Welcome to my Cobra Replica build blog.
Please contact me if you would like to know more detail as i progress."CR3514@live.com.au"

Monday, May 6, 2019

Bonnet Gaps, Rivets, and Scoop

After mounting the Bonnet Locks, I made up a little gauge block to mark out an even gap of 3.5mm around the Bonnet edge.
The opening in the body is very well formed and finished, the Bonnet however is over size from the laminating of the inner and outer skins and needs a bit of clean up.

I used dimensions from various documented cobra examples for the bonnet and scoop Rivet patterns and decided on 23 scoop rivets and 29 bonnet rivet patterns.

Finding the centre of the car to align the scoop was difficult with the LH & RH sides of the centre line not being identical at various points along the body.
This made the scoop look slightly tilted and off centre.
The scoop also isn't a symmetrical product either and it took me a while to realize that the slight radius in the scoop nose was the main culprit making one side slightly longer on the right hand side by 3mm, not much but enough to make a visual impact when looking straight on.

The air inlet opening in the bonnet is also about 5mm out of square to the bonnet line at the front further impacting the scoop opening look making it "wink" slightly on the LH Side.
This was also sanded back and shaped using a flapper wheel.

The scoop has the forward outrigger on each side.
To get the scoop nose radius correct, the little out riggers had to go.

After removing the out riggers, I created an even radius on the top of the scoop nose and sanded back the sides to make even.

Lots of finessing, and the scoop finally looks right.

A little more to come off the thickness of the scoop but its getting there.

This is the rivet pattern I used as a rough guide for the main dimensions, found this initially on the289register.com site and also club cobra and some builder blogs.

Scoop Rivet pattern is 11-1-11 (23)
Bonnet Rivet Pattern is 14-1-14 (29)

Wednesday, April 24, 2019

Bonnet Locks

Had the Bonnet and Boot Latch kit sitting patiently for many years,
I bought from Classic Revival at a time when Ian was intending to sell up his business.
The boot latch has a custom bracket which I thought at the time might be prudent to buy given the business may not have continued. Fortunately it ended in the capable hands of Daniel Steer, a previous employee of Ian Denner's and respected car restorer and fabricated in his own right.

This is one of the pair of Bonnet Handle and Latch Cams.
Its the oval base type, since purchasing these, I have also seen round base options.

The kit comes complete with Cams, Gaskets, and Stainless screws, which i replaced with Stainless 4mm Button Head Cap Screws.

This is the landing  on the body shell that the Bonnet Lock Cam protrudes through.
The Cam is off centre to the shaft so as the handle shaft turns to lock position, the Cam goes under the edge of the hole to lock the bonnet in position.
First step was to centre a hole in the landing and project some centre lines out to the body for transferring on to the closed bonnet. This will give me the overlapping hole centre line through the bonnet and landing

You can see in this pic that the Handle Shaft and Cam are on angle to the relatively level Landing on the Body and  the Bonnet Inner Panel.
This angle offsets the hole in the bonnet by 5mm to the centre of the Cam or 16.5mm to the centre of the Landing Hole.

Based on the 5mm offset, a new hole centre was marked and through drilled with 19mm hole saw parallel to the bonnet curvature.

Drilled an undersized 52mm hole for hole saw in the landing big enough for the Cam to go through but not quite final size in case a bit of finessing was required.

While the hole is centred in the landing, the shaft for the Handle is offset 11.5mm. towards the inside of the car

Under side of the Bonnet with Latch Holes.

Mounted the Handle.

Bonnet underside.
In this pic you can see an afterthought.
Nothing stops the handle from rotating through 360 degrees other than friction of the Cam against the body when locking, so i designed and printed an ABS plastic base plate for the underside of the handle mount that has a 3/4 boss on it and a Key that fits around the shaft and in between the boss walls to allow only a quarter turn.
Lock - UnLock.

You can see the Base and the Key in this pic along with aluminium flange and dress ring to go through the Landing and finish off the hole and protect the final paint.

Flange and dress ring installed.
After checking the Cam alignment through the hole, I used a flap sander on the drill to bring the hole diameter out to 55mm for the flange to fit through.

From the underside, you can see the angle the shaft and Cam enter the Landing hole.

This pic is the unlocked position.

In this pic, the Cam has rotated to the Locked position with the angled Cam face up against the bottom of the hole flange.

Friday, April 12, 2019

Dash Brace and Brake Bias Adjuster Mounting

After mounting the dash in for gauge location layout, I found the aluminium panel unsupported at the bottom and more flexible than I liked, so I've made up a brace that looks like the original tube brace from behind the dash to the tunnel.

On this tube brace, I've welded a bracket that the dash return lip on the bottom screws to that now stiffens it up and stops any flexing and vibration.

I also made up and welded another bracket to the tube brace for mounting 2 USB ports, 1 for the ECU and the other for Power or Media back to the radio in the boot area and a position for the Remote Brake Bias Adjuster.

Top of the Brace mounts to the dash bow.

The bottom of the tubes have 8mm studs that protrude through the tunnel and fixed from the underside.

Brace installed with Brake Bias Adjuster Knob and USB port mounted after a sandblast and Black Powder Coat by Best Coatings in Dandenong South.

Monday, February 11, 2019

Fuel Filler

Finished off the Fuel Filler Neck and installed.

The Fuel Filler Tube is a shortened Holden OE VT Commodore Wagon Filler Tube.
The top half of the tube and its vent tubes are retained but cut just after the breather valve component.
A 45 degree 2" exhaust tube is joined between the filler tube and the tank inlet tube with Mackay rubber fuel 2" hose (Part Number CH5933).
The fuel pipe has been HPC coated for rust prevention.


Still plodding along,
Made up Clutch, Brake and Accel Pedals over the last week plus took my annual anniversary pic....another year gone.

After mounting the original pedals, I felt they were too high at 230mm off the floor and i still hadn't bent them into position, the pad being under my toes when my foot was resting on the floor.
Bit of research and a look at a Tilton Racing setup i decided i would make new ones.
The main goals were to increase the space between the pedals, shift the pedal layout to the left about 50mm and lower the height by 25mm so the pedal pads were under the ball of my feet.

Built a 3D model in Inventor, then exported the DXF drawing and cut on the CNC.

Pic of the cut 8mm MS profile for the Brake Pedal, The original un-bent Brake Pedal in the back ground.
The smaller hole to the right is the pivot point, the larger hole is for the balance bar bush.

Pre-assembled before welding, machined the pivot tubes from solid stock on the lathe.

Also tilted the Pedal Pad slightly back so it was better presented to the foot angle.

Turned the pad side ways to suit OEM VZ HSV  Aluminium Style Pedal Pads.

Built the clutch pedal up the same way, Painted and assembled ready to install.

Pedals fitted with VZ HSV Commodore Pads.

Brake & Clutch Pad Part number: 92113883
Accelerator Pad Part Number: 92113881

Clutch Pedal on the left is same profile but from 6mm MS and less the Balance Bar Tube.

Accelerator Pedal Assembly.
The mechanism is an aftermarket LJ/LC Holden Torana cable conversion Kit KH004 from Rare Spares.
Modifications to this were shorten the Cable Pull Arm and weld a new 3 position Cable Pull Bracket on. (key point was to make sure sufficient arc rotation to open throttle bodies fully.
Bent the foot pedal arm over about 10mm and reassembled with the VZ Accel Pedal Pad to match the Brake and Clutch Pedal Pads.

The CR chassis comes with the pedal support built in and has a Accel mount to suit Drive By Wire (DBW) pedal however I have installed aftermarket dual throttle bodies on the LS3 that require a cable pull activation method.
The original DBW mount has been removed from the pedal support.

After installing the pedals, I drilled a hole in the firewall and installed the Accelerator Cable.

Throttle Cable location at the top of the Footwell.

On the other end of the cable.
Could not find a suitable Cable Bracket to mount to the Throttle Body, I wanted to integrate GM factory Cruise Control Cable but none of the commercial brackets had the suitable hole profile.
Another round of drawings, CNC time, a bit of vice bending and some paint and a custom 2mm MS bracket was created.

In the pic below, you can see the black Cable Bracket installed with:
Lokar 48" Accelerator Cable LK-XTC-1000HT48
1/4" Spherical Ball Joint with 1/4" female threaded end which suits the Lokar Cable End.
Holley Kickdown Stud #37-12 (has same cable pull end design to suit GMH OE Cruise Cable)
VZ Commodore Cruise Control Cable.
Lokar double Stainless Steel Cable Return Spring Set SRK-4002

Sunday, July 29, 2018

Body Work

Getting prepared for paint.
Lots of bits and pieces to mount to the body, so in preparation before painting, i'm mounting all the items to make sure i'm happy with the placement, pre-drilling mounting holes and tweaking gaps so reassembly after paint is as pain free as possible.

First job was to secure the windscreen, in this pic you can see the gap between the windscreen blade that protrudes through the body slot and the gap to the hoop mount bracket.
there is 2 bolt holes to align on each side, 1 on top of the hoop, and 1 on the hidden side of the hoop.
Made 4 spacers, 2 at 10mm thickness f.or the pictured passenger side, and 2 at 6.5mm thickness for the drivers side.

Once the screen was in its correct location, mounted and marked the body holes for the windscreen centre mount l bracket then moved on to the Custom made race screen mount.
Worked out all the hole spacing's for the mount and drilled through Aluminium mount and body.

In this pic you can also see the normal windscreen demister vent.

Underneath the dash showing the demister vent slot.

I don't plan to fit a demister to the car, but installed the slots and vents for later use if i have to fit, I've allowed enough room between the under dash hoop and the dash panel.

Passenger side demister vent fitted.

Also bought a 3rd mirror to use as rear view mirror in keeping with the race look.
I have a normal windscreen mounted mirror as well if needed to get through engineering and registration.

Hand brake mounted in place.

This hand brake lever is from Ford Falcon BA/BF (part number  BA 2760 B1)
The chassis has a bracket pre-mounted for this specific item.
Mine is from a sports model with the leather grip which matches in with seat colour perfectly.

Hand Brake Cable goes through the body to the Lever.
Made up an aluminium cable guide so the cable doesn't rub on the fibreglass.
Its mounted on a plastic washer on the outside and held in place with a stainless washer and "E" clip on the inside.

Hand Brake Cable Guide from the inside of the cabin area.

Seat Belt slots had to be widened slightly to fit the buckles through.

The seat belts are horizontal mounted retractors mounted on the chassis immediately behind the rear Bulk Head.

These belts are aftermarket APV units model number K2578.
While the kits come complete with Bolts, Spacers, and Swivel Bushes, there are no nuts ? apparently nuts are optional extras.
so off to the bolt bloke for some 7/16" UNF nylock nuts.

Belt Retractors mounted behind the Bulk Head on the Roll bar chassis mount.

Seat Belt Buckle. think i need a shorter stalk.

one bonnet handle in, one to go.

Started on the bonnet gaps but decide it was best to get the latches and handles in first so the final resting place was locked in.

The gaps are a bit wild, so sanding to about 3.5mm then will put a radius on the edge to match the body
A couple of spots may need to be built up a bit.

Bought a couple of Badges from Finish Line Accessories awhile back with Vents, Mirrors, other bits and pieces. etc.

Mounted on the centre line .

Thursday, July 5, 2018

Seats - Front Row & First Class

Classic Revival make an ADR approved seat for their kit, but I wanted a more traditional looking seat.
Classic & Sports Auto Interiors in Eltham  make such a design and is a popular choice with Cobra builders throughout Australia regardless of the brand.
I settled on Leather in Black Charcoal, a Standard material and colour for C&S.
The finish is excellent with the only modification being seat warmers installed in both.

The headrest is a necessity under ADR 03/03 requirements, and the design by C&S is a nice shape and overall doesn't detract too much from the whole look, i'm very happy with them.

Both seats bolted in position after final alignment and mounting tweaks.

Left hand passenger Seat.
The seat backs sit a little higher than original, but this is a distance (height) specification in the ADR 03/03 design regulations from the hip joint to the top of the seat back.

After sitting in them, I canted the fronts of the cushion slightly to the outside for 2 reasons.

Better alignment with the pedal locations on the drivers side, and allow the seat to slide fully forward on the runners without hitting the centre tunnel.

The seat tracks sit on spacer plates to raise them about 10mm for a better leg angle and to bridge the differences between the CR factory seat location mounts and the Classic & Sports Seat Track mounting hole locations.

I actual cut the drivers seat mounts only once, luck of the draw, but ended up doing the passenger set 3 times due to differences in the locations and getting the gaps  between seat and body even.

Off the Hook - Rear Tow Hook

The front Tow Hook point was a Rally Tech Product designed for a Mitsubishi EVO, and mounted to the chassis fairly simply with custom angle bracket.
The rear has limited mounting options and with insufficient strength so the same Tow Hook could not be used.
I designed up a Tow Hook point similar in design to be through bolted through the rear chassis fuel tank mount frame.

As the Tow hook is mounted to the rear cross tube, its a bit "flexible"  if given a jolt, so i made a 6mm flat brace from the tow hook mounting triangulated back to the original Roll Bar mount on the chassis. this has stiffened up that section significantly.
The brace is mounted inside the boot area on the floor.

Milled from some 16mm Aluminium, then faced on both sides to 15mm thickness to match the front Tow Hook.

Powder coated in Fire Extinguisher Red.
It was close colour match to the front Tow Hook and a regular stock colour that Best Coatings in South Dandenong use in their production.

A spacer block lowers the Tow Hook so it has clearance beneath the rear of the body.

The holes through the tube have a steel tube inserted so the bolts don't crush the tube when tightened.

In this pic, you can see the strap brace going from the Tow Hook Mount position to the original Roll Bar 3rd Leg mount location on the chassis.

I used this strap and a another little plate to cover the fuel tank strap bolt location.

Also in this pic you can see the Quick Jack Mounts that protrude through the Boot Floor and the cover plates to seal up the opening.

Cover Plates are 1.2mm Aluminium sheet stock cut to size and will be screwed to the floor with 4mm Button Head Screws.