We’ve been on a major purchasing mission. The problem is that so many build decisions involve interlinked parts. This is a small race-car, into which a lot of stuff must fit. So if you lay your brake lines before you know where the steering column goes, you are very likely to have two components fighting over their piece of space-time. The engine bay is probably the most crowded section, and so we’ve decided to try to buy all the major components and see how they all fit together.

Our radiator is from a Honda Civic 1.8 Vtec. This should be overkill, but we really don’t want to have issues with heat. It will definitely fit lying on it’s side, but that may lead to air-locks and resultant radiator inefficiency. It will be a tight squeeze, but we should be able to mount it upright, as it was designed.

We were pointed to a very nice and small Toyota alternator. The label on the box says it’s from a forklift. It puts out 35A, and weighs about 2kg. This will still need modifications to mount it to the engine (e.g. tensioner). It also came with a v-belt pulley, whereas the Rocam has 6PK multi-v pulleys. I popped past a local auto-electrician, who was very helpful. They are sure they’ll have some old pulleys lying around which should fit.

A problem with the Rocam engine is that the oil filter clashes with the chassis. This affects how low you can mount the engine, as well as maintenance. You don’t really want to have to remove the engine to change the oil filter.

Our starter motor is a standard Sierra 2L job. It weighs a million kilograms, and was bought while a fight broke out between the cashier and a customer. People get very passionate about motor spares sometimes.

We had some good news regarding our gearbox. We had it serviced, and they gave it the all clear (after removing several buckets of sand). This is a relief, because it’s difficult to get parts for these boxes. They also machined the end of the input shaft down to 10mm. This will mate with a brass bush in the Rocam crank. We still need to cut the length down, but we will measure that with the bellhousing and various spacers all together. Our gearbox does seem to be something of a mystery. It’s a four-speed sierra box, but the output shaft is 27.2mm, with 25 splines. Everyone seems to think it should have 23 splines, and have a smaller diameter. We’ve even got a prop-shaft yoke that should fit, and it doesn’t. So we’ll be going back to the scrappy’s to find one that does.

Two of the brackets on the chassis were welded on the wrong side – they sit where the fuel tank is meant to be. We had the option of cutting them out, or changing the size of the tank. We’d already been toying with the idea of a smaller tank (with just enough fuel for a longer race), since it will have less sloshing. So we decided rather than cutting bits off the chassis, we’d get a custom tank. It arrived a couple of weeks ago, and we’ve been making brackets for it. The reduced size has meant that the filler spout is now directly in line with the chassis upright that the bracket is meant to attach to. So we’ve put a cross-bar between the uprights, and put diagonal brackets across the tank. The brackets are made from 25x2mm aluminium flat-bar. Riv-nuts were used both for the cross-bar and brackets. Stick-on closed-cell foam was used on the brackets to increase their grip – that tank isn’t going anywhere.

To save a bit of money we’ve followed a couple of web descriptions for a DIY riv-nut tool. Slight improvements have been made to minimise the possibility of stripping the Riv-Nut. A coupling nut is used, lubricated with grease, to tighten a high-tensile (HT) bolt onto which the riv-nut is threaded. The HT bolt is not turned – so it’s less likely to strip the riv-nut. The coupling nut is tightened to crush the Riv-Nut, and since it offers more thread than a normal nut it’s less likely to strip. The only problem is that it’s fairly hard to operate with the normal human-complement of hands. You might need someone to help, or attend yoga to increase your flexibility so you can use your toes.

The diagram below shows the basic principle. The anchor is simply a piece of flat metal bar, with a hole the same size as the bolt. It is against this surface that the Riv-Nut is crushed.
1. Make appropriate hole in target, and seat Riv-Nut
2. Fit the tool as shown – with grease between the anchor, washers and coupling nut. Also grease the HT bolt thread where the coupling nut goes. Make sure the HT bolt is all the way through the Riv-Nut.
3. Tighten the coupling nut against the washers and the anchor, while keeping the HT bolt from turning.
4. Make sure the anchor is pushing the Riv-Nut firmly into the hole (otherwise it can become affixed proud of the hole).
5. With another spanner tighten the coupling nut (while the HT bolt and anchor are prevented from turning). Keep track of how many turns you use – typically 2-3 is sufficient, but practice on some spare plate first. If you over-tighten, you risk stripping the Riv-Nut.

Clear as mud.

So far we’ve done 4mm and 6mm Riv-Nuts this way, and haven’t stripped any (yet).

There are a couple of tight spaces on the front left suspension brackets. Everything fits, but two of the brackets leave very little space for a bolt to go through. On one we’ve had to make a threaded stud, since there is simply not enough space for a bolt with a head to fit. This stud will take two Nyloc nuts. D filed two flat spots on one end, so that a spanner can hold the stud and prevent it from turning. This should allow the nuts to be tightened.
When we realised that we needed to make the stud, I called the local bolt shop to see if they could fabricate it for me. I was very pleased when they told me they would make it for under R7 – awesome! Once I had finalised the sizes, I placed the order for one. “One?” came the reply. “Yes please”, I politely responded. “Sorry, we can only make this if you order 100, or pay us R700 for one”, was the unwelcome reply. So I made another plan with a long bolt, two hacksaw blades (HT bolts are HARD) and a friendly lathe.

With that tricky part done, we were able to complete the assembly of the suspension. With all the springs, dampers and wishbones in place, it really is starting to look like a car. One point to remember is that the bushes of the dampers are not “pinched” by the bolts. What this means is that as the suspension moves, those bushes rotate around the bolt. If you use fully threaded bolts (i.e. no blank shaft) then eventually the thread might cut into the core of the bush. Thus for the damper bolts, make sure they have a long enough section without any thread. The wishbone bushes should be mounted with sufficient washers that the metal tube in the center is pinched when the bolt is tightened. These bushes rotate around this bush, and so fully threaded bolts are less of an issue.

Once the suspension and uprights were in (front and rear) we could mount the brake calipers. The main goal of doing this was to determine the spacers between the upright and the caliper. The rear calipers need an 11mm spacer, while the front need 15mm. It’s remarkable how accurate the assembly of the rear uprights is – which is strongly contrasted with several welding anomalies on the rest of the chassis.

We have also got the necessary fuel filters. We will put a low-pressure plastic filter between the tank and the pump, with the hope of keep anything nasty out of our fancy fuel pump. After the pump we’ve got a high pressure (metal canister) filter. I got the Golf 1.4i filter, but I really don’t think this is the best option. The piping exits in a very strange configuration, and it’s going to be difficult to mount.
The fuel-line setup suffers from having multiple pipe-size changes: it’s 15mm at the tank outlet, which must be taken to 10mm for the LP filter inlet. The outlet must then be increased to 12mm for the pump inlet, and thereafter it’s 8mm. All the size converters take up a lot of space, and are a real pain to fit.

Sorry for the long read (and well done if you got all the way to here) – I definitely should have posted something sooner. Hopefully the next installment won’t take too long.

B

This weekend we made the first proper, can’t turn back moves. First we drilled holes in the chassis, lots and lots of holes. Then we put in pop-rivets; ok, not so many pop rivets. Bearing in mind this thing cost more than a fancy digital camera, it was quite a first step (when last did you drill a hole in your camera?).

However, before we drilled any holes we decided to finish the side panels. This story is getting old, and it just needed to be finished.

We managed to get both sides finished, including top and bottom folds. They are not likely to win any awards for panel-beating excellence, but they will do the job. I would recommend that anyone thinking of doing the side panels themselves – at least get the top fold done by the machine shop. You can get it folded along the whole length, and then just chop it as you need to.

Once the side panels were finished, we moved on to the brake lines. We had already more or less finalised the shape of the brake line tubing, but they were only held in place with cable-ties. Also the section exiting the tunnel (above the diff) needed improvement. So a bit more bending was done there, to make sure the lines cleared the diff mount point and didn’t have to be forced into the T-piece. Then the first p-clip was folded over the tubing, the position marked with a center-punch, and the hole was drilled. It is quite satisfying to fix it in place with a pop-rivet – until you realise you’ve mistakenly used an 8mm p-clip for the 5mm brake-line…

Because we still have to tighten up all the bolts, and possibly put in mount-points for the T-pieces, we have not put in all the brake-line p-clips. However, all the ones in the transmission tunnel have been fitted.
We then got to work on the fuel lines. To maintain an even flow to the fuel injectors, most cars have two fuel lines – a feed and a return. Ours is no different, so we had to find space for two lines. We decided it would be better to fit one at the top of the tunnel, and the other at the bottom. You really want it out the way as far as possible, so lots of bends were put in it to tuck it behind the support struts. The top fuel line is possibly a bit far over, but hopefully it clears the gearlever and prop-shaft.
Bending fuel line is not easy – although it is similar to brake-line, it is thicker. Thumbs and knees were very sore by the time we were happy with these lines.

We saved the easy part till last – the wiring loom. All this consists of is 7-core trailer wire, which has been covered with flexible split sheathing. We are taking a bit of a risk – if the wiring fails for whatever reason, it will have to be completely removed and refitted. Time will tell if this is a bad decision.
The wiring loom was run along the bottom of the tunnel, on the driver’s side (i.e. the opposite side to the fuel lines). Although the separation won’t do much if there is a fuel and electricity leak, it’s better than wrapping them up together. To attach the loom to the chassis, the 8mm p-clips of recent fuel-line fame were used. With their rubber cover removed they fitted perfectly over the 10mm loom.

During the week D had already drilled almost all the holes in the rest of the panels, so at least that job was done. However, the floor still needed to be drilled. We flipped the chassis over to do this, which is infinitely better than trying to drill the hundreds of holes with your hands above your head. It was also an ideally parallelised task, using two drills; this sped the process up considerably. While the chassis was downside up, we also drilled the holes for the underside panel at the front of the car.
Once the floor was full of holes we flipped the chassis over again and drilled the driver-side transmission tunnel panels. Then we’d both had enough, and called it quits.

B

It would seem we were a bit optimistic regarding the side panels – the hope was that they would be completed by last week Tuesday. Needless to say it didn’t happen, although I really think we are almost there. The driver’s side panel has been completely cut out, and the top fold is done. Just the bottom folding is needed. The passenger side has been about half cut out, and the front fold is done.

A new trick we’ve been trying is to anneal the panel before folding. This involves heating the panel with a blow torch, and then allowing it to cool slowly. The temperature is indicated with soap – in our case good ol’ Sunlight liquid. When it turns black, it’s at the right temperature. This makes the folding much easier and more distinct, but tooling marks (i.e. when you bash it with a hammer) show up more easily.
Why is it that we tend to realise that we’ve made a mistake an instant after it’s been made? A split second after sending that sms/email bi!tching about the boss, you realise you sent it TO the boss… It’s the same with cutting anything – 3 seconds after you make your final committing cut, you realise you’ve got it wrong. In our case, we cut the left panel exactly the same as the right – meaning the scratched non-laser film side would have to face out. Fortunately there was enough length to fix the mistake – phew! But it did slow us down a bit.

A comment that must be made – do not underestimate how long it will take you to do the body panels. Every piece must be carefully measured, cut, adjusted, cut some more, cleaned, sanded, water-papered, placed, marked, measured, calculated, marked, punched, drilled, drilled, cleaned, drilled, riveted. And if you need to put in a fold, you can add soaping, heating, clamping, hammering and cleaning to the list. There are anything from about 10 to 13 panels (depending on how you do it) – that is a lot of work. Buying the pre-cut, pre-folded panels is definitely worth considering if time is a factor in your build.

We have also largely shaped and bent the brake lines. To form curves (that don’t pinch the Bundy tubing) we cut a 50mm circular disk from a piece of chip-board. This was bolted to another piece of scrap board, and served as a shape against which the tube could be folded. A spare piece of tube was used to “calibrate” the folding tool.

Basically a couple of different folds were made, and the actual tube length “consumed” in the loop was measured. A couple of lines were then marked on the board to indicate where folds would need to be made to form a loop that consumed a given amount of tube length. This made it much easier to plan how to fold the tubing to finish with the end connector in the right place.

Below is a picture of our Locost SA fuel tank. Although we were very tempted to try to get one made (using the off-cuts from our paneling), we decided that it just wasn’t worth the effort. One reason is that apparently aluminium welding is not tolerant of gaps (unlike steel welding, in which it’s fairly easy to fill a gap). This meant that if our cutting was imperfect (highly likely) then it may not have been possible to weld the tank.

You may have noticed that the pictures on the website behave a little differently now. I really didn’t like the way that clicking on any of the picture jumped you straight into Flickr. This is a requirement of the Flickr terms of service. I have now begun the process of migrating to PicasaWeb (a google-based picture hosting site). It is not a small job, but I think it will be worth it. As a result I’ve been able to install the “Lightbox” plugin, which is what controls the pictures in the new funky way. Please let me know what you think.

Last week started with fetching our freshly-cut aluminium panels. The problem of how to fit several square meters of aluminium sheeting was solved by the folks very generously letting me borrow their Syncro (Kombi). What a cool car – big and homely, but so manoeuvrable. Oh, and we met the chap behind the annoyed emails. He’s a good guy, but he does need a holiday.

Once the panels were safely back at the build, we decided to double-check the cuts. We were told that the actual cut would consume just 0.5mm of metal, so we did the layout quite precisely. We found that while it may be true that the actual metal loss is just 0.5mm, some of the cuts were over 10mm off. Some weren’t even straight. Fortunately it doesn’t look like any of the bits are unsalvageable, but it was a lesson.

Front calipers arrived, very cool. We had a lot of help with these, in particular from A.T.E. – great people. We also got the front disks (vented) and have ordered the rear disks and calipers.

The exceedingly messy job of packing the Lobro’s with CV grease has also been done. While it is probably less messy than the initial clean was, it’s still messier than a two-year old at a syrup festival. And with the grease being bright blue and staining everything, it’s even less tidy. Required items include a syringe and rubber gloves (read out of context, that sentence may get me into trouble).

We’ve now started cutting the panels to fit the chassis. While there are clearly a number of ways to do this, an absolutely awesome solution is to use a jigsaw with an HSS aluminium blade (Bosch). It neatly zips through the panels, is easy to control, and fast enough to get the job done. It also happily cuts off the thinnest strips (if the sizing is a little bit out). It isn’t quiet, so not good for late nights if you don’t want neighbours who hate you.

We started out using clamp-on guides to keep the lines straight, but it’s easy enough to get it right freehand. Hopefully the cutting will be complete by the end of the week.

It really feels like we’re building a car now.

B

Building a Locost does seem to be a lot of “hurry up and wait”. So many aspects of the build are interconnected, that if one part holds you up, you can’t do much else. Our next big thing to do is put in the floor. We want to do this next because it’s easier to do with the chassis up side down. However, before putting the floor in you need:

a) the panelling to do it.

b) to drill the holes for the transmission tunnel panels.

We can’t do (b) because:

a, again) we don’t have the panelling.

c) it’s better to put in the brake lines while the panels are out.

So we need to order the brake lines. This requires estimating their length, and selecting the correct fittings for the end. You need to know which fittings beforehand, because the shop will flare the ends for us, but the nuts have to be in place before flaring. To know which nuts you need requires knowing which nuts the brake calipers use. So we need to find brake calipers. Nobody on this planet sells brake calipers. Somewhere in the rant above is (d), (e) and (f).

To be fair, it’s not true that nobody sells calipers. We had a lot of help on the forum to know where to look, and phonecalls to some very helpful people (Midas, Rand Ford and A.T.E.) put us on the right path. Calipers will be got next week, hooray.

To figure out how long our brake lines need to be, we laid “simulated” brake lines using normal fencing wire. This was bent and shaped to the chassis, and held in place with cable ties. We added a few loops here and there which can be lengthened or tightened to provide a reasonable margin for error. We also were cognisant of where the T-pieces were, and made suitable breaks in the wire at these points. Once we were happy with the layout of the wiring, it was removed, straightened and measured.

Our aluminium panels have been bought and paid for, and we hope to fetch them on Tuesday – what a laugh that was. It’s amazing how certain suppliers act like they are doing you a favour. This is an actual quote from the chap at the alu place:

D (3 days after the first email): “As requested in my previous email, please confirm order, price and date of delivery.”

Supplier: “I WILL REPLY ASAP, THANKS SIR”

Perhaps his caps-lock got stuck, or perhaps he just needs a holiday?

Nonetheless, it’s now cut and ready, so when we get it we’ll have a number of tasks ahead of us.

Despite all this procurement hassle, it’s not been complete idleness. The Lobro joints are in the process of being grease-packed. That was a pleasant buying experience, with the supplier flying two tubs of the fancy CV grease (Everon) up to Jhb for us. Very cool – I recommend them.

We’ve also been back to the scrappy (as is apparent from all the pics), for almost the last donor bits. We got our steering column (including switch array and ignition), handbrake and seat runner (hopefully a plan can be made to fit it).

I aim to update the various “summary” pages with what has been learnt so far (diff, steering column, front uprights, brakes) at some point in the near future. I’ve also been playing a bit with blog software options – hence the new picture design. However, I’ll probably be back to the old style in the next post.

B