Heading into the off-season and engine thoughts

I have a spare few minutes at work so I thought a quick post might be in order. I do now see why blogs seem to go very quiet once a car is built, after all unless there's major work to be done there isn't really much to post about!

So the weather has turned, the temperature is now back to the high teens and much more in line with a typical English summer. It's still reasonably dry so I still plan to take the car out at least a few more times. But I suspect it won't be long before the battery is disconnected and it settles in for the winter.

I remember when I was building the car that I could add a small heater, and in reality I still can, the plumbing supports it and it would only need a bit of wiring for a switch and motor. It's not near the top of my list though. I think the first thing to be added is a lockable glove box or similar, just to keep odds and ends in. I've got plenty of space in various locations, I think the simplest will be between the seats at the back of the transmission tunnel. 

Over the last few months my mind has been drawn to an engine swap. It's something I had in mind almost from when I started but it's not going to go anywhere just yet. I have been thinking about a few options though;

1. Vauxhall V6.

This is partly because I know the engine fairly well, I used to have a Vectra V6 so I'm familiar with it's shape. Unfortunately it's also the most complex option purely because very few people consider it for an engine swap. It would need all sorts of work to get it to fit to a gearbox, then getting it running outside of the Vauxhall engine management would be a bit of a trial. Having said that, it's probably the cheapest engine.

2. Ford Cologne V6

The proven route, and one of the easiest. The engine came in lots of RWD configurations, even a quick Ebay search showed an engine plus gearbox labelled as 'kit car engine swap'. The only problem is that it was £1,600, and probably closer to 3K by the time I'd finished. Given that I'm not sure I spent that much on the whole car it's a difficult pill to swallow. 

3. BMW inline 6

Now this is probably the most interesting. The Austin Healey was a straight six originally, so going for the BMW option keeps it comparable. They're also RWD by default, so I'd just have to get a donor car and take out everything from the engine back. Staying away from the M series cars I could get one pretty cheap. The only issue might be the physical size of it, the straight six is obviously 50% longer than the current engine. And if it's taller that could get even harder to work with. 

4. Rover V6

This is a proven upgrade for MX5's, and it preserves the drivetrain. They're not particularly cheap but there's plenty of people who have done it for an MX5 so I'd be in good company. I'm not going to dismiss it yet but the BMW route still stays slightly ahead.

5. More exotic options (VW V5 anyone?)

Yeah I know, there are plenty of other engines with more than 4 cylinders, and some aren't that expensive. But it's the same thing, converting them to RWD. Still, there have been bellhousing suppliers at previous kit car shows such as RWD motorsport https://www.rwdmotorsport.com/product-category/bellhousings/.

6. Supercharging the current engine

Not really in the spirit of things, but it would get me extra power with the minimum of fuss. I don't necessarily want just extra power though, the car is plenty powerful just with the current 100BHP. 

End of August thoughts

 This month has been the hottest on record in the UK. Bad news for crops, water supplies and countless other things, but great for driving a car with no roof!! I've spent most weekends using every excuse to get out in the car, and virtually no time actually working on it.

It does mean that there are a few things that have come to light that I want to work on.

Rattles

OK, this is my biggest bugbear with the car, or probably more specifically the state of UK roads. I've had many occasions where I've had all sorts of rattles and knocks when dropping into the crater sized potholes our roads seem to be made of nowadays. At least the car doesn't try to wrench the steering wheel out of my hands, but I do want to go over the car and check the rattles and knocks are limited to those parts that are meant to move. I've already lost an alternator brace bar due to a loose bolt, I don't want to lose anything else!

I just want to go over the car and check everything, see whether anything needs tightening or possible redesign. For example the bodywork was designed to be tight around the upper support and lower bolt fixings, but tight in the garage may not be the same 'tight' when on the road. The outriggers could be struggling to keep things in line. Obviously there's everything in the engine bay but also on the back end there could be something knocking where it shouldn't. 

Paint

While I like the idea of 'old paint', the more I look at the car the more it just looks like a bad paint job. I am wondering whether another few layers of paint would be good. 

On that subject I've been looking at how to spray paint again. I don't want to use 2K paint as that was a nightmare to work with, and the after effects (smells!) were there far too long. The combicolor paint did work quite well, it just needed a bit more work to get it right. So I'm planning to stick with that paint but spray it. 

But I've binned my compressor. The regulator valve was questionable, the size of the tank wasn't good enough to do any meaningful work, and having it to just pump tyres up was just a waste of space. So I need another option, and currently the leader is something that isn't actually available yet, the Inokraft DX. It's an electric powered HVLP gun that is currently only in the states, but I'm hoping there will be a UK distributor soon. It seems to get good results for a decent price, and will save me money and hassle. 

Arch seam lines

The arch join to the bodywork is another weak point that I want to sort. At the moment I've used filler and paint to disguise the join, but neither are surviving very well. What it needs is a bead of 'something' to be protective, flexible and decorative. My first thought is bathroom sealant but I can't paint over that. Claude suggests butyl tape but that sounds like a nightmare. 

What it does suggest is a decent way of creating a consistent seam, using a contour scribe gauge or perhaps a pinstriping kit idea https://beugler.com/. That would get me a line to work to, then either masking tape or some similar process to get it looking even and complete. Of course, my mind has gone to 3D printing for that so I'll design something and see how it comes out. 

Fuelling

The boot still seems to smell of petrol which makes it difficult to use for shopping. I need to figure out where it's coming from. It's most noticeable when just filling up so I'm guessing it's higher on the tank.

On the subject of fuel, my range is around 200Km which makes it easier to measure on the speedo. I could probably go further if I properly drain the tank, but I'll leave that experiment until I can get some fuel in the can as a backup! I really ought to run it to empty though at some point, just to check it doesn't get too upset. 

(Small update)

Exhaust repack

The exhaust is starting to get a bit tiring, while it's great on acceleration it's not pleasant just driving. Despite it passing the IVA test on noise, I think it needs a repack or some other internal changes. Given that it's not on show I could just hack the end off, redo the internals and weld the cap back on, the main thing is understanding the process of changing the internals to kill the sound. I don't think just filling up the wadding will be sufficient, I think there needs to be a bit more of a baffle in there to force the airflow through the wadding. Basically similar to what a DB killer would do. I'll do a before and after sound test as well to confirm it's improved. I reckon at least 6dB drop would be beneficial. 

Indicator self cancelling

One thing that has bugged me about this car is the indicators not cancelling. I had put a set of markers on the steering column so I could see when the indicators were on or off, but that wasn't overly effective.

So I opened up the steering to see what was going on;

This is the self cancelling feature, a white collar that turns with the steering wheel and operates the indicator lever;

But you can see in the top picture the nubs that engage with the steering hub are broken, so nothing is happening. 3D printing to the rescue!!

I was going to 3D print an entire new collar but there's not much room and I felt a 3D printed version would be unnecessarily weak. Where the nubs go there's a fair bit of clearance so I was able to print an oversized version of the same. A bit of glue to attach it to the original and it all works fine. Of course, I needed to make sure the steering wheel was in the right position when it all went back together, and I think it cancels a left indicator slightly earlier than it does on the right, but at least I'm not an old fart driving with permanent indicators on!

Rear suspension prep

 The rear wishbones have been taken off. I forgot how heavy a hub is when it's fully kitted out! My brain is probably remembering when they were just bare hubs.

Opening up the top wishbones I can see the first issue, the paint was still on there. Thinking about it, I wouldn't have been able to remove the paint the last time as they would have had to come off the car. Now that they are off I've cleaned up all the surfaces, partly to increase friction but partly so I can mark them up and drill them.

The bolt hole is actually slightly loose. Probably not because of wear but just because I'd have opened up the hole to fit the bolt through. 

Checking the newly arrived pins shows there's spot on;

It also looks like I can use pretty much any part of the block surface. It doesn't have a top fixing so it can go into a thicker part of the wishbone as long as I drill the hole deep enough. In fact thinking about it I might want it in a thicker part, I just need to make sure the depth is more than the pin.

The plan will be to mark and drill a hole in the block on either side, decently far enough away from the centre to provide leverage and stop the turning action. Then bolt the block to each side in turn and drill through to get the required hole. I'll drill everything with a 3mm or 4mm drill first, then open it up to 5mm afterwards. Lots of cutting fluid all round!! I do have a rudimentary drill press that I could use for at least the block holes, then with that straight it would make drilling into the wishbones easier and more consistent. 

I was wondering whether I could treat myself to some new drill bits just for this task, but a quick Google suggests cheap ones are all chinesium and not worth buying, and expensive ones are too much for my meagre budget. 

(17/8 update)

Well, I completely forgot I was mid-post on this! As you might expect this all went back together fairly well, and with the pins in place the suspension is no longer twisting. I've done a few hundred miles on this design and it looks good. As with everything on this car I will check them again at some point to confirm it's all good.

End of seat, start of suspension

 Well, the seat padding came to an abrupt halt as I've purchased a pad from Lidl. Time will tell whether it's sufficient. Having a foam pad for yesterdays drive showed it helps, but even with thigh support it didn't do my knees any good. I was also far too close to the steering wheel with my legs bent. Hopefully with the Lidl pad I can keep the seat back a bit but save my back side. So no more on that for now.

Back to the rear suspension. I have some awful creaks going on from the rear, and it turns out that once again the suspension has twisted. Again, not a huge amount but it has twisted.

I need to look at the shear pins drilled through the block and the wishbone. Staying with 6mm diameter, I need to figure out the length.

Some quick measurements gives me;

• 64mm wide spacer block
• 45mm tall spacer block
• 19mm thick spacer block
• 32mm thick including the suspension plates

So that means a 30mm pin might not give the full engagement. Luckily there is an ebay listing for M6 x 32, a 10 pack is £8. I'm not in a hurry for them as I wouldn't be able to do that sort of work in the week.

What I can do is strip things down in preparation for them, although even that is probably best suited to waiting for the parts to arrive. 

I've also given the front bushes a squirt of silicon as they were a bit squeaky. Actually, I should have done PTFE rather than silicon... Ah well, that may be a clean up job to do soon!

More seat work

 Back with the seats, mainly because it's too wet at the moment to drive the car. At the show I looked at a few seats, and took some photos as a guide on what to aim for;

Admittedly I thought I'd taken a few more than just 'two', but then looking at some of the Malvern show review videos I must have missed half the show! So much I don't remember, and it wasn't because the videos were from Sunday. I must remember next year to actually enjoy the show instead of just show off my car.

Anyway, back to seats. From the photos above the angle between seat back and base is actually quite acute, almost closer to 90 degrees than I expected. As a comparison I took my drivers seat out at the weekend;

It's quite clear to see that my seat angle isn't sufficient. 

So the reason I took the seat out was to see whether I could tilt the seat back entirely. In theory it was possible, but to make any appreciable difference I'd have had to raise the front of the seat several inches. This would have put the seat back too far back which would have made it difficult to drive. It would also have made refitting it really difficult because I couldn't have got to the rear bolts. Overall I'm going to leave the seat as is. 

However having the seat out is going to give me an opportunity to make things easier for me. As I was undoing the nuts I found a couple of the bolts were fixed in place. Not intentionally of course, but it really made it easier to undo the nuts under the car. I want to make the bolts captive in some way, so I'm going to add some washers that are bent up and welded to the slider. That way the bolt is still movable but won't rotate as I tighten it. It was something I should have done the first time but never got round to it. It's a small side job and will make things easier to work on. Having said that, if I don't make changes to the seat I may not to remove them very often! 

It's back to seat padding now. I've cut the bottom layer and the first layer, they work together and help my back side. Now it's just leg support, and I think a couple more layers to produce a support will do the job. Although I did have to push the seat forward because with my legs now bent over the support I couldn't quite reach the pedals! One thought I did have was that for the seat I used a wooden back board and stapled the leather to it. I can't do that this time round because if I use a wood base I'm effectively undoing the padding that is on the seat already. I do need a solid base to work off though. I think what I'm going to do is use a play mat option as a reasonably flexible base. It'll be rigid enough to get the leather in the right place, but bendy enough to be comfortable. I think I'll have to glue the leather in place though, staples won't hold. That also means I'll need to make proper corners as I can't rely on tension to make the corners. Fortunately I got a leather sewing kit so I should be able to do something strong enough. Once the foam is glued up and correctly profiled I'll make a paper pattern. 

Malvern recap

It's the following day and the outside temperature is finally starting to ease off. There might even be a bit of rain soon which will also help. Malvern was a great day out, made even better by it being my first kit car drive.

The drive down was challenging for all the wrong reasons. Driving through Wolverhampton was as ridiculous as I remember it, all sorts of idiots out there. On more than one occasion I had drivers in lanes that wanted to be where the other one was. Thankfully driving as if I was on a motorbike meant I got out of Wolverhampton without too much pain, and I got nearly all the way down before my next issue.

Yep, my sat nav decided to have a fit! I took a wrong turn and foolishly followed the signs for the showground rather than following the satnav route, and there was no signal for it to recalculate. Furthermore it actually lost GPS signal which mean I couldn't see where I was or where I was going. Thankfully I got to the showground eventually, but I definitely took the wrong way round.

Going into the showground was a brilliant feeling though. With a fair few tintops being directed to a long queue into the car park. I felt like royalty to be guided into the kit car entrance. Then it was a quick collection of a site map, and straight in. 

The kit net folks were really accommodating, and I ended up parked up with an Enigma and the 100/4 that I've seen at the show the last few years;

The Enigma is so much bigger, I didn't realise it until I was parked next to it. I guess that's what happens when you rebody an MX5 rather than put donor parts into a chassis. Still, having three variations on a theme all lined up was definitely a great sight.

After a brief catch up with the owner of the blue car, it was time for a comfort break and some breakfast, followed by a tour of the show. It was a decent turnout, not huge but just decent. Unfortunately I didn't see any Nova's which are my usual photo opportunity. Has it got to the point now where there aren't enough on the road? That would be a sad turn of events. No Countachs either, or at least none that I saw. 

Having said that, it turns out the being part of the show rather than just a spectator threw me. Normally I'd come in via the ticket office and remember where each group was. The kitnet stand was at the top of the show, so I completely missed a section along with a range of cars. 

Apart from the great turnout on kitnet, the biggest stand was the Westfield club. And that was a big frustration for me. Don't get me wrong, I like Westfields. But if ever there was an example of a 'production' kit car that was it. A big long line of cars where the only individuality was their colour. Even down to the seat belt straps being the same brand for a row of about half a dozen cars. 

Thankfully there were plenty of examples of unique kit cars, things that were only just recognisable because they reflected so much of their owner.

By the time I got back to my car there were a few people having a nosey which felt very good. This included one guy who was actually building one! Yep, my car may have a brother very soon, someone got hold of a white wide-body kit and is building it up. I suspect I'll be hearing from them as time goes on, it'll be good to watch it being built and hopefully parked up next to mine at next years show (or possibly the year after, kit car building always seems to take longer than you might expect). 

Then it was time to go home, and the journey back was very similar. No navigation at the beginning of the journey, normal route up the A449 after that, and thankfully an easier time of it in Wolverhampton.

The car has behaved itself really well, with only a couple of issues. First is the seat, I'll get that started today with any luck. The second was the screens. While the printed brackets worked for most of my driving, towards the end they had vibrated themselves loose and the screens were folding down. Tightening them up got me home, but I think a bit of threadlock might be in order there. 

Oh, and some new ideas. Or at least one idea. My bonnet latches are decent, they work well, they haven't broken (touch wood) and having them inside means they're not visible. However at the show I saw a car that used leather straps to hold a similar clamshell shut;

I like that idea so I'm going to see if I can do my own take on the same design. The car also uses wheel arches and again that was on my to-do list if I could figure out how to do it. 

The other thing that was interesting is that the front bonnet corner supports that I had attached were initially thought to be rubber, and it surprised people when I said they were 3D printed plastic. It made me wonder whether a rubber version might be preferable, even to a point where the plastic ones on the scuttle are replaced by rubber ones on the clamshell. That may also help with water drainage, as I found out a while back when washing the car I've effectively blocked the drainage channel. Bit of a daft thing to do but not unfixable. 

So yeah, a great day out, with the drive to and from the show being so much better in my own car than in a tintop. I'm looking forward to a few other shows in the year, and then returning to the kit car show next year. Hopefully without a sore back side though! 

Welcome to 'Slimyroadster'

 

Donor car: 1992 Eunos Roadster (Import MX5 NA), 1600cc engine.

Chassis: Self build, based on the ‘Build your own sports car on a budget’ book, and including some updates from the Saturn Sports cars build guide to suit the MX5. 

Body: An Austin Healey ‘narrow body’ fibreglass shell from KAD Fibreglass products. Believed to be originally the ‘Healey Seven Replica’ from MK. (MK HSR).

Kerb weight: 687Kg.

Engine output: 115bhp at 6500rpm. 

I started this build back in 2013, and while I started with a Haynes roadster chassis, I always had a ‘full’ body in mind, perhaps something like a Tiger GTA or Sylva Phoenix. It wasn’t until Stoneleigh 2016 that I saw the Healey bodies, one known as the MK HSR and the other was the Thruxton GT. With the HSR option being cheaper I ordered one in 2018, and it arrived a couple of months later.

Total build time was around 1500 hours, mainly due to getting the donor, chassis and body to match up. The HSR was designed to drop directly on to an MK chassis and therefore didn’t align with the Haynes roadster chassis in any aspect. Keeping costs low and limiting myself to single donor parts also made other parts of the build more difficult than expected.

The IVA was taken in February 2026, and failed first time with 2 construction faults, 2 misinterpretations of the IVA manual, 1 issue with low kerb weights on the application, and a missing exhaust mount. Retest took 15 minutes, and the use of a single donor meant registration gave an age-related plate. 

Future plans include an engine replacement to suit the Healey body, most likely a straight six of some kind. 

My ‘most useful tool’ for this build has been a 3D printer, with many custom parts designed and printed. For example, the dash gauges are MX5 originals removed from the original housing, with replacement PETG 3D printed bezels.

Malvern countdown...

 It's late on Wednesday and I'm starting to look forward to Malvern. Saturday is looking better than Sunday, with sun and clouds for the day;

That should give me pleasant driving conditions both ways (although I might wear a jacket to head down!). To get to Malvern I normally just head down the M5, but it's as boring as it is long so I thought a better route would be on the cards.

Turns out following the A449 will get me almost to the showground, then I can pick up signposts for the last few miles. The A449 is not particularly twisty turny, but it's very green and nice to drive on. Well it is when you're between towns rather than driving through them. 

That's a 2 hour drive with traffic, but 80 minutes without. I'll head out around 8:30 for roughly 10am arrival, that's still plenty early. I will need a comfort break and coffee when I arrive.

(Thursday)

Despite the spectacular thunderstorm last night, things are still really hot everywhere and it's still lasting until the weekend (touch wood!). 

One task I have assigned to myself is finding a fuel pump. I have a cheap Chinese pump that, to be fair, has done alright so far. Apart from it's initial fit when I put it on backwards, it actually does what it's supposed to do. It is a bit noisy but that soon disappears as I start driving. 

I want to consider replacing it, or at least having a replacement on hand. I was trying to find a brand replacement, with CBS having a replacement for not much money. But it wasn't branded, so I was torn between CBS (hopefully) not selling garbage and it being unbranded. So I posted a question, and very quickly got reminded that a 'Bosch 044' pump is the go-to pump for builds. I remember that from very early on in my build but had completely forgotten about it. 

Of course, it was so long ago that Bosch 044 no longer exists, it's been replaced by a Bosch '200'. So I'm on a mission to find one at a decent price. It just so happens that I'm going to a car show this weekend so I'll take a look there. 

Fitting it shouldn't be too bad, I may need to re-terminate the hose and maybe enlarge the bracket but apart from that it should be fine. The benefit of replacing the pump also means I'll have a bit more headroom for any future engine upgrade. 

I also had an idea about 3D printing a seat base. I have a reel of TPU that works really well to create 'soft things'. Why not print a cushion? Admittedly it would take a while and I'd want to print a test piece first, but I'd be able to print any profile I wanted. It's an interesting experiment, probably massive overkill considering sponge would be quicker, but isn't that the point of 3D printing? Why do a job the easy way if you can use a 3D printer, take 3 times as long and get 80% of what you were doing in the first place? 

(as an aside, that reminded me I needed a TPU cap for the dashcam connection. That's all done now, hopefully it'll keep moisture and prying eyes away from the memory card)

(Friday)

It's a bit less sunny out there, the temperature is down a fair bit but still worthy of being out and about. Of course, I'm not, I'm stuck at work with a release going out at the end of the day and we're working our socks off to get it done in time. At least I'm busy, unfortunately it's not 'car related' busy :( .

The TPU test pieces have been printed. I went for a 2 inch square by 1 inch deep pad, no walls and gyroid infill. This is a 'collapsible' infill that is deliberately less sturdy than pretty much any other type of infill. I started with 5% infill, that's far too squidgy. It would give no support at all. 10% went too far, that was rock solid. However that could be good for the base where most of my weight is. 8% works well though, that's comparable to my sponge so would work really well. Whether it would last as long as sponge I don't know, and to be honest it took so long to print such small test pieces that I suspect I'll just use sponge for the final product! 

One thing that did occur to me is that I need to do a pre-drive check tonight. I've not looked under the bonnet for a while and it'll be worth me doing a quick once over to confirm nothing else is loose. I also want to buy something for lunch tomorrow, it'll be the first time I'll be able to sit in my car and eat lunch compared to just sitting on the grass or wandering around eating a sandwich. Normally I pop to the supermarket just before I get to Malvern (there's a Tesco nearby) but this time I think I'll be a bit more prepared. 

(Saturday!)

Well, it's a nice sunny day, a bit cool which should make the journey very pleasant. Everything is packed and I just have the pre-drive check to do. I'll see everyone at the show!

Dash back together and seats update

The dash is now back together, the reset button looks good and the defect on the edge is pretty much gone;

The car has been cleaned and ceramic coated so I'm ready for Saturday. 

In the meantime I had a go at profiling the seat. It does look like for comfort I need to bring my knees up quite a bit. A fellow Locostbuilder sent me a link to a thesis where it talked about seat positioning, this is one of the photos;

This also confirms the amount of knee angle that I should be aiming for. Even in this picture the pedals are lower than the seat, whereas for mine they're at the same height.

As a guide I tried some rolled up blankets as bolsters;

This is a 3 inch roll, and while it helps it's not enough. Also that's based on the back of the seat still being the same height. Adding a second blanket gave me this;

I think this is on the right track. The seat base is 18 inches deep so I'm thinking;

• First 6 inches will be a 1" thick pad
• Middle 6 inches will be a 3" pad
• Last 6 inches will be a 5" pad

Given that I want as much of the 5 inch pad as possible, I'll profile the other two layers to come up and meet it. This sort of stack (side view);

Even that might be overkill. For example many tintops just have an edge bolster for support, like these Porsche Recaros;

Or Cosworth recaros;

So I could do this;

The final option is the 'messy' option, which is a bag of PU foam and a bin bag! That would be to form a well fitting seat while I'm sat in the car. I'd still need to bump it up a bit, the expanding foam would only fill gaps where my butt wasn't touching the floor but I still want to have some padding for my back side.

I did have a thought that I could 3D print a seat pad... I have TPU and I reckon maybe 10% infill might work. I'll print a test piece and see if I can sit on it comfortably. 

Hot weekend

Well, the good weather is seven days early but fingers crossed it'll still be warm next week. This weekend it's up to 28 degrees on Monday. This will be the time when I figure out whether an all-aluminium interior was the best way to go. It did occur to me that the edge trim in the car is 3D printed, and while I left them on because they looked good, I also have doubts on whether they can survive high temperatures. Even the glue fixing them on could go a bit 'gooey'. If it does I'll just remove them, they were going to be removed anyway so it's not an issue. 

In any case, I'll get the car out and see whether it becomes unbearable in the heat. When my next post is 'third degree burns on my hips and elbows' then you'll know things got too hot!

I did discover why my diff was pretty dry though. Basically as soon as the propshaft was removed the oil would have come out, so it would have been dry since it went on the car. Such a daft thing to do and hopefully I've not done any terminal damage to the gearbox. If I have then it's <£100 for a new one, but it's not a few minutes job. 

Lets see what's on the 'to do' list;

• Heel/foot plates. Both passenger and driver need somewhere to rest their feet, it's surprisingly hard work to keep straight legs. It's mainly going to be just a bar across at an appropriate point, a bit closer on the passenger side with the driver side being just before the clutch pedal. 
• Reshape seats. Along the same lines as the above, I want to tilt the seats back or create a bolster under the thighs. I still have some pleather so I think some decently supporting foam would do. I did think about an old angled pillow that we have lying around but it's not actually that supportive. I've learned that seating actually needs to be a lot harder than you might expect to be comfortable. I can see why some seats are basically solid, or at most with a small layer of foam. 

(Later that weekend)

Well, heat is heat, and driving in a car with no roof or cooling is like having a hot hairdryer in your face. It's mostly a nice experience, but I didn't last many miles. On the subject of miles, I've started a fuel spreadsheet. Yeah I know, probably the epitome of dullness. But without a fuel gauge I need to have an idea how far I can get.

A 5.7 gallon tank gives me around 200 miles range. Just as a comparison, Malvern is around 50 miles away so I can get there and back without filling up. 

More work

 Bodywork fixes are looking good;

I'll need to rub down the paint once it cures but it looks a lot better already.

While the dash was off I had a look at the odometer reset button. After several hours of looking for the parts, I put things together and planned out where it would show on the dash. Then a few hours redesigning and printing the bezels got me here;

It looks good with the speedo temporarily behind the bezel, but I can't put everything together until the paintwork is polished and finished. I'm optimistic it will work well, then I'll be able to use it as a fuel gauge. 

I'm on countdown to Malvern now, two weeks to get it spot on. I'll do the paintwork in the week and get it all back together, then one last run on the weekend to make sure it'll make the journey. Then a clean and ceramic polish to finish. 

Gearbox oil, jacking point, wiring clamp, bodywork fixes

 I got lots of little jobs done yesterday. Start with the biggest one, the gearbox oil. 

I've wanted to do the gearbox oil for some time now, I'm aware that I've replaced all the other fluids except for Gearbox. So I bought a couple of litres of the recommended GL-4 oil and had a look at what is required. While the job itself is quite awkward on the MX5, it turns out the drain and filler plugs are both accessible from the engine bay in my car. The filler plug was first, that needed some persuasion but came off in the end. The plug itself didn't show any signs of issues apart from 20+ years of gunk. I'm 99% sure it's never been changed.

The drain plug was similarly easy to come off, and that's where I found an issue. It turns out there was very little oil in the gearbox, nowhere near the 2 litres that should have been in there. Once it was refilled and the plugs went on, then the job was finished but I wonder how much damage has been done by the gearbox being empty. I suspect sometime in the near future I'm going to need a new gearbox, at least for now it should be happier. Second gear is still the noisy one so I won't push it. 

That was the main job I wanted to do this weekend, and it turned out to be a lot quicker than I thought. 

I actually started the day with the rear jacking point, partly because I thought I would need it to do the gearbox oil. The jacking point was pretty straightforward, although my welder was not happy for some reason. Lots of sticking wire and burn backs on the tips. Part of it was welding upside down, but I think I'm overdue a new tip and shroud anyway. I'll do that before I need to weld again.

So I now have a rear bar in the right position for the jack, which should make lifting the entire rear a lot easier. No pics unfortunately, I seem to be forgetting photos of work in progress.

The next job was the wiring loom clamp on the engine. The one above the exhaust had melted and distorted so it needed to be replaced and reinforced. The design is as before, but now I have a layer of 1mm steel round it to keep the shape. Once it was all bolted together I could see it was going to be a bit stronger, and at least the wiring and the coolant pipe that is being held by it won't drop on to the exhaust. I'll still monitor it to see if it's sufficient, I may have to upgrade to ABS if this isn't good enough. I don't like printing in ABS mainly because my printer can barely cope with the temperatures, and it warps really easily. 

The last jobs were the bodywork. Just under the passenger dash I had a scratched panel where I managed to drop it during fitting. It shouldn't have bothered me but I found I was looking at it every time I drove. It actually took a lot more work than I thought as the scratches were quite deep. Still, half an hour of sanding and polishing got it back to 'nearly' sorted. I left the panel at 1200 grit as I don't want the panel shiny. 1200 grit is roughly where it started, a slightly matt finish with no swirl marks. 

The other mark on the bodywork was again on the passenger side, a dent where filler didn't work properly, and then the paint also chipped. It's another thing that I didn't really need to fix, but I've done it anyway. Or at least I'm halfway done. I filled the hole yesterday, I'm about to go at it with some sandpaper to get it flush, then touch it up with some paint. It is just pretty labour intensive work, a couple of hours at least I reckon. But it'll be worth it. Again it's because it's so close to the passenger seat that it's very visible.

I'm also tempted to have a look at the odometer reset button, just see how much work it would be to restore it. It would be mainly replacing the 3D printed part, as well as cutting a small notch out of the panel. I just need to make sure I can get it in the right place. 

Oh yeah, and the rev counter is bouncing again. I am hoping it's simply a bad connection, but I suspect it might need a new one. 

More miles, first issue

More miles now, and a full tank so an opportunity to work out my mileage again. 

The first journey from full tank to full tank was 102.5 miles for 12.3 litres, which works out to be 38 miles per gallon. This fill up was 21.23 litres and it got me 162.8 miles, which is 35 miles per gallon. Given the first was motorway and the second was 'fun' it looks about right. 

Now the issue. Coming back home I got a clunk clunk under the car right under my feet. Everything seemed ok so I got home and had a look;

 The tensioner bolt for the alternator has decided to undo itself and escape. Thankfully it's just a standard bolt so I'll replace it with some threaded rod and some nylocs so it can't go missing again. Nothing else looked loose so I'm counting that as a win.

Oh yeah, and I forgot the main thing about an open top car... sunburn! My face feels like I've been in the sun for hours, I assume it's a combination of the actual sun along with the drying effect of the wind. 

I also want to look at a jacking pad for the rear. Something in the centre within reach of my jack would be ideal. At the moment it's going on one of the boot supports;

It works but it's sketchy and lopsided. If I put a bar or flat panel at roughly the same depth then that'll be a centre lifting point. With the jacks just ahead of them it works out quite stable;

The front should also get similar treatment although I don't have many ideas there as the front of the car hangs down too far for the jack to get under. 

First 50 miles

 This morning dried up so I thought I'd take the car out on it's maiden voyage. A quick first few miles and back showed everything looking good, no leaks and no spray of diff oil so that's all sorted. A short wee break and a few more miles, visiting various relatives on the way. Everything seemed to be quite healthy. There were some unusual 'smells' but I can't tell whether they were from the car or from the outside world. After all it's a UK spring and all sorts of stuff happens!!

Once I'd got back and got the feeling back in my legs (heel rest and seat pad to be done very soon!), I had a look under the bonnet and round the car.

Firstly the screens worked well. I no longer have the draught on the top of my legs which was part of the wind chill I had from Bristol. I still get some wind buffeting in my face but it's tolerable to drive without a helmet now. I tried a few different screen angles but it turns out the one I had that 'looked ok' is actually the best one. So that's a huge tick in the box for getting to the kit car show.

Everything under the bonnet held up well despite the additional heat. Well, apart from one bracket. It's PETG but it's right above the exhaust, and it's in tension rather than compression;

 I suspect if it gets any more pliable the coolant pipe will become detached and drop on the exhaust. I need to reprint a new bracket and then encase it in steel, similar to what I did for the fuel pipes. 

Oh, on the subject of fuel pipes, no petrol smell anywhere. That particular demon has been well and truly exorcised.

The main thing that I think needs some work is the rear suspension. I modelled the upper wishbones off a Westfield design where the MX5 upright is next to the damper;

The problem is I then also included a camber adjuster;

I was thinking that the damper and the upright were close enough to not put rotational forces on the bracket. Unfortunately I was wrong, it is basically twisting the bracket on the bushes. It's not enough to unwind the bolt but at some point something is going to get upset. 

I have replaced the washers above with a solid plate as below;

But essentially what I need to do is make the wishbone wide enough to accommodate two bolts. The second bolt will then provide the shear strength to prevent rotation. That then gets me back closer to the Westfield design. The fact that Westfield used the design at all suggests it does work with the right layout. Another Westfield design also puts the damper off from centre;

As a short term fix I could just weld the plates together, but that won't allow me to change the camber and that's on my 'to do' list. I am wondering whether I have enough material to redo them entirely, including enough on the wishbones so I don't have those spacers (but still have the option of camber adjustment). I may have the bush tube but I am 99% certain I don't have enough of the seamless tube. 

Then I'm wondering whether I should change the design so the damper is directly above the upright so forces get transferred in a line rather than rotationally. But then I could make it so the joining plate is horizontal rather than vertical. 

I guess some planning/design is in order.

(The following morning) so I'm having an early morning conversation with Copilot... yeah I know. Copilot is only as good as the questions you ask it. In this case I asked what the friction force was for the plates, and it came back with around 400lbft of torque required to overcome the friction of the steel surfaces. That's on a fully torqued M12 bolt with clean surfaces.

The second question was how much force would be applied if the shock absorber was 1 inch away from the pivot. The response was 80 lbft. Now just looking at the photos I can see it's a little more than 1 inch, but at this point it's just about multiplying the numbers. In theory it would have to be five inches away to apply enough force to overcome the friction. It's not five inches away so I 'should' be in range.

The last question was 'how to improve it', and there were two options. A friction shim or a shear pin. The friction shim is basically some other material to increase friction. Think brake or clutch pad material, that sort of thing. It makes sense but a quick google suggests I can't exactly buy a 'sheet' of this material. 

The shear pin is a much better option for this application. Basically a hardened steel pin through the two suspension pieces and the bracket in the middle. Two 6mm pins would work fine. If I can't find long enough pins to get through all the plates I'll use ones on either side and rely on the welding in the middle. So I need a maximum of 8 pins (2 per hole, 2 holes per side, 2 sides). The standard quoted is DIN 6325, and while Amazon is showing me furniture pins, Ebay has some listed for less than a pound each. I still have a couple of weekends before the show, and apart from taking the rear suspension apart this isn't major surgery. I'd have it done in half a day at most. 

The one thing I want to do today is to get the car lifted up and get the brackets realigned and retorqued, just in case it was something silly like the lack of torque on the nut. I also want to clean off the paint in case that is acting as a lubricant. When I was getting the torque figure it was based on clean steel with flat mounting surfaces. Those surfaces aren't clean or flat, so again this means the pins will work better than just trying to increase the friction. 

I have a registration!

I have to give credit to the DVLA people, they really turned things around quickly. Between paperwork and registration being assigned was 13 days. It would have been quicker if the postal service had delivered an information request on time (6 days for a letter to arrive, how is that good service?!). 

So now I have an age related plate, or at least the email confirming it. I still have to wait for the paperwork to arrive (by post!) before I can go buy my number plates. I was going to get them online but to be honest buying them from a shop is only a couple of quid more expensive. I really can't wait now, screwing the plates on will be the final step in getting it roadworthy.

Of course, I'm sat here now with the beginnings of man-flu, and the prospect of a slightly damp bank holiday weekend, so it's not as if the postal delays are making that much difference. The paperwork didn't arrive today (Friday), and we tend not to get post on a Saturday so it'll be Tuesday at the earliest.

(Later that week) It's now Thursday and I've not had confirmation that the new cheque has arrived with the DVLA, and there's no sign of any paperwork. Seriously, can the postal service get any worse? I wanted to get a few hundred miles driven over multiple weekends before I head to the kit car show, at this rate I'll still be waiting to buy the number plates!!

However it is very reassuring to know that the car now fully exists;

It also shows correctly on askmid as insured. The donor car is also gone, that just returns 'vehicle details could not be found'. So everything online looks good. 

As I mentioned above I was ill over the weekend (it managed to stay with me from when I finished work on Friday until I started work again on Monday. This week has been slowly recovering back to normal, and hopefully I'll be getting some garage stuff done this weekend. One of the first things I need to do is take it for a drive and give it a shakedown. That'll allow me to check the new diff seals, the rear suspension, and the front screens. I also want to start doing some more work around fuel economy which again needs some miles driven.

The same also applies to the foot rest and thigh pad, as well as checking the passenger side footwell temperature. It's right next to the exhaust and I didn't check how hot it gets in the car because of it. 

(Friday update)

Well, thankfully the paperwork arrived today, and a quick detour to the local shop got me two new plates which got fitted after work;

So the car is effectively finished, IE it is a roadworthy car that can be driven. Of course it's not completely finished, I still have a fair few things to do as well as simply driving and enjoying it.

I didn't get to drive it tonight as it was raining, but tomorrow is looking dry. I've got a few hours in the morning to take it for a spin and see how it drives.

Windscreen done

From this;

To this;

Personally I think they've come up really nice, although time will tell whether they do their job. I've not done the bottom seal yet though, I want to test drive and see the effect. It'll also give me a chance to test various angles to see if there is a 'sweet spot' where the wind goes over the top. 

I've also done the rear number plate, this is version 5 (or maybe 6);

This one is just a small support that will disappear behind the plate. The front won't be mounted on anything, I'll just screw it straight to the bodywork. It'll need to be slightly curved on the front but that shouldn't be an issue.

The last job for now is just a small bolt cover in the boot, to cover an exposed bolt thread. It wasn't a major one, I just knew I'd scratch myself on it at some point.

I have also heard back from the DVLA. Unfortunately it's not a V5, it was a request for more paperwork. In my specific case, I'd forgotten to sign the cheque. So I've spent the last two weeks waiting for something to happen, when nothing could happen. Anyway, the signed cheque is now on it's way back so hopefully that will be fine now. They didn't ask for anything else so I'm taking that as a good sign. Maybe now the paperwork has been reviewed once, the cheque can be cashed and I can get my plates. 

Diff and windscreen

First job for the weekend was the diff seals. Autodoc got them delivered Saturday morning so I thought I'd have a go at fitting them. Just take the wheel off, pop the stub shaft and seal off, new one on, job done. Nah, not that simple unfortunately.

Despite my best efforts I just couldn't get the angle to remove the shafts, so in the end I took the diff out. Which needed the boot to come out. Not a big deal for either of them, just a bit time consuming. It was so much easier with the diff out though, the first shaft came out with a sharp thump;

Having it on the floor also meant I could put the diff on it's side to save the oil. The seal was toast which was a good sign;

A whole section in the bottom left was folded in. Even if the folded section had maintained a seal, the creases would have let oil out.

New seals both sides, then a quick top up. I reckon I got about 100ml of oil in before it reached capacity. Given a full diff is only 0.75 that was a decent amount but not so much that the diff was knackered. Well, at least I'm hoping that is the case!

Next job was a bit of painting. The steering column was looking a bit rough, as was some of the interior steel sections. A quick coating of matt black sorted both, hopefully once it's completely dry it'll protect a bit better. 

Then it was on to the windscreen. Starting from last post where I had cardboard cut outs, I printed the hinge and trial fitted the windscreen.

Straightaway I realised that the hinges were too chunky. I liked the idea of chunky hinges but together they were almost the width of the screen.

Then the second issue;

The curve of the car meant the screens were pointing out like ears. It was quite pronounced with the square glass but even with the rounded glass it was going to look weird.

So there was a few things to fix. First was the angle, that wasn't too difficult. A few trials with some spacers showed that if one side went up 3mm and the other side went down 3mm, the 6mm difference would put the screens horizontal. The second fix was just to make the brackets a lot narrower.

I've ended up here;

The screens aren't perfectly horizontal as that would look as out of place as ones parallel to the car. I think this angle is spot on. I'll set the angle at 70 degrees to start with, and have the lowest (inner) edge to be 10mm off the surface. The outer edge will then be 16mm. I'll leave the bottom wiper until the screens are on, just in case I decide they're not needed. I think they will be just to stop wind getting in from underneath. 

Oh, and the initial hinge design used Nyloc nuts to make things tight. That didn't work, it was just too stiff and I even broke one of the initial brackets tightening it. So now I have some TPU washers that should lock things in place. Of course, only a test drive will show whether it's strong enough so that will be a while yet.

In terms of fixing them to the car, as long as I'm not too close to the dashboard then there's nothing underneath to screw into accidentally. So only a few more fixings to go for the screens, basically brackets to screens and brackets to car. 

Next job is the rear number plate holder, version 4. I've took the old one off (with only some trouble removing the old sealant), now I need to print a reduced version. I'm staying with a full sized plate but I want to make sure there is no exposed support. The only exposed printed part will be the number plate light itself. That needs to be done as one piece so I don't have glue lines in it. I'll probably go for a centre piece big enough to fit on the bed, then just a couple of T pieces to provide side support. I'll also do a similar design for the front plate, obviously without the light.