EGT gauge M20C

[Htwjr]

Just got my first plane and the egt gauge just has marks but no numbers. It is my understanding that the marks represent 25 degrees each but from what temperature?

[danb35]

Nobody knows, and it doesn't matter.  Absolute EGT values are all but meaningless, and until people started using digital engine monitors, nobody knew or cared about the numbers.

 

Congratulations on the new plane!

[triple8s]

 Congrats on your new plane! I know not your flying background, however if it is your first Mooney you are in for a learning experience as I surely was. The "C" was a money maker for the MAC and an extraordinary machine. Fast, economical,cheap to fly and maintain durable, can live on grass and is at home at big airports when you hear "Mooney _ _ _ keep your speed up for traffic" by golly you can do it. I absolutely LOVED my "C" soon after I got it I was also concerned about the EGTs so I bought a UBG-16. I owned the "C" for 4 years and the only time I EVER had any abnormal EGT readings was at low alt, WOT, and in a climb with mixture leaned a bit too much. I'd say if you lean till it stumbles a bit and then richen some you'll be fine but I personally like to see the temps CHT & EGT so I can get used to trends and whats normal and then catch things early on but you definately dont have to have a digital monitor. One thing you will find is the need to lean the engine while on the ground, was very important in my "C" I am by no stretch a Mooney exert or an expert pilot, I do know what my "C" wanted and leaning was on that list. I hope you have make many happy memories in your new vintage Mooney.

[Hank]

Lean until the needle stops moving, then enrich the mixture two lines. My EGT has numbers, but she almost always peaks at the same spot.

On the ground, I pull back about half way and rarely stumble at runup.

[TWinter]

After getting the necessary spending done as far as it being new to you.. I suggest find a good deal on a JPI830, or a monitor with the same features. Veteran pilots may be able to tune by ear and then pull some out. That's great, but I'm one of those who gets nervous when they say lean until "rough", then add some. I'm not that confident. I'm a fan of the JPI units. If I lean by the numbers of the JPI it is always dead on track w/ my planes factory EGT. Not an answer to your question, but my .02 on EGT. Something to think about later down the road. Good luck w/ the new plane

[Htwjr]

Thanks for the replies. As for the new plane, I have only flown it a few hours so far but the more I am around it the better I like it. Just got finished buffing it out so now it's looking much better too.

[Stefanovm]

Lean until the needle stops moving, then enrich the mixture two lines. My EGT has numbers, but she almost always peaks at the same spot.

On the ground, I pull back about half way and rarely stumble at runup.

Won't this procedure put you in the dreaded red box area? I have numbers on mine, but follow the procedure of:

Go to seal level on a standard day,

On take off note needle position.

This postion will keep you safe if not exceeded, no matter the power setting below 75%. At low power settings you can be more aggressive like the lean until needle stops moving..... I have to keep mine very lean on all taxiing. However it is an E.

[Hank]

Your injected engine is different than our carbed one. The procedure you describe is good, but difficult to do with an unnumbered scale.

For a C, I try to either use the charts or the formula MP + RPM = 47 or less and lean away. LOP just doesn't work well, the distribution is too uneven between cylinders.

When taxiing, my EGT doesn't move much at all, despite the red lever being halfway back.

[DS1980]

Stefanovm is correct. Lean until roughness then enrichen two lines? This is fine for 60% power and below but I don't think this is the case. My avatar is the red fin graph. Learn it, live it, love it.

[Cruiser]

to the OP, the EGT is a relative measurement gauge. That is why you don't have numbers. The important point on your gauge are is where the needle get to its highest reading. That is your peak EGT. This value will change with altitude and your power settings. Since there are many different peak EGT values, it is not important what the actual number is. 

 

Now when you lean the engine and watch the EGT gauge. As it climbs and reaches the peak point, you should note that point on the gauge. If each line in 25°F you can then enrich the mixture by one, two, three or four lines (25, 50, 75 or 100)° ROP (rich of peak)

or....

continue leaning the mixture one or two lines (25, 50) LOP (lean of peak) for economy operation. You probably won't get two lines lean, you will notice the roughness first.

 

I hope this helped.

[Cruiser]

Thanks for the replies. As for the new plane, I have only flown it a few hours so far but the more I am around it the better I like it. Just got finished buffing it out so now it's looking much better too.

these type of messages are always much better when accompanied with pictures.       

[N601RX]

The Alcor gauges start at 1200 and each large tick is another 100 deg

[carusoam]

The Alcor gauge has a readily accessible knob on the back of it to adjust the needle reading. Depends on who touched it last, for what reason.

Since the single EGT gauge is relative, it can measure peak EGT and the mixture can be set relative to peak.

Not bad for a self powered, 47 year old, single function, gauge...

Best regards,

-a-

[AmigOne]

Excellent article by Mike Bush "EGT myths debunked"

http://www.gami.com/articles/egt_myths.pdf