Non-Turbo 2H with high EGT (1 Viewer)

[KiwiDingo]

500 - 650 degrees "C" is not at all very very low. It equates to over 1200 degress F and is very much near the piston melt down range.
My question is where and why did was a pyrometer that is calibarted in the metric "Celcius" sourced to begin with? I have honestly never heard of such an animal. I wonder if it really a gauge that is calibrated in "F" and has been miss-labeled as being calibrated in "C". That makes alot more sense.

Pretty much every single EGT gauge you can buy here in my country is in Celsius. I live in a metric country.

Yes, 550-650 degrees is quite low and completely safe. Just remember EGT is NOT the piston temp.

 

[AirheadNut]

500 - 650 degrees "C" is not at all very very low. It equates to over 1200 degress F and is very much near the piston melt down range.
My question is where and why did was a pyrometer that is calibarted in the metric "Celcius" sourced to begin with? I have honestly never heard of such an animal. I wonder if it really a gauge that is calibrated in "F" and has been miss-labeled as being calibrated in "C". That makes alot more sense.

I think most places in the world apart from North America have pyrometers in ºC. As @KiwiDingo said, EGT doesn't equate to piston temperature. While aluminum will begin to melt in the mid 1200ºF range, engines with aluminum pistons can run with EGT's much higher than that with no ill effects. Part of that is due to the cooling oil jets squirting the bottoms of the pistons, partly because the cylinder gasses are only that temperature for less than half the time (only on ignition and exhaust stroke). I've run my TDI engine with aluminum pistons and cylinder head at 1350ºF pulling mountain passes, and when I had bad injectors would regularly see temps in the 1400-1550ºF range. VW specs the turbo for a maximum turbine inlet temperature of 1682ºF.

 

[IanB]

500 - 650 degrees "C" is not at all very very low. It equates to over 1200 degress F and is very much near the piston melt down range.
My question is where and why did was a pyrometer that is calibarted in the metric "Celcius" sourced to begin with? I have honestly never heard of such an animal. I wonder if it really a gauge that is calibrated in "F" and has been miss-labeled as being calibrated in "C". That makes alot more sense.

Here in Canada we buy what's available, and that's usually from the US and they use F rather than C. The REST OF THE WORLD uses C, it seems nobody in AUS has an EGT in F.

 

[dyna150]

There's only so much heat you can produce in the cylinder by using atmospheric pressure intake air and fueling to match. The exhaust has little to no back pressure without a turbo so has better flow of the hot exhaust gases out of the cylinder and actually has a bit of scavenging which keeps the cylinder/ head temps much cooler. Adding a turbo does the opposite by increasing intake pressures which then needs to be compressed which creates a lot more pressure/heat and is often matched with extra fueling making even more heat inside the cylinder/head. The turbine wheel and housing restrictes the exhaust causing high back pressure (EMP) which effects the flow and actually reverses it in a lot of cases during valve overlap causing more hot exhaust gases to stay inside the cylinder which is why EGT is so critical on turbo diesels but not so much on n/a diesels. EGT on n/a diesels can be much higher but actually have much lower temps inside the cylinder and head compared to turbo diesels

Hello,
I was just reading your answer and it is really usefull for me.
I have a Toyota Dyna 1997 with a 3L N/A and the previous owner putted a EGT in it and told me to true to keep it under 1200 F or 650 C … bit as the truck is pretty loaded (it is an expedition truck) it makes it slow if ai keep the temp that low.

My plan is to put a motor temperature gauge to avoir motor overheating (or prestone temperature gauge) … do you think it is a better way to avoid motor damage ?

 

[KiwiDingo]

If it's a n/a diesel I wouldn't even bother having an EGT gauge. You have nothing to worry about.

 

[dyna150]

If it's a n/a diesel I wouldn't even bother having an EGT gauge. You have nothing to worry about.

Thanks a lot !

 

[sodafeld1]

Interesting re dig. Pure aluminium melts at 660c..but alloys would melt at different temps.

 

[KiwiDingo]

Keep in mind the temps shown on the EGT gauge isn't the temp of the pistons.

 

[sodafeld1]

Keep in mind the temps shown on the EGT gauge isn't the temp of the pistons.

very true, like the flame tip is hotter than the base of the flame.

Guess the ceramic coating piston heads was also a n attempt to dissipate the heat too...but shouldn't be necessary for n/a either

 

[Dougal]

Hello,
I was just reading your answer and it is really usefull for me.
I have a Toyota Dyna 1997 with a 3L N/A and the previous owner putted a EGT in it and told me to true to keep it under 1200 F or 650 C … bit as the truck is pretty loaded (it is an expedition truck) it makes it slow if ai keep the temp that low.

My plan is to put a motor temperature gauge to avoir motor overheating (or prestone temperature gauge) … do you think it is a better way to avoid motor damage ?

You'll be smoking like a train to get a non turbo diesel to 650C.