VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #1  
Old 04-17-2016, 09:15 AM
ChuckGant's Avatar
ChuckGant ChuckGant is offline
 
Join Date: Oct 2015
Location: Collierville, TN (M41)
Posts: 120
Default Engine Management Alarm Settings

Hello all,
I am trying to minimize the number of nusacence alarms I get with my GRT EIS4000 set-up, so I was wondering what values are common for:
EGT
CHT
Cylinder Head cooling rate
Max fuel flow
Max fuel pressure

Thanks,
Chuck
Reply With Quote
  #2  
Old 04-17-2016, 09:31 AM
Kwright's Avatar
Kwright Kwright is offline
 
Join Date: Sep 2009
Location: Roy, UT
Posts: 56
Default

Your settings depend on engine and fuel system. However, in general there is not a max for EGT. MAX for CHT is generally 400 degrees because of the physical property of aluminum losing 50% of its strength at that tempeture.
__________________
Kent Wright, UT
N216KW
RV6
Reply With Quote
  #3  
Old 04-17-2016, 09:36 AM
Kyle Boatright Kyle Boatright is offline
 
Join Date: Aug 2005
Location: Atlanta, GA
Posts: 4,219
Default

Quote:
Originally Posted by ChuckGant View Post
Hello all,
I am trying to minimize the number of nusacence alarms I get with my GRT EIS4000 set-up, so I was wondering what values are common for:
EGT
CHT
Cylinder Head cooling rate
Max fuel flow
Max fuel pressure

Thanks,
Chuck
The fuel related settings are be determined by your engine choice - engine size determines flow, injected or carbureted determines pressure.

EGT is a relative measurement that I use for information, not warnings. Mine is set such that I am unlikely to get a warning.

CHT, I would use Lycoming's red line if I was in flight test, and would lower the setting later once you have a handle on your engine's behavior. I think my CHT warning is set at 425, which is far below Lycoming's red line.

I do not have a warning enabled (or I have the parameters set very loose) for cylinder cooling rate. Given that I treat my engine pretty well, if I'm ever doing a rapid power off descent, I'm doing it for a reason and don't need a flashing light to distract me.

My personal philosophy is that I don't want to be warned (distracted) by blinking lights and buzzers until something is a problem. My scan will (hopefully) identify looming problems in time to manage the problem(s). Other philosophies are viable too...
__________________
Kyle Boatright
Marietta, GA
2001 RV-6 N46KB
2019(?) RV-10

Last edited by Kyle Boatright : 04-17-2016 at 07:13 PM.
Reply With Quote
  #4  
Old 04-17-2016, 09:50 AM
az_gila's Avatar
az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 10,011
Thumbs up

More reading here -

http://www.vansairforce.com/communit...195#post669195
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
Reply With Quote
  #5  
Old 04-17-2016, 03:14 PM
flightlogic's Avatar
flightlogic flightlogic is offline
 
Join Date: Nov 2013
Location: Prescott, AZ
Posts: 1,614
Default limit settings and warnings

I think knowing the menu process for those limit settings is a good thing operationally... so go in and just bump them all up a bit. You will find settings for your engine and cooling flow that eliminate the normal range alerts... but are still there for an unusual occurrence. It might take a few tries. Then, the alarm going off will get the correct reaction and you can pull the power back and level off if something spikes.
__________________
"Kindness is never a bad plan."

exemption option waived. Donation appropriate.
Reply With Quote
  #6  
Old 04-17-2016, 03:58 PM
rightrudder rightrudder is offline
 
Join Date: Mar 2014
Location: Laguna Hills, CA
Posts: 1,805
Default

I also like a CHT alarm at 425 F for my Lycoming, as that's the highest recommended for continuous operation. I rarely exceed this value (and only for a few seconds) on steep climbout on a hot day. When it flashes red, I know to reduce climb and go full rich mixture, if I'm not already there.

Other limits are set to pretty generous values, to avoid unnecessarily blinking lights. I'm pretty strict on the instrument scan, and it's so easy with an EFIS that displays all pertinent info in a strip along the bottom of the display.
__________________
Doug
RV-9A "slider"
Flew to Osh in 2017, 2018 & 2019!
Tail number N427DK
Donation made for 2020
You haven't seen a tree until you've seen its shadow from the sky -- Amelia Earhart
Reply With Quote
  #7  
Old 04-17-2016, 04:32 PM
BobTurner BobTurner is offline
 
Join Date: Dec 2011
Location: Livermore, CA
Posts: 6,797
Default

If you also have a GRT EFIS, the EFIS and the EIS can be set to different alarm values. e.g., CHT over 410, EFIS flashes, I should do something. CHT over 420, red light (EIS) flashes, I must do something NOW.
Reply With Quote
  #8  
Old 04-17-2016, 08:20 PM
RV10inOz's Avatar
RV10inOz RV10inOz is offline
 
Join Date: May 2008
Location: Brisbane Qld. Aust.
Posts: 2,271
Default

Here is the APS recommendation and you can read John Deakins articles for more background info if you wish.


EGT No limit, however realistically if you want a spark plug failed alert, set it to go at about 1580dF and that will give you an indication.
CHT Set this to 400dF, if you have a two stage YELLOW/RED make it 400 for yellow and 410 for red. NO HIGHER. If something nasty happens you want as much advanced warning as you can get.
Cylinder Head cooling rate This is a junk feature, set the number as high as you can so it does not ever annoy you
Max fuel flow Set this at 20GPH on a 4 cylinder and 30 on a 6, if you get a big enough leak to trigger it you want to know about it
Max fuel pressure Refer to the manual but off the top of my head it is 45PSI for injected engines, I have never seen one get past 27-30

Remember realistic alarms should not give nuisance alerts, but they must alert you as soon as reasonably possible.
Hope that helps.
__________________
______________________________

David Brown

DYNON Authorised Dealer and Installer


The two best investments you can make, by any financial test, an EMS and APS!
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 08:36 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.