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EGT Gauge Added


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Added an EGT Gauge, Start & Domestic Battery Monitor and USB Charger.

This is on a mechanical Cummins, C8.3, have always been curious about EGT temperatures, today was my test drive day.
Pulling out of storage, I usually go slow for a time to let the engine warm up. The EGT moved almost immediately from 250 degrees at idle to 450 degrees.
Rolling down the road on flat pavement the EGT stayed about 900 degrees.
Was surprised how sensitive the EGT is to accelerator changes, small rolling hills, increased accelerator pressure to maintain 60 MPH and EGT climbed to 1100 degrees immediately.
As soon as I crested the hill and backed off the accelerator the EGT immediately dropped back to 900 again.
From a stop sign, foot on the floor, EGT went to 1100 degrees, as soon as the pedal was released, back to 900 degrees.

I have no idea if these measurements are about average or what to expect.
1300 degrees is the danger point so I have read.
I can see, pulling mountains, the importance of the EGT Gauge on a mechanical engine.
I am guess, those with electronic engines the Engine Computer will take care of the injector fuel flow and EGT temperatures.

Thought this might be of interest to my fellow mechanical Cummins owners.

Travel safe.
 

EGT Project.jpg

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The gauge, sender and special cable is from Banks Power (www.bankspower.com).

The sender is installed in the exhaust manifold PRE Turbo.

I debated a long time about Pre or Post Turbo, but my shop mechanic said they could drill the manifold with no problem and mount it Pre Turbo which would be more accurate. Post Turbo readings can be 300 or 400 degrees cooler, so I am told.

I have a great deal of trust with my shop; Carpenters Buss Sales, Elm Mott, TX and went with their advice.

Running the cable was the hardest part of the job, coming from the engine, along the frame rails forward, there was an entry point from my single roll out bay (38 foot coach) which comes out under the refrigerator, then forward behind the couch to the dash area.

There are other vendors of EGT Gauges that do not require the "special" cable but were out of stock for the longest time and the Banks Gauge was readily available.

Good luck and safe travels.

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You might skim through this  post on iRV2:

Boost increase on ISC-350 by adjusting wastegate - iRV2 Forums

It documents my long experiment with increasing boost to control EGT.  It's a very long thread but you can find a lot of info about your questions.  You will also see posts by folks (Wild Card, for instance) who know little or nothing, but have "digital diarrhea" and cannot stop themselves from posting about things they have only read about, but KNOW nothing about.

I installed an EGT gage at the turbo inlet, using an AutoMeter gage that used ordinary wire to go forward to the cockpit from an amplifier located near the thermocouple's wimpy output.

To summarize, I was surprised at some things.  1) the EGT of a bone-stock ISC-350 can easily hit 1400*F under WOT for 60 seconds, as when accelerating from a rest area to merge with traffic.  2) increasing boost will undoubtedly reduce EGT under all conditions.  I SUSPECT (do not know) that is the reason the Banks Engineering performance kits usually include a higher-capacity turbo.  3) even on the electronically controlled engines (ISC, at least) increasing the boost does NOT cause the ECM to call for any more maximum fuel than it was originally programmed for, so there is absolutely NO power increase from increasing boost.  4) as expected, adding fueling by any means raises EGT.  5) RPM has a huge effect on EGT.  You can easily reach 1400*F at low throttle settings if the RPM is low enough.

It's inconceivable to me that Cummins did not test their ISC setup extensively before releasing it to production, so I THINK (do not know) that the possible damage from excessive EGT is very time-dependent.  That is, some excessive EGT can be tolerated quite safely for limited periods...because valve head and piston temperatures are NOT the same as EGT.  I have questioned Cummins extensively and never got anything close to an answer to, "How HIGH can EGT be for how LONG before there is the possibility of damage?"  It surprised me the answer is not readily available.

My experience with an EGT gage on my 1993 Dynasty 8.3-250 was much like yours in regards to EGT.  It was also AutoMeter brand, but used the long Type-K wire from the thermocouple to the gage in the cockpit--quite a PITA to install.  Changing the fueling plate in the injector pump to increase fueling resulted in considerably higher EGT (easily 1400*F) and more power, but required that one be mindful of throttle position and RPM.  At the time, I had not tried increasing boost to lower the EGT.

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I do not have an exhaust temp gage on my motorhome but always had them on my trucks. Truck manufacturers will install them after the turbo because sometimes the probe will come of and then go through the turbo completely destroying it. I was told by Caterpillar and Cummins mechanics both that with the probe after the turbo that 900 degrees was about all you wanted. Occasionally would see it get that high on a steep grade or in a head wind. Just drop a gear to lower. The newer computer controlled engines it was hard to get it that high. The old non computer engines not so much. It depended on who had set the pump up. Not sure, but I think 1400 degrees is pretty hot. If I remember correctly 1200 will damage aluminum parts. They use to be called pyrometers

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Terry, yes, I have read of the sender coming apart and that was my greatest debate, but my shop indicated they had not seen this occur, certainly guess it is possible, time will tell and I will keep fingers crossed that all goes well.

As noted, my surprise was how quickly the EGT increased / decreased with throttle movement.

As VanWill52 noted, have no doubt under heavy load, climbing a mountain, the EGT can get pretty high, pretty quickly. But I thought the electronic (ISC) type engines would monitor fuel flow and EGT, but maybe not as closely one would think.

I read the two suggested article, appreciate the links. For me, I think 1200 is my comfort point and back off once there.

Thanks for the input, ya'll have a good day.

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On 7/16/2021 at 4:20 PM, CRY1942 said:

Added an EGT Gauge, Start & Domestic Battery Monitor and USB Charger.

This is on a mechanical Cummins, C8.3, have always been curious about EGT temperatures, today was my test drive day.
Pulling out of storage, I usually go slow for a time to let the engine warm up. The EGT moved almost immediately from 250 degrees at idle to 450 degrees.
Rolling down the road on flat pavement the EGT stayed about 900 degrees.
Was surprised how sensitive the EGT is to accelerator changes, small rolling hills, increased accelerator pressure to maintain 60 MPH and EGT climbed to 1100 degrees immediately.
As soon as I crested the hill and backed off the accelerator the EGT immediately dropped back to 900 again.
From a stop sign, foot on the floor, EGT went to 1100 degrees, as soon as the pedal was released, back to 900 degrees.

I have no idea if these measurements are about average or what to expect.
1300 degrees is the danger point so I have read.
I can see, pulling mountains, the importance of the EGT Gauge on a mechanical engine.
I am guess, those with electronic engines the Engine Computer will take care of the injector fuel flow and EGT temperatures.

Thought this might be of interest to my fellow mechanical Cummins owners.

Travel safe.
 

EGT Project.jpg

I just added EGT to my ‘96 Windsor C8.3 as well. Discovered very similar readings, however was a bit alarmed that temps immediately jumped to over 1300 going over mountain passes in the northwest. I had to back off the throttle to keep temps in the 1200 range. Totally stock C8.3/275 HP engine w/70k original miles. 
Assuming the new gauge is accurate that is very concerning that it would be very easy to generate damaging EG Temps.

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Mike; I agree, temperatures can soar quite quickly. I was surprised how quickly temps can climb and how quickly temps reacted to throttle input. Climbing a mountain most likely will require one to "back off" less fuel being fed to the Cummins and shift the Allison down to a lower gear, will move more water through the radiator. We are making our first trip this week to the beautiful Texas Hill Country and am looking forward to using and monitoring the EGT.

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Unfortunately, there is no EGT input to the ISC model ECM's.  The ECM does NOT reduce fueling to control EGT.  I know that seems strange, but I'm guessing Cummins just tested their programming extensively and limited fueling to what they felt was safe.  The only recognition I've seen from Cummins was when I read SOMEWHERE in their literature, "Limit full throttle conditions"--sort of an admission that damage might occur under extreme conditions.  I have no personal experience with that kind of damage, nor have I read of anyone having that kind of damage, but it certainly appears possible, when a bone-stock ISC can easily reach 1400*F.

One thing you will quickly learn from watching the EGT gage is how heavily it is influenced by engine RPM.  You can tame EGT on a long pull by keeping the RPM high.

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VanW; would be interesting to put an EGT on an electronic engine to see what it does. No doubt Cummins years of experience with diesels, they probably have it figured out pretty well. My limited knowledge, but shifting the Allision down on a climb will increase RPM as you suggest and move more water through the radiator to help cooling.

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7 minutes ago, CRY1942 said:

VanW; would be interesting to put an EGT on an electronic engine to see what it does. No doubt Cummins years of experience with diesels, they probably have it figured out pretty well. My limited knowledge, but shifting the Allision down on a climb will increase RPM as you suggest and move more water through the radiator to help cooling.

My 2000 Dynasty has the ISC-350 engine, and it is electronically controlled.

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Back in the day before electronic engines some guys would open up the fuel pumps on their trucks so they could be first to the top of the hill. Didn't always make it because they would pull a sleeve or burn up a piston. If you set you had your fuel pump set a a derated horsepower you could just drive the truck and not spend your time worrying about it. I think the electronic controlled engines now you can just drive unless you have altered it with a chip or something. Thirty-eight years of experience here with my own trucks and one motorhome.

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Bone stock, mechanical, C8.3, no experimenting for me, just drilling the EGT sensor, pre-turbo was enough of an experiment ! LOL.

Will be off to Fredericksburg, TX on Friday and look forward to watching how the EGT Gauge works over the mountains (well actually hills here in TX  :classic_smile:).

Appreciate the input from all, everyone have a great day and travel safe.

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Pre-turbo not a good idea. If probe fractures and breaks it will destroy your turbo. I have never seen a truck engine with the probe pre turbo since the late 60's.

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7 hours ago, cterryl@sbcglobal.net said:

Pre-turbo not a good idea. If probe fractures and breaks it will destroy your turbo. I have never seen a truck engine with the probe pre turbo since the late 60's.

I cannot discount that failure as a very remote possibility, but the great majority of EGT probes are mounted in the exhaust manifold, as per the installation instructions.

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For someone who has a couple mountains (the Sierras in ca/nv) AND my EGT, fuel pressure gauge (FASS fuel system) and pulling 5K lbs, that as soon as i get turned toward a steeper portion the EGT does climb however watching my rig do its thing that when the speed starts to drop the trans has already shifted from direct then will shift down another gear to keep the RPM right around 2K RPM.

Now to be fair i bought my MH used and someone had installed the Banks stinger kit on it, with that i understood it monitors inputs, Egt, Ect, Throttle position, and gear to give max power while protecting the engine... so far when im in the seat i trust but verify its doing its job, an always ready to knock it down a gear if temps start to climb.F6C46376-6B0E-46CF-BA68-4144E7A97134.thumb.jpeg.f98d116a1f8f6f52f56071109c149158.jpeg

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I have a 97 Windsor, Cummins C8.3 with Banks kit (installed before I bought it so I don't know what it includes), with pre-turbo EGT gauge.

EGT is around 800-900 at highway cruising speed. In the east (lower elevations) at full throttle EGT will move pretty quickly to 1000-1100. After about 30 seconds going up a hill it will start creeping up to about 1250 and stabilize; below 1600 rpm EGT will continue to creep, downshifting manually to keep rpm higher will keep EGT lower (the Allison like to downshift around 1400 rpm which I think is too low). 

Climbing the bigger passes out west above 6000 feet, I have to watch EGT much more closely, and occasionally back out of the throttle some to keep EGTs under 1300. 

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On 7/17/2021 at 7:31 AM, CRY1942 said:

The gauge, sender and special cable is from Banks Power (www.bankspower.com).

The sender is installed in the exhaust manifold PRE Turbo.

I debated a long time about Pre or Post Turbo, but my shop mechanic said they could drill the manifold with no problem and mount it Pre Turbo which would be more accurate. Post Turbo readings can be 300 or 400 degrees cooler, so I am told.

I have a great deal of trust with my shop; Carpenters Buss Sales, Elm Mott, TX and went with their advice.

Running the cable was the hardest part of the job, coming from the engine, along the frame rails forward, there was an entry point from my single roll out bay (38 foot coach) which comes out under the refrigerator, then forward behind the couch to the dash area.

There are other vendors of EGT Gauges that do not require the "special" cable but were out of stock for the longest time and the Banks Gauge was readily available.

Good luck and safe travels.

Thanks for the tip on running the cable.
I've been wanting to install an EGT gauge on my coach, but wasn't looking forward to cable routing. LOL

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David, the special "Type K" thermcouple wire is stiff and appears slightly fragile and prone to kinking.  It is indeed a bear to run.  The gages like the AutoMeter one I installed use ordinary copper wire, making the process infinitely easier.

Since I have found so many times that I needed extra wires running from the engine bay to the instrument panel, I finally used this as an excuse to run TWO 7-conductor, 14 AWG trailer wiring cables front to rear and end them with terminal strips front and rear.  The multi-conductor cable is neoprene-sheathed and very flexible, waterproof, and rugged--You can yank on it when necessary while snaking it forward.  The box marked "EGT Gage" is the "amplifier" that allows the millivolt signal to be transmitted over ordinary copper wire.

Van

20210613_092325_resized.jpg

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23 hours ago, vanwill52 said:

David, the special "Type K" thermcouple wire is stiff and appears slightly fragile and prone to kinking.  It is indeed a bear to run.  The gages like the AutoMeter one I installed use ordinary copper wire, making the process infinitely easier.

Since I have found so many times that I needed extra wires running from the engine bay to the instrument panel, I finally used this as an excuse to run TWO 7-conductor, 14 AWG trailer wiring cables front to rear and end them with terminal strips front and rear.  The multi-conductor cable is neoprene-sheathed and very flexible, waterproof, and rugged--You can yank on it when necessary while snaking it forward.  The box marked "EGT Gage" is the "amplifier" that allows the millivolt signal to be transmitted over ordinary copper wire.

Van

20210613_092325_resized.jpg

That's a great idea, I'll probably do the same when I get to it.
What route did you take through the center of your coach?
Mine has a couple conduits that run atop the center of the bays, but they're both pretty full already.  Not sure I could get a snake through there.

Thanks.

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2 hours ago, dl_racing427 said:

That's a great idea, I'll probably do the same when I get to it.
What route did you take through the center of your coach?
Mine has a couple conduits that run atop the center of the bays, but they're both pretty full already.  Not sure I could get a snake through there.

Thanks.

My conduits were also crowded, but using a metal snake to draw a nylon cord through enbabled me to get it through.  I used two people, one at each end, to yank and wiggle it as I went.  I removed the overhead panels from my storage bay. I drug the two cables through bound together.  Had that process encountered difficulty, I might have tried pulling one at a time.

If you use nylon cord for your "pull snake", lash the ends of the two cables together tightly with small nylon twine binding the "pull snake" to the two cables, then tape the end where your "pull snake" exits the bundle so that it is smooth and pointed, I think you'll be able to get it through.  I let my two cables enter the FRB (front run bay) under the driver's window, then go upward into the console.  From there, it was easy to snake it up behind the instrument panel.

Good luck!  It is really handy to have spare wires available on a terminal strip.  There are OEM spare wires available running from the engine compartment to the instrument panel on EVERY Monaco I've ever worked on, but they are varying sizes and many folks report not being able to find them at all.  They are ALWAYS there somewhere, but having terminal strips at each end is handy.

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  • 5 weeks later...

On my 94 Dynasty with the 8.3. I had issues with high EGTs. I ended up installing a larger more modern Borgwarner S362 turbo. It was a direct bolt on affair for the most part. Lowered my EGTs about 2-300 degrees while increasing boost over 5-6 psi. I had also tweaked the P-pump for more power. She was downright sporty with the Borg. I may end up putting a slightly larger version on my newer Dynasty 8.9. 

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