Pyrometer Guage Max temp?

[shromani]

Looking to get all guaged up Pyrometer, Tranny, Oil Pressure etc. I'm looking at the autometer webiste.

What range of guage to I need for a Pyrometer with a stock 1hd-t? 1600F or 2000F? Also what temperature should it read before I "safely" shut it down?

Any other suggestions for guages? On a side note I was thinking of getting counter to track the number of hours the engine is running as mileage isn't always an accurate indicator of engine wear. Why??? I dunno, cause I can

[cruiser_guy]

It depends on where the pyrometer is sensing. If you install pre-turbo then your safe point is a maximum of 1200 F or so, (it doesn't vary between engines much as it's based on the melting point of the aluminum pistons). Post turbo is a bit of a guessing game because you need to guess how much the exhaust cools coming through the turbo but it is believed to be about 150 - 200F so your maximum would be about 1000F.

I have the Isspro gages because I like the colored dial, it lets you see at a glance where you are.

[sandcruiser]

I would get a pyro that reads up to about 1400 or as close as you can to that. Above 1400 is pretty academic: no matter what the actual temp, you are in very dangerous territory.

Funny-- this is one the few guages that I would actually welcome a "dumb" guage without numbers. All I really care about is when it gets to about 400* F (I like it "cool" for shutdown) and when it hits 1100* F (that's when I back off on the skinny pedal). Between there, I don't really care if it is 800 or 900.

[Towpack]

Don't forget that when shutting down after a high temp run (1000+)
let the engine idle for a couple on minutes AFTER the gauge is indicating a low of @400.The pyro is measuring the temp of the gases coming out the engine and not the temp of the actual turbo housing.That's why when you lift off the throttle the temp will drop like a stone but obviously the heavy metal turbo housing and manifold etc will retain the heat much longer.The relatively much cooler gases coming out at idle will help cool the turbo much quicker than just killing the engine.

[crushers]

disagree, but then i usually do...

[sandcruiser]

Wayne: disagree with my post or with Towpack?

Here's my thinkin: the pyro is measuring exhaust gas temps, but is subject to heat soak. It is a metal probe in a cast-iron housing, after all.

As support-- if I do 1000 degrees, then come to a stop while the temps are 800 or so... my EGT doesn't drop like a rock at all, it takes a while to get down near 400, then takes at least a full minute to get under 400.

I'm also pretty cavalier about shutting down even if it reads just over 400. If I've idled for 20 or 30 seconds, I know that the turbo has had water and oil circulating through it and has cooled down, possibly below the temp of the cast-iron manifold.

I may be wrong, and I welcome education from anyone who has alternate theories.

[Dougal]

Originally Posted by Towpack

Don't forget that when shutting down after a high temp run (1000+)
let the engine idle for a couple on minutes AFTER the gauge is indicating a low of @400.The pyro is measuring the temp of the gases coming out the engine and not the temp of the actual turbo housing.That's why when you lift off the throttle the temp will drop like a stone but obviously the heavy metal turbo housing and manifold etc will retain the heat much longer.The relatively much cooler gases coming out at idle will help cool the turbo much quicker than just killing the engine.

Very true.

I showed exactly this on a ski trip last weekend. Drove to the top of the hill, idled it down to 200C and shut the engine down leaving the key on to watch it.
I started the engine again when the probe hit 300C and again idled it down to 200C.
After that it climbed a little, but not enough to bother with a restart.

It's the heat from the high temperature manifold and head soaking back into the now trapped exhaust and probe.

People with nonturbo diesels and petrols have problems too. Usually they shut it down at the top and watch it start to boil the coolant a minute or two later.

[crushers]

disagree with Towpack.
if you have idled down to 600F then the engine has already been 'idled' down for more than a minute at street speeds.
the cast will hold heat but not to the degree that towpack is suggesting is harmfull to the engine.

to shut an engine down that is at 1400F then you will experience the oil boiling since no circulation is occuring.

it really is the simple to understand.

now, if you WANT to idle the truck un-necessarily to make yourself feel better then by all means do it.

[mainlander]

I got my pyro, boost and h2o gauges from summit racing (they are all VDO gauges) and the pyro was only $99 with the thermocouple. Best deal on the planet from what I could see. My pyro reads from 250*F to 1600*F

I find that my EGT's drop faster if I'm driving around 30km/hr rather than ideling so this is a better way to cool down the system rather than just let the truck run for a minute or two. It really doesn't take more than a minute for my EGT's to drop down from 850*F highway temperature down to 300*F just driving from the offramp, down the street even to the gas station if I'm not "on" the skinny peddle heavy. Maybe it's all in how I have my fuel set. I certainly does climb faster and like to stay high when i've had the fuel set higher.

All my numbers are pre-turbo just to clearify.

[sandcruiser]

I agree that slow driving will cool things off faster than idling. I usually try to mosey into wherever I'm parking. And/or if I am going to have to turn around to drive away anyway, I'll do it before parking (back in vs. nose in) to give the truck some time to circulate/cool etc. But sitting for a full minute? Not gonna happen unless my egts are reading above 600 or so.

[Tapage]

I found in my 1HD-T let cool it down to 350 it's pretty faster ( much more than my 2H do .. water cooled turbo uhh ) but as same as cool down it can reach much more than 1250 faster If I wan't ( let it do ).

I'm pretty sure that my 1HD-T can handle much more than 1300 - 1400°F coz I know it now that I have the pyro .. but before .. and the pre owner .. ?

20 PSI at idle and as much as 64 PSI oil press ..