Normally these come pre assembled by GD, however they were having problems with their hydraulic press so it presented an extra step for me to contend with. First the outer races of the taper roller bearings need pressing in to the hubs, as I don't have a press ended up outsourcing this to a local HGV workshop. Now the bearings can be packed with the supplied grease before being laid into the outer races within the hubs; the outer bearing is held in place with a seal cup which is gently tapped in to place with mallet and copper drift. The inner bearing has an alloy cap instead of a seal.
Gav's GDMk4 Cobra Build
Building a modern alternative of the classic AC Cobra, progress so far...
Overview
Monday 13 November 2017
Uprights & Hubs
Normally these come pre assembled by GD, however they were having problems with their hydraulic press so it presented an extra step for me to contend with. First the outer races of the taper roller bearings need pressing in to the hubs, as I don't have a press ended up outsourcing this to a local HGV workshop. Now the bearings can be packed with the supplied grease before being laid into the outer races within the hubs; the outer bearing is held in place with a seal cup which is gently tapped in to place with mallet and copper drift. The inner bearing has an alloy cap instead of a seal.
Differential
Mounting is straightforward with 3 bolts in the front, 4 to attached to the angle bracket and 2 bolts with nuts to hold the bracket to the chassis. Once all the bolts are in loosely they were tightened up permanently. Whilst this all sounds a five minute job, it took two of us almost an hour!
Saturday 2 September 2017
Rigid Brake LInes
The 'T' piece was loosely bolted to the pre-installed rivnut adjacent to the lower diagonal brace mount, this was tightened fully once the pipework was complete. Starting at the front a handheld pipe bender, I created the first bend then offered it up to make sure it was right before continuing with the next. This process was repeated until all the bends were complete.
The pipe route is shown in the pictures below:
From 'T' piece, along lower frame and under engine mount... |
...continues along lower frame then up round tube to aluminium block. |
The flexible hoses are different lengths, the short one goes right and the long one goes left |
The rear 'T' piece is bolted in the centre under the frame above the front diff mount, the rivnut here was a little loose so I tightened it with a spare bolt and a couple of nuts. I used the same process of offer up, mark, bend, check, move on as I did for the front pipe, starting at 'T' piece and moving towards the alloy block.
Two shorter rigid pipes go from the 'T' piece to some brackets where they meet the flexible hoses. The brame was drilled and tapped for the 'P' clips.
The pipe route is shown in the pictures below:
From 'T' piece along right hand upper frame rail... |
...up frame rail above gearbox... |
...final right angle to alloy block. |
Right hand side from 'T' piece to flexible hose bracket |
Left hand side from 'T' piece loops under fuel pipe, functional but not pretty, will redo this! |
Fuel lines pt1
The pipe runs along the left hand top chassis rail to just behind the body mount, then dips down slightly to avoid the handbrake cables, over the front diff mount before doing an 'S' bend outboard and over the driveshaft. I drilled and tapped the frame to secure the pipe with 'P' clips, adding a little grease in the holes to hopefully stop corrosion.
90 degree bend approximately 25mm in front of cross member |
Routed along right left hand top chassis rail... |
...slight downward bend rear of body mount... |
...over front diff mounting plate... |
...'S' bend outboard and over left hand driveshaft. |
Chassis Collection
Old 4 man tunnel tent is a perfect fit for a Cobra! |
Chassis is only about 75kg so easily goes on the roof (didn't do much for my fuel economy though!) |
Thankfully I have a large estate car |
Front suspension components |
Rear suspension components |
Monday 5 June 2017
Side Repeaters
I had been putting off the side repeaters as I couldn't decide which ones to fit until seeing some LED ones on the GD stand at Stoneleigh. They come with a black rubber grommet and optional chrome surround and I managed to pick them up at the show from CBS.
Fitting these is very straightforward once you've decided where you want them. Some people place them towards the rear above the louvres but I chose to put mine further forward.
I placed 25mm wide masking tape along the top and forward edges of the louvre opening, then another strip above and one behind. Where the tapes overlap creates a diamond shape above and inline with the forward edge of the opening.
Drawing a cross to join the opposing corners of this diamond gave me a centre point to drill a 20mm hole. Once the edges are cleaning up the side repeater just pushes in. I've order some two pin Econoseal plugs which I'll install later.
Repeat for the other side, all in about 20 mins work.
Stop switch
I had forgotten to install the brake light switch when I installed the pedal box, so that was removed again. Not an easy job on your own unless you have 'go go gadget arms'!
As I'm using the Lexus engine and intend to utilise the cruise control, I kept the swith from the donor. This switch has 4 wires, two for the brake lights and the other two for the cruise control.
I created a small bracket out of 25mm x 2mm flat aluminium bar with a slight bend in the middle to position the switch at the correct angle. I then drilled and tapped the pedal box and bolted it on with M5 button heads and spring washers.
I've also installed a second switch on the clutch pedal which will stop the starter operating unless the clutch is depressed, thus never accidentally starting it in gear.