EGTs - normally aspirated LD28

[windsock]

250 C. = 450 F.
400 C. = 720 F.
450 C. = 800 F.
550 C. = 990 F.

Congrats. Thanks for the great pics.

How'd you locate the spot to drill (from the outside). Any particular tricks? If you used measures, maybe you could post a list or pic of your working sketch - give the next guy a reality check.


Cheers, Rufus

Thanks for the congrats to by the way Rufus, am tired and missed that in my first reading of your post. thanks also for the conversions.

I'll just edit the figures you put up to include actual readings of the water temperature now I did the same drive again.

EGT C _ _ F _ _ _ Water temp (Deg C)
250 C. = 450 F. _ 45
400 C. = 720 F. _ 60
450 C. = 800 F. _ 75
550 C. = 990 F. _ 83ish

To note too was that the reading over various threads had me expecting rapid changes in EGT temps etc. Although the gauge moves quickly up and down in resposne to engine it was not as quick as I expected. This could be for three reasons.

1/ I got the end of the probe too close to the hollow (I doubt it though as I sighted into the chamber when locating the probe).
2/ It is only measuring cylinders 4, 5, 6 and therefore it is not exposed to the full force of the constant flow of EGTs that a probe in all six cylinders would be.
3/ My expectations were wrong and the probe is in the right place and all is good

None the less, am very pleased with the time and money spent putting this in and am looking forward to the next road trip whereby I can better understand what is happening on long hills etc.

Next time I am out on a steady drive I'll note somemore numbers like rpm, etc also.

Phil

[rlaggren]

That pic's just what I was hoping for. Don't know if I'll get there for a while, but you just increased the chances of the average guy getting good threads on the sensor.

Rufus

[windsock]

Hey Rufus,

Glad the picture was useful. I could also take one of the other side if necessary with approx measurements. I would feel better though if someone with a North American spec manifold confirmed the bump location before anyone drilled on my measurements. Just in case there's a difference.

If in any doubt about where to drill the hole I recommend dropping the exhaust tube off the manifold and just locating the bump to be sure.

I actually used the pyrometer to modify my driving today. Got stuck a bit off-road and had to use the load pedal hard on a few occasions (up to 4000rpm). Was able to judge engine head heat and ease back accordingly. Was a good experience to see just how little it takes to potentially give it too much. Also, little things too like the difference in EGTs driving into a head wind. With aerodynamics like this truck, at 95kph going from a calm flat stretch of road into a hard headwind makes the EGT go from 450C to 550C in a 100metres of flat road

Cheers,

Phil

[asavage]

I installed a pyrometer thermocouple in my '82 Wagon's exhaust manifold. I chose a spot at random.

(click on image for larger)


There seemed to be plenty of material to retain the brass adapter bushing. Not very thick, but adequate for the task.

[windsock]

Hi Al,

yeah I figure you are right about there being enough material to thread without aiming for the bump. Also considering it is a tapered thread cut means it wasn't going to move for nothing. I got five (I think) turns of thread in the thinnest section of the hole and was very happy to see that. The only reason I took the whole manifold off to drill was there was a leaky gasket I needed to replace and I was too broke after spending money on the gear (and the tap to thread the hole ) to then buy a 90 Deg chuck for my drill. My existing drill wouldn't have been able to drill where I wanted to. Glad I was able to replace the gasket, it was shot to pieces. Engine now is distinctly quieter than previous .

Cheers,

Phil