Outer Limits 4x4 Board

Im rebuilding a naturaly asperated ( turbo later ) td42. Im wonder what sort of mods i can perform on the engine internally to increase power? Motor will be turboed at a later date but i would like to modify motor while i have the time and opertunity. I own a cylinder head reco shop so i have axess to automotive machinery, parts and equipment. So if anyone has any information or has had any sucess modifying these motors give me a yell. Anything from mild to wild would be considered. Thanks Des Diesel.

get some turbo spec pistons and get it fully balanced and a sligtly lumpier cam and get some head work done and some aftermarket injectors
get the injector pump modified too + electric fuel pump


make it rev aww yeh

Des,
What is the original build date of your TD42? Non-turbo engines built after August 1993 don't like being turboed as they don't have the same oil squirters for piston cooling that the earlier non-turboed engines do. Leads to prem. failure with cracked pistons, pre-comb. chambers etc.

Have a choice of two motors, the original 92 motor or a 2002 motor ( if g/box bolt parern and injector pumps are the same). Will run the gu harder pistons, but are looking for info on injector pump mods and what is the ideal pressure for the injector's. If you know of any diffrences between the 92 td and the 2002 td turbo motors (minus turbo) let me know. Thanks Des

Just to clarify things for me....the 2002 engine had a factory turbo right? If so, then use this engine as it's already got the right rods, pistons and cam for being turboed, plus it has the better oil squirters too.

The GU engine will bolt up to the GQ gearbox no problems. Rebuild injectors with new nozzles and increase breaking pressures to 150 ats, this will settle down to about 140 ats eventually. Get the injector pump modified with the 12mm plunger element, plus mods to the governor and aneroid.

GQ TROL wrote:Just to clarify things for me....the 2002 engine had a factory turbo right? If so, then use this engine as it's already got the right rods, pistons and cam for being turboed, plus it has the better oil squirters too.

The GU engine will bolt up to the GQ gearbox no problems. Rebuild injectors with new nozzles and increase breaking pressures to 150 ats, this will settle down to about 140 ats eventually. Get the injector pump modified with the 12mm plunger element, plus mods to the governor and aneroid.

I agree with Mitch, plus high flow the turbo as the standard turbo dump pipe will need to be work to get it flowing more freely- then you can also up the boost pressure.

Daniels

insane, where would you find the original built date of the motor. Is it just the same as the on plates?

insane, where would you find the original built date of the motor. Is it just the same as the on plates?

Just take the chassis number of the vehicle in to your local Nissan dealership and they can look it up for you and give you the month and year of manufacture.

What if you dont have the chassi number of the donor vehicle ?

What if you dont have the chassi number of the donor vehicle ?

Then you have to make an educated guess of the age, based on things like does the engine have all the EGR bits, is the vacum pump on the alternator, 2 bolt or 4 bolt engine mounts, has it got the early gearbox or the newer closer ratio'ed box etc. If the engine is still in the truck, does the truck have the front side light indicators etc.

What if you dont have the chassi number of the donor vehicle ?

Then you have to make an educated guess of the age, based on things like does the engine have all the EGR bits, is the vacum pump on the alternator, 2 bolt or 4 bolt engine mounts, has it got the early gearbox or the newer closer ratio'ed box etc. If the engine is still in the truck, does the truck have the front side light indicators etc.

GQ TROL wrote:Des,
What is the original build date of your TD42? Non-turbo engines built after August 1993 don't like being turboed as they don't have the same oil squirters for piston cooling that the earlier non-turboed engines do. Leads to prem. failure with cracked pistons, pre-comb. chambers etc.

can the squirters be changed between engines i have an early and a late motor.

I don’t mean to be rude but I question this August 93 engine date as being the last of the good early engines.

I have a 93 ST coil cab, cab-chassis, TD42 non-turbo.400.000klm and still going strong. (Complete with it’s 1/2 ton of tools on the back, we work on earthmoving gear)
Nothing new there, but my business partner just sold his late 94 ST coil cab, cab-chassis, with turbo.( he was offered a 95 but got a better deal on the 94) Again 400,00 klms and still going strong. Was only fitted with an intercooler after the first 200,000 klms. Only thing done to the engine was a slight tweak to the original fuel pump, 92 rear wheel kw on dyno.

The turbo was fitted from new, by Nissan (it was fitted by an outside turbo company but came with a full factory Nissan warranty)
It was quite common here (Western Australia) at the time for the local Nissan dealers to do this, as the farmers loved them. They were a cheap tractor that they used for towing their large (up to 7 tonne) spray booms, then use to drive to town latter on. These were generally fitted with an engine oil cooler and a thermo fan as well, but no intercooler.
Out lasted the Land Cruisers they had been using by miles.

Mid 95 was the date from which all hell started to break loose.
There were a number of engine blow-ups after mid 95 through early 96.
At this time Nissan stopped fitting them, or would have them fitted but would not take any responsibility if things went wrong.
Seems to be Nissan change the engine set up, pistons, cams and a few other bits but did not tell anyone they had done it. Result the turbo suppliers (and fitters) did not change there set up to accommodate this, result BANG.
They’re where a few court cases going on after this between several parties.

At the time about 75% of Nissan’s cab-chassis market was in Australia.
There were several Japanese engineers running around here for a while, doing tests and gathering info, some of which I assume went towards the new TD42turbo in 98.

Just my couple of cents worth.
Tony

I don’t think it was rude to question it all Tony.

From what we’ve found, in terms of which factory non-turbo TD42 engines being suitable for fitting aftermarket turbos and running stupid amounts of fuel and equally ridiculous amounts of boost, August 1993 seems to be the end of it. This is from a engine performance and lifespan perspective only for Offroad Racing, winch challenges, rally sprints and hill climbs etc (of which we do all with the same truck).

August 1995 saw more changes to the TD42 internals, aswell as the move away from the brake vacuum pump off the back of the alternator, plus the introduction of the closer ratio gearbox etc.

I don’t doubt the good run you (and countless others) have had with fitting turbos to the later non-turbo TD42 engines, provided only sensible adjustments to the fuel and boost are made. But for those who want A LOT more performance, they would be pushing the odds somewhat to be expecting the same lifespan from a later TD42 engine with aftermarket turbo and fuel pump mods.

We’ve been getting factory turbod TD42-T engined Patrols (and Safaris)here since August 1993, and prior to that Nissan NZ was also giving warranty on aftermarket turbos fitted to non-turboed TD42 engines, provided they were fitted by their supplier when the vehicle was purchased new. My old man still has his 1991 Patrol he bought new with the aftermarket AXT turbo fitted. My mate bought my Grandfather’s 1990 Patrol (inline fuel pump) with the same setup. Both have done over 500,000kms which is a lot by NZ terms.

In short, if I wanted decent amount of horsepower (300+HP like in the pics below) out of a TD42 engine, I would reach for the pre August 1993 or any factory turbo TD42 engine everytime and modify it accordingly.

Awesome pics Mitch

Thank`s for that GQ TROL, I never even new they made a change in 93.
Think I`ll stick to my policy of never working on cars or trucks.

Awesome pics Mitch

That's the old truck too. Heaps of fun, but was only a matter of time before it bit back ;-)

Thank`s for that GQ TROL, I never even new they made a change in 93.
Think I`ll stick to my policy of never working on cars or trucks.

No worries at all Tony. We're still very much learning as we go along. The more busted engines we pull down, the more things we find. I'm sure what I've touched on above is just the tip of the iceberg. Would love to get inside the head of a Nissan engine designer and find out the good oil on these donks.

GQ Trol, would a 1995 "closer rati box" fit a 1990 td42,
would it be worth it?

Cheers Ian.

[quote="GQ TROL

No worries at all Tony. We're still very much learning as we go along. The more busted engines we pull down, the more things we find. I'm sure what I've touched on above is just the tip of the iceberg. Would love to get inside the head of a Nissan engine designer and find out the good oil on these donks.[/quote]

I’d say that with 300+ HP you’re getting out of them, you more than exceeded what the Nissan engineers had in mind.
Mind you, increase in HP is usually inversely proportion to life expectancy and thats the one thing Nissan did get right They seem to go forever.

GQ Trol, would a 1995 "closer rati box" fit a 1990 td42,
would it be worth it?

Cheers Ian.

Yup, they bolt straight up to both the earlier GQ TD42 engines, and the later GU TD42-T engines too. I'm chasing one at the moment for the race truck, but they're pretty thin on the ground.

Ratios are:
First = 4.262:1
Second = 2.455:1
Third = 1.422:1
Fourth = 1:1
Fifth = 0.85:1

Earlier boxes are:
4.556:1,
2.625:1,
1.519:1,
1:1,
0.836:1.

Tony
You wouldn`t by any chance be a Bio Diesel man. Your signature sounds familiar
Alex

lexi wrote:Tony
You wouldn`t by any chance be a Bio Diesel man. Your signature sounds familiar
Alex

No I am not Alex.
It`s something I would like to have a go at.

Thanks for you're info it is allways a great help talking to someone with hands on experiance. In regards to dragging a lot more grunt out of the td42 should i look at modifying the oil system ( can i get a high volume oil pump ) or any other components? Is fuel delivery and turbo the only way to beef up horse power? Thanks again Des

Thanks for you're info it is allways a great help talking to someone with hands on experiance. In regards to dragging a lot more grunt out of the td42 should i look at modifying the oil system ( can i get a high volume oil pump ) or any other components? Is fuel delivery and turbo the only way to beef up horse power? Thanks again Des

Yes, definitely look at installing oil-cooler.

Other than turbo and fuel pump mods, the biggest bang for your buck would be LPG injection / fumigation (do a search, plenty of info, can be destructive if you go too far though) and intercooling (air-to-air or water-to-air). If you're searching for the last 5-10% of performance, then balancing the internals, porting the head, modifying the cam etc would be useful.

this talk of oil skirt cooling has got me thinking.

say around the 98, 99 onwards patol diesels. is the setup of these systems any good? are there any differences between the factory turbo and non turbo models?

this may have an impact on a future buy. being as the future buy will probably cop a fair bit of modifing. i.e wanting good power but having a motor thats built to handle it.

I bought my TD4.2 on the reputation of the one's before it, I would have had reservations if I had known about the engine information first, why change a time honored recipe? Still I would have bought a gq but probably not the 96 I would have looked for a 92-93.

Ever since I found out about the engine I wondered what they were trying to achieve now with this new information about the gearbox ratios and it all makes sense.
The later GQ were softened and became more of a tourer/refined. The engine might also make a bit more HP to pull those ratios too down low I dont know??. Still I would have rathered the older setup.
Begs the question is the transfer ratios still the same? 1st high is a great bumpy and level fire trail gear, now I know why I go straight to Low 1st early for anything more.
Great informative thread.

cheers fnq

i have a 95 GQ TD42 and its been modded as i said before ...
running 15psi no dramas at all ... i wouldn't be overly worried about
turboing a later model TD42

Fnq (and others),
When modifying these later engines, if you remember nothing else but this...keep it sensible (fuel and boost) and you'll have years of trouble-free 4wding ahead!

Transfer ratios are the same in the GQ's.......2.02:1 in low box.

I assume the gearboxes have been changed yet again for the GU vehicles, owing to the 5th gear problem which never existed in the GQ's? Interested if anyone knows for sure about this?

Bloody well better last!! I will take it personally if I dont see 700k before a teardown , it's swaying N/A.

The ratio's like the later engine seem to indicate a few more HP N/A than earlier engines?. Certainly it looks like less of a tow vehicle and more of a tourer until 4th and 5th. Only way to even the score would be with a few more HP I know mine is happier to rev than any I had driven before (non turbo) but I didn't know why - still dont really, but it will keep pushing toward and through redline in 3rd like a petrol engine does just does it all slower. The few older ones didn't behave quite like this one.
All just guesses anyhow.

cheers fnq

As I said: I'm working in supercharging my TD42, 1993 m.y. I mounted the vortech2 supercharger, the puleys, everything... I'm waiting for the new cone air filter, to move the vacuum tube that goes from the pump regulator to the intake manifold (in a normal td42 engine with INLINE injection pump, the pump has a vacuum tube that goes from the pump to the intake manifold...which I have to put it in the air filter case)

Now, questions: how to give more fuel for the injection pump?!?! I mention I put already a electrical fuel pump, but to give more fuel from the injection pump to the injectors is something else...;-)).

Any answer will be highly appreciated!!

Thanks