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Thermocouple replacement

2K views 6 replies 4 participants last post by  drinkypoo 
#1 ·
On to my next project. The Isspro R607G pyrometer hasn't worked for a while. I built a test rig and confirmed the gauge works and indicates the correct temperature for each reference voltage. I connected my test rig where the thermocouple wires would connect to the R660 lead wire so I know the lead wire is OK as well. I'm pretty sure the thermocouple is history. Now I need to figure out what probe to order. I'd like to have the replacement on hand before removing the old one since the old probe has been there since 1993. I fully anticipate it falling apart upon removal. Not sure which probe to order. The current probe is installed in the exhaust pipe just off the drivers side manifold. The original installer welded a bung onto the pipe and the probe is the threaded type. I'm assuming I need the R650S, but every time I assume, I end up in trouble.
Any thoughts?
 
#2 ·
Give Isspro a call. I hear they are very easy to talk to.
 
#3 ·
if you know the voltage range you should be able to figure out which type of thermocouple. most automotive thermocouples are type K but there's no guarantees. What's the voltage range?
 
#4 ·
LOL, there I go again assuming you know all the thoughts in my head. The R650S is a K type rated for 1600 degrees and the R607G goes to 1500. My question was more about length. I don't know the diameter of the pipe coming off the exhaust manifold. I'm assuming (here's why I get in trouble) that the pipe isn't very big and so I would need the shorter probe. I could crawl under the truck but it has been raining and it's dark when I go to work and dark when I go home. (Whiner right?) Plus the wife home schools our spawn and she gets very annoyed if I head straight to the garage or driveway after a 12 hr work day. Something about needing a break from the little buggers....
 
#5 ·
The depth of the probe is adjustable. I just put a set of Isspro gauges in a '95.
 
#6 ·
Right, plus they offer thermocouples that don't even have to be screwed into a welded in pipe bushing. About everything you want to know is on their website.
 
#7 ·
When I installed my ISSPRO thermocouple, I actually wound up having to make a new pipe fitting adapter. I got the kind with the weatherpack connector, so I had to buy their cable, too. The thermocouple has a 1/4" dia. body, and you simply install it as you would 1/4 inch tubing. The difference is that the fittings they give you let you slip it all the way through the fitting instead of just into it. Neither of the fittings I got with my thermocouple fit the bung that ATS used, but I was able to simply go to the hardware store and get one that would fit, then drill it out with a 1/4" bit so that the thermocouple would slide through it. I installed the thermocouple as deep as it would go and still stick out a little bit, and it didn't touch bottom, so that seemed like a good place for it. It works.

I think I literally bought this one from these guys, not sure.
ISSPRO R658SHT-8F-PL Thermocouple at DieselManor

I am using an Auber EGT gauge, but that's irrelevant, type K is type K :)
 
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