Exhaust Gas Temperature (EGT)

SMOKEY · Post by **SMOKEY** » Fri Oct 13, 2006 4:11 pm

Hi all, this is a subject that I'v been battling with for a while after fitting a new Head to my 2LTE Toyota. I Know that head cracking is the result of over heating, but also know that mine had never over heated on the coolant side. Having worked as a Diesel Mechanic for the last 30yrs I know that full throttle and hard lugging makes high EGT; with this in mind I fitted a EGT gauge pre Turbo. The results I got where horifying, I was getting readings of 800 + deg C and was used to temperatures of 650 deg C on big diesel engines. I haved struggled to find any information on smaller high performance diesels until now, and this site only confirms what my finding are. I was going to PM this to OLDBLUE as I know he is interested in this but thought others will get good information from this site.
http://www.steves.co.za/index.html
put cursor on services click on performance exhaust systems click on exhaust temperature gauge click on what EGT is safe?
Good reading on rest of site also.
DON'T GET HOT,
FITZY.

oldblue · Post by **oldblue** » Fri Oct 13, 2006 4:29 pm

Hi Fitzy, Makes good reading, and ill save it.

SMOKEY · Post by **SMOKEY** » Fri Oct 13, 2006 4:44 pm

Don't just save it Kev. Fit that gauge.
FITZY .
PS ; Jaycar Electronics ph 033791662 http://www.jaycar.co.nz have a kitset EGT gauge for $75.00.

rudrty · Post by **rudrty** » Fri Oct 13, 2006 5:52 pm

hey smokey
i need to get a pyrometer (i think its spelt like that) an exhaust temperature gauge.
the EGT gauge you speek of, that would be the same thing??

oldblue · Post by **oldblue** » Fri Oct 13, 2006 6:15 pm

Fitzy, I can't seam to work that catalogue to see these EGTs

DaveM · Post by **DaveM** » Fri Oct 13, 2006 6:43 pm

Is this the one?

http://www.jaycar.co.nz/productView.asp ... BCATID=347

Toyhatsu · Post by **Toyhatsu** » Fri Oct 13, 2006 6:56 pm

Found a similar jump in temps when I went from post turbo mounting to pre turbo mounting of the pyro....maybe that is something to do with it....also found any air leaks or blockages in the intake system would send the egt soaring. I am running a daihatsu diesel, and I regularly get into the 700c range when pushing it. This lot seem to have some good advice when it comes to performance tuning diesels http://www.bankspower.com/tech.cfm, though it might only relate to big yankee diesels.

Will have a look at the site and educate myself a little more.....

SMOKEY · Post by **SMOKEY** » Fri Oct 13, 2006 7:42 pm

DaveM, yes this is the kit. rudrty-- if you are going to turbo --- fit a pyro; gauge, EGT; the same thing.I fitted a VDO gauge about $300.00 not cheap but cheaper than a new motor.I havn't had anything to do with the jaycar kit but alot cheaper option if you are handy tinkering with electronics.
Toyhatsu---- if you look at the steves site, 720deg C is ok.
PS, rudrty---- PM me if you want any information, I live in HoonHay Rd.

Toyhatsu · Post by **Toyhatsu** » Fri Oct 13, 2006 9:26 pm

First time that I saw that temp was okay. From the surfing i have done normally they give around 600-650 tops, but that could be post turbo. I am going to get the donk performance tuned using the pyro so it will be interesting to see what the tuners think...

Jerry · Post by **Jerry** » Sun Oct 15, 2006 12:16 am

Toyhatsu...

Have you got a 2.8TD Rocky/Rugger?, has yours got the factory aircon in it? Mine has the aircon radiator with a fan that only goes on when the aircon is on....It likes to get hot occasionally...

....was considering ripping the aircon out and putting 2 electric fans in its place (on demand), the other problem is when you have been playing in muddy bogs it gets inbetween the 2 radiators and very hard to clean...

Toyhatsu · Post by **Toyhatsu** » Sun Oct 15, 2006 9:05 am

I have a dl 51 donk in a hilux. Found it cheap on the old buy sell etc.

I run the original radiator and it is only a two core setup and not that efficient at cooling. I have an electric fan behind it because the original visco failed. It works pretty good and is especially noticeable when moving slow and revving hard. I have done other performance mods on the engine so it is putting out a lot more power and heat. It will require an upgrade to a three core radiator at least before I am completely happy with the temps I am running.

If you are still running a visco I would consider locking the thing up (bolt through it) or changing out the silicon in the fan clutch and running it. It may be that the visco is not doing its thing and that may be the whole cause. If that is the case then I would fit a single electric fan to the rear and see how that goes. If that is not doing the bizzo, then I would look at putting a better radiator in etc etc.

Have been told that heaps of different things like timing, air in the water system, water pump can effect cooling so I would bear all that in mind before outlaying heaps of coin. PM me of you want any other info on my mods etc etc

Jerry · Post by **Jerry** » Sun Oct 15, 2006 3:02 pm

Ok I've just had a quick look......I have a spare DL5x motor sitting in the Garage (non turbo good for spare parts...got a spare F & R diff as well), the fan on the spare motor is harder to turn round whereas the one in the truck is looser? (spins easier)

I Don't know much about these viscous fan thingys....would the stiffer one be better?,

Toyhatsu · Post by **Toyhatsu** » Sun Oct 15, 2006 3:35 pm

Visco's are a bit tough to estimate if they are in good nick or not. In general if the thing is original and you've got say 80k on the clock it will need servicing or replacement (what I have heard at least).

I discovered mine was stuffed when I got it properly warm and could wobble the thing quite freely on its mounting, as well as spin it. Maybe try this when you've had a decent run.

I don't think you can tell if the visco is good when the thing is sitting. That said, I would put the stiffer unit on because intuitively it would seem to be in better nick and try it out like that.

If your visco is working properly there should be noticeable noise at startup as the engine starts and then there will be a roar as the thing cuts in and activates for a short period of time. It would be interesting to compare the loose one with the stiff one at start up and see if it makes more/less noise etc. Viscos are set up to cut in at a certain heat and then when the heat goes down they free wheel. In theory you should be able to hear it (?) cut in around 95 degrees and then cut out once the temperature has come down a bit.

Guess it is just a matter of suck it and see.....oh and if you sell the rugge r at any point give me a yodel, as I would be keen to have a spare motor at some point...

mudy · Post by **mudy** » Mon Oct 16, 2006 8:54 am

Hi after alot of surfing it seems 550 degree celsius post turbo and 650 -700 pre turbo is the safe benchmark and not for extended periods. Redline have pyros for $60
http://www.redlineperformance.co.nz/mai ... =2&pid=450
Have had one fitted for last 8 months with no problems

oldblue · Post by **oldblue** » Mon Oct 16, 2006 1:58 pm

On the 1KZ-TE Motor is there a place to fit the EGT Prob into the manifold, or do i need to take it of and drill and tap a hole to suit.

Toyhatsu · Post by **Toyhatsu** » Mon Oct 16, 2006 7:16 pm

Most likely you will have to strip the manifold off and do the drill and tap bizzo, will probably need a decent sized tap though. Good idea to have it in the manifold and not after the turbo as the difference can be huge, and seems to vary according to the rpm of the turbo...

Jerry · Post by **Jerry** » Mon Oct 16, 2006 7:19 pm

On a slightly related topic most 4wd's have a 1st low turbo disable switch in the gearbox...my daihatsu workshop manual says there is one...so if you tap into that you can get more power at the flick of a switch (or thats my theory anyway)

SMOKEY · Post by **SMOKEY** » Mon Oct 16, 2006 7:34 pm

Hi Kev, not sure of the 1KZ motor, Mr Toyota was never to generous with extra fittings. My guess would be you will have to drill and tap. Try and fit the probe where the four pipes go into one just before the turbo, that way you are reading all cylinders. My VDO kit had all the fittings required. One problem with fitting pre turbo is if ever the probe burns or brakes it will destroy the turbo and then the motor. But look on the bright side ---- it will keep us mechanics in work :lol:

.

GQTROL · Post by **GQTROL** » Tue Oct 17, 2006 6:57 am

Convention is to install the pyro 3 inches behind the exhaust wheel of the turbo....usually someplace on the bend of the dump pipe. Drill suitably sized hole and weld the threaded collar in place, taking care not to heat it too much or the threads distort. 550 degrees C is a safe max for post turbo installs.

oldblue · Post by **oldblue** » Tue Oct 17, 2006 9:05 am

Would I be correct in saying the dump pipe is the 90degree Cast Iron thingy on the exit of the turbo,
Could I then just drill and tap it to the thread size, with out the need to weld. as it would have to be utaloyed, then post heated.

Toyhatsu · Post by **Toyhatsu** » Tue Oct 17, 2006 7:49 pm

I had the pyro installed behind my turbo and the temperatures it gave were significantly different from the pre turbo placement. This is important because amongst other things the initial damage which is caused to the engine when egt's get too high involves the melting of the edges of the alloy turbine wheel.

It could be argued that you can guess at what the heat drop is as the air passes the turbine, and determine if the egt's are safe from there. The first gotcha is that you would only be guessing the drop, and would never know for sure. The second gotcha to this approach is that the variation is not constant. For instance if you are burning a heap of fuel, but the turbine is not spinning fast ( thus lessening the use of the heat energy), the egt would be higher than if the turbo was spinning at a higher rate and using more of the heat energy.

I was concerned that the probe might get hot, melt off and go into the turbine blades etc. I read what they said on the banks diesel tuners site and they reckoned that this hardly ever happens......so I pays my money and I takes my choice...but it iscertainly easier to install post turbo....
If you have got the time and an intercooler it might be a good idea to set up the pre and post intercooler pipes with a fitting to accept the pyro. It is interesting to know how the cooler is working and whether an upgrade might be on the books....

I just drilled and tapped my pyro into place, though you will probably need a decent size tap. By the way, what is utaloyed?

oldblue · Post by **oldblue** » Tue Oct 17, 2006 9:08 pm

Its a Trade name for a blow pipe type gas tourch that deposits a fine powdered metal ie (cast iron) which is induced into the flame,and depossited onto the parent metal.
Probbly know by some other name.

GQTROL · Post by **GQTROL** » Wed Oct 18, 2006 7:03 am

Turbine (exhaust) wheels are either steel or ceramic.

The temp difference between pre turbo and post turbo is approx 100Â°C, and this is fairly constant. As I said earlier, 550Â°C post turbo is a safe max.

The theory that you can be burning alot of fuel but the exhaust wheel isn't spinning fast does not hold water.....fuel delivery is controlled by the aneroid via boost from the turbo. So only if you modify the pitch of aneroid plunger can you increase the fuel independantly of what the turbo is doing. So unless you've played with the aneroid, this isn't going to occur.

If you're worried about the probe melting, then you're in line for a new engine anyway given that the melting point of cast iron is about 1200Â°C and mild steel is about 1500Â°C.

xtremitys · Post by **xtremitys** » Mon Nov 06, 2006 9:56 pm

hopefully i don't get kicked off this site so early on as i just joined up as moving out to christchurch some 2 weeks ago from melbourne .

http://www.oilburners.net
http://www.turbodieselregister.com

plus there are a few other ones , which i can't remember at the moment , was building a Jeep 68' J-truck project and was going to drop in a 4BT Cummins , so was searching high and low for information on diesels when i was living in brisbane .

have fun
rick

oldblue · Post by **oldblue** » Sat Nov 11, 2006 9:57 pm

Must of been a BIG PRICE RISE?http://www.redlineperformance.co.nz/main.cfm?id=2&pid=450

oldblue · Post by **oldblue** » Mon Dec 04, 2006 8:20 am

Just fitted a VDO Pyrometer, It came with a 5m wire to join the prob to the guage.
My question is; If I have reduced that 5m of wire down to approx 1m, will that alter the readings on the guage.?

Aaron · Post by **Aaron** » Mon Dec 04, 2006 8:49 am

Is it an electrical gauge? ie the resistence of the sender unit changes with the heat, if so it shouldnt make much difference.

I havnt ever fitted one so Im not positive, but if its the same as oil and water temp gauges then it wont change much at all.

It almost looks factory :thumright:

Toyhatsu · Post by **Toyhatsu** » Mon Dec 04, 2006 1:45 pm

The pyro will read the correct temperature irrespective of the cable length.

SMOKEY · Post by **SMOKEY** » Mon Dec 04, 2006 1:56 pm

Hold on there Kev, The fitting kit is supplied in correct lengths calibrated for the probe, I'm sure I read on my Fitting kit not to alter it. I coiled mine (not to tight) and cable tied it out of the way.
Be interested to see what temp; readings you get. Keep us posted.
GET EGT,
FITZY.

Toyhatsu · Post by **Toyhatsu** » Mon Dec 04, 2006 2:04 pm

When I did my install I had a test cable length in which was shorter than the cable I finally installed. I did not notice any difference in EGT from the two lengths, spose it could vary according to the gear you use?

Exhaust Gas Temperature (EGT)

Exhaust Gas Temperature (EGT)

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