Welcome
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"
Please contact me if you would like to know more detail as i progress."CR3514@live.com.au"
Regards
Dave
Dave
Saturday, February 28, 2015
Saturday, January 24, 2015
A Little Progress, Bonnet Struts, Overflow Bottle, Washer Bottle
Not much to report of late, busy with work and family.
Fitted the Overflow Bottle, Washer Bottle and ordered some fittings to plum it all up.
Also fitted the Bonnet Hinge Cross Member and Bonnet so I could test fit the Struts and check clearance to the engine.
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Here you can see the strut mounted from the chassis to the hinge.
A strut is fitted to each hinge.
Also the Bottles fitted to a cross brace between the suspension mounts.
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Drilled a new 8mm hole in the hinge, the existing holes are only 6mm and too close to the edge.
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Works well, with minimal effort to open and close.
Didn't take a pic yet of the passenger side Header, but you can see in this pic its progressing.
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Needs Stripes.
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Clearance is hard to see in this pic, but there is plenty, and if it ends up being too close, I'll open up the opening a bit more.
Fitted the Overflow Bottle, Washer Bottle and ordered some fittings to plum it all up.
Also fitted the Bonnet Hinge Cross Member and Bonnet so I could test fit the Struts and check clearance to the engine.
Here you can see the strut mounted from the chassis to the hinge.
A strut is fitted to each hinge.
Also the Bottles fitted to a cross brace between the suspension mounts.
Drilled a new 8mm hole in the hinge, the existing holes are only 6mm and too close to the edge.
Works well, with minimal effort to open and close.
Didn't take a pic yet of the passenger side Header, but you can see in this pic its progressing.
Needs Stripes.
Clearance is hard to see in this pic, but there is plenty, and if it ends up being too close, I'll open up the opening a bit more.
Thursday, December 11, 2014
Headers Part 1.
The space for headers, particularly the rear 2 cylinders, is very tight on clearance to the foot wells, and steering rod between the column and rack on the CR, This necessitates a custom made header design,
Other criteria for me was to also utilize as much OE emissions controls as possible to get me through the certification engineering and registration process.
The emissions need to meet IM240 requirements, and noise db, so my header design needs to be able to adapt from OE Catalytic converters and under-body muffled rear exit design to the 4 into 1 of the iconic cobra side pipes in the future if I want to go this way.
At the moment, I'm thinking under-body but exiting to the side behind the doors.
A while back, I procured the Cats from another CR builder friend, they were to be discarded from the donor wreck he got his Engine and Trans, Diff and several other components from, (thanks Phil).
After figuring out if I could make them fit in the space, which entailed finding short merge collectors, and some tube routing concepts, i made up a stand to hold the cats in place while i played with different tube locations.
Firstly, I decided on 1.75" tubes, a little research suggested this was the ideal tube size for a mild almost stock LS3.
Drivability is all I'm after with this combination and 434HP in stock form in a 1000kg car will be plenty for me.
I bought some exhaust modelling blocks from "Icengineworks" via Summit in 2", 3" and 4" CLR and some straight blocks, enough to do 1 side at a time.
The blocks come in kits as well with all sorts of other bits and pieces, but I didn't need to obtain these and I'm glad I didn't buy the full kit.
After playing with the blocks, and different options of over and under the steering rod, i finally settled on the above.
This design has all the pipes over the top of the
steering rod which will make for easy removal if required.
The blocks are very quick to adjust to make fit and too maximize the use of bends with minimal cuts and welds.
In this design, the 1st 2 pipes have only 1 join each, and the 3rd has 2 joins and the rear pipe has 3 joins.
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In this pic you can see the merge collector, I bought these from SPD Exhausts in the US.
Get yourself a catalogue, great bits and pieces.
The ring above it is a flange I had laser cut. Actually i had six cut, 1 each for the headers, 1 for each collector, and 1 for each of the 4 into 1 side pipe assembles.
This is so I can split the collector off the header and mount the side pipes to at a later date.
The 2 flanges will have V-band clamp rings welded to them for connecting together.
So basically, as you can see in the first pic, the blocks have alignment arrows.
Where the arrows align, the blocks are curved in 1 continuous arc plane, Where they don't align is the point of a change in the arc plane, so I marked this point with a marker pen. on the changed plane then separate at the mark and cut the component from the matching radius mandrel bent pipe.
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VoilĂ !
Here you can see the 2 bends tacked together in the same orientation as the model.
You can also see the marker pen on the join at the change in arc plane.
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Eventually, you end up with this.
I have never done this before, and I'm really happy with the result.
Next step was too remove the pipes and weld the joins, before reassembling to the flanges again for final welding.
After tacking it all up, remove the header and mounted to a spare LS1 head to keep it from warping when I welded it all up.
In this pic, you can see I've flapped and filed out the MIG welds on the tubes for a smooth flowing look.
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Test fitting the collector again before final welding.
Mig welded up all the flanges while clamped to the spare head.
.JPG)
All done except for O2 bungs and V-band clamp flange on the CAT outlet.
A view from underneath.
Next is to model up the left bank and do it all again.
Other criteria for me was to also utilize as much OE emissions controls as possible to get me through the certification engineering and registration process.
The emissions need to meet IM240 requirements, and noise db, so my header design needs to be able to adapt from OE Catalytic converters and under-body muffled rear exit design to the 4 into 1 of the iconic cobra side pipes in the future if I want to go this way.
At the moment, I'm thinking under-body but exiting to the side behind the doors.
A while back, I procured the Cats from another CR builder friend, they were to be discarded from the donor wreck he got his Engine and Trans, Diff and several other components from, (thanks Phil).
After figuring out if I could make them fit in the space, which entailed finding short merge collectors, and some tube routing concepts, i made up a stand to hold the cats in place while i played with different tube locations.
Firstly, I decided on 1.75" tubes, a little research suggested this was the ideal tube size for a mild almost stock LS3.
Drivability is all I'm after with this combination and 434HP in stock form in a 1000kg car will be plenty for me.
I bought some exhaust modelling blocks from "Icengineworks" via Summit in 2", 3" and 4" CLR and some straight blocks, enough to do 1 side at a time.
The blocks come in kits as well with all sorts of other bits and pieces, but I didn't need to obtain these and I'm glad I didn't buy the full kit.
After playing with the blocks, and different options of over and under the steering rod, i finally settled on the above.
This design has all the pipes over the top of the
steering rod which will make for easy removal if required.
The blocks are very quick to adjust to make fit and too maximize the use of bends with minimal cuts and welds.
In this design, the 1st 2 pipes have only 1 join each, and the 3rd has 2 joins and the rear pipe has 3 joins.
In this pic you can see the merge collector, I bought these from SPD Exhausts in the US.
Get yourself a catalogue, great bits and pieces.
The ring above it is a flange I had laser cut. Actually i had six cut, 1 each for the headers, 1 for each collector, and 1 for each of the 4 into 1 side pipe assembles.
This is so I can split the collector off the header and mount the side pipes to at a later date.
The 2 flanges will have V-band clamp rings welded to them for connecting together.
So basically, as you can see in the first pic, the blocks have alignment arrows.
Where the arrows align, the blocks are curved in 1 continuous arc plane, Where they don't align is the point of a change in the arc plane, so I marked this point with a marker pen. on the changed plane then separate at the mark and cut the component from the matching radius mandrel bent pipe.
VoilĂ !
Here you can see the 2 bends tacked together in the same orientation as the model.
You can also see the marker pen on the join at the change in arc plane.
Eventually, you end up with this.
I have never done this before, and I'm really happy with the result.
Next step was too remove the pipes and weld the joins, before reassembling to the flanges again for final welding.
After tacking it all up, remove the header and mounted to a spare LS1 head to keep it from warping when I welded it all up.
In this pic, you can see I've flapped and filed out the MIG welds on the tubes for a smooth flowing look.
Test fitting the collector again before final welding.
Mig welded up all the flanges while clamped to the spare head.
All done except for O2 bungs and V-band clamp flange on the CAT outlet.
A view from underneath.
Next is to model up the left bank and do it all again.
Saturday, November 1, 2014
Engine Mount Spacer and Chassis Wiring
Started and completed the chassis wiring up to where it will go through the firewall.
I am going to run 3 looms in the car.
One for the parts on the Chassis such as Fans, Horns, ABS sensors, Fuel Pump, Windscreen Pump, and some water and diff oil temp sender, and another for Engine and Transmission, and a 3rd for body mounted components like Lights, Dash Wipers etc.. etc..
I'm not intending to put ABS on the car, but put the wires in the loom as a "just in case" I ever decide too, or maybe traction control.
Also after reading about sumps protruding below the frame rails, I laid a straight edge across the rails below the sump, dead level just scrapping the sump surface, so I decided to lift the engine slightly for clearance.
10mm Spacer added under engine mount.
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I cut the spacer on my mini CNC mill from some aluminium stock, then put in the tumbler overnight to smooth all the edges.
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In this pic, you can see how level the sump to frame rails was.
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ABS wire from the upper control arm to the sensor in the side of the knuckle.
The sensors are factory VE Commodore/
The plugs are off the shelf Narva AMP 2 pin plugs.
The clips holding the loom to the upper arms are bike cable clamps suggested by another CR builder.
These ones came from ebay in a, stainless steel, 6 pack and are 28mm diameter.
.JPG)
Fuel pump and float sensor is wired.
I also tested to make sure it works...all good.
I am going to run 3 looms in the car.
One for the parts on the Chassis such as Fans, Horns, ABS sensors, Fuel Pump, Windscreen Pump, and some water and diff oil temp sender, and another for Engine and Transmission, and a 3rd for body mounted components like Lights, Dash Wipers etc.. etc..
I'm not intending to put ABS on the car, but put the wires in the loom as a "just in case" I ever decide too, or maybe traction control.
Also after reading about sumps protruding below the frame rails, I laid a straight edge across the rails below the sump, dead level just scrapping the sump surface, so I decided to lift the engine slightly for clearance.
10mm Spacer added under engine mount.
I cut the spacer on my mini CNC mill from some aluminium stock, then put in the tumbler overnight to smooth all the edges.
In this pic, you can see how level the sump to frame rails was.
ABS wire from the upper control arm to the sensor in the side of the knuckle.
The sensors are factory VE Commodore/
The plugs are off the shelf Narva AMP 2 pin plugs.
The clips holding the loom to the upper arms are bike cable clamps suggested by another CR builder.
These ones came from ebay in a, stainless steel, 6 pack and are 28mm diameter.
Fuel pump and float sensor is wired.
I also tested to make sure it works...all good.
Friday, September 19, 2014
LS3 Dual Quad EFI Intake Manifold
In a previous post, I was intending to fit the Holley Dual Quad LS cathedral port inlet manifold to the LS3 rectangular port heads by making up an adapter flange, however, this became unnecessary as while I was emailing Holley about some other details to do with the throttle body linkage, I learned that they were prototyping an LS3 version.
Some special arrangements via Summit Racing resulted in me obtaining one.
Holley Dual Quad LS3 EFI manifold part number 300-134
Fitted up with the original LS3 injectors.
Two different sized rail mounts are included with the kit to suit LS3/LS7 style injectors or the longer EV1 style injectors.
New replacement lower injector O-Rings are also included.
The overall manifold sits about 1/4" higher than the cathedral port version.
The fit up however wasn't plain sailing,

Here you can see the manifold doesn't fit up to the stock heads with a gap between the faces.
The overall casting was too wide to fit between the head port machined surface.
There is sufficient material on the manifold to make it fit by machining off a bit of the flange.

In this pic, you can see the edge of the flange overlaps the casting at the top of the head port face machined area.
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Set up in the mill for machining.
Could easily file off each flange to fit if required.
I machined a few millimetres off each side of the flange casting.
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Finished mods.
The mounting bolts holes for manifold to head are in perfect alignment and the ports are very well matched to the stock heads.
I'll post some more pics of the injector rail to manifold mounting shortly, forgot to take pics.
Some special arrangements via Summit Racing resulted in me obtaining one.
Fitted up with the original LS3 injectors.
Two different sized rail mounts are included with the kit to suit LS3/LS7 style injectors or the longer EV1 style injectors.
New replacement lower injector O-Rings are also included.
The overall manifold sits about 1/4" higher than the cathedral port version.
The fit up however wasn't plain sailing,

Here you can see the manifold doesn't fit up to the stock heads with a gap between the faces.
The overall casting was too wide to fit between the head port machined surface.
There is sufficient material on the manifold to make it fit by machining off a bit of the flange.

In this pic, you can see the edge of the flange overlaps the casting at the top of the head port face machined area.
Set up in the mill for machining.
Could easily file off each flange to fit if required.
I machined a few millimetres off each side of the flange casting.
Finished mods.
The mounting bolts holes for manifold to head are in perfect alignment and the ports are very well matched to the stock heads.
I'll post some more pics of the injector rail to manifold mounting shortly, forgot to take pics.
Monday, August 25, 2014
Fuel Tank - Finished
Well, finished off the fuel tank installation today,
First stop was Clark Rubber for some small rubber bumpers to fit to the chassis to insulate from the tank and some Neoprene for the straps to insulate from the tank.
Some careful bending to get the straps to fit neatly and all bolted up
First stop was Clark Rubber for some small rubber bumpers to fit to the chassis to insulate from the tank and some Neoprene for the straps to insulate from the tank.
Some careful bending to get the straps to fit neatly and all bolted up
Friday, August 22, 2014
Tank Straps & T-Bolts, some more Progress
Here's some more pics of the straps progress.
Received the T-Bolts back from HPC coatings.
As usual, first class finish and service.
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Straps held together with Stainless Steel Rivets.
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Straps finished,
Ready to install.
.JPG)
This is as far as I got,
Need to buy some tank strap rubber insulator material, and some pads to insulate fuel tank to chassis.
.JPG)
Almost there.
More pics soon.
Received the T-Bolts back from HPC coatings.
As usual, first class finish and service.
Straps held together with Stainless Steel Rivets.
Straps finished,
Ready to install.
This is as far as I got,
Need to buy some tank strap rubber insulator material, and some pads to insulate fuel tank to chassis.
Almost there.
More pics soon.
Tuesday, August 19, 2014
Tank Straps & T-Bolts - Unfinished
I like the look of T-Bolt designed strap clamps and V band clamps, Turbo clamps etc, and thought I would try to replicate this for the fuel tank straps instead of the usual hole in a strip of material bolted to the chassis.
Initially I thought I would be able to buy this type of product but after searching the web and calling several clamp manufacturers, I found only 2 that would custom make small runs of parts, Clampco in the US, and Hilton Manufacturing here in Australia. There maybe others, but I couldn't find them.
I visited Hilton, in Dandenong, they are truck tank and band manufacturers, they make T-Bolt Band Clamps but the scale is far too big for my use and their tooling cant make what I needed for my application, so that left Clampco in the USA,
I sent an email with my specs, and they advised they make this item from 1-1/4" x 60 thou strip (32mm x 1.5mm) with 3/8" (10mm) T-Bolts to any length required, it came with a hefty US$900 price tag excluding freight.
So I decided to have a go myself.
Firstly, the T-Bolts,
First effort was a poor looking result, butt welding a 10mm bolt shank to a 10mm rod,
Second effort was much improved, 16mm rod with a 10mm hole through the middle, then a bolt with the head cut off inserted in the hole half way and welded in place from the top.
Ground off to finish the part, I made 5, 4 off to be coated, 1 to use in a forming jig I made for the straps.
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This is the forming jig I made from 2 scrap pieces of angle iron, a hole between them for the T-Bolt to be pulled through.
In this pic, the strap is about to be pulled into the slot.
The straps were laser cut from 1.5mm polished stainless,
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As you tighten the nut, it pulls the T-Bolt into the groove forming the strap around T-Bolt end.
.JPG)
This is the second jig I made from another bit of Angle Iron, a hole in it for the T-Bolt to hold the strap firm against the vertical angle, then 2 bolts through the horizontal with a bar bridged between them.
The bar is placed so it will press down just in front of the t bolt forming the strap around it to make a "P" clamp.
In the end, I stuck it in the press instead of winding the nuts down.
Pressed and formed.
Straps finished but awaiting the T-Bolts to return from coating.
After assembly the straps will be closed up and held with stainless rivets.
The rivets take no load other than holding the assembly closed.
More pics when I get them finished and on the car
Initially I thought I would be able to buy this type of product but after searching the web and calling several clamp manufacturers, I found only 2 that would custom make small runs of parts, Clampco in the US, and Hilton Manufacturing here in Australia. There maybe others, but I couldn't find them.
I visited Hilton, in Dandenong, they are truck tank and band manufacturers, they make T-Bolt Band Clamps but the scale is far too big for my use and their tooling cant make what I needed for my application, so that left Clampco in the USA,
I sent an email with my specs, and they advised they make this item from 1-1/4" x 60 thou strip (32mm x 1.5mm) with 3/8" (10mm) T-Bolts to any length required, it came with a hefty US$900 price tag excluding freight.
So I decided to have a go myself.
Firstly, the T-Bolts,
First effort was a poor looking result, butt welding a 10mm bolt shank to a 10mm rod,
Second effort was much improved, 16mm rod with a 10mm hole through the middle, then a bolt with the head cut off inserted in the hole half way and welded in place from the top.
Ground off to finish the part, I made 5, 4 off to be coated, 1 to use in a forming jig I made for the straps.
This is the forming jig I made from 2 scrap pieces of angle iron, a hole between them for the T-Bolt to be pulled through.
In this pic, the strap is about to be pulled into the slot.
The straps were laser cut from 1.5mm polished stainless,
As you tighten the nut, it pulls the T-Bolt into the groove forming the strap around T-Bolt end.
This is the second jig I made from another bit of Angle Iron, a hole in it for the T-Bolt to hold the strap firm against the vertical angle, then 2 bolts through the horizontal with a bar bridged between them.
The bar is placed so it will press down just in front of the t bolt forming the strap around it to make a "P" clamp.
In the end, I stuck it in the press instead of winding the nuts down.
Pressed and formed.
Straps finished but awaiting the T-Bolts to return from coating.
After assembly the straps will be closed up and held with stainless rivets.
The rivets take no load other than holding the assembly closed.
More pics when I get them finished and on the car
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