Lj78 water temp/pyrometer

[Chang-kuao-lo]

the pyro(s) warns me before i put a hole in a piston (whether it's too lean, or too rich in the case of a diesel) or that it's about to detonate, instead of me finding out by when it sounds like a drawer full of cutlery in a clothesdryer and craps out at 130mph. and meanwhile the temp guage is telling me everything is hunky-dory.

the temp guage tells me more about what the cooling system is doing than what the engine is doing. besides, a pyro is a very useful tuning tool.

 

[kzj78]

could you give me details on the gauges and sensors you installed? I have looked online and there are so many over a whole range of prices that I have no idea where to start and what is good. I always like personnal recommendations!!! Looking at a water temp gauge first.

Regards
Mark

Mark, I went with the Autometer Guages. Pyro, boost and water - as recommended AND installed by Wayne - I too like experienced recommendations.

I went with:

AutoMeter 3644 SPORT COMP II PYROMETER EGT GAUGE KIT

AUTOMETER SPORT COMP II 35 PSI TURBO BOOST GAUGE 3604

AUTOMETER SPORT COMP II WATER TEMPERATURE GAUGE 3631


Purchased from this eBay vendor at about the best price that I could find shipped to Toronto around 5 months ago.

Here are some rather poor night time shots of the inside of the truck - Wayne had a custom aluminum plate that he had made in the past for this install back in his LJ days. Fit like a glove.

 

[kbushnz]

That looks good.
I have my EGT pyro above my speedo so I can see it in my line of sight. And when the alarm is triggered the light gets your attention.

 

[gotoy]

i will use laymans terms (since i don't know the correct terminology anyway)
the pyro reads the heat being generated from the cylinders. the harder the engine works the more heat being expelled. climbing hills, towing, passing, bucking a head wind etc all cause the engine to work harder. since the pyro reads air instead of fluid it can respond extremely fast to changing characteristics of the engine, showing you what is happening inside the engine in REAL time and not delayed time.

the coolant temp reads the coolant, the coolant is heated by the castings around the coolant, the castings are heated by the combustion of the engine. the coolant temp can take minutes to react and register on the gauge. the pyro takes seconds.
by the time the coolant temp gauge reads the change in the engine temp the damage could already be accomplished.

i have seen the pyro read 1400F and the water temp not change. i have seen the water temp read in the red while the pyro is already back down to 600F. the two work completely independant of each other. you need both gauges to know what is happening.

hence, if you are to install just one, i recommend the pyro. it really changes how you operate a diesel. the myth is diesels LOVE TO LUG and nothing can be further from the truth. diesels generate tons of heat when lugging. diesels can expell heat easier and more completely if they are reving at a reasonable rpm.

if climbing a hill and the pyro climbs to an uncomfortable level then drop a gear, (speeding up the engine) and watch how fast the pyro drops back down.

and that, kids, is your leason for today.

cheers and peace.

Thanks for the info and being patient to write.

How can the temp and pyro be used together? If they can be.

 

[crushers]

i am not sure of your question.
this is what i think you are asking, if i misunderstood just ignore the ramblings.
since one moves quicker than the other it allows for change of driving habits.
but caution must still be exercised since on a very long climb i have seen a puzzling result. climbing the hill from Hope to Kamloops in BC i had been keeping the pyro at 1100F in the old HZJ75 turbo and not a close eye on the water temp. this "hill" climb is excessivly long and the water temp had started to rise. when i noticed the temp it was close to the red on the factory gauge (i don't remember the reading on the aftermarket gauge). this shocked me so i pulled over and waited for the engine to cool. even at, what i thought, was a safe EGT measurement the resulting coolant heating was unacceptable. since then i have posted that 1000F is the safe temp to max at for long periods of time.

the pyro is for quick notification of engine internals, the water temp is for the "holy crap, i need to keep an eye on this" notification. without the pyro many, if not all of us, would have over heating issues much sooner and much more often.

cheers

 

[Gun Runner 5]

The "plight" of the LJ78 owner.....so many gauges to monitor, we never get to enjoy the scenery outside. We can tell our grand children that when we were younger how much fun we had looking at the pyrometer and water temp. gauge.
.....1978HJ45

 

[crushers]

when you get good you can see the gauges out the corner of your eye while looking at the dreaded Grim Reaper in your rearview mirror as he comes for your "head" ...

 

[Gun Runner 5]

when you get good you can see the gauges out the corner of your eye while looking at the dreaded Grim Reaper in your rearview mirror as he comes for your "head" ...

You truly missed your calling: Motivational Speaker
.....1978HJ45

 

[Chang-kuao-lo]

the koso meter is nice because as you get closer to the "redline" temperature you program in, the lcd screen will slowly turn red, and then start flashing when you get to that temperature. it gets one's attention real quick without looking directly at it.

 

[Gun Runner 5]

the koso meter is nice because as you get closer to the "redline" temperature you program in, the lcd screen will slowly turn red, and then start flashing when you get to that temperature. it gets one's attention real quick without looking directly at it.

Real men don't need flashing lights and buzzers. The loud knocking sound, drop off in RPM and the steam coming out from under the hood is all the indications we need.
......1978HJ45

 

[gotoy]

Read Project Dodge Mega Cab Diesel Performance Gauges: Off-Road.com

Interesting about the point where aluminium melts!

 

[crushers]

hhuuummmm,
yep, welcome to the Fear Factor of diesels and tweaking them.

 

[stayalert]

I've read with interested this and other threads and am preparing to install oil pressure, water temp. and pyro. SIMULTANEOUSLY......Now.....which is the proper sequence for gauge placement Left to right???????


This being for a RHD '87 JDM BJ74 13bt

 

[Gun Runner 5]

Mine went from "top to bottom." Just make sure the water temp. gauge and pyrometer are in plain view. ( and keep a light foot on the accelerator).

 

[crushers]

most important is the pyro
so
locate it where YOU can see it best.

 

[Gun Runner 5]

most important is the pyro
so
locate it where YOU can see it best.

I don't know if my LJ78 represented the "norm" however after installing a 3L head, 2-1/2" exhaust, rebuilt radiator, toyed with the boost/fuel, I was still running water temps. in the 220-230(F) degree range in the Summer especially when using the A/C. ( and yes I went 45mph up the hill and 65mph down the hill). I tried 3 different t-stats which made virtually no difference. If you are in an area where A/C is not required you may have better results. I really liked that Cruiser....really did not like that engine.

 

[kbushnz]

I don't know if my LJ78 represented the "norm" however after installing a 3L head, 2-1/2" exhaust, rebuilt radiator, toyed with the boost/fuel, I was still running water temps. in the 220-230(F) degree range in the Summer especially when using the A/C. ( and yes I went 45mph up the hill and 65mph down the hill). I tried 3 different t-stats which made virtually no difference. If you are in an area where A/C is not required you may have better results. I really liked that Cruiser....really did not like that engine.

Have you serviced the hydro fan clutch thing for the radiator fan...
If its out it will not come on and pull that air thru...

 

[Gun Runner 5]

Have you serviced the hydro fan clutch thing for the radiator fan...
If its out it will not come on and pull that air thru...

I know longer own the LJ78.

 

[stayalert]

Have you serviced the hydro fan clutch thing for the radiator fan...
If its out it will not come on and pull that air thru...

fan clutch oil viscosity gauge is def. needed