Running repairs

Sun visor

There was a rattle, but at first I couldn't work out where it came from. Then I found it was from a sun visor. A grub screw on one of the visors had worked loose and fallen out. I couldn't find the screw, so had to buy an M4 x 5mm replacement grub screw from eBay (4 for £1.18).

Apologies for the poor photo. Little grub screw can be seen here

Cooling fan mounting

Two of the four fan mounts had broken after only 1,200 miles, as I previously reported. So I ordered a new fixing kit from Car Builder Solutions for £12 plus postage of £4.20. When I received the parts, the old mountings were removed by undoing the caphead bolts from the rivnuts, which held the fan in place.

Fan mounting point and rivnut can be seen here

The new mountings were then fixed in place.

New mounting fixed with a dab of nut lock

Coolant pipe fixing

I had damaged the jubilee clip which secured the hose from the thermostat to the radiator by tightening it too much. So the coolant leaked from the hose. A sticky mess! A replacement W4 stainless steel clip was bought from eBay for just £1.05. The hose did not have to be removed to do this. The jubilee clip was simply fully loosened, then fixed over the hose (after removing the old clip). Then tightened.

Leaky Cobra and broken fan mount

Coolant leak

I have had a coolant leak for some time from the thermostat housing. Unfortunately there is no drain point in the system, so a hose needs to be disconnected. Messy!

First I drained down the system and removed the thermostat housing. This was cleaned up where it mated to the block. Next I applied Hylomar blue sealant to the mating surfaces. After a bit of fiddling I got the thermostat and housing back in place, bolted up and filled ......... but it still leaked. So I repeated the process. It leaked again! So a glass of wine was called for.

After relaxing a bit, I thought of three reasons why this may be happening - the thermostat was not being correctly aligned, the bolts were too long and not allowing the housing to be nipped up or both.

So the next day I checked the bolts and sure enough one was not going in to the block far enough. The bolt was shortened a little to allow it to screw in fully.

Next I fit the rubber thermostat gasket in to the housing, using sealant in the recess where the rubber gasket sits. Then I put two tie wraps through the top of the thermostat and threaded these through the housing. I located the thermostat in place, making sure that the pressure release thingy was in the correct place (there is a recess in the rubber seal). Next I fixed the tie wraps around a bolt to secure the thermostat in the right place and so that it could not be moved whilst fixing. Sealant was applied yet again to the clean mating surface, before the housing was offered up and bolted in place. The tie wraps were removed, the hose reconnected and the jubilee clip tightened. The system was then re-filled gradually, making sure that no air was trapped (tip - get the front of the car higher than the back). Success!

Thermostat housing re-fitted

Radiator fan

Whilst messing about stopping the leak above, I noticed that two of the fan fixings on the driver's side had broken after only 1,200 miles!

Broken fan fixing. Tie wrap can now be seen below it.

What I should have done was to fit tie wraps as well to help stop the mountings moving. I have ordered new fan fixings to replace the broken ones. Guess that is the problem of such a big fan.

Small things

It has been snowing on and off today and is very cold in the garage, so time in there was kept to a minimum!

Speedometer

After using the wrong diff ratio the first time, I recalculated the speedo setting with the correct ratio at 27,868 for the ETB gauge. This will need putting in to the speedo prior to using the car.

Front dummy number plate

After spraying the dummy number plate satin black, I fitted it to the car using 19mm P-clips and button head bolts.

Dummy number plate can be seen here

Clutch reservoir

I noticed a fluid weep from the reservoir, so had to remove it and refit. Looks like it is cured.

Coolant

Following my abortive attempt at filling the cooling system, I had to drain the fluid because of a leak at the thermostat housing.

Leak under thermostat housing on right of photo

I rescued the fluid, so that I could re-use it! The thermostat housing leak was sealed with Hylomar sealant and then refitted to the engine and the hoses. Care was needed not to trap the thermostat between the housing and the outlet, otherwise it couldn't be sealed (as I found out!).

Reseated and sealed

Coolant, clutch, IVA, ECU etc

Coolant

The coolant system took around 16 ltrs, 70% water to 30% antifreeze. This was added to the stainless steel expansion tank at the front of the engine compartment.

Coolant header tank

It was poured in gradually to reduce the risk of air locks. All pipes were checked for leaks at this stage. There was a leak in the thermostat housing - mutter, mutter. As this had a rubber O-ring I had not used any sealant. I should have - another lesson! So that's a drain down tomorrow. Not difficult, but a job I could do without.

If you are doing yours, remember that I have a Chevy LS6 engine. The amounts may differ on other engine types.

Clutch fluid

The reservoir was filled with DOT4 fluid. An auto bleed system was used, so that I could do it on my own. Air pressure from one of the tyres was used.

Clutch reservoir. Bleed nipple is on right of two pipes - not easy to get at

Oh, and I noticed that a wire had broken to the knock sensor, so I had to repair this.

ECU

The ECU was fitted to the centre under dash tray using button head bolts in to rivnuts. I made sure that there would be clearance for the gauges and that the connector would fit the ECU in that position.

ECU bolted to centre tray

The remote button for the speedo was fitted to the central tray too. It is concealed, but can be operated from the driver's seat. There is a gap between the underside of the tray and the transmission tunnel top.

NOTE: Fit a PC flylead to the ECU to make access to the ECU easier. See IVA and Post IVA category in the Build Process.

Tachometer

The dip switches on the back were checked to make sure that the settings were correct. For the ETB tacho the first 3 switches are set to 1 (on) and the remainder are set to 0 (off) for the LSV8.

The speedo will need setting too, but for the first calculation I had used the 3.23 diff and the later chassis (including mine) have a 3.07 diff. So I need to re-check the setting with ETB.

The faulty switch for the rear fog light was replaced whilst I played with the dashboard.

Starter heat shield

I had left this off for some reason. So it was added. Needed to remove the dip stick first.

IVA items

A dummy number plate is needed for the IVA and was made from MDF, sprayed black and fixed to the bar at the front in the nose using two 19mm P-clips.

The rear number plate lamp had the bolt changed for a button head to comply with the 5mm radius rule.

Hexagonal bolt swapped for button head

Flexible heating pipes

Oh b****r!

The flexible heater pipes had slipped off most of their outlets/couplings or they were easy to pull off. This had happened even though I had used tie wraps at every end. So tie wraps are out for me for this job.

Jubilee clips used to replace tie wraps

Solution, secure these again to the outlet or the coupling using jubilee clamps. A lesson for me. Do it right the first time to avoid re-doing the work!

Under dash trays and dashboard plus door seal finishers

At last, some work after a break doing some housework! Well work on the new house. So I am back to building the Cobra after almost a three month lay off. Yes I did a few small jobs, but now it's down to it properly.

Some essential, but easy jobs first. The bonnet was secured properly. The pivot bolts were re-attached, as were the gas struts. Next the remaining caphead bolts and washers were used to secure the hinges to the bonnet.

Then the wires were extended to attach to the horn. A tie wrap secured the wires to the compressor to ensure that they do not flap about.

Wires tie wrapped to compressor

Under dash trays

I had already fitted the centre under dash tray (see a previous post) a while back. The centre tray is where the ECU will sit.

The outer trays were secured to the front cross brace (the brace nearest the bulkhead) using self tapping screws. This will allow access to the dash if needed, at a later date. I had been putting this off. I thought that dodging the swarf from drilling the holes would be difficult. It wasn't as the holes could be drilled without getting right under the dash, I simply leaned in to the footwell and drilled the holes.

Hole in the underside of dash tray drilled through to the cross brace

The outer trays were fixed to the front brace only.

Under dash tray secured by self tapper

They were temporarily held at the dashboard end by racing tape. The trays will be sandwiched between the dashboard bottom and the rear most cross brace (nearest the driver/passenger).

The footwell heater outlet holes are pre-cut in the GD panels, but the laser cut holes were too small for the plastic vent, so needed opening out. I used the electric drill and a burr.  Here one part of the vent pushes through the hole, securing with the flexible lugs. Two small slots in the trays and squares on the vent stop them swivelling. The other part clicks over the vent on the upper side.

Driver's side vent in place

The other side is handled in the same way.

Door seal finishers

I have decided to replace the door seal finishers. I was not happy with those bought from Europa having seen the GD items. The GD finishers are not cheap, but they are good!

Front nearside door seal finisher in place

The rear door seal finishers will take a little more thinking about before I can fit them!

Engine loom part 2

Final bit of engine loom sorted today. If you are building a GD427, then do connect up the loom before you put the body on. Or at least connect up the loom to the gearbox and starter motor. It is so much easier to do it at that stage.

Reverse lights

The reverse light switch on the gearbox had two wires. These were now tucked away alongside the gearbox and within the chassis. So after jacking the car well up at the front and crawling under it, hands shredded, I finally managed to connect the bullet connectors together. Not the easiest or most pleasant of jobs.

Lacerations

Speed sensor

The speed sensor was in theory simple too. The car was jacked up well at the side. After crawling under the car, I managed to get my hand into the transmission tunnel at the back of the gearbox and remove the sensor, which was held in by one bolt and a locating plate.

The two wires were attached to the sensor using two thin connectors out of a waterproof Delphi double connector! The waterproof seals and some silicone were used to make sure that the connectors stayed in place and kept dry.

Speed sensor with wires siliconed in place

The installation was a reverse of the previous process. Don't lower the car until you have tightened the bolt :) Just don't expect this to be easy to get at!

Starter motor

Another nightmare to get at! The starter motor is tucked up behind the exhaust headers, with the solenoid on top.

Starter motor wires in place

The thick red wire from the battery and the red wire from the loom marked 'starter' are connected to the lower thick terminal. The other wire, slate and red, is connected to the thinner stud on the solenoid. The small wire terminal will not go on the wrong stud.

Bulkhead 'grommet'

A very rewarding job. Nice finisher!

An aluminium two piece bulkhead grommet had been machined by Keith Akerman for his car and I managed to get one from him, a real work of art!

Components of bulkhead grommet

GD don't do a part for this. It was easily fitted around the loom and pushed through the bulkhead. The bulkhead hole needed a bit of filing to open it out, before fixing the 'grommet' with four buttonhead bolts. A very neat solution and much better than having to fabricate one myself.

Neat!

Fuel pump

The short wire on the loom marked 'Pump' was connected to the white/purple wire of the body loom. This went to the fuse box, so needed cutting from the fuse box. The body loom is designed for a non-LS engine car, which has a different pump arrangement. A male connector was added to the cut wire and then connected to the wire on the relay block. See photo below where the cut wire can just be seen coming out of the fuse box and is taped up in black.

Fuel pump wires sorted

The relay block will be attached to one of the underdash trays later.

So now I just have the sensors to connect up on the engine - oil pressure, oil temperature and water temperature for the gauge, when I get them. All easy to get at. Well relatively .....

Thermostat

Luckily I realised that there was no thermostat in the housing, thanks for telling me Kyle, so I bought one from Monkfish. Great service and very prompt delivery. Whilst I was at it, I replaced the seal.

New thermostat and seal

It was simply a case of undoing two bolts on the housing, replacing the seal and inserting the thermostat, then putting the bolts back in place.

Where the thermostat goes

Header tank hose

A new piece of hose was attached between the block and the header tank (because I had originally used vacuum tube - not a good idea!).

Correct hose!

Handbrake

The handbrake was attached to the bracket to allow me to locate the position of the fixing holes. The end of the handbrake (the end with the button) was positioned in line with the front of the door opening. The holes in the mounting plate were marked through onto the floor and drilled. Bolts went through the bracket and through the holes in the floor. The bolts were secured with nuts and shakeproof washers on the underside of the car, using large washers to spread the load.

Handbrake in place

At this stage the handbrake could not be adjusted as it is a hydraulic/mechanical handbrake, so the brake fluid needs adding and bleeding first. However, the handbrake cable could be secured to the chassis with tie wraps, to keep it away from moving parts.

The carpet will be cut later, once the gaiter is received and fitted.

Gear lever

This was simply a case of attaching the lever with two bolts into the threaded gear lever stub on the 'box and then securing with nylocs. Once in place, I opened out the transmission tunnel hole slightly with the Dremel so that it would not foul against the GRP. Now I can select gears!!

Gear lever. Escutcheon is only laid in place.

Chevy LS6 heater hoses and vacuum tubes part 2

Heater hoses

Here are pictures of the heater hoses fitted. I bought the heater hoses from SFS Performance and the stainless steel heater pipes from GD.

Offside hoses to heater

Nearside hoses to heater

Front view

Vacuum tubes etc

The hose to the header tank and the overflow, were fixed in place.

Header tank hoses 

The vacuum tubes from the air intake to the rocker covers were also installed.

This required a tee piece to be inserted near to the rocker cover vent (I will replace this with a polished metal tee later). The hose was tie wrapped to the cross-member to keep it away from the belt tensioner. The superfluous vacuum take offs will be blanked off shortly.

Chevy LS6 cooling and heating hoses part 1

It is so cold at the moment that I have spent nearly two days working out where the hoses and vacuum tubes go and which take off pipes on the LS6 engine need blocking off in my Cobra. Well it is better than going out in to the garage and is so much warmer!

Here is how I will connect up the numerous hoses and vacuum tubes to my LS6. 

Heater

There are the following connections:

• 2 take-offs to the engine block on the lower offside
• 2 take-offs to the heater on the nearside inner wing

The take offs to the heater outlets on the engine at the offside are connected using hoses running around the front of engine (under the upper brace bar/cross member) and back along the chassis rail at the nearside to the heater outlets.

I have used GD's stainless steel heater pipes to add a bit of bling! Only the front is shown in the photo below. There is another pair of pipes that fit to the nearside of the chassis.

Front stainless steel heater pipes fixed to the upper brace bar

Cooling

A short hose connects the upper outlet from the engine to the long side of the header tank. The longer hose connects the header tank to the top of the radiator. 

Another short section of hose connects the lower coolant outlet to the long stainless steel pipe. NOTE: Check that there is a thermostat in the housing, I didn't have one! Re-seal using Hylomar blue sealant if you don't want any leaks - even with the rubber seal in place! At the other end the 90 degree hose connects this pipe to the lower connection on the radiator.

Cooling hoses and header tank

The header tank is fixed to the top brace bar with button head bolts, although the hose helps hold this in place. The bracket goes around the bar. Here I used rivnuts.

Rivnuts inserted in the upper brace bar

Vacuum

Looking from the offside, there are the following connections:

• 1 take off from mid left of plenum
• 1 take off from top right of throttle
• 1 take off from lower right (underneath front) of the throttle 

  

  Throttle body from offside

Block off the mid left take-off from the plastic plenum.

Block off the top right outlet from the throttle.

The connection to the lower right of the throttle (virtually underneath the throttle pot) is not used - no need to block this off.

Looking from the nearside there are the following connections:

• 1 take off from mid right of the plenum
• 1 take off from under the left of the throttle - simply connects to other side of the throttle
• 1 take off pipe from the head (with a cross link pipe between the two heads)

Throttle body from nearside

Link the bottom right pipe from the cylinder head (with the cross link) to the lower take-off on the header tank.

Connect a hose from the higher header tank connection down to the lower part of the chassis. Clip this to the chassis.

The mid left breather on the throttle is not used. Block off this stub from the plenum.

The lower left take-off is not used. No need to block off as it just connects to the other side.

There are 2 take-offs from the rocker covers (1 on each)

Offside rocker cover

Nearside rocker cover

The offside rocker cover is connected to the air intake and a pipe also goes around the back of the engine to the nearside rocker cover vent.

There is 1 take off at the rear of the plenum which is blocked off.

Rear take off from plenum

Air intake

The long straight section of the air intake is fitted towards the engine – vacuum take off to the offside and the air sensor to the nearside. The air sensor came from Canems. This needs drilling out for a grommet. The sensor is simply pushed through this grommet (there is already an undersized hole here).

Hole in the air intake for the sensor on the near side

The stainless steel air intake outlet is connected to the offside rocker cover pipe vent at the front. Here a tee piece is inserted to take the vacuum pipe around the back of the engine to the nearside rocker cover vent (at the rear of the engine).

Fuel rail

The screw end of the fuel rail is covered with a dust cap. This acts as a fuel bleed.

Threaded end of fuel rail on nearside

Fitting the cooling fan

The fan

I decided to fit one fan behind the radiator. Some people fit one or two fans in front of the radiator. Fitting behind (suction) appears to be more efficient and should get fewer insects bonded on to it!

I bought a 16" suction fan with curved blades that can flow around 3,400 m3/h, from Car Builder Solutions.

Mounting the fan

I pinched the fixing method from Simon (see blog link on right) and blagged some 6 mm thick x 25 mm wide flat bar aluminium from Keith Akerman!

The principle is to fix the bars to the radiator, then fix the fan to the bars.

After cutting the aluminium to the correct length, I drilled two 4 mm holes close to each end of each bar to take 14 mm long rivets.

Aluminium bars with holes drilled in ends

Next the cheek nipping bit. I marked the position of the bars and drilled the holes corresponding to the holes already drilled at the end of each bar onto the radiator frame. All the blogs said that there was no risk in hitting any of the radiator cores, even though everyone had some trepidation in drilling the holes! I made sure that the holes were near to the outside of the radiator, just to be safe, prior to drilling. The bars were loosely fixed to the radiator using pop rivets, just pushing them in place.

Radiator edge with holes drilled for bars

Next the mounting feet were attached to the fan and the holes were marked on the bars. The bars were then drilled to take the M5 rivnuts and countersunk from behind (radiator side).

Bars riveted in place after fitting rivnuts facing fan

Rivnut in mounting foot

The fan was then laid over the four rivnuts to make sure it still fit. Then the pop rivets in the end of each bar were fixed in place. Finally M5 button head screws and washers were used to secure the fan.

Fan secured to bars

Mounting the radiator assembly

The upper radiator frame was re-attached to the chassis, using two bolts. The 'fixing kit' supplied by GD consists of two small sections of rubber hose and a few nuts, washers and bolts. The radiator was located using the protruding pegs from the radiator to the top radiator frame through the rubber mounts. It was then fixed onto the lower mounts using the two nuts and bolts supplied. This results in the radiator being at an angle with the top towards the front of the car. This is a straight forward job.

Fan mounted to radiator

Radiator and fan mounted into chassis