilicate (Pyrex TM) graduated cylinder ($10 on Amazon.com) with Odonnell 20% nitro Car Fuel at room temperature. I heated it over night (in a well ventilated garage) with a 150 watt spot lamp and reflective aluminum foil make shift oven. Nitro methane has a boiling point of 217F so it flashes off quick. The remaining oil measured at 7.25 to 7.5 ml at room temperature so the % oil in the fuel was from 14.5% to 15%. I can now add the necessary additional castor oil to give the 18% desired for boat fuel. Maybe 20% for engine break in. [:'(]Odonnell.

rageman

Jetpack,

Do you have a calculator that will calculate the oz dilution required to change a 50% nitro to a lower percent nitro by addition of methanol and the resulting % oil?

jetpack

My Feedback: (1)

No sorry I dont.

It comes down to basic math skills.

You have to convert your content percentages to volume amounts (ounces each) the total fuel mix contains, and then subtract the percent methanol added from each.

Then with your new total volume of mix, use the calculator to bring back up your total amount of oil.