EGT Probe Under Cylinders

[Karetaker]

Howdy Everyone. I am ready to install my EGT probes and notice that I have only seen probes mounted on the "outside" of the exhaust pipes and none facing in towards the engine case. I was planning to mount mine such that they would be under the cylinders, facing towards the engine case.

Thoughts?

 

[Norman CYYJ]

Pain in the butt to install and service.

 

[Jetmart]

What is the potential benefit of installing inside. They do no harm on the outside.

 

[Scott Hersha]

I would install them in whatever position is easier for installation, or servicing sometime in the future. If you feel that it would look better if they were hidden, I would have to ask, who will see it? If you are shooting for a “judge me” award at an airshow, I can tell you, that as a SNF judge, it wouldn’t matter. Do it in a way that is easiest to install/service/inspect.

 

[Taltruda]

I always thought inside would be better to avoid breakage too… but I’ve only seen them outside.. I say go for it if you can get to change them without taking the exhaust off!

 

[PilotjohnS]

Most important

I was told be a retired exhaust guru, it is best to keep the probes all the same distance from the cylinder exhaust gasket, and at the tip of the flame cone. To do this and to avoid any one being in a bend, they had to be close enough to the exhaust flange that only or or two could be from the inside.
I was worried the ones sticking away from engine would hit the cowl, but Vans cowls are big enough so there is plenty of room. From the outside, it is easier to support the leads, too. JMHO. YMMV

 

[Karetaker]

Thanks for the replies. I'll think about it some more prior to drilling holes in my exhaust.

 

[olyolson]

EGT probes

Mike,

On the EGT probes the worm gear to tighten it is on the side so you could mount it either way (left or right) for the most convenient way to tighten. If you turn it around so the probe is on the inside then how will you drill the drill the holes without removing the exhaust (unless it’s not installed yet). With the probe hole drilled on the inside I think it would be very difficult if not impossible to tighten it. You may also find it problematic if you wanted to safety wire the clamp screw.

 

[Carl Froehlich]

Keep in mind you may route some stuff under the cylinders - so probes facing inward would be problematic.

I suggest deferring prop install to the last step.

Carl

 

[Ralph Inkster]

EGT probes are fairly robust so worrying about damaging them isn’t much of an issue as long as you remember to leave room for spark plug access later (socket & wrenches).
& don’t over tighten the clamp!

 

[Karetaker]

Howdy everyone. You all raise good concerns and I appreciate the feedback. I only installed the exhaust "headers" at this point, bolted to the cylinders to get an idea where I can fit the EGT probes and be able to get them in and out. I'll remove the "headers" to drill, if I decide to go with them "inside".

 

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Well, I for one, have never heard or seen one broken off or damaged beyond bending back. In normal use of course, not in the wrecking yard.
Never heard of any hitting the cowl.
I like simple and on the outside is simple and easy access.
I've had all kind of discussions about the looks and location of tons of stuff.
I always fall back to the "you have a zipper on the front of your pants" Pretty convenient and obvious. Girls have theirs on the side or back so they don't show. Good? bad? Go figure,
I like easy access.
My three cents worth Art