Tips/Tricks for keeping engine cooler to give longer run times

[Tuckman]

Hey guys, any one have any tips or know of any upgrades to keep a standard savage 4.6 engine cooler? i find it anyoying when it gets to hot and i have to stop and let it cool and i know thats what you meant to do cos i always check its temp with a temp gun but is there anything i could do to get a little more time out of it??
thanks

 

[Rolex]

It's in your tuning.
What are the outside temps where you are, and what temps are you getting on the engine?

 

[Lessen]

You're actually sort of asking two questions that pull at one another. In order for you're engine to run cooler you need to richen your High Speed Needle on the carb ( just a little bit counter-clockwise). Now obviously when you richen the fuel mixture that means you're using more fuel which is not going to help your runtimes any. Runtimes and nitro vehicles are pretty much a standard.. short. The easiest way to get more runtime is to obviously change the way you drive it. Less full throttle will yield less fuel being burnt. You can possibly achieve slightly longer runtimes if you make a significant change to your gear ratio, like a clutch bell with 1 or 2 more teeth, however, that assumes that you run your vehicle in a limited space where the extra gearing wouldn't allow you to reach the highest end of your engines rpm range. If you're just buzzing back and forth down the street or through the yard at full song then it won't make a difference at all.... except for top speed of course.

 

[Racer 1966]

What are you calling too hot? If you check temp and it's hot, you can richen it a bit and temps will come down quick. No need to completely stop unless you're way over 300 when you check it. A larger aftermarket cooling head will help.

 

[Scrogg]

The Savage tends to run warmer after 1/2 the fuel tank is consumed. Set the LSN a tad richer, it will run cooler but you will give up a little off the line performance.
Cut a big hole in the windshield of the body for plenty of cooling.
Lower oil content in your fuel will reduce operating temps as well.

 

[Lessen]

Lower oil content in your fuel will reduce operating temps as well.

I think he means higher oil content.

More oil = more lubrication = less friction = less heat

 

[olds97_lss]

I think he means higher oil content.

More oil = more lubrication = less friction = less heat

Yeah... you'd think so. However, IME, I get better temps out of 11% oil/25% nitro than I did out of 12% oil/20% nitro. And I got better temps out of that than 14% oil/20% nitro.

I think with the higher nitro rating, you can run a richer needle setting, but still get good performance. With the higher oil content, it doesn't burn as good or as clean, so you loose power. Which in turn causes you to run it leaner to get better power.

Believe me, I would have disagreed with this as well until I tried the 11/25 I've been running the past year. I at first bought it for my LRP, but it ran so nice that I didn't bother keeping 2 different fuels for all my rigs.

I did find running a bit cooler plug helped as well with the ignition timing. A hotter plug tended to make the 25% detonate, which robs power and causes excess heat. I'll play more with glow plugs next year to see what works best. I found out late in the season that I had inadvertently bought a med-cool plug when I normally run a med-hot plug. The engine ran better than ever with it.

 

[Scrogg]

Olds we are right.
What burns cooler? Oil or fuel? Think about it.
Anyone who doubts me try a gallon of Trinity platinum 30% fuel with a cool to medium cool plug in a BB engine.
You will gain a ton of power at cooler temps and the engine will tune easier.
Higher oil content causes you to lean the engine too far to achieve a proper operating temp.
High oil content fuels are meant to help prevent noobs from burning up their engines.