12HT EGT temps please ! (1 Viewer)

[relaxedcruiser]

Hi all you 12HT users,
I asked this before but never got any good respond.
How high do the EGT's max out on a stock HJ61 ?
Just would like to know what the factory thought to be sustainable - I'm quite happy backing of at 600°C (1112 °F) since some since I fitted the EGT gauge. That seems to be alright and also is around what most people believe is sustainable.
That is measured pre turbo at 0.8 bar (11.6 psi) boost with a slightly tweaked pump, opened up dump knee+76mm (3") exhaust with straight through muffler. No intercooler. So not stock anymore ( as most are'nt ...)

But has anybody measured the MAX pre turbo EGT's BEFORE modifying the setup, completely stock ?

 

[David*BJ70]

Pre-turbo, 2.5'' exhaust, 33'' tire, all the rest is factory settings --> always lift my feet as soon as I reach 600°C (+/- 1100°F).

My Auber gauge's red light turn on at 900°F and I usually don't push any higher except when overtaking on the highway or when climbing long hills.

I am cushy... I am not the type to try to reach the maximum EGT in order to know what the maximum is . Others do and know it ...

 

[JettaGLi16v]

I haven't yet installed an EGT in my HDJ81. That being said, I've had numerous VW diesels which all have an identical VE Pump, and all have iron blocks, aluminum heads, and forged pistons and rods. I would usually see 1200F on a WOT pull in a high gear, and it didn't concern me. I used to see numbers at or around 1500-1600F when I had an extra hopped up Jetta with a small exhaust. After I did a 3" turbo back, that knocked off at least 200F at WOT in 4th or 5th.

1100-1200F is pretty OK in my opinion.

However, I recently melted two pistons in my turbo diesel Rabbit pickup while racing someone in a BMW estate, but I don't think that can be pinpointed to high EGT's.

 

[cruiserpilot]

1100-1200 would be normal max. I run a GTurbo at 20 psi and on hills and hot loaded that’s as
high as it gets.
A friend who is a heavy mechanic explained to me so long as the EGT readings my gauge gives
me are active I’m fine. If I run hot and it maxes out, then I reach the top of the hill and back off,
the EGT should drop immediately. If the reading stays high, despite reduced load then
I have an issue.

 

[relaxedcruiser]

Thanks for all the input guys,
still waiting for someone with max. readings of a completely stock 12HT setup.
I would think that with a stock wagon while towing heavy or just going uphill fast you should not have worry about the EGT at all.
I'm happy to respect the 600°C / 1100°F in my truck, but just out of curiosity would like to know how high those temps would climb in stock setup.

 

[David*BJ70]

So, you basically ask if someone overheated is 12HT and had watched is pyro gauge as the engine seized or died

 

[AirheadNut]

I don't know about the 12H-T specifically but with other Toyota diesels I've had they tend to run pretty hot when stock. My 2L-TE would easily hit 600ºC (1100ºF) post turbo if I let it, and the 1HD-T could hit 700ºC (1300ºF) pre turbo climbing hills without trying too hard. It should be perfectly happy if you keep it under 650ºC (1200ºF) sustained. In general with factory turbo direct injected engines it is the blades in the turbo that start to suffer from extended high temperatures. For my various VW TDI's the factory specifies maximum Turbine Inlet Temperatures rather than EGT's, and they're in the 850-915ºC (1550-1680ºF) range depending on the turbo used. Metallurgy in those applications has come a long way since the late 1980's.

 

[relaxedcruiser]

So, you basically ask if someone overheated is 12HT and had watched is pyro gauge as the engine seized or died

actually not really.....but I still have the imagination that you don't need to worry about the internal temperatures of a stock engine as long as the water temp stays in the normal range.
Back in the 90's I traveled with my Peugeot 2.5 Turbodiesel powered Landrover 109 through the Sahara and with only an electric fan had to watch the water temps not climbing too much in soft sand (not thinking about EGT's at all then)- while ordinary diesel Landruisers were ploughing past me with their hard labouring straight sixes. I watched them and thought.. wow cool - factory setup with a big engine and you can go hard all day without harming the engine - not unlike a tractor with lets say 60 hp which can labour all day on a field without being too much concerned engine wise.
My 12ht egt's are rising quick if I go fast uphill in fourth , easily surpassing 600°C / 1100°F if I'm not backing up. And I would'nt say that I have wound out the max fuel screw much. Just a bit - but I have'nt any comparison really. No black smoke under full boost visible at any time - thats how I adjusted it.
I like engines which are - and I don't know the english word for it, in my native german it woukld be: "Vollgasfest" which means direct translated "full-gas-consistent"or "WOT consistent"
- which can labour no matter what is coming without being overly affected. Before I had the Landcruiser I thought that the big straight six powered Cruiser engines were all like this. But here I am - babying the otherwise great engine uphill. ( still quite fast babying though )
Thats why I want to know how high the stock temps are climbing - and I still believe that you don't need to worry about egt's if everything is stock.
Keep the thoughts (and measurements) coming !

 

[Nz Nath]

@relaxedcruiser fit that ct20b turbo I gave you and you should be able to stop watching the egt guage. It should produce more boost for the same rpm and load, but it's also meant to be more efficient so inlet charge temperature should be lower.

 

[colby1979]

It's not a 12ht but I fit an egt to my non-turbo 1hz so I could have another gauge to watch while other vehicles pass me, about the max I can get pulling long hills at moderate elevation (3000-5000ft) is 1150F, although I start backing out at 1100 most of the time. Also, I have bumped my fuel up a bit and run a set of Genie extractors. IMHO, 1200f is OK for short periods and 1100f is a nice safe max for longevity of the engine.

 

[relaxedcruiser]

@relaxedcruiser fit that ct20b turbo I gave you and you should be able to stop watching the egt guage. It should produce more boost for the same rpm and load, but it's also meant to be more efficient so inlet charge temperature should be lower.

Hi mate,
yep - I look at it often and think one fine day I'll have the time to finally fit it.
I have a spare Auber EGT gauge - and will fit it to monitor the inlet charge temps before and after swopping turbos.

 

[relaxedcruiser]

Thank you all for your input !

But is there really nobody here who has an EGT gauge on his or her completely stock 12ht and read it while going flat out up a long incline while slowly loosing speed ?

 

[relaxedcruiser]

Bump....

 

[Paco]

I should have some numbers for you next week, but not completely stock...

My CT-26 took a crap so I installed an Ebay special while I decided to what route I wanted to go. In the interim I installed a 3" exhaust and EGT & boost gauges. Only drove it a short while and not any long uphill pulls. On short hills I was around 800 to 900f.

Am now completing install of a Winks turbo so will have new numbers for that as soon as I get it dialed in.

 

[relaxedcruiser]

Thanks Paco,

I aprecciate your response and I am interested how you are getting on with that new turbo setup.
But as your setup is not stock anymore the readings are not the ones I'm after.

If there is anybody out there with a comletely stock HJ61 and installed a egt sensor pre-turbo ......
please let us know how high those temps are climbing.
That's just for interest - and as I believe that you can go flat out with a healthy stock engine without doing harm to it.

Let the numbers come !

 

[roma042987]

Most people don't install egt gauges until they have a reason to be concerned about temps...at that point it's no longer stock. I rebuilt my 12ht to factory specs and purposefully didn't install a worrisome egt gauge to take my attention off the road ahead and keep me from enjoying the drive and grunt of the 12ht. My bj42 has an egt gauge and to be honest I get tired of watching it like a hawk all the time.

 

[relaxedcruiser]

I really like my egt gauge - instruments in general - and find it very interesting to see even so minor changes in terms of engine load. Like cruising on an open road with lets say 230 °C and see what impact the AC has in terms of egt (its around 70°C) (Edit: That's bull**** - I must have looked at it while the load on the engine was increased)
Does'nt stop me from enjoying the great vehicle. As I said it's only out of pure curiosity and I'm very happy with my current setup.

 

[appels]

So Gents. This is my question. Numbers are great but like Roma suggested, they’re a distraction. Let’s put this into perspective. What would constitute a reason for having an EGT?

These motors must be able to take high EGT’s for short durations. That’s normal driving.

I have a 12ht, 3 inch exhaust, 14psi, 300,000kms and auto. Runs like a dream. We sit between 100km/hr and 110 Km/hr on east coast Australia Highways. Never on it too hard unless overtaking.

By the way, I’m not towing anything. If I was I’d consider getting one for obvious reasons.

Cheers.

 

[cruiserpilot]

So Gents. This is my question. Numbers are great but like Roma suggested, they’re a distraction. Let’s put this into perspective. What would constitute a reason for having an EGT?

As a pilot, these gauges are information of the current state of health. I have about 8 rows of analog gauges doubled up to monitor.
I don't watch them much, but I can tell you the minute one is not where it normally is - it's noticed. That's the reason for the gauge.

 

[Dougal]

What are you trying to find out with these temps?

EGT on a mechanical diesel is influenced by how restricted the air-filter is and the condition of the turbo blades. It's not a single number that's going to be consistent with two stock engines of this age. You can calculate A/F ratio pretty well for stock engines based of injection pump calibration (cc/1000 shots), boost, engine capacity, VE and stock power/rpm.