Dumb question-good reason
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Posting Guru
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From: shawnee KS
Dumb question-good reason
I don't have a turbo so I don't know. Is a pyrometer the gauge for exhaust gas temps? What is the thermocoupler, and why does it make a difference where the pyrometer is mounted in relation to this? I have true dual exhaust and I would like to know what my EGT's are as I would like to turn up my pump a little bit but I don't want to have a meltdown. So where/how do I put in the gauge? Plumbing is not a problem, but do I need 2 gauges, one for each side? I guess if I did the 2 gauge thing I would have a better idea of how both banks of my IDI are running, huh? Dave S., what would you do in my shoes?
Post Fiend
Joined: Nov 2004
Posts: 5,638
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From: Manitoba
You want the pyrometer pickup (thermocouple) as close to the exhaust manifold as possible, so right below the exhaust flange in the Y pipe. Some members have installed the pickup in the manifold itself just before the flange, but that is tricky with the manifold in the truck.
One guage is fine, most engines produce the same heat both sides.
One guage is fine, most engines produce the same heat both sides.
Senior User
Joined: Apr 2005
Posts: 392
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From: NC
the thermocoupler is a probe that generates millivolt current for the gauge to operate. Diffrence of befour or after a turbo, I feel befour turbo gives you the real temp of the exhaust and faster responce on the gauge. after turbo gives you a lower then acutal temp since the turbo will suck up a few hundred deges. in your case i would stick with one gauge and drill and tap the drivers side exhaust manafold right between the last port and the flange. no diffrent then a turbo setup. i think doing both sides would be overkill
Fleet Mechanic
Joined: Sep 2005
Posts: 1,509
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From: Ladner, British Columbia
As they said above the "thermocouple" is the probe that puts out a small voltage signal that increases with temperature. This signal is then sent to a gauge in your cab that will show the temperature.
The closer you are to the outlet of the exhaust on the motor the better the reading you are going to get. Your measurement could be already several hundred degrees cooler by the time you measure it on the combined exhaust pipe so the best place would be on the exhaust manifold itself.
I drilled and tapped my passenger side exhaust manifold on the second (or third cylinder, can't remember) from the front. I remove my right front tire and mud shield and used one of the re-enforced flat spot on the manifold to drill my hole. (It almost looks like the manifold was made for drilling and taping at that spot.
With the probe at this location I get nearly instant temperature feedback as the probe literally points right into one of the exhaust ports on the engine.
Make sure you follow any wiring specifications that came with your gauge and thermocouple, some have specific requirements on length, wire size, etc.....
As you said above, a pyro is a good thing to have if your are going to start adjusting your IP fueling rate.
Seb.....
The closer you are to the outlet of the exhaust on the motor the better the reading you are going to get. Your measurement could be already several hundred degrees cooler by the time you measure it on the combined exhaust pipe so the best place would be on the exhaust manifold itself.
I drilled and tapped my passenger side exhaust manifold on the second (or third cylinder, can't remember) from the front. I remove my right front tire and mud shield and used one of the re-enforced flat spot on the manifold to drill my hole. (It almost looks like the manifold was made for drilling and taping at that spot.
With the probe at this location I get nearly instant temperature feedback as the probe literally points right into one of the exhaust ports on the engine.
Make sure you follow any wiring specifications that came with your gauge and thermocouple, some have specific requirements on length, wire size, etc.....
As you said above, a pyro is a good thing to have if your are going to start adjusting your IP fueling rate.
Seb.....
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Posting Guru
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From: shawnee KS
Okay-two conflicting posts. Driver's or passenger's side? Also, if I put one in each side- that would let me instantly know if there is a problem, right? Kinda like watching the smoke on each side of my dual exhaust.
Posting Guru
Joined: Oct 2005
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From: Powell River B.C.
Only one IP runs both sides of your engine so either install one egt, or go aircraft style and put in 8, that way you will know what each cylinder is doing. (On an aircraft you can easily change out each cylinder, so dont waist your money, you only need one EGT). I put mine in the top of the manifold on the drivers side at #6 cylinder, just below the brake booster, easy to get at and close to the wiring grommet in my firewall. Cast Iron manifold is easy to drill and tap for the installation.
Post Fiend
Joined: Nov 2003
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From: Nutter Fort, WV
I would just run one.
Drivers side or passenger side makes no difference unless the lead wire will not reach the passenger side manifold.
As for running two, you could do that, but I think if something was out of whack enough to see it on the pyrometer, you will be feeling it also.
Where the thermocouple is located is what makes the difference, you can put the pyrometer anywhere as long as the cable is long enough. You don't want to cut or splice the cable either as that will change the reading on most brands of pyrometers.
Why I say install in the exhaust manifold, the pistons are the first thing that will fail from to much heat. Why not put the thermocouple as close to the pistons as you can.
Anyplace else you mount it will require calculating the piston temp by adding a vague number to the reading to determine the piston temp.
Drivers side or passenger side makes no difference unless the lead wire will not reach the passenger side manifold.
As for running two, you could do that, but I think if something was out of whack enough to see it on the pyrometer, you will be feeling it also.
Where the thermocouple is located is what makes the difference, you can put the pyrometer anywhere as long as the cable is long enough. You don't want to cut or splice the cable either as that will change the reading on most brands of pyrometers.
Why I say install in the exhaust manifold, the pistons are the first thing that will fail from to much heat. Why not put the thermocouple as close to the pistons as you can.
Anyplace else you mount it will require calculating the piston temp by adding a vague number to the reading to determine the piston temp.
