crispyspa

What are peoples observations on the type of fuel used and overheating problems?

I got my 2.5r t-maxx years ago and used Top fuel 20% and had overheating problems from the get go. I Bought an OS .18 tm to replace the 2.5 and used O'donnel 20%.
My budget got tight and I started using 10% airplane fuel which contains 18% oil (1/2 syn, 1/2 castor). Aside from the drop in power, there has been really no difference until recently when I noticed some overheating.

I also used the aircraft fuel to break in a new .18 cv-r in my rc10gt last summer, and just this last weekend, that engine shucked the piston skirt and sent aluminum powder throughout the engine also causing the top bushing of the con-rod to explode.

If the low % nitro and High oil content fuel is the problem, why? Why would a "cooler" fuel with more oil cause overheating? I use the same fuel in my airboat engines and have no problem.

If the problem is not the fuel, what is it?

I did notice some overheating in my airplane engines with a fully synthetic fuel (which I got rid of), but never used it in the car engines.

safeTwire

My Feedback: (2)

IMO ALL engines need to be broken in. During this process a tremendous amount of friction creates heat. Lubrication and TIME will prevent damage.

I take plenty time to break in an engine. Also, I add castor oil to the fuel.

There is not any calculated or formulated amount of time for break in, the engine "tells me" when it's broken in via a distinct change of sound and performance.

Mclovin350z

You want a lower oil content. There's extra friction in a fresh engine, and yes it will add to the temperature, but not much. The biggest concern when breaking in an engine is hot-spotting the piston and sleeve. This is avoided bydoinga slow, proper break-in. Fuel with less oil (like 10-12% oil content) will run much cooler than traxxas fuel with 16%oil......Airplane fuel is for airplanes!

crispyspa

Why is that? Seems strange, but there has to be a reason.

I would think that a higher oil content would be cooler because of the added lubrication. Could I run the lower oil content fuel in my airplane engines and be OK?

What about the nitro content? Does a higher nitro content make an engine run cooler?

Mclovin350z

Less oil = more methanol, methanol has a cooling effect. Oil also burns hot and doesn't burn well in nitro engines. Airplane engines run at consistant rpms and need the oil.

Trust me, there's a reason why most engines can run AND live on only 8% oil. I run 11% oil and they hold up great while running nice and clean.

More nitro only adds power and maybe a little heat.

crispyspa

Ahh. That clears things up a lot. Thanks Mclovin. LOL LI like the Superbad reference.