legacycentral bbs

so where should I locate an EGT?
I cant affor one now but since I'm building my exhaust I'll put 1 in and plug it.

Best place is on the #4 exhaust manifold.

On the driver side exhaust manifold, between the #4 and #2 cylinders, there's a little flat spot in the casting that is supposedly very convenient for drilling and tapping.

Is that people's favorite approach? Drilling and tapping? (as opposed to using the hose clamp approach or the the welding approach?)

Where are you going to hose clamp to? And what are you going to weld? The sensor to the manifold?

thanks guys, I wont worry bout ti for now as its not related to the pipes I'm doing.

BAC5.2 wrote:Where are you going to hose clamp to? And what are you going to weld? The sensor to the manifold?

Errrr.... yes? Um, I dunno I'm the one asking the questions! (first turbo car). So, are you indirectly TELLING me that there is nothing to clamp or weld it to? Or are you really asking?

All I know is my EGT from autometer just arrived with instructions for those three options:
* Weld the bushing (provided) to manifold or header, then screw in the threaded fitting, then screw in the sensor
* Tap it
* Hose clamp it to header or manifold (using the provided hose clamp and fitting)

PS - sorry for the hijack, Kidwired, but I figured this on topic with what you are trying to do as well.

no problemo, its on topic.
the 1st 2 options I get. the 3rd. Mmmm do they mean drill a whole and clamp the sensor to the manifold? sounds pretty ghetto, even for me.

Yeah that's what they mean!

Yeah, people do sometimes just drill a hole and clamp the sensor on. It leaks some, and is kind of ghetto, but it's easy.

Welding on a bung seems ideal, but drilling and tapping the manifold works okay if there's enough material. Technically you're not supposed to cut threads in most types of cast iron, but not much is being asked of these threads so it works okay.

I asked my mechanic to put it where you guys said... but he actually put it all the way at the far end of the manifold, where the gas from 1+3 meet up with the gas that came all the way around the engine from 2+4. I bet it's at least a foot from 1+3, probably 4-6 feet from 2+4.

Question: What do you guys think? Is this going to be too far from the cylinder heads to get good readings? The most important thing is I want them to be comparable to most other people's readings so I can use the 1600F rule of thumb and stuff like that.

Slow Res:
http://www.freewebs.com/rallysam/P5180002b.JPG

Fast Res:

BTW - Here are other threads I found on EGT placement. None of them really address my current situation, but maybe they will help others:

http://bbs.legacycentral.org/viewtopic.php?t=17739
http://bbs.legacycentral.org/viewtopic.php?t=1668
http://bbs.legacycentral.org/viewtopic.php?t=303
http://bbs.legacycentral.org/viewtopic.php?t=17570

And here are the votes I compiled from these various threads:
dscoobydoo: 8-12 inches from cylinder #3
morgie: just after where #1 and #3 manifolds join up
Aaron's ej22t: 3-6 inches from cylinder #3
vrg3: driver's side between #2 and #4
legacy92ej22t: #4
(all locations refer to places in the exhaust manifold)

Huh. It looks like he used a spot that was originally meant to hold one of the heat shield bolts. That might mean somewhat slower reaction time if the probe doesn't protrude as far into the gas flow.

I think you'll probably see slightly cooler EGTs at this point than you would closer to the ports. But it's not all that far from the #1 and #3 ports. The 1600 degF rule of thumb is just a rule of thumb anyway, so I'd say be a little more conservative with what you do with the readings and you'll probably be okay.

Yeah, it's not too far from 1+3. My bigger concern is the gas from 2+4, which has come a LONG way.