Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: dlkj07 on October 29, 2022, 08:52:23 pm

Title: EGT probe install location
Post by: dlkj07 on October 29, 2022, 08:52:23 pm
I'm installing an Exhaust Gas Temp gauge and wanted some recommendations on where to install the probe. I definitely want it pre-turbo. Should I just stab it where one of the 2 flutes dump into the turbo? I seem to recall on the 5.9 Ram Cummins that cylinder 6 had the highest EGT but not sure that's the same with the ISM's. I'm not that anal so I think getting an average EGT from all cylinders will be fine...this isn't an airplane Pierce 😛

Also, I plan on using one of the extra wires that run from the engine bay to the dash, shouldn't have any issues right?
Title: Re: EGT probe install location
Post by: master2301 on October 29, 2022, 09:44:14 pm
Is the wiring Iron/Constatine or Chromel/Alumel? Just wondering if you are installing a Type K or Type J indicator.
Title: Re: EGT probe install location
Post by: Olde English on October 29, 2022, 10:24:00 pm
Unless you remove the turbo prior to drilling then mount the eg down stream of the turbo the temperature difference will be minimal. When you drill into the manifold it's almost impossible to stop swarf from dropping into the exhaust system.
Title: Re: EGT probe install location
Post by: WS6_Keith on October 29, 2022, 10:46:26 pm
Mine is installed where you have your left picture, towards the front of the coach or the back of the engine.  #6 runs the hottest in the smaller engines, so I assume the same in the ISM.  I drilled slowly, with grease on the bit, and did the same with the tap, to keep all the shavings from going into the turbo.  I also used a shop-vac on the hole after.  That was 10k miles ago, so no issues.

As for the wiring, no, you can't use a standard wire.  Type K thermocouples require a special wire with alumel and chromel as the two conductors, to work properly.  This is also why my probe is installed, but the wire has not been run.
Title: Re: EGT probe install location
Post by: Doug W. on October 30, 2022, 10:17:48 am

Also, I plan on using one of the extra wires that run from the engine bay to the dash, shouldn't have any issues right?

I used one of the existing extra wires but only with an extension module.

Auto Meter Diesel RV EGT Pryometer Gauge 0-1600 Degrees (https://www.parleysdieselperformance.com/products/auto-meter-diesel-pusher-rv-egt-pyrometer-full-sweep-electric-gauge-0-1600-degrees)
Title: Re: EGT probe install location
Post by: dsd on October 30, 2022, 10:50:54 am
Unless you remove the turbo prior to drilling then mount the eg down stream of the turbo the temperature difference will be minimal. When you drill into the manifold it's almost impossible to stop swarf from dropping into the exhaust system.

Installing a clean/filter removed vacuum being used as a blower you can pressurize the exhaust slightly and facilitate blowing cuttings up out of the hole you are drilling. Always preferred with manifold removed. Drilling a hole anywhere in a cast exhaust manifold will localize stress. Does not require much installation torque, less is better IMO
Scott
Title: Re: EGT probe install location
Post by: dlkj07 on October 30, 2022, 04:16:36 pm
I used one of the existing extra wires but only with an extension module.

Auto Meter Diesel RV EGT Pryometer Gauge 0-1600 Degrees (https://www.parleysdieselperformance.com/products/auto-meter-diesel-pusher-rv-egt-pyrometer-full-sweep-electric-gauge-0-1600-degrees)

I almost bought that exact setup but ended up getting a Max Tow because of the digital read out along with analog. 
MaxTow Double Vision 1500 F Pyrometer Exhaust Gas Temperature EGT Gauge Kit - Includes Type K Probe - Black Gauge Face - Blue LED Dial - Analog & Digital Readouts - for Diesel Trucks - 2-1/16" 52mm Amazon.com: MaxTow Double Vision 1500 F Pyrometer Exhaust Gas Temperature... (https://a.co/d/1ZWHIzQ)

I called Max Tow and asked them if I needed any special wiring to extend the included wiring and he said no, I could use the existing wires on my coach to extend it. Wonder if he didn't know what he was talking about.

Curious if the Auto Meter extension module would work the the Max Tow meter...if I need it at all.
Title: Re: EGT probe install location
Post by: dlkj07 on October 30, 2022, 04:17:35 pm
Is the wiring Iron/Constatine or Chromel/Alumel? Just wondering if you are installing a Type K or Type J indicator.

It's a type K

MaxTow Double Vision 1500 F Pyrometer Exhaust Gas Temperature EGT Gauge Kit - Includes Type K Probe - Black Gauge Face - Blue LED Dial - Analog & Digital Readouts - for Diesel Trucks - 2-1/16" 52mm Amazon.com: MaxTow Double Vision 1500 F Pyrometer Exhaust Gas Temperature... (https://a.co/d/1ZWHIzQ)

Title: Re: EGT probe install location
Post by: dlkj07 on October 30, 2022, 04:57:07 pm
Here's a quick video of what my original plan was.

https://youtu.be/JiXZP3HU39Y

Title: Re: EGT probe install location
Post by: WS6_Keith on October 30, 2022, 06:13:36 pm
Thermocouples generate voltage based on their temperature.  These output a millivolt signal that must be increased in voltage to be usable, using a "thermocouple amplifier" which requires power to amplify the signal.  In your case, this will be in the head of the gauge, so you have to use thermocouple specific wire from the thermocouple to the amplifier input. 
Title: Re: EGT probe install location
Post by: dlkj07 on October 30, 2022, 06:30:24 pm
Thermocouples generate voltage based on their temperature.  These output a millivolt signal that must be increased in voltage to be usable, using a "thermocouple amplifier" which requires power to amplify the signal.  In your case, this will be in the head of the gauge, so you have to use thermocouple specific wire from the thermocouple to the amplifier input. 

So I wonder if that's where the auto guage extension module comes into play?

MODULE, WIRING EXTENSION, FOR STEPPER MOTOR INCANDESCENT PYROMETER GAUGES (https://www.autometer.com/module-wiring-extension-for-stepper-motor-incandescent-pyrometer-gauges.html?gclid=Cj0KCQjwwfiaBhC7ARIsAGvcPe4PDT0mWVSocqv47RMGv3Uoi4sHEzJgU_kv6a3gHAuVfO8bFvX5DEsaAtdLEALw_wcB&gclsrc=aw.ds)
Title: Re: EGT probe install location
Post by: master2301 on October 30, 2022, 06:35:50 pm
Autometer Q&A

WILL THIS WORK WITH A AUTOMETER 3844 GS ELECTRIC PYROMETER GAUGE KIT WITH GREEN LED LIGHTING?
Asked by: jgreen
Thank you for your question. No, this will not work with any LED LIT GUAGES.
Answered by: Zach from AutoMeter
Date published: 2019-11-18
Title: Re: EGT probe install location
Post by: Barry & Cindy on October 31, 2022, 04:47:58 pm
Pyrometer probes always use specific wire types and in most cases must be calibrated for accuracy with ice and boiling water. But there are Exhaust Gas Temperature systems that come with short pre-calibrated fixed length probe wires that connect to an engine area module. Any coach wires can be run from the module to dash gauge.

This is the VEI system we used and recommend:

Digital Pyrometer & Boost Gauges - VEI Systems (http://www.foreforums.com/index.php?topic=20537.msg149993#msg149993)

For simplicity, we drilled into steel 4" tube just after turbo and held probe in place with a special constructed large hose clamp that had a pre-drilled hole to keep probe in place. We just compensated and used a lower max temp for driving up mountains.

This VEI digital dash meter also displays max temp and the matching boost gauge displayed max boost.