top mount 75 series intercooler

[jrmc47]

Hi all...has anyone put a top mount 75 series v8 intercooler in a gen 2 2.8 diesel?
EGTs are doing my head in ...(sits on 400 @90 kph ...700 with camper on @ 90kph) ...I think would probably need Delica valve cover with filler right at front or maybe use v6 remote filler.....non turbo inlet manifold that points out the side rather than up and custom piping... custom brackets to hold it up.. the top mount 75 series v8 intercooler is 3 times the size of the paj one...should make a difference....any thoughts anyone???

[old Jack]

Reducing you air inlet temperatures by changing the intercooler will only have a minor impact on the EGT's. I suspect money would be better spent looking at the cause of the high EGT's, like fuel control, exhaust restrictions and engine tuning.

Did the last of the 3.2litre Tritons with the 4M41 engines have a larger front mounted intercooler and would these fit with less cost and hassle?

OJ.

[Martynhpajero]

Are you measuring in the manifold or in the dump pipe? I'm guessing the manifold, with temps that high. My 4M40T sits on about 350 cruising at 100. EGT measured in the manifold just before turbo.

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[pharb]

Are you sure it's not just overfueling?

When I first got my NJ 20 yrs ago I enquired with the local injection specialist about a pump rebuild because it was a bit smokey.
He said the first thing they would do before pulling pump off was put on dyno and adjust maximum fuel pressure screw. Apparently this particular pump tends to increase fuel pressure as it wears.

So I decided to have a go myself on my "road" dyno.

I live on a fairly steep hill so I just hit the hill at a rolling start at about 1500rpm in 3rd gear and gave it full throttle. At a particular point up the hill I noted the speed.

I then returned home and backed the screw off 1/4 turn and did the hill test again.

Repeated adjusting screw and doing hill test until I couldn't acheive the same speed, then wound it back up a bit.

That was at about 250,000km, then put a set of change over injectors in about 300,000km. Haven't bothered touching in since. Now at about 450,000km.

I don't have an EGT gauge, have done 2 trips to Kunnanarra with camper, maxed out weight wise (and maybe a little more without any issue.

The nature of a diesel engine is you can over fuel and the engine will only burn what it can and eject the rest out the exhaust producing heat and smoke.

Excess fuel in a petrol in contrast will actually restrict combustion and cool the process. Running lean will actually cause heat issues.

[NJV6]

Also check that it’s running the right boost levels, if they have dropped back that’ll cause egt’s to rise as well.

[jrmc47]

Are you measuring in the manifold or in the dump pipe? I'm guessing the manifold, with temps that high. My 4M40T sits on about 350 cruising at 100. EGT measured in the manifold just before turbo.

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temps are measured in the dump pipe so I would imagine the manifold pre turbo temps would be higher

[jrmc47]

Reducing you air inlet temperatures by changing the intercooler will only have a minor impact on the EGT's. I suspect money would be better spent looking at the cause of the high EGT's, like fuel control, exhaust restrictions and engine tuning.

Did the last of the 3.2litre Tritons with the 4M41 engines have a larger front mounted intercooler and would these fit with less cost and hassle?

OJ.

hi Old Jack
the engine has 209 kilometres on it from full reco except the pump...has a 2.5 flow through exhaust on it....diesel mechanic set the pump timing and lift...doesn't blow any smoke that I have seen

https://www.factorydirect4x4exhausts.com.au/4x4-exhaust-systems/mitsubishi-pajero-2-8l-td-nj-nk-nl-2-5-aluminised-exhaust-system-with-pyro/

td04 turbo

https://www.ebay.com.au/itm/Kinugawa-Upgrade-Turbocharger-94-97-4M40T-Pajero-TD04L-15T-Oil-Cool-Extra-60-Tq/281368275702?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I have used the v6 oil cooler as an extra Trans cooler and it is a/c and also has a winch...so no room left for front mount cooler

[jrmc47]

Also check that it’s running the right boost levels, if they have dropped back that’ll cause egt’s to rise as well.

Hi NJV6
boost levels are high enough to trip the manifold blow off valve if I give it stick...and thats about 13.5 lbs of boost I think

[Dicko1]

I,d get the fuel flow checked...possibly on a dyno. Running high temps is often a sign of over fuelling...had the same issue on an old troopy a few years ago. Had the air/fuel ratios checked and problem solved after adjustments done...

[Martynhpajero]

Have a read of the build thread by Mcreight 911 " More power for ya 4m40. Heaps of tuning info.
If your pump timing is retarded it will also cause high EGT. I think because the fuel is still combusting on the way out the exhaust...

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[jrmc47]

I,d get the fuel flow checked...possibly on a dyno. Running high temps is often a sign of over fuelling...had the same issue on an old troopy a few years ago. Had the air/fuel ratios checked and problem solved after adjustments done...

yeah I think that is the next stop...running out of $$ tho...

[jrmc47]

yes you are right ...I advanced it a couple of days ago to get the temps I have now...otherwise it was undriveable

[jrmc47]

Are you sure it's not just overfueling?

When I first got my NJ 20 yrs ago I enquired with the local injection specialist about a pump rebuild because it was a bit smokey.
He said the first thing they would do before pulling pump off was put on dyno and adjust maximum fuel pressure screw. Apparently this particular pump tends to increase fuel pressure as it wears.

So I decided to have a go myself on my "road" dyno.

I live on a fairly steep hill so I just hit the hill at a rolling start at about 1500rpm in 3rd gear and gave it full throttle. At a particular point up the hill I noted the speed.

I then returned home and backed the screw off 1/4 turn and did the hill test again.

Repeated adjusting screw and doing hill test until I couldn't acheive the same speed, then wound it back up a bit.

That was at about 250,000km, then put a set of change over injectors in about 300,000km. Haven't bothered touching in since. Now at about 450,000km.

I don't have an EGT gauge, have done 2 trips to Kunnanarra with camper, maxed out weight wise (and maybe a little more without any issue.

The nature of a diesel engine is you can over fuel and the engine will only burn what it can and eject the rest out the exhaust producing heat and smoke.

Excess fuel in a petrol in contrast will actually restrict combustion and cool the process. Running lean will actually cause heat issues.

HMMM that would have the same effect as retarding the engine because the injectors would crack earlier...makes sense...retarded engines (LOL) have high egts..might advance the pump timing more today to see if it makes a difference

[jrmc47]

Just to update ..have pushed the pump over to the block and got the egt's down to 350 around town and 450 - 550 @ 100 kph with camper on
I think its time for a pump rebuild..any one have any idea on $$
cheers
BTW ...blows no smoke so not overfueling

[stumagoo]

not a huge diesel guy but its my understanding that black smoke is excessive overfueling - it may be that you are overfueling but not in the extreme sense and as such cant see it as you drive.

I do know that as mentioned fuel timing aslo plays a big part - it may be that the pump is wearing and/or the fuel timing is not set right

I also had a mate who had similar issues with his patrol - it turned out his was tuned in a major city that had premium diesel and the smaller city he lives in did not have that readily available and he had to get retuned for the different diesel quality