breezerboat

I read a lot about this, but am not sure what the answer is. I just put one of those venom temp gauges on my truck. I'm in the middle of the break in stage of the new truck and wondered what temp is too high after I get it broken in.

HJJFFFAA

200*F to 260*F. Don't lean it out too much though during break in. Try to stay just above 200*F.

scoobs92

what is the air temp where u live that has a lot to do with breakins

Argess

well....just to add trouble....the temps HJJFFAAA mentions are the temps one measures at the glowplug. I think the Venom meter has a probe that fits between the fins where it's quite a bit cooler. You might want to use temps....hmm....say 30Degress less than he says. Anybody else on this?

breezerboat

tell me if this is correct.
to make it run cooler, I turn the HSN out 1/8 turn at a time. That would make it run more rich.. thus cooler??
to make it run hotter, I turn the HSN in 1/8 turn at a time. and that makes it run more leand... thus hotter???

Am I correct?

HJJFFFAA

Oh, well then subtract a few degrees. I think Argess is right on that about 30*.

Argess

Yes. Here's a useful link:

http://www.*********.org/cars_eng-tuning.htm

Here's a useful video as well:

http://www.youtube.com/watch?v=prX0OeQLrbw

twomanytoys

The best way to set up a temp guage is to use a point and shoot. Then set the probe wire on the head where it has the most accurate reading. Once you do this you wont need a point and shoot gun. You cant just add a probe wire and expect it to be right. You have to calibrate it.

Gex_61

The Venom guage is pretty accurate. Make sure you put the sensor low on the heatsink, near the glow plug. I don't use mine all the time, but when I do use it, it seems to read the same when compaired to my other guages. If mine were 30* off, I would never bother using it.

If you are near a track or someone who has a different temp guage, I would double check with them.

SAVAGEJIM

That is correct. Loosen the screw to richen, thus cool. Tighten the screw to lean, thus heat up.

But what engine are you running? A small block or a big block? Small blocks do not retain much thermal energy where big blocks do. So a big block engine will like temps a bit higher, say anywhere from 250 to almost 300degrees F. Many small blocks are more comfortable from about 225 to maybe as much as 270degrees F.

More caveats: The glow plug range, % nitro, number of head shims in your engine, and even the brand of fuel determine the heat at the plug. Worse, if you put on an aftermarket bigger heatsink on your engine, if that heat sink is TOO good at taking out too much heat, you could be fooled into thinking that the engine is running cooler than what it really is, especially if you miss the plug and temp the side of the heatsink hole of the plug recess in the heatsink.

Honestly, I would really learn to tune without the use of a temp gauge. Learn to recognize good engine sounds vs bad engine sounds. Learn to see if enough exhaust smoke is coming out vs if not enough is coming out.

Here are some really good vids on how by sound and smoke ques (no temp guage needed).
http://www.youtube.com/watch?v=prX0O...eature=related
http://www.youtube.com/watch?v=4Nt5t...eature=related

Listen very closely to the sounds and memorize them. If you engine is not making the bad sounds, then regardless of temp, your engine is running good.
Believe it or not, I have hit 300degrees F with a big block and the engine never ran too lean! And sadly, I had a small block run too lean and it was still under 250degrees F.
So, temps are decieving, depending on plug, fuel, engine, ambient conditions (humidity, altitude, outside temp) can sway our touchy nitro engines.

breezerboat

Thanks Savage man. My problem is that I am the first of my friends to get one, so I don't really have people that can help me much. My other friends are about to buy one, especially now that they have seen my car haul ***** down the street.
The engine I am tuning is a .18 Pro? It's the one that comes in the MGT 3.0. I am really learning a lot. And I think my new truck seems to be doing great thus far. I am using the 20% Nitro fuel. I don't know anything about shims. So, is the .18 a small block? I think I am through with the break in. It's been running anywhere from 185 degrees to 210 degrees.

SAVAGEJIM

For that engine, yes, it is a small block. When you are running it, so long as it sounds good and does not make those bad sounds like shown in the vid, then your needles are set correctly. 185 might be too cold, I find that small blocks tend to like temps above 200degrees F. But your engine might still be new and you still have to keep it that rich so that it does not make the bad sounds of being too lean.

However, don be shy about leaning just a little as you go along, Here is the reason. Your engine is still tight, even though you have already broken it in. But please note that even it has been broken in by the manual, it is not yet FULLY Broken-in. Fully broken-in will maybe be about 8-10 tanks for the chinese engines AE puts in the MGT. So, as you run each successive tank, turn the needle in just a tiny pinch, maybe as little as a 16th of a turn. Pay attention to the engine sounds, and do a brief full trigger high speed pass while you run. If the engine makes a bad sound like "Wub! Wub! Wub!" that means it is too lean, so richen a quarter turn out, and begin to lean in slowly again untill that noise is no longer made at full trigger.

Keep on leaning in in very small increments until the engine is FULLY broken-in, say the 8-10 tank mark. Then, your needle settings will gravitate around that final setting, maybe an 8th turn in or out depending on the outside conditions.

HJJFFFAA

.18's and smaller are small-blocks. .21's and bigger are big blocks.

breezerboat

Oh wow. Thanks. You really did a good job explaining it so I can understand. I am only about 3 tanks in, so my break in is still going. My next tank I plan on playing a little with no full throttle. Beat those boring figure eights I've been doing. The engine really sounds great and I plan on doing that leaning out stuff you talk about next tank. I will do what you say and only do about a 16th a turn each tank. I guess there is no reason in taking it slow. I really screwed up my race car (first nitro vehicle for me, I just got for xmas) by turning that screw in a lot.. and not doing any break in. This new engine sounds stout and the smoke coming out is just like I see in videos.

SAVAGEJIM

Yep, thats correct.

But dot forget the new caveat being created by Traxxas and OS. Traxxas introduced a small block with a near big block displacement, the TRX3.3 (3.3cc = .20ci). And OS, to make a direct Traxxas drop-in upgrade engine (The "TM" series, "TM" meaning for "T-Maxx"), the OS .21TM.
Both of these engines are small blocks by mounting ears and bolt pattern convention, even in their crankshaft dimensions (I think), but they will have temp ranges closer to a big block because of the amount of fuel-air they combust.

breezerboat

OK, I have another question for you Savage. Should I cut a hole in my windsheild or not? I see some have hole and some don't. Does it even matter?

SAVAGEJIM

That is up to you actually. I personally out of habit cut a hole in my windshield of all of my RCs. I know for on-roaders, they definitely benefit from holes cut in the windshield to allow more air to pass through the heatsink. For MTs, since they are higher above the ground, they can actually get most of the air from the open underside of the body. I just cut holes in the windows out of habit.

tonydig11

I fried my first 2 nitro stock motors from not breaking in. I come from a motorcycle background and they tell you to break in motorcycle engines but it is a myth and the engine runs better if you break it in like your going to ride the bike. I brought this theory to my nitro engines and it did not work at all. I have now been in nitro for 5 years and learned the hard way to take your time during break in. get temps in the 200s. you usually have to lean the new motor a hair to get temps in the 200s. you want the heat to help set all the parts. Then you want the engine to cool down between tanks for at least first 5-6 tanks. once you hit tank 3-6 start leaning like savage said. As long as there is smoke coming from exhaust you should be fine. always temp your motor tho if over 250 i always make it richer. I always run a rich motor to save engine life . i will run a lean "race" setting when in the A-main of race day if i have a chance to contend for the win. you will loose some power with a rich setting but extend the life of your motor. running a little leaner is not bad but less oil means more wear and tear