Welcome to Flightinfo.com

  • Register now and join the discussion
  • Friendliest aviation Ccmmunity on the web
  • Modern site for PC's, Phones, Tablets - no 3rd party apps required
  • Ask questions, help others, promote aviation
  • Share the passion for aviation
  • Invite everyone to Flightinfo.com and let's have fun

Continental IO-520A

Welcome to Flightinfo.com

  • Register now and join the discussion
  • Modern secure site, no 3rd party apps required
  • Invite your friends
  • Share the passion of aviation
  • Friendliest aviation community on the web

Travis Jr

Member
Joined
Feb 16, 2006
Posts
22
Anyone with experience know what EGT's/CHT's to expect while being fairly easy on it?

I have been running it at about 1300 to 1400 degrees on the EGT, getting a fuel burn of around 16-17gph. This is with full throttle and around 2300 to 2400rpm.


Also, this engine is not turbocharged, so do I need to do the whole 1" per minute reduction in power?
 
Firstly what altitude; fuel flows at 2000 are going to be a lot higher than at 14000.
Single cylinder egt? If so, you are going to have to run ROP and about 3gph higher than if you have all-cylinder egt, in most cases.

Main controlling factor is the CHT in any event. The book may say do not exceed 425 or something like that but I would keep them below 390 at all times, preferably below 375. Again, without all-cyllinder chts you are going to run it rop in most cases, or at least anytime above 65%HP
 
What kind of aircraft is it in? They run hot in some so there's a chance you'll be keeping it on the rich side if you go for the 65% power or below setting where some manuals allow for operation up to peak. 50-100 rich of peak always took good care of any 520 that I ran.



Don't do the lean of peak thing unless you have a good monitor and the ability to pay attention to the gauge. The old guy with a baron at our airport lost track of what he was doing and cooked half of his top end...
 
I'm with icefr8 on the rich of peak operation. As in lean the mixture until the EGT peaks, and then enrichen the mixture to 100 degrees ROP.

Stock EGT gauges on those engines never seemed to be terribly acurate as far as being able to set a specific temperature. This is becuase the EGT reading is an average of all the cylinders. So one cylinder could be running very lean (hot) and another cylinder running very rich (cold). Apparently this has to do with one type of fuel injecter being used on all of the cylinders. Since the intake manifold branches off to each cylinder at a different point, the mixture varies from cylinder to cylinder. The method of finding a peak EGT and then running 'rich' of that value should ensure that no one cylinder is running hot enough to eventually damage itself.

I'm with gravityhater in keeping your CHTs well below redline on the gauge
(390 sounds right). But I would never run the mixture leaner than I described above to RAISE the CHTs to 390. This also ties into your question about the 1" per minute. I would definitely follow that rule. I memory serves me correctly, once you get the MP down to around 17" (give or take) the temps are low enough that the engine cannot be shock cooled. With proper planning 17" (or there abouts) should give you an airspeed that is low enough to start configuring for landing.

A writer on avweb.com (Deakin?) has written many articles on this in the past. They get pretty detailed but are worth the read IMHO. Some of these articles talk about running Lean of Peak and explain why you cannot do that correctly with the stock engine.

Hope this helps.
 
Last edited:
Now some of those fancy aftermarket injectors and a super egt/cht gauge would allow lean of peak. But by the time you've bought all that you've spent all your gas money. The old timers say that they used to run the big old radials lean of peak all day/night long. I guess that was the flight engineers job though.
 
We put a VM 1000 in it, so I can monitor each of the cylinder temps pretty accurately. Also, it's in a Lancair, so the cowl is pretty tight.

The numbers I mentioned were at around 5000-8000ft with CHT's around 350. I just wanted to get a ballpark, so I don't fry anyone's engine.
 

Latest resources

Back
Top