New EGT Sensor location

[maus92]

I'm in the process of installing new engine sensors on a O-360-A1A on my RV-8A during its avionics MLU. The old CHT sensors are the ring type installed around the plug, which will be replaced by a bayonet type screwed into the cylinder head ports.

The original EGT sensors were installed in a way I'm not entirely happy with. Three of them were mounted about equidistant from the head, but the fourth is about an inch or so farther from the head. Also, the probe holes on a couple of them are perpendicular to the centerline, while others are more "swept back" which I prefer. The old sensors did not provide consistent (or no) readings, which may be related to the sharp bends in probe wires, both at the sensors, and where they were folded to shorten their overall length.

Anyway, is it possible to weld a patch over the old holes, and drill new ones that are more consistent in location and sweep? Is this a big enough worry to attempt to modify / fix? Thanks!

[BillL]

The general answer is YES, the hole can be welded over with a TIG. Since you ask though, you should have an experienced welder do this with the correct filler rod for your exhaust, possibly back shielded.

[maus92]

Thanks Bill. Yea, I don't own a welder anyway, so I'd have to find somebody to do it. Do you think it is necessary, as far as the placement of the probes are concerned (the one being inconsistent distance wise with the others?

[BillL]

Originally Posted by maus92

Thanks Bill. Yea, I don't own a welder anyway, so I'd have to find somebody to do it. Do you think it is necessary, as far as the placement of the probes are concerned (the one being inconsistent distance wise with the others?

I am not an expert on the placement of the probes, on my AWI system, they are all predrilled.

Vetterman FAQ: "What is the correct EGT probe location?
EGT probes should be mounted one and a half to two inches below the cylinder port. This places the probes in the flame front which will give the most correct reading."