Sunday, January 24, 2010

Shakedown Blues

So, the washers are in, the front axle is once more complete, so it’s time for a blat! Except that us rally types don’t just go for a blat – we go for a ‘shakedown’. Now in other circles, a ‘shakedown’ has a different connotation, involving extracting money from people by dubious means. We do that in rallying, too, but we call it ‘sponsorship’.

The purpose of a shakedown is to test the car in a semi-race scenario, and iron out those annoying gremlins which might just stop us from finishing a rally. And if something falls off or breaks, we can grit our teeth and sound happy about it, because it’s ‘better to happen now than in the rally’. However, equally important in this case was to give Ian Rodgers an opportunity to get to grips with the vehicle, and to show me that he could navigate.

So I spent Friday fabricating a mounting in the rear door for my new toy from the States, a 24v rattle-gun, and another for the hydraulic jack. Oh, and trying to find someone to run as chase car with me, because if something does go horribly wrong it’s good to have someone in the vicinity to bail you out. Failing to find anyone else both (a) free and (b) willing, I persuaded Sheila to be our support crew.

Saturday dawned. Well, I suppose it did, but it’s hard to be sure when the country is covered in a thick grey duvet of fog. By 8.30 we were on our way, peering through the gloom and dodging the heavies down the truck road leading to the Abu Dhabi-Al Ain road. Here starts the old SS6 of the Desert Challenge –a 166km route ending just outside Dubai, and therefore not used since the DC became an exclusively Abu Dhabi affair. Soon after 9.30 the fog had thinned enough for us to get moving, and Ian managed the tricky navigation around the farms and tracks pretty well, considering he’d never done the stage before. The car was pulling strongly, the engine temperature was fine, and as the sun gained strength the new roof-vents brought a cooling breeze into the cockpit.

50km into the stage, on a rather flat section with no real challenges, the steering became suddenly heavy and it was obvious that we’d lost power steering. Knowing that the belt that drives the power steering also does some other more mission-critical jobs, like powering the water pump, fan and alternator, it seemed a good idea to stop before anything bad happened. But a quick glance under the hood showed that something bad had, in fact, already occurred. The serpentine belt was off, but the fan and its pulley were also lying in the bottom of the fan shroud. The massive shaft – ¾” I guess – which should connect it to the water pump had snapped like a twig. ‘Oh, bugger’, I said. I may have said it more than once.

Sheila was waiting for us to come through Nahel Town, some 50km from an underpass which was our nearest road access. She negotiated the 10km of tracks and low dunes between that point and our location, and we soon had the race car hooked up to our faithful road-going Patrol. So now I had to tow the race car out, while Ian drove it without much in the way of brakes or steering. After a couple of minor dramas we reached the underpass and – having enough problems already – we decided not to risk the attention of the law by towing it back to Dubai.

That meant 150km back to Dubai, pick up the trailer, back to the underpass, load up the race car and back again to Dubai. By which time it was dark, we’d covered well over 600km and we were knackered.

So, with only three weeks before the ‘Highway to Hail’, we have a broken car. Again. Now the questions are, what caused the problem, and how can we avoid a repeat? Should we change to an electric fan and/or even an electric water pump? The recommendation from Kolby at Turnkey Engines in the States was always to go for twin electric fans of 1600-1800cfm each, whereas the gurus at Marks 4x4 in Oz said to stick with the mechanical fan. However, it looks as though the heavy load on the shaft from the fan may be at least a contributory factor – although until we dismantle the water pump we won’t know if the pump bearing has seized.

After further discussions with Rick at Carwise, we’ve decided to go for the electric fan option. We can fit twin 13” high-performance Pacet Pro-Fans into the available radiator area, which each shift close to 2000cfm, and we need Kolby to ship us another high-output water pump. Hopefully within this week these two items will be winging their way towards Dubai – TNT permitting.

But let’s look on the bright side – it’s ‘better to happen now than in the rally’. There, I said it – through gritted teeth.

3 comments:

Grumpy Goat said...

Yay! Comments are enabled!

Grumpy Goat said...

Having cheered at the ability to comment, I'll now take the opportunity to commiserate on your breaking the car.

Am I right in believing that, compared with a fan driven by the serpentine belt, electric fans would suck less power straight off the engine? If so, this is surely a Good Thing.

Ian the Dog said...

In principle, the viscous fan clutch should only be actively driving the fan when the temperature demands it, otherwise it should free-wheel. The clutch felt very stiff, so probably it was driving pretty much full-time and yes, taking power out of engine. But the real questions are, is it more reliable, and can it shift enough air to cool efficently? Because with the LS2 V8, power isn't in short supply!