Custom 4.2 Nissan GU Patrol: A watched kettle never boils

ByUnsealed 4X4April 1, 2019
Custom 4.2 Nissan GU Patrol: A watched kettle never boils
This once-grenaded GU Patrol will never do it again
Words by Mark Kendrick. Images by Wes Whitworth.

Thomas runs RMS Performance Engineering in Mackay, Queensland. Working primarily on Patrols day in, day out with tuning and upgrades and especially keeping them cool (see our article in Issue 059!). How could a bloke renowned for keeping kettles off the boil drive anything but a TD42-powered Patrol? Tom was after a test mule for his business that doubled as a family tourer, with all the best parts to showcase the professional workmanship he offers to his customers. A test mule and family car don’t often go hand-in-hand, unless you’re absolutely confident in the reliability of your upgrades. A show car and real off-roading don’t always go together either, but Tom has somehow managed to pull off the trifecta!


The venerable GU in glorious metallic blue was picked up for a song after the ZD30 engine did what they are best known for. Despite having sat around for a year or so it was in otherwise immaculate condition and looked like it had never been used off-road. Tom spent six months stripping down and rebuilding the Patrol with virtually every nut, bolt and washer checked or replaced to make sure it was the best build it could possibly be. Every component was inspected, modified or replaced to be sure. All that was over three years ago. Tom has put over 40,000km on the odo since, with big trips up Cape York and the Victorian High Country, as well as being his daily driver. Has it overheated? Not once!

The perfect blank canvas didn’t take long to change its stripes. Even before bringing it to his workshop Tom had the vehicle sent to Coles Customs where Mitchell Cole designed and made all the bar work including the winch bar, sliders with scrub rails, and a rear bar with swing-out tyre carrier. It was only then that the GU was taken into Tom’s care. The first round of modifications included ditching the broken 3.0-litre engine and swapping in a black top (non-turbo) 4.2-litre diesel, which was extensively refreshed using Mahle pistons, a high-volume oil pump, a ported and polished head and a proper engine balance.

All this in-house work by Tom had it ready for the turbo install, which uses a United Fuel Injection-sourced TD05-20G that Tom also modified to better suit his driving desires and matches the modified 12mm injector pump. This set-up is capable of over 300HP although Tom has it tuned to a more conservative 260HP for trouble-free touring. A front-mounted 600x300mm PWR intercooler with Radius Fabrications snorkel, airbox and plenum feed cool air to the engine. If you read the article last month you may note the single-core radiator Tom recommends; he has them custom-made by ADRAD, and they work a charm coupled with the special fan that Tom sources from United Fuel Injection. The exhaust is a Roo Systems 3-inch system, just a basic off-the-shelf kit but does the trick without sounding naff.

As built, this GU was an automatic, but that clearly wouldn’t suit a bloke who loves old-fashioned mechanical injection diesel engines. Among other things, Tom’s workshop specialises in gearbox conversions. RMS manufacture bespoke wiring harnesses that keep all the same functionality of the ZD30 engine and auto but mated with the TD42 and manual gearbox. Tom fitted a clutch built by NPC, which uses a Dodge Viper pressure plate and standard Exedy friction plate with a custom-made flywheel. This seemingly motley collection of parts gives enough pressure to stop the clutch slipping despite running high horsepower and torque.

As well as a tourer, Tom’s GU has to be fit for a work car. While the bar work was going on the outside, Cole Customs also installed a mine site compliant Roll Over Protection System (ROPS) roll cage inside the vehicle. One of the few bits of steelwork that isn’t custom-made is the roof rack, an ARB product on which the awning, four LED driving lights, a couple of work lights and the solar panel are mounted.

Hiding in the front bar is a Runva 11XP winch, running synthetic rope. The bar also supports a pair of aerials, which Tom switches between depending on terrain, and a myriad of small LED work lights useful for technical slow speed off-roading and ground lighting around the campsite. Beneath the bar, the front diff appears armour plated and well braced, diff internals have been swapped for an ARB Air Locker while the rear diff has had the factory LSD shimmed up nice and tight.

Superior Engineering made most of the suspension arms, including the adjustable Panhard rod and Superflex radius arms, which allow the front suspension to fully cycle the King remote reservoir off-road racing shocks. New, higher mounts for the shocks had to be fabricated due to their closed length. The rear also uses the King shocks and Superior heavy-duty control arms. The bump stops have been replaced with hydraulic alternatives on custom mounts to keep the 35×12.5×17 Nitto Trail Grapplers from hitting the guards and the suspension has been raised three inches using Superior’s flexy coils.

The power put down by the big aggressive tyres on Method Beadlock rims call for good brakes, with Bendix pads gripping slotted rotors that are better at dissipating heat than the plain originals. To steer the big tyres, the standard Patrol system has been retained however the steering pump has been fitted with a smaller pulley to increase rpm and internal pressure. A power steering cooler has been installed on the chassis rail to keep the fluid temperatures down. These small modifications mean Tom can turn 37-inch tyres with one finger on the steering wheel, while stationary.

Tom uses a yellow-top Optima battery for cranking, with a slimline 130Ah AGM battery mounted in the rear and charged by a CTEK DC/DC system which is also fed by the 100W solar panel. The AGM battery powers the Waeco CF80 which is never turned off. The Waeco fridge is on a tilt slide which itself is mounted on a set of drawers. The drawers have been modified to house the dual-battery controls, inverter and work light switches.

From the driver’s seat, Tom has a collection of Auber Instruments digital gauges in a pillar pod to keep an eye on turbo health. A Uniden UHF radio is fitted in the compartment where other models have an airbag, connected to two aerials which can be switched between easily depending on the terrain. A handheld is mounted on the roll cage for the spotter to use too. Tom has built a remarkable package from the ground up, with everything working in concert as it should. We don’t know how you spend any time in the workshop when you have such a great Patrol to escape civilisation in!