12ht pyro location (1 Viewer)

[TheFirm]

I have bought a pyrometer for my HJ61, and i'm struggling to decide the best place to install it.. I want to install it pre turbo, but after removing the exhaust manifold i noticed that the front three cylinders exhaust gases are split from the rear three cylinder right up until the turbo flange.
Is it a bad idea to install the probe where it will only see half the engine's exhaust gases?
The alternative is to intall the probe at the start of the exhaust housing of the turbo, nice and close to the flange where the gases 'collect'. This worries me though as would there be too much residual heat to obtain an accurate reading?
I want to avoid a post turbo install unless it becomes the best/safest option..
What have others done?
Thanks.

 

[jason tincey]

i just put mine into the exhaust manifold as when i did a search this was were most people were placing them. .

 

[rideglobally]

here is where i installed mine, as you probably know there is a "vane" i installed it in such a way that it is catching the heat on both rear and front of the manifold

 

[TheFirm]

Thanks for the reply guys..

Rideglobally, from your pics i can't understand how you would be getting heat from the front & rear cylinders?
In the first pic it looks as if you've drilled it right into where the vane is?

And Jason, how do you find the egt figures are with only half the gases? And what maximum egt have you tuned yours to?

 

[cody c]

The temperature difference between one cylinder to the next "should" be negligable. As far as having half the gasses on it, it shouldn't make any difference for the most of us. If its really important to you, you could a separate pyrometer and install at the exit of each port, I believe there are some electronic gauges that will accomodate this. but not worth it for most of us IMO.

If you want all the gasses to go past your thermocouple you could install it post turbo, but usually temps have dropped about 100-200 degrees after the turbo. In general most of us install it pre turbo to get more accurate cylinder head temps.

For the 3B crowd we try to keep it under 1000-1100 degrees for any extended period of time, and under 1400 for very short time period. After intercooling it it seems to drop highway temps about 80-150+ degrees or so depending.

 

[Tapage]

if I need to choose between all cylinders but post turbo or half cylinder pre turbo .. pre turbo would be my choice.

 

[Tim-HJ61]

And what maximum egt have you tuned yours to?

600°C is generally regarded as safe to sustain.

650°C eek, bit too much

700°C ..... trying not to do that again, but I did have to get to the top of the sandhill.

YouTube - Warren River Dune Climb - Callcup Hill

Some wild characters say 900°C is doable.

Tim

 

[Lasse]

Old thread I know, but it turned up during a search and helped me some and might help others in the future so I add my own solution to the problem as well

Drilled and taped the heat shield screw hole. Take note; you will need an extra long egt probe!
I drilled at least 40-50mm before I got trough.

 

[fitzmooney]

I actually drill and tapped the turbo. Been there for 4 years with no problems.

 

[Lasse]

Only downside; with a turbo change you need to drill and tap it again. This is the reason why I chose the manifold

 

[maat]

how often do you change a turbo

 

[Lasse]

Not to often I must say, but I for one like to experiment with different turboes and tune mye engine quite a bit. Therefor in my case it happens often enough, in most people's cases; about never

 

[TLC Norway]

@Lasse, Which turboes have you swapped in?
And what other tuning?

 

[Lasse]

As of now I haven't changed the turbo on this engine. I haven't had the time yet and the vehicle is still pretty new to me.
I am however thinking of installing a Garret vnt turbo around GT30-32 size and I have a huge WTA intercooler waiting to be installed.
So far I run the stock turbo combined with a water injection system, experimenting a little with an ethanol-water mix. Added a little bit more fuel on the on boost screw only, so still pretty laggy for a diesel. Will turn up on the off boost/main screw as well. Oh and I run with the wastegate shut to achieve around 1.6 bar boost.

Nothing to fancy.

 

[Cribbsy]

Old thread I know, but it turned up during a search and helped me some and might help others in the future so I add my own solution to the problem as well

View attachment 932274
Drilled and taped the heat shield screw hole. Take note; you will need an extra long egt probe!
I drilled at least 40-50mm before I got trough.

Old thread I know, but it turned up during a search and helped me some and might help others in the future so I add my own solution to the problem as well

View attachment 932274
Drilled and taped the heat shield screw hole. Take note; you will need an extra long egt probe!
I drilled at least 40-50mm before I got trough.

Digging up an oldie here but I'm about to drill and tap my 12ht manifold for a pyro probe and was going to use this same location. It looks as through I will drill directly through the middle "vane". Anyone else Drilled it in this location? I like the idea of it being there and getting all the cylinders

 

[Paul DiNapoli]

chiming in on an old thread hoping someone will educate me.

so assuming a 12HT didnt come from factory with a pyro - if they drove fine for the first 20 some years of their life without a pryo....what does a person gain by adding one later?

2nd question = so now you have this temp data - what do you do with it?

600°C is generally regarded as safe to sustain.

650°C eek, bit too much

700°C ..... trying not to do that again, but I did have to get to the top of the sandhill.

YouTube - Warren River Dune Climb - Callcup Hill

Some wild characters say 900°C is doable.

Tim

after a pyro install = now that you have this knowledge - how do you "not do that again"? <-- are we talking pull over and let it cool down? what if you're on a long hill climb to get wherever you're going - engine is just going to heat up again...and presumably this truck might have made many long hot hill climbs in it's past w/o the benefit of a pyro.

just trying to understand what this all means. My FJ62 will end up with a diesel powerplant in the future...and I live in mountainous state so everywhere I go i have long steep grades to climb.

 

[Silveredition]

Just to add another perspective...
I have my Redarc Pyro installed in the dump pipe immediately after the turbo. I know a lot of people think pre-turbo is the only way to go, but I disagree... I have seen temp graphs showing the delay in temp readings post turbo compared to pre, however mine is almost instant.... As soon as I plant my foot, or begin a climb the egt gauge increases (maybe a second or two delay...), and the same with it coming down when backing off. It may not be exact combustion temps, but I know what the egt usually is, and it is more the increase in temp that I look at...
I have my alarm set at 575 degrees Celsius, and if that sounds, I slow down until it clears.
When towing my boat (in any temperature, but more so when the outside temp is above 40 degrees Celsius) I drive to both the egt and the top radiator hose coolant temp (alarm set at 94 degrees Celsius).
With 574000kms on the engine, and boost up from the factory 7.5 to 11.5 I use this as a way of looking after the engine to hopefully get another 20 years out of it, regardless of the fact that it has been fine for the previous 30 years without it....

 

[MarkSP]

Good information

 

[POPO AGIE]

chiming in on an old thread hoping someone will educate me.

so assuming a 12HT didnt come from factory with a pyro - if they drove fine for the first 20 some years of their life without a pryo....what does a person gain by adding one later?

2nd question = so now you have this temp data - what do you do with it?



after a pyro install = now that you have this knowledge - how do you "not do that again"? <-- are we talking pull over and let it cool down? what if you're on a long hill climb to get wherever you're going - engine is just going to heat up again...and presumably this truck might have made many long hot hill climbs in it's past w/o the benefit of a pyro.

just trying to understand what this all means. My FJ62 will end up with a diesel powerplant in the future...and I live in mountainous state so everywhere I go i have long steep grades to climb.

The climb out of Pendleton, OR I would want to know what my exhaust temps are and also know what the boost is. I use both gauges accordingly and down shift when the temps are high and the boost is low.

I have had a diesel pickup since 95 and I have monitored the EGT and boost in the last 3. I was pulling my 5th wheel on I80 across Nevada in a hell of a head wind. The 6.7 never got high enough to worry about. I looked and it 1550+ and had to get out of it. The air filter was crushed it was trying to get more air.