EGT Probe install

[PilotDerek]

Can anyone tell me or direct me to where I can find info on where the egt probe should be installed? My egt readings are very low and looking at my probes they seem like they may be too far down the exhaust (approx 4 in). Wondering if the low readings across all four is the probe placement or the meter. Any help appreciated.

[jetdriven]

I think the probes are supposed to be 1.5 to 2" from the head.   Our j takes a type k egt probe from Alcor, all 5 of them.   There is a type J also.  

[Cris]

Go to the insightavionics.com site where you will find installation instructions for the GEM 602-610 series including probe placement instructions.

[danb35]

...and you can get EI's installation instructions at buy-ei.com.  In short, 2-4" from the head, and they should all be a uniform distance.  Absolute EGT values are all but meaningless.

[PilotDerek]

Thanks, EI says 1 1/2 is ideal, Insight says 2-3 in. Either way sounds like mine are too far away. Anyone know if it would be bad to just install new probes higher leaving the other ones in place (since their is a hole there)? Recommendations welcome.

Dan, I'm not looking for absolutes but when the gauge barely registers 1/4 of the way up on all four cylinders after a half hour of flight something is wrong. The engine was overhauled last year and it sounds/reads like they installed the probes low.

[Cris]

Depending on the mfg you might be able to reset the guage as opposed to getting new & expensive probes. I know that can be done with a screw on the Gem 602 case & the Gem 610 uses the HP palm computer to set the bar height. I'd imagine others can chime in on the EI or JPI units. What is your guage mfg?

[carusoam]

Key word here is probably re-calibration or scaling.

 

Since absolute EGT is not critical, getting it to read properly in the scale is what is important.

With the simple Alcor unit, a screw on the back of the guage shifted the scale.  Electronically, this should be possible as well.

re drilling holes does not sound appealing.  It would include welding over the old holes as a proper cure.  Leaving un used probes sounds like a bad idea leading to a future exhaust problem.

Early Acclaim owners experienced leaks around these probes.

Best regards,

-a-

[PilotDerek]

Quote: carusoam

Key word here is probably re-calibration or scaling.

 Since absolute EGT is not critical, getting it to read properly in the scale is what is important.

With the simple Alcor unit, a screw on the back of the guage shifted the scale.  

[carusoam]

Derek,

It helps to have a friend with a small screw driver make this adjustment.

If you have the standard Alcor unit, it does not come alive until you have the engine producing.

If you are alone, it takes some trial and effort.

alcor recommends setting the needle at 65% power pointing to an asterisk that may be silk screened about two thirds up the scale.

Note: the first time I made an adjustment, the needle moved more freely.  If the plane had not been flown, this may be an issue.   Exercise the needle using the screw and return it to it's original position.

Note 2: using a screw driver behind the panel is very close to where 12v power has no covers.  Use typical precautions.

Best regards,

-a-

[PilotDerek]

Quote: carusoam

Derek,

It helps to have a friend with a small screw driver make this adjustment.

If you have the standard Alcor unit, it does not come alive until you have the engine producing.

If you are alone, it takes some trial and effort.

alcor recommends setting the needle at 65% power pointing to an asterisk that may be silk screened about two thirds up the scale.

Note: the first time I made an adjustment, the needle moved more freely.  If the plane had not been flown, this may be an issue.   Exercise the needle using the screw and return it to it's original position.

Note 2: using a screw driver behind the panel is very close to where 12v power has no covers.  Use typical precautions.

Best regards,

-a-