changing a 4.2 petrol to 4.2 diesel????

[offroadbiker]

If you get a satisfying answer, please post for the rest of us

[Tinus lotz]

i am worried about diff rasios , dashbord refcounter ,gearbox fitting on engine ,gloplugs ect

[offroadbiker]

Those things are a bit greek to me, I am solely looking at feul consumption as I have to admit the 4.2 Petrol is just a bit to heavy for my pocket at the moment

Was trying to get some info on the GQ with the V8 with claimed consumption of 7.5 to 8km/L but the seller is not responding to me....

How reliable is this motor and conversion and is this consumption reachable with this motor?

[Peter Connan]

Dirk, just my No engine transplant will ever be worth while from a consumption point of view. You cannot possibly save the bucks you spent.

A decent engine conversion (without the cost of the engine) is going to cost you more than you paid for that car.

[Alex Roux]

Dirk

In my view, to get light consumption with a modern V8, you still need a light vehicle, and no parafinalia on the roof.
If you set the ECU too lean (low fuel relative to air), it is not good for the engine. You can set it lean below 2000 revs, but not above that. Engine can do damage otherwise, and it won't feel much like a v8 anyway.
To do 8km per litre on the V8, is not impossible though, but you will need to have a very disciplined/humble foot on the pedal, and no luggage on the roof. Not worth it.

Also, the 4.2 diesel is not all that light on fuel either.
However the ZD30 engine is, if well managed with the EGT. Still I think this is the only real way you can travel at a reasonably light fuel consumption overland in a vehicle of this weight.

Except for....and people on this forum may curse me for this, but I think by now, the Toyota D4D engine has proven itself in terms of durability (unlike the older KZTs, that seem to overheat with age)
They are accessible, given how many Tunas roll, but not as cheap as the Lexus. Around R20,000 a piece. And their consumption should be similar to the ZD30. Not a bad engine at all.

Tinus: As far as I know diff raitos are the same, but greabox ratios are different. But I stand corrected.
Mine still use the original diesel gearbox though.

[Tinus lotz]

thanks guys i agree buy the car u want or rob a bank its gonna cost u money anyway

[Stefaansie]

I agree with Thinus.

Buy the car you want, unless you want to build the car you want, and money is no problem.
I found my diesel GQ 2 years ago with turbo fitted in '98 already. I drive kinda enthusiasticaly(?) and have done 160kph(that's 155kph GPS) a couple of times. So, she's not lazy at all. Best consumption I ever got was 9,25km/L with 31.5" tyres and driving like a tannie. Driving down to Mosselbay once, avg consumption was around 7,5km/L, heavy towing with stuff on the roof has given me, the worst ever, 6,2km/L.

My intention is not to brag or anything, and I truly love the sound of the V8, even the 4,2petrol. But my truck developes 161kw and 469Nm according to SAC( I doubt it only a little bit though, but still have the printout) and that puts a smile on my face every time I drive her.

So,
Dirk, sit n Turbo op daai petrol, maak hom goed warm en as jy dan mooi ry gaan jy mos goeie brandstof verbruik kry of hoe?

[offroadbiker]

Nee sal defnitief nie self so transplant doen nie, sal my anaway hele rukkie vat om net ver genoeg te ry om daai verskil te probeer opmaak. Het die Trol nou vir 'n jaar en saam met die trip in die Kaap om te gaan haal het ek nog nie eers 5,000km gery nie

Maar 7km/l teenoor 4km/l =240km op 'n tenk waar ek nou net 320km kan dit 560km wees en dit maak nogal 'n verskil die dat ek na die V8 gekyk het, maar moet eerlik wees as dit by sulke ombouings kom is ek maar skrikkerig want mens hoor soveel "horror" stories.

Die diesels is ook so bledie skaars soos hoendertande so ek is srikkerig om te verkoop en dan sit ek sonder 'n voertuig vir hoe lank terwyl ek wag vir diesel om dalk sy verskyning te maak En ek dink ons het mooi by Kagiso geleer om nie 'n ander voertuig as 'n Trol te koop nie

Sal maar nog 'n jaar moet uithou dan is my finansies beter as nou en dan kan ek hom meer geniet

[Grant]

Dirk,

The diesel option is not only about the consumption. As Christo, Greg, Cedric and I say, "REAL TRUCK DO NOT HAVE SPARK PLUGS " . The torque we generate low down offer it own benefits and with our turbo's we are not far off on power. I test drove a 4.8 auto and was disappointed, probably with the auto gearbox more than the engine. Love my diesel and it is still running very well. As for speed my Troll will do 160 to 165km on GPS, but brakes and muddies are not happy at that speed. I am happy at 100 to 110 kph, and fuel consumption is around 6.5 to 7.2 lt/100.

The GQ diesels in SA are as scarce as honest ANC parliament members. Nissan SA did not import these to SA. IC Nissan Boksburg imported 10 from Aussie. Got confirmation on this from salesman, and Nissan only found out of the importation once IC registered the Troll for warranty.

A diesel conversion should not be to difficult but as you have said, getting hold of a diesel engine and gearbox is the problem. A friend of mine with a 60 series LC fitted a turbo, and what a difference. He has just finished the Put Foot Rally and averaged 6,3 lt/100 and love the extra power the turbo offered.

[bogeyman]

I removed the TB42i engine from my GQ GRX ( It was fuel injected) and replaced it with a TB45i bought from Engine den for R25k.
All the major stuff like bell housing , engine mountings , exhaust flange , radiator pipes and fan position was exactly the same.
I had to use the flexplate and starter from the Tb42 (it has an autobox).
The pipe from the throttle body to air cleaner had to be modified and the throttle position sensor for the gearbox had to be re mounted.
One major difference is the distributer. Old engine had external coil , new engine has internal coil.
I mated the old ecu harnass with the fuel injection wires and Maus Performance added a chip and connected the coil and pickup wires.
The car runs like new with everything working perfectly. I get an average of 5.5 to 7 km/l depending on conditions. It has done 50 000km after the new engine with very few niggles. And lots more power. Not counting my workshop time the mod cost me R40k.
I also own two non turbo 4.2 diesel pickups and the fuel consumption on these vehicles is similar to the petrol 4.5.
The tb42 and td42 blocks look very similar and I wont be surprised if the petrol bellhousing will fit the diesel engine. Wiring and fuel will be very easy to change but cooling and brake vacuum will be more difficult.
Diff ratios on diesels are generally geared "longer" lo allow lower rpm and when you change diff ratios there are many other problems like inaccurate speedo , ect and you will have to experiment to get the optimal ratio.

The other guys give the best advice: A standard factory spec vehicle will give you the best combination of performance and reliability.

Chris.