How Do I Install This EGT Probe??

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Locked79

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To me that looks like it's completely wrong. The tip of the probe must be in the center of the exhaust stream. If your running a 3" exhaust, the probe must be at least 2" long. 1.5" to reach the middle of the exhaust stream and 0.5" for adjustment and flange width.
 
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Probe needs to be long enough to reach the center of the exhaust stream, ideally. So the one you have will not work properly. Most have a longer probe with adjustable insertion depth.
 
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All great info, thanks so much all!
Yep, grab an Auber digital gauge and probe. They are nice and fast and it's far easier to see changes in temp, compared to an analogue gauge.
It's actually an Auber gauge and probe. It appears the previous owner simply purchased the wrong probe.

Sent from my SM-G920V
 
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I was told by a local tech that you don't need it in the centre really as the exhaust gasses will be more along the outside instead of dead centre. if you think about it this makes sense as once the exhaust gasses turn they will be forced to the outside rather than stay in the centre.


If you only get the tip in then you're measuring the manifold wall temp more than the gas temp.
 

Dougal

 
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I was told by a local tech that you don't need it in the centre really as the exhaust gasses will be more along the outside instead of dead centre. if you think about it this makes sense as once the exhaust gasses turn they will be forced to the outside rather than stay in the centre.
He's wrong.
 

Dougal

 
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The idea with the centre is it is the best flow for all cylinders giving an accurate reading on what the engine is doing.
Centre also measures gas temp. The manifold is roughly halfway between engine bay temp and exhaust temp. The closer you get to the manifold wall, the more you're measuring the manifold.

EGT is an important measurement. You are better off not doing it than doing it badly. Because doing it badly will let you think you're safe when you're not.
 
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I've gotta agree with Dougal's logic here.

The manifold has too much thermal mass, it won't change temperature as quickly as exhaust gases and could influence the probe.

Ianb's photos are on the money.
I drilled and tapped my probe with the manifold and turbo installed.
Use grease on drill bits and tap to trap any swarf, clean and regrease regularly. Cast iron swarf is little granules. The small amount that may fall in the manifold blows through as soon as the engine is restarted.
 
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Dont suppose someone would post a link for best egt gauge and probe for my LJ78. Just picked it up Friday and wanting to start getting ahead of overheating prone engine. If possible. TIA
 

IanB

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What kind of gauge do you want? Auber Instruments has some neat digital displays, but finding a place to put them can be an issue. I prefer an analog needle style gauge so you can just glance and get the info you need quicker than reading an digital display. VDO is what I used.
 
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