YS 50ST - Head Temperatures

[nautskye]

Hello Everyone,

What should the head temperature be on a YS 50ST during break-in and tuned?
Perhaps you could give me a normal range for each?

[nautskye]

Since there have been 52 views and no replies- I'm starting to wonder if I'm asking the right question? How important is an engines head temperature? I know that in Finless' 600N video series, he says that the head should be cool to the touch (~100 F). I've also read that if you run too lean you can damage your motor.

[archiebald]

I'll probably get flamed for this but....

Unless you are running a carbsmart, on an onboard sensor that can hold a peak reading I don't see the point in trying to work with head temperatures. How are you going to measure them? If you hover for a minute, then land and approach the heli, the head is immediately dissipating heat as soon as you reduced the throttle. (This is exactly what the head is designed to do of course). Bearing in mind it takes at least 15 to 20 seconds to get the head speed down to zero then get a IR heat sensor on the head (which are notoriuosly difficult to get meaningful readings from anyway), then by the time you do actually get a reading, it is going to be way off what the head was actually running at when in the hover. Personally I would have thought that after all this mucking about and getting the wrong reading anyhow, you are more likely to end up making a mistake on tuning your engine by using this approach.

In other words, it really comes back to tuning by using ears, eyes and throttle response (without a governor engaged) to get the best out of the engine. Its really not that difficult to do (even I can do it), as long as you remember to start rich and go lean in baby steps.

[nautskye]

Thanks archiebald, that's what I was looking for.

[DavidH]

As for using a Carb Smart. The mixture of the engine has to be set up close to correct before you can use the Carb Smart. You can't just install and it get the mixture correct. It can only adjust the mixture so much each direction. So it needs to be close before relying on the carb smart to adjust it.

David

[archiebald]

DavidH - very true comment.

Plus - I'm copying and pasting a section of the opening post from here http://www.helifreak.com/showthread.php?t=75072

(should have been posted in engines and mufflers anyhow IMO (MODS!!!! Where are you)

Now, even after start up..take off and one easy circuit..you can see how active the carbsmart is. One circuit..land..go to idle and you can watch the mixture arm moving from rich to lean as the engine cools sitting in idle. It only takes a few seconds after landing to see it doing its job.

This backs up what I was saying about trying to get a meaningful head temperature manually. If a carbsmart is changing position so quickly, it goes to show that when you land, the engine is cooling off immediately.