Panel Beating

I suspect, when I finish this project, people will ask what the worst or most difficult part of the build was. Well, at this stage I would like to submit "fitting the rear panel" as the biggest pain in the proverbial back side to bestow my time in the garage with this car.

It should be simple. The panel comes pre-cut and with two right angle bends for attachment to the underside of the chassis and to the supports from the roll bar. What is required is two curved bends of about a 3 inch radius to form the corners around the small boot space. This presents the first problem as, due to the existing bends, it is not possible to bend the sides past the 90 degrees needed to form the curves. Well I can't do it anyway.

After a couple of days trying to get it to look right, and some more help from my brother, I think we've make a reasonable job if it. At the moment the chassis is sitting on a couple of trestles to raise it to a workable height so the imperfections in the bends are visible, but when it it on the ground and the trim is in place it shouldn't be so obvious.

Next job, fitting it. Again, should be straight forward, there are defined points to attach the panel to the car, and its clear where it should fit. Along the sides it should line up neatly over the wheel arches, and at the back it attaches to the supports from the roll bar and to the underneath of the chassis. No matter how I offered it up to the chassis, the panel was either too far forward of the wheel arches when the roll bar supports lined up, or too far back from the supports when it lined up with the wheel arches.

The answer as it turned out was painfully simple. It seems that somewhere in the manufacturing process there is a tendency for the supports to dip down slightly. GBS say they haven't workout out how and why this happens but it is safe to bend the supports up slightly to make the panel fit. I'd already worked this out by the time I spoke to them but it was good to have it confirmed.

In case you are concerned about bending said supports, I used the logic that if the welds broke I probably wouldn't want to drive the car anyway.

At last it fits. I've now attached it with rivets and adhesive so it's really not going anywhere. There is a thin bead of piping trim that runs between the rear panel and the top shroud. This was a little tricky to get right, but after spending some time getting the bends neat, it actually looks pretty good (as long as you don't look too closely at the bends in the panel underneath it).

Electrics

I decided to try to save a bit of money by doing the wiring for the car myself. This sounded like a simple enough idea as this is after all a fairly small and simple car. I am re-using the steering column from the MX-5 so the switches for the headlights, indicators, and windscreen wipers will be incorporated in to the new loom.

Starting at the back I have a loom that incorporates the brake, indicator, reverse, fog, and tail lights, along with the fuel level sender. This is wired back the the fuses and relays mounted on the engine side of the firewall.

The loom that runs to the front of the car connects the headlights, indicators, fan, and horn. These are all terminated on connector blocks ready to be linked to the lights when installed. The engine obviously requires a lot of wiring, but this will be kept separate.

The stalk switches from the MX-5 Steering column are wired to a junction box under the passenger foot well. These will control the headlights, indicators, and wipers.

There's a lot more to this wiring business than you might think. For example, the indicators also have to act as hazard lights. The hazards need to be able to flash with the ignition switched off, and the indicators should only work with the ignition on. There also needs to be an indication on the dashboard when the hazard lights are active, so there needs to be two separate flasher units, one each for the indicators, and the hazards.

It's been a little difficult to check the wiring with no lights connected but I have managed to test some of them and I am pleased to say that so far all have work as planned. The indicators can only be seen so far on the lights on the dashboard and I don't think there is quite enough load for the flasher units to work properly so the lights just fade on and off. Hopefully that will be resolved when I connect the exterior lights.

The dashboard is now more or less finished. I've wired it on an extra length of cable so to enable the whole panel to be removed and allow access to the wiring and ECU attached to the firewall.

That's where it is at the moment. Rear panel to do, and get some lights on.

Back in the Garage

I can't believe it's been 5 months since my last post on this blog. It's not that nothing is happening, just for some reason I haven't managed to convey work to writing. I am still contributing to the Complete Kit Car magazine Running Reports feature which I would recommend for anyone interested in understanding what it is really like to build a kit or one-off car.

For the people who tell me, or at least I hear about, who are looking at this blog to see how the car is getting on, sorry for leaving you in the dark! Let get you up to date...

There are two main sections that have had concentrated effort since I last wrote - Brakes and Wiring. Lets start with Brakes now and I'll do wiring in a few days.

For some time I have resisted putting the brakes on the car. The limited space in the garage means that with the brakes fitted there will very little room to move around the car to do other work. Unfortunately I got to a point where I could not carry on until I had the brakes fitted and knew the pipework was good and didn't need anymore work. I already had the rear suspension and drive shafts fitted so it makes sense to fit the rear brakes on the uprights, the front ones however can be attached to the pipework and bled, and left tied up to the front shock absorber mounts.

The brakes are the original Mazda MX-5 brakes. I have stripped the front ones down, sandblasted them, and panted them (roughly) the same colour as the GRP nosecone and wheel arches will be. The rear ones were not so easy as they contain an over-complicated self-adjusting mechanism for the handbrake - more on that later.

With the help of my brother (OK to be fair, he did most of it) we fitted new rubbers, seals, and pistons to the calipers. I later sprayed the rear ones orange to match the fronts. See the previous post from February for more details.

I bought a full set of brake pads and disks for the car so before putting the calipers on and filling the system with horrible brake fluid, I trial fitted the newly refurbished calipers with the pads and disks. Front - no problem. A little tight, but the hub rotated and nothing that wont free up with a little running. Rears however, not so good.

Basically, the pads and disk will not fit inside the caliper. They are about a millimeter too wide, which is miles by brake tolerances. A bit of research reveals that handbrake is to blame...

It seems the complicated self-adjusting mechanism embedded in the calipers has a tendency to self-adjust itself to a point where it cannot be adjusted back. I won't pretend to understand how this can happen and rather than spending hours, or probably months, working out what can be done about it, I have purchased some shiny new ones, and pained them orange.

Fitting them and bleeding the system was relatively easy when you have someone to help who knows what they are doing. More thanks to my brother for giving up his weekend, rewarded only with all the curry and beer he could consume (and he can consume a lot).

One problem we have was a fracture in one of the copper brake lines. Copper with work-harden, meaning it becomes more brittle as it is bent. The line that failed was the first one I fitted to the car, and it is certainly possible I worked it a lot more than it should have suffered as I tried to route it round the chassis. It was the first brake line I have ever fitted after all!

New role of copper pipe purchased and fitted.

The brakes are now in place and the system is bled and working nicely. There is a pressure sensor in the rear T-piece that will trigger the brake lights when the rest of the electrics are fitted.


Electrics next. Give me a few days...!

Suspension and Side Panels

And again I leave it several weeks between updates. I am resolved to start posting shorter updates but more often. Lets see how that goes, but first I need to bring this blog a little more up to date.

In the last post I had got as far as putting the engine in. The throttle body was the main concern there but a look around the internet and a chat with Richard at GBS has put my mind at rest as there are a few options that will fit in the car. Nothing further to report there and I think it's probably going to be one of the last things I do on the car.

I have the rear suspension on now. I tackled the left side first as there is more room that side of the garage. The wishbone suspension arms are supposedly identical on both side but some trial fitting with the uprights with the new bushes fitted suggests that there are some slight differences. The drive shafts as returned from GBS after modification look pretty much new. The CV joins certainly are but I thought they reused the shaft itself, if so they have been cleaned up very nicely. I found the best combination of wishbone arms and set about attaching the left side suspension arrangement. The CV joint slipped easily in to the wheel bearing with the aid of a little grease, but the other end did not want to go in to the differential housing.

When I took the MX-5 apart I really messed up one of the CV joints by hitting it too hard trying to get it out of the wheel bearing, and as putting it in to the differential housing required hitting the same end again, I was a little apprehensive about the liberal application of hammers. The problem is the end of the CV joint shaft has a ring on it to lock it in to the gearing within the differential. The ring takes a bit of force to get through whatever hole it must pass through to arrive in its working position and with being new it wasn't going in without a fight. After a few hours of gingerly trying to persuade it home, I ended up just hitting the other end with a bigger hammer. Job done. To completely fit the right hand side suspension took about 15 minutes...

Side panels now. These need to be installed before the front suspension can be fitted as the wishbones pass through the holes in them. When I drive the demonstrator at GBS I noticed there were no obvious rivets holding the panels on. Turns out there is a quite lethal adhesive known only as "Black Stuff" used for holding panels on kit cars (and to be honest holding anything on anything) which I duly purchased. Starting with the left panel I put a thin bead of Black Stuff around the edges and areas that would contact the chassis and offered it up to the side of the car. No kidding, I had about 5 seconds to make minor adjustments before the Black Stuff took hold and the panel was stuck solid. It drys completely in about 24 hours to I put a few clamps on to hold it in position and left it to set.

With the left panel successfully attached I did the same to the right, this time with a little more Black Stuff (possibly too much), and offered this one up to the chassis. This time I had about 2 seconds before the panel was stuck fast. A little stressful that job, but I'm glad it's done.

Next up: electrics. I'll make that the subject of my next post, but as a taster... I will be making my own wiring loom for most of the car but I need to use some of the old MX-5 loom for the connectors. We ripped it out complete from the Mazda and put it in a box:

Perhaps the box wasn't big enough. Never mind, until next time...

Engine Fitting

At last I have been able to get back to the serious business of car building. I had originally wanted to have pretty much finished the build by this Easter, but in hindsight that was never going to happen...

I thought it was about time to get the engine and gearbox out of the way and in to the car. In order to achieve this I needed to fit a new Clutch (something I had never done before), attach the Gearbox to the engine, and rig up the engine hoist to slot the combination in to the engine bay.

After removing the old clutch it turned out the spigot bearing also needed replacing which meant removing the flywheel, another new experience. Once removed, the old bearing slipped out easily with the aid of a hammer and the right size socket. The new one also fitted neatly with the help of the same hammer and socket. Flywheel replaced, on with the new clutch.

I had bought a special tool to help line up the clutch plate but it turned out to be just too short to fit through to the spigot bearing so the job needed to be done by eye. Not as difficult as I thought it would be but I did spend a few hours making sure it was right. The gearbox attached using the original bolts which I cleaned up on the bench grinder.

The drive shaft has arrived from being shortened at GBS which I have attached to the differential (I'll add about more about that to a later post). Now just need to slot the engine and gearbox in to the chassis...

I'd bought an engine hoist to get the engine out of the Mazda so it now gets its second use. By now it's gone 4 o'clock on a Sunday evening and I am thinking that I really should leave all this to another day but for some reason I persisted. Actually fitting it was actually incredibly easy. The engine and gearbox just needed a bit of guidance as it lowered in to the chassis, using the load leveling bar helped a lot. Slotting the end of the drive shaft in to the gearbox was the only tricky part, but really the whole activity would have been much easier with another person.

One problem that may turn out to be more serious is the intake manifold and plenum chamber does not fit in the car. There is a crossbeam right where the intake curves down preventing the engine from lowering in to the correct position.

The options are to lift the engine up a bit or to remove the intake and chamber. I tried packing out the engine mounts with washers but to get it high enough for the manifold to clear the crossbeam means the rocker cover will touch the bonnet and will probably need extra space meaning bonnet scoop or something, so I opted to remove the intake for the moment and put off thinking what to do about it.

I've started putting the rear suspension on, which I'll take up in my next post.

Restart...

Again, a long time since my last post. I hit a bit of a slow spot over the holiday period, weather, travel, work, travel for work, and generally not liking the cold that much, conspired against the project. However, I am back on it and can report on brake lines, calipers, fuel lines, and fuel pumps... I think.

The last of the brake lines are now routed and the ends flared, that is except the front right line to the caliper as the spare female unions have disappeared somewhere in the depths of my garage. I've had to move the line slightly at rear of the tunnel now I have the handbrake assembly. The cable from the handbrake lever brushed against the brake line when pulled on. The new route is slightly lower and actually helps with the routing of the fuel lines.

Brake calipers have now been cleaned up and refurbished. Help from my brother again here and I admit to having been a bit worried about tackling this job myself. The most time and care needed to be taken when cleaning and rubbing down the inside of the cylinders around the slots for the seals. The seals themselves are fiddly to get in and one wrong move could put a dent of crack in them rendering them useless. The rear calipers incorporate an over complicated handbrake mechanism that is supposed to self-adjust somehow. We couldn't work out how it was supposed to work, only that the whole mechanism was ceased on one side.

I am pleased to report that all seals, pistons, and dust covers are now safely installed, and looking very professional if I may say so.

Fuel lines now. I am advised that these can effectively be 'hung' from the brake lines as long as they are secured near the p-clips. I got a couple of sheets of aluminium for odd panels and brackets that might need to be made up and cut a mounting plate for the filter and low pressure pump out of this. These mount neatly behind the differential with a piece of fuel hose connecting them. I need to finalize the routing for the fuel lines as the come out of the tunnel and run to the pump and tank, for that I need to fit the hand brake assembly.

At the front I have mounted the swirl pot and high pressure fuel pump in front of the driver side foot well. Quite a neat job, but the pump needs a bit more foam padding around the bracket to make it tight.

So, a fair bit of progress it seems. I am painfully short of space in my garage so I intend to fit the engine and transmission next, which should free up some space to fit the side panels and suspension. It might even look like a car soon..!