350 degree engine temp!!!
 

Hey guys, so yeah.I'm new to the hobby, and as the title of this post states, I had a run-in with overheating today.I have the Redcat Shockwave (knew going in I'd make mistakes, thus, I bought a 140 dollar buggy) and it only has about a quart of fuel ran through it, but today I was rompin around at a local rc dirt track and suddenly it started to lose its power. I checked the engine temp and it said 351!!! It was starting to smoke out of one of the cooling fin holes too. Now my questions are these: The glowplug is still good and it's slightly wet to the touch. Doesn't that mean I'm running rich? Also, there's a very nice trail of smoke that comes out of the exhaust pipe. Doesn't that indicate a proper tune?Obviously not though because of the temps. I made a rookie mistake and lost the stock needle settings as point of reference too.

This happened right after Iput in a new glow plug. It's an OS HOT, which probably isn't the right plug right considering it's only a .16 buggy motor? Ilet it sit for a few minutes,and when the temps dropped, it was running fine again, full power. I realize that I boogered up the engine, but do you guys think I can still maybe salvage another quart or two out of it?It stillsounds good. ButI'm totally lost as to how to get the damn temps down on this thing. It can't possibly need to go more rich on the needles.

In a nutshell ( I know I'm ranting): How should I go about lowering the temps of the motor when it seems I'm already running super rich?And number two, do you think the motor is past the point of no return? Iput in after run oil needless to say, but I don't think that's gonna help anything.

I definitely respect these nitro motors now more than ever though. They're pretty resilient, but DAMN they're more tricky than I expected!

Any feedback would be appreciated.

RE: 350 degree engine temp!!!
 

High heat means you'e either running lean or the engine is being run under heavy load, such as with sticking brakes or through tall grass, or even at WOT for far too long.

I've hit almost 400degF with one of mine due to running too lean and too long through tall grass. Didn' hurt it, but I cna't say that's always the case.

Check your vehicle for any binding parts, richen the HSN on your engine by at least 1/4 turn, don't stay on the throttle for extended periods and stay out of tall grass.

RE: 350 degree engine temp!!!
 

How was the compression when you re-started it? I got an OS over 400 doing donuts in an touring car, ran perfectly fine after that, like nothing had ever happened.

RE: 350 degree engine temp!!!
 

Not sure who you are asking, but in my engine, compression was always fine. That particualr engine did appear to be detonating...I could hear it when it came down to idle like a sizzling sound. That would occur at about 325degF.

Engine parts won't melt at 400degF, but the mixture could be so lean there isn't enough lubrication, or the combustion chamber gets so hot, you get pre-ignitiion or detonation, not sure which.

It would appear the occasional slip that allows high temp running doesn't necessarily ruin anything. Depends on other conditions, like the % oil in the fuel. Even hot, it has to be rich enough to keep running.

I'm unsure of the exact numbers now, but I know with another engine, I would always be running around 280degF on grass and was surprised that with the same tune, same day, etc., I could only get it to 225degF on pavement. So it can get hot, but still not be running lean.

RE: 350 degree engine temp!!!
 

I was asking the thread starter. Under certain conditions you can heat up an engine and not do any damage... like running it under load, or running a really low end pipe. But when the cause of the heat is friction by running lean (not preignition or high fuel consumption), you can fry an engine before it even hits 280.

RE: 350 degree engine temp!!!
 

I did eventually destroy that same engine.....from running it too cold. It was my test mule engine and had a very hard 2 year life. Eventually I tried adding an extra head shim and I couldn't get heat to build in it, so I foolishly kept the rpms up trying to warm it up. Crank-pin broke. Had another engine that decided to go WOT on start-up (always check other peoples work!) and before I could stop it, the rod broke. Running a cold engine at WOT is probably the next worst thing to running an engine so lean there isn't enough lubrication. But as said, merely being hot isn't so bad....it's if the heat is coming from lack of lubrication. That's why I usually adjust my top end just short of screaming. If it sounds like it wants to blow up, it just might.

RE: 350 degree engine temp!!!
 

Thanks for the replies guys. Sorry im just now getting around to responding...

As far as the compression, that didnt seem to be affected really at all. When it happened, I pinched the fuel line to stop the engine and let it sit for 3-4 minutes. Then I started it up and it came on with just one pull. Ran fine, albeit it still hit like 290 after just about 2 minutes of running, and yeah, it was in rough terrain (thick grass, damp dirt). This happened 2 days ago. I had to go to work afterwards, so I never really got a chance to inspect it all. Until last night...

Last night I was gonna run it around with a friends Stampede, but it would not start. Now it did get rather dirty the previous day (still haven't had a chance to clean it. Will do that tomorrow.), so I'm thinking maybe the fuel filter is clogged, not letting the fuel in to the carb, not sure, it's pretty hard to see if any is getting in. I'm also wondering about the little washer that came on the OS plug that I installed the day that it overheated. It's missing now, not sure at what point it fell off. But could this be creating a bad seal w/ the glow plug, allowing the compression to escape the head? The pull starter seemed a little easier to pull than normal, that's why I ask that. But then once I kept trying a little longer, the pull starter actually started to "skip" is what I'd call it. Just pulled with no grab, so now I'm worried about my pull starter too! Man, I love this hobby, but my first car/experience of it is giving me a lot of headaches! Of course it's my fault. Ive been messing with the needles to much and i've been careless in several other ways. It's NOT the cars fault, so don't start dissin redcat lol.

Keep the comments coming. I like learning all I can about this stuff! Oh, and btw, the glow plug is good. The piston is free-moving, not binded in anyway and it's a good color and doesn't look damaged. So the culprit of the non-start issue pretty much has to be that washer for the glow-plug or in the fuel lines right?

RE: 350 degree engine temp!!!
 

My nitrostar 15fe never gets over 180, i think i may lean it out a taad since its so rich it doesnt even smoke, rather just spits raw fuel/oil out the exhaust.

RE: 350 degree engine temp!!!
 

You may be running a touch rich!!!!http://www.rcuniverse.com/forum/js/f.../msn/75_75.gif