Page 9 of 12

Re: "Jasper" - Y61 4.2D

Posted: 27 Nov 2017 12:21
by ricster
Mine at 120 km/h aircon on, flatish road, I probably average between 420 and 500 deg C. The 500 deg is with a headwind, 420 deg with a tail wind, irrespective of whether loaded or not, but with roof top tent on, I'll push closer to an average of 480 - 550 deg. Switch the aircon off and that drops about 20 deg off.

But again, depends on where your temp probe is fitted...

Re: "Jasper" - Y61 4.2D

Posted: 27 Nov 2017 15:42
by Michael
Both Ian and Christoph's probes are pre turbo as yours Cedric.
Ian, your EGT's are running on the low side because your pump is deliverling a bit less fuel than it should which in return gives you a lean mixture and thus the low EGT's.

Re: "Jasper" - Y61 4.2D

Posted: 27 Nov 2017 15:47
by Michael
Now on EGT's I like to have the engines like Christoph's around the 550 pre turbo with short bursts of up to 600, but I would like to have them closer to 550 for safety.

On the engines with the turbo pistons you can push EGT's to 650.

I have just fitted a Madman on a NA TD42 and the client is actually struggeling uphills to keep EGT's under 550, so just another example of the non turbo engines that can very easily reach very high temps

Re: "Jasper" - Y61 4.2D

Posted: 29 Nov 2017 08:55
by ces
Now this is getting interesting...

Did a short run to town and back with a heavy cattle trailer. Loaded (700kg trailer+700kg load) the following readings:

4th, 2000revs-2200revs, approx 85-100km/h - EGT 550-600
3rd, 3000-3200revs, approx 65-80km/h - EGT generally below 450

So, according to me that proves what Tinus said about the higher revs and more air. Feels counter-intuitive, but the readings don't lie.

Another thing, this is the same trailer on the same road that I burst a water pipe with in February. Was a bit scary :confused:
But, no worries, the water temp touched 100 C only once. Radiator fixed properly!

C
IMG_20171127_161822.jpg

Re: "Jasper" - Y61 4.2D

Posted: 29 Nov 2017 08:57
by ces
TijmenvdS wrote: 27 Nov 2017 12:17
ces wrote: 27 Nov 2017 09:55 EGT:
Max 578
Min while cruising 450ish
I passed 550 on 6 occasions, 3x while accelerating after a turn-off, 3x going up an incline.
Average about 520

c
Before the intercooler that is where mine ran aswell.
SO I reckon in about 10,000km I might just fit a small one on top. Just to cool things down a bit :biggrin:

Re: "Jasper" - Y61 4.2D

Posted: 29 Nov 2017 09:02
by hugejp
I had the same on an old g-wagon 5cyl 2.9D

Up hills especially, if you kept the revs up ie. spun the viscous at a higher rpm & kept the engine out of the "labour" zone... It ran way cooler

Re: "Jasper" - Y61 4.2D

Posted: 29 Nov 2017 09:07
by ricster
Remember diesels run different to petrol... on a diesel you want less fuel and more air to achieve the best combustion ( obviously it's as a balance between the two ). So the more diesel in the chamber the hotter it will burn, causing higher EGT's. Adding more air to the same amount of diesel in the chamber will cause for a cooler burn but still very powerful as all the diesel is burnt efficiently. So basically a diesel you want too run lean.

A petrol motor will burn up if you run it lean, so therefore you pump a bit more fuel in to get it to run cooler, so you will run rather a rich mix than a lean mix

Re: "Jasper" - Y61 4.2D

Posted: 29 Nov 2017 17:16
by Michael
Christoph, ek het vir jou n mooi top mount cooler soos die TD42T bakkies vir n bargain...... sal gesels oor hom as ons weer praat.

Then if we can just get your diesel pump to spec and do the cooler you will not bwlieve the difference in power and temps

Re: "Jasper" - Y61 4.2D

Posted: 30 Nov 2017 22:25
by ces
Michael wrote: 29 Nov 2017 17:16 Christoph, ek het vir jou n mooi top mount cooler soos die TD42T bakkies vir n bargain...... sal gesels oor hom as ons weer praat.

Then if we can just get your diesel pump to spec and do the cooler you will not bwlieve the difference in power and temps
Ons sal weer praat Michael, thanks.

Re: "Jasper" - Y61 4.2D

Posted: 13 Mar 2018 15:13
by ces
Chaps,

I've taken my car back to Michael at SOJO to have that top-mounted bakkie intercooler fitted. Also to be done:
- panelbeating on bonnet to properly fit scoop, and fixing some other spots
- Diesel pump proper calibration
- Optimum set-up by Michael
- TOMBO radiator (thanks Tinus) - my old one kept leaking in the top tank

Keep you posted.
Christoph

PS - In the mean time I've also had to fit a new starter (after market Chinese) and alternator with vacuum pump (Hitachi). All done locally in Lichtenburg at TMT Auto Elektries. (One of the brushes in the alternator broke off, which in turn broke the regulator. The car's diagnostics were happily oblivious, but MADMAN picked it up immediately. So, no other damage!)