Weld or tap probe for EGT gauge?

[chicagoavenger]

Well I have a faze egt gauge and the instructions say to weld the fitting into the manifold. From what I read here I'm supposed to just tap it and screw it on. I called slowboy and they said I have to weld it and then I called R&D Performance and they said to tap it. Which one is it?

 

[EvolvingGST]

Well I have a faze egt gauge and the instructions say to weld the fitting into the manifold. From what I read here I'm supposed to just tap it and screw it on. I called slowboy and they said I have to weld it and then I called R&D Performance and they said to tap it. Which one is it?

I drilled and tapped mine, My knowledge is that most people do that reason being that the EGT probe decays after a couple of years and so you will have to replace it... And all my other friends did it this way... Maybe different companies different installations?

 

[weith1111]

I don't have the same brand but mine is just tapped and screwed in.

 

[SethA]

Well I have a faze egt gauge and the instructions say to weld the fitting into the manifold. From what I read here I'm supposed to just tap it and screw it on. I called slowboy and they said I have to weld it and then I called R&D Performance and they said to tap it. Which one is it?

Do they mean weld a bung in that has female threads to accept the probe? If so, I don't see why you can't just drill and tap the manifold and not use the bung. If you were installing the probe in a thin piece of metal (like an tubular manifold) you might need to weld in the bung because the thin wall would not have enough "meat" to cut threads into.

Seth

 

[ISUJakey]

Do they mean weld a bung in that has female threads to accept the probe?

Correct. I am going to have a bung welded on simply for the extra structural support of the thermocouple via more material for it to thread in to. Plus the more threads there are, the chance of them stripping out from removing/installing the thermocouple is reduced.

 

[chicagoavenger]

Do they mean weld a bung in that has female threads to accept the probe? If so, I don't see why you can't just drill and tap the manifold and not use the bung. If you were installing the probe in a thin piece of metal (like an tubular manifold) you might need to weld in the bung because the thin wall would not have enough "meat" to cut threads into.

Seth

yup just the bung part to accept a male fitting

 

[hopwoodp]

Hey,

I have the same question. I have the new sbr exhaust manifold in and it didn't come tapped for an egt probe. I currently have my installed on my stock o2 housing ( don't ask ). I want to weld a bung on there so I can switch mine out when the one I have on there goes bad.

The question is - where can I buy a bung for my egt probe? Is it the same size as the o2 sensor threads? I have heard of many different ways to install the egt probe but, they seems shady. SBR told me the tap size was 1/8" npt and drill it with a size 27 bit. That seems either way too small or there is other stuff missing. Now, if they are referring to the actual pipe fitting then maybe I can understand because the hole inside a -4(an-ntp) hose is 1/8". But, the egt probe seems to be bigger than that.

 

[SethA]

Hey,

I have the same question. I have the new sbr exhaust manifold in and it didn't come tapped for an egt probe. I currently have my installed on my stock o2 housing ( don't ask ). I want to weld a bung on there so I can switch mine out when the one I have on there goes bad.

The question is - where can I buy a bung for my egt probe? Is it the same size as the o2 sensor threads? I have heard of many different ways to install the egt probe but, they seems shady. SBR told me the tap size was 1/8" npt and drill it with a size 27 bit. That seems either way too small or there is other stuff missing. Now, if they are referring to the actual pipe fitting then maybe I can understand because the hole inside a -4(an-ntp) hose is 1/8". But, the egt probe seems to be bigger than that.

You can make your own bung if you want, just drill and tap a chuck of steel. You might also be able to simply buy a coupling in the plumbing department at Home Depot and cut it in half and weld it in. Make sure you grind the galvanize off. McMaster Carr or a plumbing shop should sell a stainless half coupling (not galvanized) if you want to go that way. A coupling may have a fairly thin wall so get a #3000 fitting if possible to make it heavier. You may need to chase the thread with a tap after welding if it pulls out of round.

www.mcmaster.com

There are probably DSM vendors that can sell you a bung, but I have never looked.

I am not sure if the O2 sensor thread is the same.

I think some numbers got crossed up with SBR. 1/8 NPT is 1/8-27, 27 is the pitch (27 threads per inch). The tap drill size should be an "R" drill (.339), 5/16 would probably work.

Seth

 

[chicagoavenger]

I just got mine back what they did was tapped it half way and then welded around it. Looks great and sealed shut. if I ever take it out I can just cap of the fitting. hopwoodp, the number that Seth gave you sounds correct. I forgot what they told me but sounds right. The shop charged me 20 bucks to do it with the cleaning.

 

[hopwoodp]

Ok Cool. I will check it out later on. Thanks for the help guys!

 

[snox135]

One problem you may have with drill and tapping the manifold, is that the probe will touch the other side of the manifold. Which will effect the readings if it is touching the manifold. Your readings just won't be as accurate as they could be. But if you measure it and it won't touch then drill and tapping is much easier.

 

[chicagoavenger]

How far in the manifold should the probe be, I'm assuming halfway?

 

[snox135]

Yeah, half way is about where you want it. The big thing is to make sure it is not touching the other side and make sure it is also far enough in the manifold.

 

[chicagoavenger]

Thanks for the info everyone.

 

[1FASTRICE]

i have the greddy egt and mine is tapped and works perfect..i think tappin it would be your best bet