Help with EGT Probe and a Suggestion on Fire Extinguisher

[edasmus]

Hi Ernie....

I have been doing a little research on these EGT probes as my front engine is out for overhaul and I would like to replace as many of these probes as I can.

So what I have learned is the same as you as far as the PMA Alcor 86156 no longer being made. My rear engine has this probe. The Alcor 86156 is a Type "E" probe. I have no idea what that means (vs. the seemingly more common Type "K" probes) but the Spruce probe you mentioned is also a Type "E" probe. The Universal MM-112-1 and MM-112 differ only by the connector on the wire lead, otherwise they are identical. I just purchased two of the MM-112-1 EGT probes hoping they will work.

I spoke with both Alcor and Universal on the phone and they were both very helpful. From what I understood, there is a resistance difference between the old Alcor 86156 and the new Universal probe. They both agree the Universal probe will cause needle movement on our old Cessna EGT gauges that I believe you and I have the same units in our 1973 C337G models. My old Cessna EGT gauge has adjustable pointers so I can align them after leaning which makes any changes during cruise obvious. I'm hoping that the Universal probe causes enough movement on our old Cessna gauges to make them useful. I will not know for another 6 weeks or so if they work.

The Type "K" probe that a previous post mentioned works with my JPI EGT/CHT display. Those Universal EGT probes I have had success with in the past.

Let us know if you have any other success with this.

Good Luck,

Ed