I feel a bit like someone being mentored after rehab. Every day or two I get an email from Andre, along the lines of “you haven’t touched a drop, have you?“. Although instead they are more like “how’s the build progress“. And I must confess, I do find myself running out and doing something on the car, just to report back with some progress. Unfortunately progress on the car has resulted in neglect on the blog, so this may be a long one. I recommend just looking at the pictures.

The fuel tank has a very nice hole in it, to fit a fuel gauge. However, our’s is going to make use of the more technological “dowel dip stick” method, which doesn’t need that hole. So the hole was covered. Note the engraved “1” to help future lining up (because it wasn’t really machined to micron specifications). It will be sealed using some sort of petrol-proof sealing ring/paste.

I started feeling bad about the way the scuttle had been mounted. So I welded up the old bottom holes, and fitted riv-nuts to the top holes. So the scuttle is now mounted using riv-nuts. I think it’s a better solution, although sub-optimal to damage the chassis powder coating.

Then we took another shortcut, buying the windscreen from Wiekus. It’s beautifully done, far better than we could. Part of the package is the rubber seal along the bottom, which ensures a very neat fit with the scuttle. It is his own custom design, specifically with an angled groove for the base of the windscreen.

He also supplies a printed cutout sheet for the support arms, which I glued to a piece of 1.6mm alu to make temporary brackets to mount the windscreen.

Fitting the windscreen to the scuttle is fairly straightforward. First I wanted a straight line on the scuttle, so I clamped two pieces of wood to the chassis, rested the ruler on them, and drew a line on the masking-tape-coated scuttle. This was a useful reference to ensure the mounts were properly horizontal.

Then attach the rubber to the base of the windscreen and shift the whole thing around on the scuttle until there seems a reasonable fit and roughly even spacing on both sides.

Then comes the scary part – cutting the rubber. I tried a couple of knives; it needs to be sharp and have a thin, flat blade. The best ended up being a super-sharp serated Victorinox kitchen knife (don’t tell the missus).

I put a thin layer of oil on the blade, which prevented it from sticking. Because you want a nice smooth edge running down between the bracket and the scuttle, fading to nothing, you must extend the rubber a bit past the end of the windscreen. Simply cut in a straight line down. It might take a couple of practice goes to get it right, but Wiekus gives you a bit of extra length to make some mistakes first. Once you’re satisfied with your abilities you can cut the other end (no going back after that). I purposefully cut it slightly too long, to fill the gap with the bracket.

Although the fit is slightly imperfect, it should come right once the rubber is stuck down on the chassis.

The windscreen was on the critical path, because it needs to be in place to fabricate the roll cage, which is done at the same time as the exhaust, which is done before the wiring and the cooling brackets. Now the car can go in for its exhaust.

The final fuel lines have been put in, although the last couple of holes must still be drilled for the p-clips. This includes replacing one of the original lines, which clashed with the gearbox. The gearbox won. It always wins.

I put my new MIG welder to use, welding the engine mounts to the chassis plates. Fixing the engine position means you can move forward in several other areas.

Once the engine position is finalised, the prop shaft can be manufactured. Ours was done by SAJCO in Strijdom Park. Frankly, they were amazing. The only specification they needed was the length from the gearbox oil seal to the diff input flange. I took them our yoke, which they didn’t fit but was useful for spline sizing.  There are at least two input shaft sizes in the wild for the Ford Type 9/Type E box, so you need to get this right.

I also gave them an old Sierra prop shaft, which they took some parts from including the flange to connect to the diff, and some of the tubing.

The amazing part? I dropped the bits off at roughly 12h30. At 15h30 they phoned me to tell me it was ready. Very impressive.

Using a suggestion from Deon I made an adjustable alternator bracket.

Start with some accurate small pilot holes. In this case I wanted an 8mm groove, so the pilot holes were drilled 7mm apart:

Then drill a set of bigger holes – 7mm now:

As you can see, the holes start to run into each other:

After this, drill with the 8mm drill bit. Then file the points down to make a flat groove (it’s quite easy at this point):

Who needs a milling machine anyway.

It’s some progress – haven’t touched a drop (of not working on the car).

B

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

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.

Is it poor internetiquette to put a keyword in the post that has nothing to do with the post? Probably. We have… a GEARBOX.
With a Rocam-based Locost, you have two choices for gearbox. The 5-speed Type 9 gearbox, or the 4-speed Type E gearbox. There are good arguments for both:

• Type 9 seems stronger
• Five gears vs. four…
• Type E is lighter
• Type E is much more common

Ultimately our decision was made when we found a very good deal for the 4-speed.

Some pointers for selecting your Type E (thanks Brad):

• Input shaft should be 1″ diameter, with 23 splines
• Input-shaft cover plate should have 4 bolts (not 3) connecting it to the gearbox body
• Gear lever should be the bolt-on type (three bolts). NOT the screw-in type.
• Check that you can get into all the gears (four forward, one reverse)

Like most things from a scrappy, it was in pristine, shiny condition when we fetched it. Other than being covered in filth, of course. And the aluminium tail casing was unbolted. And the main gearbox cover was off. And it was full of sand.

So out came the cleaning kit. It is easier to do once you’ve had some practice – paraffin painted everywhere to loosen the greasy gunk. Then Clean Green to wash it off. Repeat. Repeat. Repeat.
Once most of the sand was removed from the outside, it was time to tackle the inside. Paraffin was poured in, and the top cover re-installed. Then shake and leave for a day. This did a good job of softening and rinsing the inside. Pour it out, put in some fresh paraffin, and do it again. A bottle-brush was employed at some point just to loosen anything stubbornly sticking to the bottom.

The next stage was some cheap engine oil from Pick ‘n Pay. A flexible coupling (BIG word!) was made from hose-pipe and a 10mm drill bit, which allowed me to connect the electric drill to it.

Without the prop-shaft attached, oil poured from the tail-end, which served to flush out any stubborn grit. This will be repeated a few times just to make sure.

We also got our racing seats, and the seat runners were properly stripped of unnecessary layers. Along with the seats we got a fuel tank (seats and tank from Locost SA). The tank is excellent, with baffles inside to minimise sloshing. Photos of these bits soon.

Unfortunately it’s been almost 2 weeks since any work was done on the panelling. This starts again soon. We also have to finalise and check the brake lines quite soon.

For further inspiration, I went to the recent Zwartkops SuperTrax day. It was awesome to see all the other Lotus-type cars and get an idea of where we are headed.

Thanks for reading this far, please drop a comment, a criticism or just say hi.
B