How can do you know the engine is running at a normal operating temperature without a temp gun? How does the water test work?

Water boils under 150 degrees... So spit test is totally fake on engines. Temps aren't a big deal as long as ur getting smoke out exhaughst on power and not bogging/ engine dieing. To answer question in other thread to. No having fuel drip out pipe means ur engine is fat. Lean bottom end and tune engine to feel.

After you are done racing or driving look at your glow plug. I usually can tell by ear but that come with experience. As nitroxray said if you nose over or cannot richen your engine enouh then you are too lean or have an air leak somewhere. Check fuel line, exhaust seals and your carborator. Overly wet spots indicate leakage.

For checking the glow plug...
If it is distorted or melted at all then yu a running to lean. You will also notice some melting of the piston if this is noticed and the condition is really bad.

If the plug has a heavy coat of oil on it then you are burning rich. As said before if fuel is noticed coming out raw from the exhaust then you are very very rich and should continue slowly leaning it out. This condition coyld also be caused by a bad filter or a worn out glow plug.

If the plug has none of the above and just a slight browning of the first portion of the wire then its rught where it needs to be.

Actually, water boils at 210 degrees.

http://chemistry.about.com/od/howthi...t-of-water.htm

That method works very good but only works when the plug is new.

I always go by sound, smoke and performance. I it sounds good a d idles down then it's in the range. 220-280 IMO

2 things to keep in mind.
1. On a hot day it will run hotter. On a cold day, it will run cooler. You are not going to get an engine to run at 260* safely when its 40* outside. If you do, more then likly you are too lean.

2. All engines are different. Even the same engine, from the same company may be different. So if one runs great at 220*, anothe may run great at 250*. This is normally not the case when using the same brand and type but different brands will do this. Alphas and Reedy motor like to run hot (250*+) while Sirio and OS tend to run a little cooler (200*-250*).

Its a crap shoot to say all engines run at a said temp. Just find where it likes to run at and keep an ear out. Use your temp gun to check if you are unsure about which way to tune. Its a tool. Just like a screwdriver or wrench.

When i started i was a little freaked out by temps too.

You will learn soon that temp tuning doesnt mean much. It is a good idea to check every so often to get an idea of what your particular engine likes.

Go by performance. your engine should idle well, and run strong from idle to bottom to top, with no lags or bogs.

ALWAYS look for some smoke when you nail the throttle. Smoke = lubrication = not too lean. A little rich is always better than a little lean if you want your engine to last.

IMO, engine temperature measurement is dependent on a lot of factors. Ambient temperature is one. Cooling, be it electrical or mechanical is mainly dependent on ambient temperature and the coolant (air/water/chemical) circulation.

If you use temperature to profile your engine, make sure that the rest of the parameters are kept constant and don't base your profiling from someone else's data. He or she may be in a place where the temperature and air circulation are different from yours.

+1 i like this.

Yes if you like to look at temps, get a profile base on YOUR setup such as stated in the quote. There are quite a few factors that can throw temps off between your engine, and a fellow racers. Even if you have exactly the same setup (and engine). Many might not think about it, but even running a different brand of fuel, or even a new gallon of the same fuel might be slightly different and cause temp differences (although unlikely in the later). Not to mention differences in tune and such. Like i said too many factors.

Typical temps to look for, 210f being low side in most cases, 280f+ and you are likely too hot. As stated ambient plays a big role.

im bran new to rc's, i can't get my car or truck past 170F. i actually set them back to the company to break them in for me and tune, but when i got them back we realized they were tuned at 3600 ft above seal level, and i am at 16 ft above sea level.

i have the hsn set at 4.5 turns, the truck runs amazing, the only thing is the temp. is it bad for the engine running less then 200F
(i just posted the same thing in another thread b4 i seen this one)

Try leaning it out once its fully broke in, depending on the motor it can take almost 2 gallons while others do it in half a gallon. If it runns erratic when you lean it, return it to the setting it is now and wrap the head or a section of the head with tin foil to cut air flow and see if that brings it up. You should be bewteen 190 and 210 during break in, and always have it above 200 when running.

I live in the desert and somedays over here it gets up to 112 degrees over here during the afternoon. How could I combat this so my engine doesnt get hot? Richen it?

its already broken in, i got the company to do it for me when i bought the car. i will try the tinfoil trick. thanks

some ppl recommend cutting a few holes in the body to allow air threw to cool the engine down. i cut 1 side of the windshield out on mine.

In theory, since at sea level the air is denser, meaning more air/volume you would want to run a tad richer than you would at say 3600 ft.

Best way is to still tune for performance and make sure it makes power and some smoke.

Yes going rich will bring temps down. Too rich and it will bog, and may still even bog a little at a high temp. If ambient temp gets that hot when you run you may want to step down to a colder glow plug. Surely it doesnt get too humid in the desert, so there is another reason for a colder plug. Might want to go a step or two colder than what you have been trying.