Hey My engine is running hot now...

[emu67]

Guys - I have an SH .21 Pro and it seems to run on the hot side when I get it tuned to run well. Makes lots of power, smoke going out the pipe, smooth transition. It runs at 240 to 250 degrees when it is 80F outside. Anyway, I ran it today, it's 100F outside, and it started running around 270F and so I detuned it to run cooler.

Have you guys seen this happen with a 20F increase in ambient temp.? Oh, when I stalled the motor after refueling and stalled it, it wouldn't start up because it was kinda of "vapor locking". It didn't do that when it was 80F outside.

Anyone have experience with this when running with hot outdoor temps?

 

[AC48]

270 may be a little hot, but if you see good smoke and its running good then you should be set. Usually 280 is the limit for .21s.

 

[emu67]

I ran my buggy again today; made the mistake of making the LSN too lean. I richened it out a bit, the buggy ran better and the temps went down to 240 - 250 F while making good power. That's weird b/c I thought the LSN didn't really affect temp. Ah well, it seems to work so that's what I'll go with.

 

[AC48]

Sounds like you got a good tune now, 240=250 is just about right where you wana be. The LSN affects it when at idle, but if gets hot when its idleing it will cause the highend to be a little warmer just becuase it was hotter at idle if you understood that haha. Anyway, sounds like you're all set.

 

[Rolex]

The LSN has a LOT to do with running temp. I worked on an engine for someone not too long ago, and after idling for about 3 or 4 minutes, it went over 300. That was at IDLE.
If the LSN is too lean, adjusting the HSN will not help temp or performance very much.

 

[emu67]

What is the temperature that the engine should be idling at anyway?? I've heard 200F but I'm not sure if that is true. Anybody know??

 

[Rolex]

200-220 is good.

 

[emu67]

Thanks for the info. I'll make sure to use that when I'm tuning.