EGT Probe Placement

[hombre]

I'm installing a permanent EGT probe and gauge on cylinder #2 as it has always tested as the hottest cylinder (makes sense being in the middle). There are many opinions out there on exactly where to place the EGT probe, but the best consensus seems to be 4" from the back of the exhaust valve.

Opinions from resident hotrod gearheads appreciated before I drill...

 

[Sidecar Flip]

Walt:

I'd say as close as practicable to the exhaust port while still allowing easy access to the thermocouple and welding the boss in to accept it.

On diesels, you always locate the stinger on the hot side of the turbo.

I don't know what brand of probe (stinger) you have but there stingers come in various response rates. EGT Technologies sells all different probes as does ISSPRO.

At least you are supercharged and not turbo'd. A broken stinger tip will destroy a turbo, right now.

 

[Pig9r]

Here's where Triumph placed them:

 

[Sidecar Flip]

If Triumph used the hex bungs, they are too far away from the exhaust port to give really close readings. Because the engine stock is in a very mild state of tune, I suspect the bungs were for sensors other than EGT.

 

[Sidecar Flip]

before I drill...

Where? In ANWAR? South of the Florida coast? In Wyoming or Utah on Federally owned land? Don't keep us in suspense any longer..................

 

[hombre]

If Triumph used the hex bungs, they are too far away from the exhaust port to give really close readings. Because the engine stock is in a very mild state of tune, I suspect the bungs were for sensors other than EGT.

I was looking at the same photo... I think the EGT probes are above the big hex bungs, but it's hard to tell. I see the EGT connectors but can't quite make out the probes. At any rate, most feel that's even too far from the exhaust valve.

 

[R34ME]

General rule of thumb is no more than 100mm from the tip of the exhaust valve

 

[hombre]

General rule of thumb is no more than 100mm from the tip of the exhaust valve

Thanks, Stefan! That jives with the 4" recommendation.

 

[Sidecar Flip]

Thanks, Stefan! That jives with the 4" recommendation.

Walt.....

Are you going to use bulkhead fittings or (I don't know the composition of your headers) use the appropriate glue to attach the mounts?

 

[hombre]

Walt.....

Are you going to use bulkhead fittings or (I don't know the composition of your headers) use the appropriate glue to attach the mounts?

Flip, the SPA EGT "stinger" probe is held by an 1/8" NPT fitting that has a compression nut controlling stinger depth. My headers are 304 stainless... requiring a threaded "boss" to be welded to the pipe the hold the NPT thread.