My pyrometer can't be right!
Post Fiend
Joined: Jun 2004
Posts: 9,293
Likes: 10
From: Parker, CO
Kris, I'm not sure which gauges you are running, but they might actually be working properly. Some gauges are just more "lazy" than others. I've noticed that when switching from Autometer gauges over to the DiPricols. The DiPricols are much quicker and more responsive, including cooling down to 300 degrees at idle in less than half the time of the Autometers. Also your cruising temps sound normal with that amount of boost you're running. Speed, terrain, and altitude play big roles. You won't see cruising EGT's around 600 degrees unless you keep your boost below 5 psi.
Fleet Mechanic
Joined: Feb 2005
Posts: 1,797
Likes: 1
From: Northern Colorado
Originally Posted by jtharvey
Guzzle, you are correct, that's where the pyro connects to gauge wiring. Seems to me if they were touching, the gauge would peg to one extreme and not just be marginally off.
Kris, your numbers seem about like mine. I don't know if I count though with different injectors. The only thing that seems a little off is I think it should have cooled down further than 400* after 3-5 minutes, especially if ambient was that cold. Do you have a differenty pyro probe you could try?
Kris, your numbers seem about like mine. I don't know if I count though with different injectors. The only thing that seems a little off is I think it should have cooled down further than 400* after 3-5 minutes, especially if ambient was that cold. Do you have a differenty pyro probe you could try?
If winter salts were to get trapped in the shrink wrap, this may cause a small amount of voltage leakage between the terminals, but that would also show up as a lower voltage i.e. lower pyrometer reading.
This is why it is important not to try to shorten the pyrometer wiring since the pyrometer is calibrated to the voltage drop that the manufacurer's length of wire will cause. Shorting the cable length will cause less voltage drop and more voltage at the gauge. You will see a higher reading than what it should be so I don't think that the connector is the problem.
Originally Posted by HKusp
Oh yeah, nice to see you posting again Guzzle. I haven't seen you here in a good while. I hope all is right in your world. You have helped so many of us here, I for one am eternally grateful.
Elder User
Joined: Sep 2006
Posts: 627
Likes: 0
From: Middleton, Idaho
I just put a set of AutoMeters in a buddies truck and can confirm that if the wires come in contact with each other you will get a no read on the gauge itself. The wire connectors are offset that go to the gauge but are not from the probe, which means you have to fold the one side when you put the connectors together. Talked to Autometer about shortening the one side and got a infatic no, just fold it and tape em up. And then put on the shrink wrap.
My pyro temps run about 100 less than what Kris posted.
My pyro temps run about 100 less than what Kris posted.
Elder User
Joined: Oct 2005
Posts: 786
Likes: 0
From: Reno nv
Two ways to go here:
1: known new/good replacement of thermocouple. same reading probably means that meter is off or (more probable) Temps ARE that high.
2: borrow someone's Fluke with a temp probe and wire the two T/C wires accross the probes. Read millivolts, and compare with published charts for T/C type Ie: Iron constantine. Place probe in oven and crank oven up to 500, let sit for 15 minutes and look to see if oven goes to 500 with mercury oven thermo and compare readings. Take a new GOOD soldering iron (weller or better) and look for the temp on the tip, touch thermo to tip and see if it reads tip temp. Should be 600 to 900.
All this stuff is generally +- 10%. If you want QUALITY, find a precision instrument CALIBRATION lab and pay to get the unit calibrated to temps. They may not be able to calibrate it, BUT they will give you a conversion chart.
MY $.02: I think your temps are high, but cannot comment on the cause since I'm an instrumentation person, not a mechanic.
1: known new/good replacement of thermocouple. same reading probably means that meter is off or (more probable) Temps ARE that high.
2: borrow someone's Fluke with a temp probe and wire the two T/C wires accross the probes. Read millivolts, and compare with published charts for T/C type Ie: Iron constantine. Place probe in oven and crank oven up to 500, let sit for 15 minutes and look to see if oven goes to 500 with mercury oven thermo and compare readings. Take a new GOOD soldering iron (weller or better) and look for the temp on the tip, touch thermo to tip and see if it reads tip temp. Should be 600 to 900.
All this stuff is generally +- 10%. If you want QUALITY, find a precision instrument CALIBRATION lab and pay to get the unit calibrated to temps. They may not be able to calibrate it, BUT they will give you a conversion chart.
MY $.02: I think your temps are high, but cannot comment on the cause since I'm an instrumentation person, not a mechanic.
Posting Guru
Joined: Mar 2007
Posts: 1,905
Likes: 2
From: East Peoria, IL
i have the same thing with my autometers..i see everyone saying they run 5-600 going 70-75 and i run about the same as you going that speed. At 72 MPH the other day, i was 800 +/- 25 degrees
always wondered about this....
always wondered about this....
