DIRTY STUFF

THESE VNS WERE TO BE DRIVEN THE ENTIRE DISTANCE IN FOURTH GEAR ONLY. THE AVERAGE SPEED AROUND THE 45-DEGREE LANG LANG TRACK WAS SET AT 180KM/H, AND EACH CAST-IRON ENGINE WOULD BE BELLOWING AT 5000RPM!

WILLIAM PORKER

I HAVE a watch. I have never worn this elegant wristwatch, which has been stored inside a bottom drawer in my office for the past 25 years. There is a story to this piece that marks time – although the tiny battery inside has long lost all its electricity, I keep this small souvenir to remind me of a warm Melbourne morning and a 180km/h average for too short a time around a famous test track.

This watch has a flat biscuit of a stainless-steel case, the hours marked in gold on its face. There’s the word Castrol in red above the centre pin but below that, written in bold green etched with red, is the reason why I was given this watch at a press conference: TXT, Castrol’s first ever fully synthetic engine oil, announced to the Australian retail market early in 1990.

Castrol needed launch publicity, and this is how I came to be involved in their marathon endurance attempt. I was writing for several motoring magazines back then, including Wheels, where I was contributing a monthly column. Castrol approached then-editor Peter Robinson with an idea for a feature story – a marathon test involving two new V8 VN Commodores, and Holden’s Lang Lang proving ground.

Their plan was for Larry Perkins to dismantle their engines, gearboxes and rear axles and rebuild these back to factory specifications in his Melbourne workshop, fill the engine sumps with the new TXT oil and haul these shiny new sedans to the 4.83km banked saucer track at Lang Lang.

With permission from Holden’s top management, a team of experienced test track pilots would take turns in driving sessions of two hours each for 16 long days, just to prove that Castrol’s new synthetic oil would keep the five-litre V8s alive over that distance, but with a major torture element added: These VNs were to be driven the entire distance in fourth gear only of their five-slot box. The average speed around the 45-degree four-lane banking of this dramatic concrete saucer was set at 180km/h, and each cast-iron engine would be bellowing at a steady 5000rpm!

All up it would be 64 two-hour-long test sessions, and Castrol was supremely confident their new product was not about to fail – they were going to rack up 30,000km with each unbelievably stressed car, only changing the TXT once at the 15,000km mark, and the camshafts, bearings and pistons would live through all this.

Then Larry would tear down the engines again when this marathon was over, and show the results to the press in his workshop.

My involvement was an invite to Lang Lang on behalf of Wheels, with free flights and accommodation and the promise of several laps close to the surrounding Armco guard rail, right foot hard down on the accelerator and the speedo needle rock solid at 180km/h. Although I had driven plenty of racecars on road circuits before this, this was going to be something really different.

A Castrol guy picked me up in the early morning and we drove south to Lang Lang. I got through their guard at the gate, and watched as the two VNs circulated high on the banking until one rolled down and stopped on the infield, where I took over the test pilot seat and, with three other Castrol execs as passengers, lit the fuse and accelerated hard through the gears of this stillhot motor car.

It’s not difficult to race at 180 on that almost ripple-free concrete. They said at the start I could almost take my hands off the steering wheel at this speed, and the Commodore would still track safely high up in the outer lane. The nerves take a bit of a hit when the silver Armco is blurring past a metre off your right-hand door at 3km a minute, but I kept my concentration tight and conversation to a minimum, with the engine audibly screaming that life was incredibly tough when the tacho needle sat steady at 5000. I did wonder if they had fitted decent high-speed tyres to this machine.

But I got in a dozen laps before the execs pulled the pin on my marvellous fun, and as I was easing off to end up back on the infield and hand over again, they told me the unofficial lap record around there was currently held by Frank Gardner, at somewhere over 220km/h in a racecrafted BMW. I didn’t disbelieve them.

Both VNs had their problems during that ultimately successful run: leaking water pumps, rock damage to a radiator, and forced cylinder head changes caused by severe exhaust valve seat recession through drinking unleaded fuel. I flew back down to inspect the dismantled engines with Larry, but apart from the deep exhaust valve pockets in the five-litre heads, all the other bits were virtually unmarked.

The TXT had done what was asked of a brand new product, but it doesn’t live on auto shop shelves anymore. Castrol has morphed it into their classic range of oils; you can now buy the same full-synthetic stuff as 5W-30 Edge, and remember Lang Lang. s

THESE VNS WERE TO BE DRIVEN THE ENTIRE DISTANCE IN FOURTH GEAR ONLY. THE AVERAGE SPEED AROUND THE 45-DEGREE LANG LANG TRACK WAS SET AT 180KM/H, AND EACH CAST-IRON ENGINE WOULD BE BELLOWING AT 5000RPM!