IT SEEMS like forever since my new VG hardtop has had any love (Urban Warfare, SM, Oct ’15), with work stacking up everywhere.
But things have slowly been progressing, with the 5.3 getting a strip-down, a wash-up and the new cam installed. While the fabrication process was still going on, I’d left the dummy 5.7 in place in the car to continue mounting stuff up.
After the initial thrash to get it mounted and the manifolds made, we’ve had a bit of a rethink and redesign, and we ended up remounting the engine to try and get it a bit closer to the centre of the engine bay. This meant raising the motor so the log manifold would clear the steering box, which was better than the mill being lower and on a really pissed angle to the diff.
When we made the steampipe log manifolds, we used bits we had lying around to make the front crossover pipe, and while effective, it was just downright ugly. It ended up cocked at an angle, as we were short of a few bends. So we ended up re-doing the crossover and wastegate pipe – basically everything except the manifolds. While the turbo did end up sitting a bit further forward than we would have liked, the idea of a little extra clearance between the back of the turbo and the surrounding components for the dump pipe was more appealing.
Once we had the engine in place and at the desired height, we boxed in the top of the engine mounts (square tube section), tacked them into place and drilled them for mount bolts.
One of the main parts of the build has been the rear end. Valiants traditionally don’t entertain a big tyre, as the leaf spring sits on the outside of the chassis rail – if you try jamming anything bigger than a 235 radial under the arse it will rub on the spring. But US Car Tool does an amazing spring relocation kit – much better than the similar Mopar Performance item. They even do a minitub kit that allows you split the wheel tub and fill the centre strip with a factory-looking panel and a spot-welded seam.
While we are only running a 235 radial to start with, we needed to get the springs moved inboard, and given the enormous success of the locally made Gazzard Bros split leaf springs, traction bars and rear sliders, we decided to shout the old
girl the very best money could buy. In the interim we had assembled a Competition Engineering sheetmetal nine-inch housing with a Strange case, 3.7:1 gears, Moser axles, full spool and EL Falcon rear discs brakes.
Getting the rear chassis section removed for the spring relocation was the easy part, but installing the new front spring mounts was a little trickier than expected. While the US Car Tool replacement sections do have three holes drilled in them to coincide with the original front mounting holes, when you start running a string line to other parts of the car (to ensure that the diff will be parallel to the front wheels) you run into problems. Cars like these are all over the shop, with up to two centimetres’ difference between the main mounting points for the suspension and driveline components. In the end we ran a tape to the front axle line to ensure the front leaf spring mounts were parallel to the front of the car, so the rear end wouldn’t be skewed sideways.
We also had to ensure the chassis replacement sections were mounted parallel to each other and level to the rest of the car.
Once they were welded into place, the next issue was to get the springs bolted in and the traction bars clearing the new chassis section. We began with the centre spring hole in the new front spring mounts, but it was clear the bolt in the triangular plate for the traction bars was going to hit, so we started notching the spring boxes.
After chatting with the Gazzard boys, we decided the spring needed to go in the top hole, but the bolt
was not going to clear and we didn’t want to keep notching as it would remove strength from a really important part of the car. The trick was to fabricate a bush with the ends drilled and tapped to take flush-fitting Allen-headed cap screws. This way the triangular plate on the Gazzard Bros bars remains fastened and the whole assembly fits up inside the chassis section.
With this all sorted, the next challenge was to fit the rear sliders, which replace the rear shock rubbers.
This process can be one of trial and error, as the rear shackle bolt needs to be far enough back in the slider so that as the car launches and the spring separates from the body, the rear of the spring can slide forward. It also needs to be mounted not too far back so there is room for the spring to compress when the car bounces. It all has to be set up with the car sitting on the ground and the full weight of fuel it will carry in the back.
The spring perches designed by the Gazzard boys are clever – instead of the usual U-bolt configuration that most leaf-spring cars run, these are scalloped perches that weld to the housing. These can also be a trial-and-error exercise to fit, as the car needs to be on the ground to set the correct pinion angle.
While a lot of this rear-end set-up was quite fiddly, the equipment we’ve used should make it worthwhile. With good suspension, a 235 radial tyre and the Haltech engine management, we hope to get the car into at least the bottom 1.3sec mark in the 60ft, and mid-1.2s after further development.
The next step will be to get the tailshaft installed so the pinion angle can be set, and finish fabricating the oil pan and pick-up so we can finally start getting the 5.3 fitted up. After that, it will be on to the fuel system, and some alloy work in the engine bay to mount the radiator and the pressure pipe from the turbo to the intake. Not to mention a bunch of smaller jobs like fitting the BA brake booster and VZ Commodore master cylinder. The list is never-ending, but we should have it all ready and together for Drag Challenge 2016. That’s the plan, anyway. s