EGT and Oil temps

[CSIPSD]

900 degrees EGT, sustained.. or 200 degrees EOT is where I always start thinking about down shifting. 5th gear usually does it, keep the RPM's between 2200 & 2450..... or Slow down to what the loaded Big Trucks are doing (or a little better).... Geared accordingly.

Your leaving a TON of performance on the table using 900* as any kind of a marker...

Max EGT from International (guys who make out motors) is 1250* sustained. You can pull all day long at 1250* and not hurt a thing. You can also go well over that line for short times and not hurt anything as well.

Your watching EGT's not to protect the turbo, your turbo exhaust wheel could stand temps in the 2000-2200* range with no damage. Your watching your EGT's to protect your aluminum pistons.

Aluminum starts to soften at about 1300*, however you have to remember that EGT stands for Exhaust Gas Temp, not piston temp. You have a layer of air that protects the piston, cool fuel coming in at every stroke along with cool air. You have piston cooling jets that spray the bottom of the pistons with oil to cool them (see pic)

Bottom right hand corner you can see the U shaped jet.

Oil temp is a differant story... Your PCM will begin to defuel at about 240* depending on the PCM code. Most of the time your oil temp will run about 10-20* above the water temp. With a 7.3l you will never have issues with oil temps unless you have a serious mechanical issue. Pulling 30k GVW I have never seen oil temps over 238* at the HPOP and 250* at the cooler.

 

[DaveBen]

Your EGTs are effected by the location of your exhaust thermocouple. If very near the exhaust port is more accurate than further down the exhaust down pipe. Closer to the head the better.

Dave

 

[nswsparky]

Your EGTs are effected by the location of your exhaust thermocouple. If very near the exhaust port is more accurate than further down the exhaust down pipe. Closer to the head the better.

Dave

Actually bulldog said that the most accurate spot is 3inches from the intake of the turbo have it too close to the exhaust port you will get erroneous readings. Mine is mounted right before the turbo in the up pipe

 

[DaveBen]

Where you mount it is YOUR choice. I choose to mount mine right under #3 exhaust port. Seems to be accurate.

Dave

 

[CSIPSD]

Your EGTs are effected by the location of your exhaust thermocouple. If very near the exhaust port is more accurate than further down the exhaust down pipe. Closer to the head the better.

Dave

Correct... Everything I said was based on the correct mounting location for the pyro... PRE-TURBO... Be it in the manifold or in the up pipes.

Again, your watching EGT's to protect the pistons, not the turbo. The closer you are to the pistons the better off you will be.

 

[dieseltech1]

why would you mount a pyrosensor so it only monitors a couple of cylinders they are made to monitor the whole exhaust system temps so you have an idea what the engine is doing as far as exhaust temps all heavy duty pyros are mounted within 6 inches of the turbo outlet and the eot will run about 20 to 30 degrees hotter then ect

 

[DaveBen]

why would you mount a pyrosensor so it only monitors a couple of cylinders they are made to monitor the whole exhaust system temps so you have an idea what the engine is doing as far as exhaust temps all heavy duty pyros are mounted within 6 inches of the turbo outlet and the eot will run about 20 to 30 degrees hotter then ect

There are a couple of different thoughts on this. First off, I use the pyro for EGTs in a good running engine. If your aim is to isolate a bad cylinder then you would want a pyro in each exhaust port, like an airplane engine. This will give you a fault very quickly and in an airplane you would not want to continue engine operation. In a truck you could continue without harm to life and limb. In general a single pyro is good enough to determine if your engine is getting too hot for safe operation. Melting pistons is NOT good here and is what you want to avoid. Your statement "are mounted within 6 inches of the turbo outlet" is not accurate. You want to change the word "outlet" to "inlet". The turbo uses too much energy from the exhaust to be very accurate. It is your truck and you can do with it as you choose.

Dave

 

[dieseltech1]

dieseltech1

ok dave if you want to locate it in the up tube your still only looking at one bank what if an injector fails on the other side and starts to over fuel the turbo does not absorb that much heat to cause an issue and if it did then then aftermarket companys would install dual pyros for each bank however they install them in the outlet also these are not airplanes and dont reach extreme altitudes to were you can adjust carbs to compensate for heat

 

[DaveBen]

It is your truck and your choice. I just tried to explain what I did and why. You can do what ever you want.

Dave

 

[CSIPSD]

why would you mount a pyrosensor so it only monitors a couple of cylinders they are made to monitor the whole exhaust system temps so you have an idea what the engine is doing as far as exhaust temps all heavy duty pyros are mounted within 6 inches of the turbo outlet and the eot will run about 20 to 30 degrees hotter then ect

Because it gives you a good working area. If you have a cylinder that is not firing big deal, you will notice the change in the motor... However if you run a post turbo pyro and "guess" the wrong redline you could easly have some pictures like I posted above.

The CORRECT place to mount a pyro on a V-8 truck is pre-turbo.

THe only time I might mount a pyro post turbo is on a I-6 or such, and even then I would mount it preturbo.