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Here’s how to build a tough petrol Patrol for any track in Australia

WORDS BY ALLEN HODGES, PHOTOGRAPHY BY 4WD ACTION

BUSHPROOFPETROLPATROLS MADE

PLUS!ESSENTIAL MODS EVERY PETROL 4WD OWNER MUST KNOW

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Righto, so if you’re a one-eyed Nissan fan you know that you can’t improve on perfection, right?

Cough, ahem. That being the case, there’s still a whole lot you can do to get your Patrol running even better than perfect. All the hype is TD42 this and TD42 that, but in this article we are going to look at the highly neglected petrol motors, from the RB30 and TB42 in the GQ, up to the

GU’s TB45 and TB48. We’ll show you what you can do to them to make them a bush proof beast.

Everyone that has a petrol Patrol knows the old tip of sealing the dizzy, but we are going to go beyond the basics. The crazy bit is, these petrol motors leave the diesels for dead in terms of stock perfor-mance, but all you’ve gotta do is get a couple of other basics right and you’ll have something almost as reliable as well.

When it comes to preventative maintenance the age old trick of sealing your electrics is one that should be done before every-thing else. Using dielectric grease on your plugs will prevent water and dirt from settling on your plug contacts and causing rust which in turn becomes a bad contact point and gives excessive resistance in your circuits and then stops on you in the middle of nowhere.

GQ CARBY MODELSRB30 and TB42Seal the dizzy with some silicone or flange sealer, make sure you don’t use an acid cure sealant as it will create corrosion inside the dizzy. When you are sealing your dizzy cap be careful that you don’t get sealant inside the dizzy as it will cover the points and won’t fire. A little trick is to tap a thread on top of the dizzy cap, screw a push in fitting in and run a hose from the dizzy into your breather tube. From there, use an electrical spray grease to create a barrier on your spark plug lead ends and plugs on the alternator, starter motor and around the bottom of the fuse box. Also remove the fuses and spray the contacts to prevent rust if they get wet.

GQ AND GU INJECTED MODELSTB42e, TB45, TB48The injected engines have a lot more plugs and contacts to seal from dust or water. To give yourself that added bit of insurance, electrical grease can be used to limit the amount of water or dust that gets in. Grab your can of electrical grease, start at the air box and disconnect the air flow meter plug and spray the contacts. Carry out the same process on the injectors, sensors, alternator plugs and spray around the bottom of the fuse box in the engine bay. Remove the plugs from the ECUs and spray with electrical grease also; this will prevent any corrosion in the ECU plug if water gets into the cab. To prevent water getting into your ECU itself you can spray with a rubber sealant or Plasti-dip as this will help to keep it dry internally in the event of a deep water crossing.

SEALING YOUR ELECTRICS

HOW TO CLEAN YOUR MAF SENSOR:• Remove the two Philips head screws that hold the MAF

sensor into the inlet tract after the airbox.• Carefully lift the MAF sensor off the inlet tract and guide

the MAF’s tube out of the cylinder in the inlet.• Being careful not to physically touch the two hot wires on the

end of the MAF, give the wires a good spray with MAF cleaner spray until you can see the dirt or grime dissipating.

• Wait for the sensor to dry completely, then replace the MAF into the inlet pipe.

TIP! The seal between the top of the MAF sensor and the inlet pipe isn’t too flash and can easily get caked with mud and debris. An easy, five minute fix is to apply a very thin smear of sensor safe silicone between the two flat surfaces of the sensor and the inlet.

For a lot of 4WDers, the affordable 4500 GU is a way to get into a modern vehicle on the cheap

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GQ TB42 CARBYWhen it comes to common failures in the GQ TB42 carby models, the carby itself is always an issue as they continually give you grief with the automatic choke. A lot of people fix these models by fitting a 350 Holley, but this is not always a good replacement as they take a lot of mucking around to tune and you are going from a four barrel carby to a two barrel. A good replacement is a re-jetted Nissan Bluebird carby as they bolt straight on and you can fit a manual choke to them to get rid of the auto choke gremlins. Or, if you’re feeling adventurous, read our section on EFI conversions…

GQ TB42 CRACKED HEADS The alloy head on the TB42 is prone to cracking, if the engine is allowed to overheat. Make sure you’re running fresh coolant at all times, check your radiator for blockages and ensure your viscous fan is cutting in when it should – get the motor up to full operating temperature, then turn it off. Wait until the fan stops spinning completely, then try spinning it. It should rotate only with a bit of persuasion – if it spins freely, it’s worn out. There is gel you can buy from auto parts stores to put in the fan hub to make it lock up earlier and work more efficiently. When it comes to maintenance always ensure your valve clearances are set correctly, because if they are too tight the exhaust gases won’t escape properly and will cause excessive heat in the top of the motor. It’s a relatively easy job that can be done by a competent 4WDer with a good service manual, basic hand-tools and a set of feeler gauges. Be warned though – getting it wrong can cause serious top-end damage so only proceed if you’re absolutely confident.

TB45 ENGINE FAILUREThe TB45 has a known bottom end problem, with the conrods failing. This was due to the rods having been machined down more than on a TB42 to allow the motor to run smoother. A fix for this was simple but a little costly – you can fit the rods from a TB42 into the TB45. They’re essentially the same rods but are actually stronger as they hadn’t been machined down as much, and don’t fail like the ones from their younger brother.

MAF SENSOR CLEANINGAny EFI owner knows how sensitive various sensors can be to the proper running of your 4WD. So, it makes little sense to ignore possibly the granddaddy of all sensors – the MAF or Mass Air Flow sensor. In short, the MAF sensor influences almost all of the engine’s operating parameters by measuring the amount of air entering the motor at any given time. Cleaning the MAF is a sure fire way to improve the economy, throttle response and general running condition of the motor. Get yourself some specific MAF sensor cleaner, and treat your MAF to a bath.

COMMON PROBLEMS

THESE PETROL MOTORS LEAVE THE DIESELS FOR DEAD!

By now a lot of GQ and GU Patrols will be up in the

300,000km+ region – perfect time to ditch that factory

clutch before it leaves you stranded in the bush, check out

the Drivetech 4x4 clutch kit

The 4.8Ls aren’t bad from factory, but open em up with an aftermarket ECU and watch the roost they throw!

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FITTING A SNORKEL TO YOUR CARBY GQ

Every 4WD can benefit from an after market snorkel like a Safari Snorkel. When you fit a snorkel to a carby GQ whether it be a TB42 or an RB30, you should remove all the intake hoses to the air filter, and replace the air vortex from the system with an aluminium pipe with silicone hose joiners. The factory intakes are not waterproof or 100 percent dust proof, so the first big water crossing you see, you’ll fill your intake and engine with water. The air filters on these models don’t seal perfectly either. The answer is a small silicone hose, sliced up the middle and glued to the outside of the filter housing along the lid seal to create a better seal. Remove the rubber hose that runs from the filter to the engine breather and check it for splits. Refit with hose clamps to eliminate the risk of water being sucked in from either end.

FITTING A SNORKEL TO YOUR INJECTED PATROL TB42, TB45 and TB48

Always seal your intake piping and filter housings. A simple trick is to remove all the piping and run a bead of acid free silicone around the inside lip, and then refit with some new hose clamps to ensure a proper seal. Also remove the lid from the airbox and run a piece of rubber foam around the channel in the bottom half so when you refit the lid it creates a water-tight seal between the two housings. TB45s and TB48s have a different airbox and piping setup but the same trick can be carried out with the hoses and the air box lids.

4.5L AND 4.8L POWER UP MODSThe 4.8L has the advantage of being controlled by an ECU. This gives owners the bonus option of running an upgraded ECU that can be re-tuned to be an all-round fire breathing animal that is also better on fuel than standard. Haltech is one such aftermar-ket manufacturer that designs ECUs to your needs and helps tune them so you get good fuel economy as well as good off-road power and torque. The Haltech Pro Plug-in is a plug and play system that allows you to use the factory connector and adjust everything from the brake pedal input up to a nitrous activation switch, and also reads all the factory sensors and switches. Haltech’s Platinum Sport 2000 is a wire in engine management system for the TB45 and TB42 models that allows for sequential injection, direct fire ignition and allow for all engine modifications including, but not limited to supercharging, turbocharging, camshaft swaps and bore and stroke adjustments. Don’t get us wrong – it’s the ultimate in upgrades and tunability, but we’re talking big bucks here. There’s the cost of the ECU, then of anything up to a dozen or more dyno runs to get the ECU maps spot-on. Budget up to $5,000. When it comes to power levels, these petrol motors leave the diesels for dead!

UPGRADES FOR YOUR TRUCK

EFI CONVERSIONSSick of your old RB or TB stalling out on hills, sucking the juice and running rough? Fuel injection, especially the basic types found on the factory fuel-injected versions of these same motors, fixes all of these problems. It’s even relatively easy to do, because all you’ve gotta do is get a hold of all the factory EFI gear – from a fuel-inject-ed 4.2 GQ Patrol, or a VL Commodore/R31 Nissan Skyline.

With the TB42, everything bolts straight up off a TB42E. You will have to run an aftermarket fuel pump (the VL Commodores ran an external in-line pump down near the tank, which can be easily adapted to most fuel systems) or get the factory tank-mounted one and adapt it. You’ll also have to splice the harness to fit the ECU and sensors into the Patrol harness. Another option is an EFI inlet manifold and an LPG set-up. This will let you run straight gas using the factory throttle body and a gas converter, which eliminates the need for an ECU and the necessary sensors.

RB30 Patrols also have the option to run fuel injection, the best option is to get a six-cylinder VL commodore and strip the top of the motor off and bolt it to your Patrol bottom end, this gives you the bonus of having all the sensors in place and factory ECU ready to splice into the patrol harness. You have the option with the RB30 of turboing it and running an aftermarket ECU to give you more power.

DAN REBER4WD ACTION JOURNO

“Righto; call me biased, but I reckon the TB42E is the ultimate underdog of the 4WD world - a real unsung hero. Built on very much the same platform as the diesel variant, the TB42E is a dirty old workhorse with a few fancy bells and whistles bolted to the outside. But don’t let the EFI nature fool you; these are simple old dinosaurs to work on, modify and fix trackside should you ever have a problem. I’ve put my GQ in some pretty horrible places, driven her hard and rarely been within 5000km of the scheduled servicing and I’ve probably had less than one minor hiccup a year – if that. The main killer for most people with the TB motors is the fuel economy – fair call. It’s not all bad news though; some new ignition components, servicing and a tender right foot can get you under 17L/100 on the freeway and you’ve still got a rip-snorting amount of power to play with when the going gets tough. Would I trade mine for a diesel? Not on your nelly!”

FROM THE OWNER

Don’t let anyone tell you that you can’t

take a petrol 4WD through water!

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QUICK SPECS

Straight from the Drivetech 4x4 catalogues, here’s a list of the most commonly-sold spare parts across the entire petrol GQ and GU Patrol range.

PARTS &SERVICING WITH

RB30 CYLINDERS: Inline sixFUEL SYSTEM: CarburettorPOWER (KW): 100kW@4000rpmTORQUE (NM): 224Nm@3000rpmBORE X STROKE: 86mmx85mmCOMPRESSION RATIO: 9.0:1VALVE GEAR: Single Overhead Cam

TB42 CYLINDERS: Inline SixFUEL SYSTEM: CarburettorPOWER (KW): 125kW@4,200rpmTORQUE (NM): 352Nm@2,800rpmBORE X STROKE: 96x96mmCOMPRESSION RATIO: 8.3:1VALVE GEAR: Single Overhead Cam

TB42eCYLINDERS: Inline SixFUEL SYSTEM: Fuel InjectionPOWER (KW): 129kW@4,200rpmTORQUE (NM): 320Nm@3,200rpmBORE X STROKE: 96x96mmCOMPRESSION RATIO: 8.5:1VALVE GEAR: Single Overhead Cam

TB45eCYLINDERS: Inline sixFUEL SYSTEM: Fuel InjectionPOWER (KW): 145kW@4,400rpmTORQUE (NM): 350Nm@3,600rpmBORE X STROKE: 99.6x96mmCOMPRESSION RATIO: 8.5:1VALVE GEAR: Single Overhead Cam

TB48eCYLINDERS: Inline SixFUEL SYSTEM: Multi-Point Fuel InjectionPOWER (KW): 185kW@4,800rpmTORQUE (NM): 420Nm@3,600rpmBORE X STROKE: 99.5x102mmCOMPRESSION RATIO: 9.0:1VALVE GEAR: Double Overhead Cam

DESCRIPTION PART COMMENTSPER VEHICLE

QTY RETAIL (EACH)Front Wheel Bearing Kit DT-WBK13 2 $110.00 Rear Wheel Bearing Kit DT-AK16 2 $275.00 Water Pump 031-004761 TB42 1 $75.00 Water Pump 031-004785 TB45 1 $95.00 Water Pump 031-004784 TB48 1 $215.00 Viscous Coupling 031-100013 TB42, TB45 1 $175.00 Filter Service Kit DT-FLT48 TB42 1 $49.00 Filter Service Kit DT-FLT49 TB45 1 $110.00 Filter Service Kit DT-FLT50 TB48 To 12/07 1 $115.00 Filter Service Kit DT-FLT51 TB48 01/08 On 1 $110.00 Front Shock Absorber DTS1004 2 $125.00 Rear Shock Absorber DTS1009 2 $125.00 Clutch Kits various models 1 From $515.00Safari Snorkels various models 1 From S420.00

For more info and to find your nearest stockist: DRIVETECH 4X4

PH: 1800 463 646 www.drivetech4x4.com.au

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