Fuel Question

[daakeung]

Is it wise to change between different brands of fuel on the same engine ?
How about changing the % in the fuel too ?

If a weaker one was used at break in.

 

[Revo Rancher]

If you change fuel %'s you need to go through a break in period with the new fuel just like as if your motor was new again.

As far as brands, if the oil content percentage is greatly different, see above.

 

[daakeung]

Thanks dude.

 

[aj200415]

I dont no about how smart they are, but my LHS guys tell me if you go to higher nitro content, you shouldent go back down. They say it stretches out the piston/sleeve or something....but thats there .02 cents

 

[vbgagnon]

If you go to 30% make sure you don't have to change your deck hight. Some engines need to add a shim, others don't.

 

[bustedgears]

What are you going to be changing from? To?

 

[Revo Rancher]

Which means you might have to change your plug to a hotter rating, or in some cases a cooler plug...I was trying to keep the answer I gave as simple as possible.

Why don't you tell us what you have in mind? What fuel do you use now in which motor, and what fuel do you plan to switch to?

 

[daakeung]

well, someone was telling me to break it in with a 10% then later up it to a 20%

 

[Diver6127]

General rule of thumb ... break it in with the fuel you plan to use or at least with the percentage fuel you plan to use.

I use 30% Byrons racing blend and that's what I break it in with.

 

[Revo Rancher]

Yeah, why do it the hard way. Break it in with the 20% you plan to end up with anyhow. Someone is giving you bad advice.

 

[Hugh]

General rule of thumb ... break it in with the fuel you plan to use or at least with the percentage fuel you plan to use.

I use 30% Byrons racing blend and that's what I break it in with.

That's about hits the nail on the head. When you change(go up) in nitro percentage,it is not necessary to completely rebreak in the engine. Take it easy for a few tanks,but you do not have to completely re-break in the engine,and be sure to re tune a little richer at first. Do not run 10% nitro,either. Virtually all rc car engines are designed to run 20%-30% nitro.
The only thing that the nitromethane ingredient does is introduce much more oxygen into the engine giving it alot more "umph". Technically,you can run an rc car engine using 0% nitro,but performance would be like that of an electric Wal-Mart rc car.
Break in the engine with what you plan to run with on a permanant basis. I mix my own fuel and run a mixture of 30% nitro,10% oil in all of my race cars. When I'm breaking in an engine,to play it safe,I'll mix up 12% oil to give it more protection for the critical break in period. I also recommend using the heat cycle method for break in. It's the only method I will ever use,with outstanding results. My engines ALWAYS run better,cooler and will smoke all of my friend's engines because I take my time and use the heat cycle method for break in. JMO.

Forgot to mention that SOME engines,depending on the manufacturer,do require shimming the head when running a higher nitro percentage. It all depends on the head clearence from the factory.