big jimmy

Anyone hear of a thermocouple probe breaking off and going through the turbo??
Or of any probes breaking, no matter where they were located??

Big Jimmy

Ph4tty

Mines rated at 2000 degrees. My pistons would melt long before the thermocouple.

Barry St John

Nope, but I have heard that they can become inaccurate over time. It was a post by Don M of f1 injectors stating that he thought it was a bad idea to trust your pyrometer too much for that reason.

Dr. Evil

Yeah, actually I did hear of one thermocouple doing that but it is pretty rare - I would think an improper install would cause that to happen more than anything else.

big jimmy

Thanks. I am waffling about pre or post turbo.
Considering its easy to do the math to know what the egt's are when the probe is after the wheel I was wondering if there was much risk associated with its pre placement. I'll probably choose to live where every one else does on these forums, placing the probe in line as the first thing the turbo will eat if anything goes wrong.

Jimmy

BigBlue

The chances of the probe breaking off are 1 in 999,999. Put it pre turbo and don't worry about it.

AlpineRAM

It's definitely not easy to do the math on a wastegated turbo- because the turbine works on delta pressure and delta temperature you will see the reduction. -when the wastegate opens the hot exhaust gas goes to the probe without being cooled by the turbine. So the guesswork starts on how much goes through the wastegate, how much through the turbine and does it mix well or is the probe by chance in a region where it gets more from one or the other.
Industrial applications that roun without wastegate and are stock will have no problems calculating the pre-turbo EGT at full power from a post turbo probe.

On a bombed truck I'd suggest going pre-turbo to know the EGTs instead of guessing

AlpineRAM

RowJ

Agreed!
It's easy to do the math... if you add 500* to all scenarios! Need to do that to cover the occasional situations where it WILL be 500* difference.

The 300* difference used by many otherwise knowlegdeble Cummins experts only works for stock, long haul, big rigs (as mentioned above).

Why mess with guesstimates when locating pre turbo has been bulletproof for thousands of satisfied DTR members?

RJ

Lil Dog

I look at over 100 engines a year with pyros mounted pre turbo, and per cylinder. I have heard and seen every type of failure and the pyro was never the culprit of turbo failure. To be honest I have seen pre-turbo pyros bent from being hit by debris from the engine and not break off. I would not hesitate to install pre turbo. A turbo is alot cheaper than replacing the engine if you want to weigh risks..

DodgeCowboy

the probes have broke when the probe was wrenched down in to the bottom of the manifold most of if not all the probes now being used a shorter verson so that does not happen.

Mark Craig

big jimmy,

I have always heard about the "one that broke", but I have never been able to find any one individual that has had his break. It's always my father in laws mothers second cousin on the other side of the family kind of deal. Go pre and be happy, you'll be lgad you did.

Mark @ DPPI

infidel

Extremely high heat is about the only thing that will melt one off.
At that point the turbo is the least of your worries.

big jimmy

Thanks everyone!

I'll be augering a hole in the exhaust manafold this Sunday.

Since I'm a woodworker I am going to make my own triple gauge mount out of some nice wood I've got- not sure on the exact location yet but not the pillar- thats not for me...




Big Jim

Dr. Evil

Jimmy....check this out: