Blog update 2020
1 May 2020Due to an unfortunate server accident last year my blogs were lost and I have been unable to recover them. All of the original content up to a point is available here on the Internet Archive's Wayback Machine.
All the original photos are here Austin 7 gallery
All new updates are being put here on my Asciimation YouTube Channel.
First drive!
May 12th, 2019The first drive, after nearly 8 years work!
In all the excitement I forgot to turn on the in car camera, sorry!
As per tradition.
A few minor updates and a film.
April 27th, 2019I made a little film of progress so far.
After yesterday’s effort I was left some comments from Jack that were quite helpful and they got me to have another look at the starter pull. I do have some solid spring wire 0.8mm diameter, used in model making, and I gave that a try down the bowden cable. It worked fine. So I reworked the system to use that. I remade the starter end connector out of a little piece of brass I turned up and a screw.
The spring wire is wrapped in a loop around the brass which fits through the hole in the starter switch. The screw screws down tight onto the brass but there is enough clearance between it and the switch so that the spring wire is free to rotate. I ended up doubling the spring wire up on itself and crimping it with some copper tube to hold it in place. The pull end has a little brass tube with two lock grub screws in it. Another part from my Weta junk box, it’s used to attach things to small motor shafts. I shall have to see if it eventually pulls through but for now it’s holding well. Looks far neater and feels better using it.
Also from Jacks suggestion I put some rubber sheet under the battery. It is sitting on a wooden base in the bottom of the box but the rubber will stop things rubbing through from vibrations. I also put some under the top strap.
I also looked at mounting the muffler. I used the same weld the inside technique to keep the outside of the flange clean. This is something TIG does well. MIG would leave far too lumpy a weld. The flange on the muffler has to be at an odd angle to get the muffler placed right against the side of the car which of course isn’t flat.
The problem will be where to run the pipe. And I had to decide which way up to weld it. With a wing on (that’s just an example, not what I will use) the pipe would have to go over it but then it will be right next to the passengers shoulder. I think that’s far too close. I could run it down and come in front of the rear wheel but then the outlet is ahead of the passenger so they will probably get fumed! You can get flexible ducting so I am thinking run it under the car in front of the rear wheel and then out a pipe at the back with the Brooklands fishtail on it. But that might look odd (although a quick test with the vacuum cleaner hose sort of worked).
With the flange welded on I painted it all black and while waiting for it to dry made a copper gasket. Cut from my old hot water cylinder, rolled flat then annealed to make it soft. With the paint dry I bolted it in place.
I doing so I suddenly realised a possible answer to something I have wondered about. Why do some spanner sets duplicate some measurements on several spanners. Like these:
You can see one is a 3/8 and 7/16 and the other is 7/16 and 1/2. I always thought it odd. But often, like with my exhaust and the pedal locking bolts, you are doing up a nut and bolt which are the same size so you need two spanners the same size. Maybe that’s why? Perhaps that’s bleeding obvious but I only just clicked. Not all sets do that of course.
Anyway, with the muffler on I think things look quite good!
At least now I can run the car with the O2 sensor and see what the mixture is doing.
Holiday!
April 26th, 2019Due to the timing of the public holidays here Easter and Anzac day ended up in the same week so for 3 days leave you could get a 10 day break. So I did. All the time has been devoted to car progress. I’ve done a lot and it’s hard to remember everything.
I left work early on the Thursday and went to Bunnings and bought some normal ply and some matt black paint. All the shops are shut on Easter Friday so I wanted to get everything I needed.
I made a simple box from the ply and glued reinforcing strips to the corners. Then I painted the whole thing matt black. I don’t know what the original finish was but I suspect the box is something people overdo on rebuilds/specials. It’s just a box, full of stuff rattling and bashing about, so I went with utilitarian rather than flashy. Also my woodworking isn’t that good!
It actually took me most of the day since I only have a handheld circular saw and setting up some of the angles was tricky. It then took another day to paint it and let the paint dry. Once dry it was mounted to the firewall. I used two screws at the front though the base and the rear is actually held by the battery isolator switch which sticks though the box and firewall into the cockpit where the switch can be reached up under the dash. It’s easy to get to but hidden. It takes a little working yourself up to drill holes through your sheet metal so I was careful and measured and marked everything with masking tape. The step drills again proved their worth. After making all the holes I touched up the paint on the edges so things won’t rust.
While waiting for paint to dry I did other small jobs. I made some plastic bushes to fit the horn into its mounting bracket. This horn has no markings on it but it looked just the same as one that Joss has with a name on it I completely can’t remember. The horn is mounted to the bonnet support rail thing just in front of the tool box.
I also mounted the speedometer and the oil gauge. I ran the oil line (with an anti vibration loop in it) up the front of the tool box. I needed to make a bracket for the speedo.
I then worked on the starter pull cable. I was trying to work out how it was done on real cars but it’s a bit vague but seems to be just a wire that goes through a bush in the firewall. That wouldn’t work on mine so I made my own bowden cable arrangement. I used net curtain wire for the outer part. It’s springy and hollow and smaller diameter than a choke cable. Inside it I am using a stainless steel cable. It’s left over in my scraps bin from my Weta days. We used cable pulls a lot for Animatronics so I had some leftovers around. At the top end I made a wooden block that clamps to the column and it feeds the cable up to behind the switch. At the firewall end I used a short 1/4 inch stud that I drilled through the middle. The inside is drilled slightly larger diameter so the net curtain outer slides into it locating the end.
From there it goes to the starter pull. To attach the cable ends I used the little connectors from out of a chocolate block electrical terminal. On the starter end I piece of copper tube is flattened over the end to the stainless cable as the ends are razor sharp and stabby.
The outer is attached to the steering column down near the pedals to keep the cable out of the way. I am currently using a cable tie but will make up something more appropriate. It seems to work but I can’t test it just yet.
Oh, I had also painted the floors, the pedals and the handbrake cover. The paint takes a few days to dry and when done I bolted everything in place. It’s all a bit fiddly but I got there. My captive plates for the footwell floors worked well and the floors are solid.
The battery leads I ordered finally arrived. But one was blue!
That was rather annoying (and I need to see if I can return it as they aren’t cheap). So I needed to rethink my cable routes. This is where having a big wooden box in the middle of the engine bay comes in handy. It’s great to attach things too. I had already attached the oil line to it. I decided to attach the starter cables to it too. I found the leather Joss gave me years ago and made some little straps to use as P clips. I think this method was used on some original Austin Sevens.
I ran the positive lead to the cut off switch then from the other side of the switch down the side of the box and down to the starter terminal. I ran the earth across the front diagonally to a stud mounted to the firewall above the coil. This is my main earth terminal. From here I am going to run a flexible earth strap down to the starter motor mounting bolts and that will be the main engine earth. The strap has been ordered from a Mini spare parts place so it’s sort of Austin Seven I guess.
I was worried about the ends of the bolts on the inside of the box being something I am bound to scrape my hands on but I found some acorn nuts and was able to use them to cover the ends.
Oh, the other thing visible there is the wooden cover I made to protect the back of the battery switch. Since that has positive on it and the box is mounted via bolts going to the body (ground) and the box is full of metal items it seemed wise to have some isolation there. I made that from some old drawer bottom ply. I don’t know what wood it is but it smelled very nice cutting it. Very sweet. It just clips in place and the cables coming out of the top stop it moving.
The other thing I did is make some battery hold down clamps. These are patterned, loosely, on the Austin 65/Nippy ones. I used 1mm steel and used some long exhaust studs to make the threaded rods. These were brazed to the brackets. A bar across the top clamps the battery down. It always amazed me how flexible some metal is. The 3mm strap over the top of the battery needed a 6mm rod welded to it to make it rigid enough not to bend. Then I am amazed at how inflexible other metal is. I broke my die holder extending the threads on the tie downs!
The brackets all had to be painted of course. The holes in the front one make the car go faster. I put heat shrink over the top strap to insulate it. A bare metal strap over the top of the battery between the terminals seems unwise! I am using a lot of gutter bolts to hold such things on. You can still get slotted head ones which work well and they come in 3/16 and 1/4 sizes. I always felt a bit bad using them, they seemed too modern. Recenty I actually thought to check what thread they are. Turns out they are Whitworth! So perfectly usable.
Other jobs, lets see… I decided if I want the car to move bolting in the driveshaft might be sensible. First I had to properly bolt in my remote gear shifter. I used fender washers underneath it to spread the load. And since everything was being done upside down I gave up on spring washers and Loctited everything. It’s all rather tricky when you are lying on your back under the car trying to get the nuts in place while reaching around in front of the hand brake (with it’s cover removed) to hold the spanner to stop the bots turning in the top. Be so much easier with two people but I have to do everything on my own. Luckily it’s a small car so doable!
Several problem arose. First my near vision is starting to go so lying under the car I can’t actually focus on the nuts and washers. I have cheap pharmacy glasses (recommended by my optometrist) which definitely help. They prove useful later on too but I will get to that. Also Loctite when wet is, ironically, horribly slick stuff. It’s hard to hold onto nuts and washers when they and your fingers are covered in the stuff.
The other issue was always check you don’t happen to have a 12 volt SLA battery sitting in the car with it’s positive terminal right next to where you are using a spanner with it’s earth connected to the body.
That lead to an interesting moment when I was under the car. Good thing it’s only a tiddly battery!
With that done I was finally able to bolt in the driveshaft, something I didn’t expect to take long. It took me ages. There were a couple of issues. The bolts, which are special D shaped head ones, couldn’t be fitted into the torque tube flange as they were too long and wouldn’t clear the housing. I ended up taking the flange off and fitting the bolts then putting it back again. All lying on my back under the car of course. The second issue is even then the bolts wouldn’t fit! This was a new set but it seems the shoulders on the bolts weren’t turned the right diameter so wouldn’t fit in the hole (the thread would go through but not the shank). This was on both the torque tube flange and the gearbox flange. So I had to use the lathe to machine down the bolt shoulders so they would fit. Finally with that done I got the drive shaft in.
The I found the grease nipple on the front sliding section hit the hand brake lever! I was able to add a shorter one which gives me about 1/8″ clearance now.
The other thing I did was work out what linkage I need for the throttle. A little problem here is the front of my firewall isn’t exactly square. So when I tightened up the throttle cross shaft it would bend slightly and bind up. I had to file a little tapered steel shim to go under one of the mountings.
I then used some plastic scraps and welding wire to mock up the linkage I would need.
Turns out I need a 3/4 inch lever. I looked on the SU carburettor site and found the shortest brass lever they do is 1 inch although they do a different style lever that is 3/4. I ordered both as well as the little lock screw for the choke cable and some new screws for the carb dashpot to replace my chewed up one. I also ordered a rod with ball ends to give me a nice linkage. My welding wire isn’t workable in practice but it gave me some idea of the lengths I need. You need the ball ends to get the actual articulation required.
Now it’s very cool you can still get all these original parts still but the postage to New Zealand worked out to be 25 quid for a few small parts! That’s just f-ing ridiculous! I did look at using the YouPost re-shipper and having the parts sent to the UK address then redirected here but if you do that you get charged VAT as well as the redirect cost so it ends up about the same. For that price they better arrive pretty bloody quickly is all I can say.
The last job I did was finally weld in the O2 sensor bung into the exhaust. I think they are usually fitted to much fatter diameter pipes! The bung is 1 inch diameter. The pipe isn’t much bigger than that. So I filed a curve into the bottom of the bung then MIG welded it on. I also drilled three mounting holes into the flanges and welded that on. Because I didn’t want huge flanges I made the diameter just enough to do up the nuts which means there is no room for a large weld around the outside. Instead I bevelled the flange and TIG welded it to the pipe from the inside. That worked very well.
This is where my reading glasses help. I use them for welding now and can actually see the weld pool! Make a huge difference. I was so busy making sure I got the flange square I forgot to look at where the mounting holes were so things are a bit off. It shouldn’t matter, they are far enough out that it looks deliberate!
I gave the pipe a coat of BBQ black and bolted it back on. Removing and reattaching the manifold and carb is actually pretty fast. A matter of minutes.
I totally forgot to weld the other flange to the muffler when I had the TIG out. When I do that I will have to be VERY careful I get the hole alignment to match the flange on the header of course. I still have an issue of where does the pipe go after the muffler but I will work that out later.
So things are a looking good. I am just waiting for the choke parts and the earth strap the I should be able to start it up again and see if it drives. I need to get some fuel line and will do temporary wiring to the fuel pump and ignition and will use a petrol can as a fuel source. I should also be able to hook up the Innovate to see what the mixture is doing now. So getting very close.
The tool box even works!
Once it is drivable I need to do the proper wiring, a fiddly job. And make a petrol tank. And wings. And get the seat upholstered. And mount the Brooklands screen. And do lights. But that’s nearly it. Oh, then get it registered.
Small jobs.
April 14th, 2019Now I know the engine runs there are lots of little small jobs to do to get the car actually driving. But I got distracted making a little shelf/tray thing under my tool board as I was sick of hunting about for scribers and punches and so on. I had a block of oak from a table leg chopped off something with a hole drilled in it that made a useful pen holder.
A few extra holes and all the scribers and punches and so on have a place to live as well as random pencils and Sharpies. Most of my commonly used tools are now on that tool board which is really handy.
I did manage to do some small jobs on the car. I brazed some nuts to some steel strap to make captive plates to go under my footwell floor sections. They hold the floor down as well as stiffen it. I was going to drill and tap them, it turns out the slotted gutter bolts I am using are Whitworth threads, but I had a moment of dumbness and drilled them out for tapping to 1/4 inch when the bolts are actually all 3/16ths. Since I couldn’t tap them brazing nuts on worked instead. They need painting and installing them is fiddly but they totally stiffen the floor nicely.
I also made a new bracket for the coil from some 3mm strap steel. The original was far too modern looking. I used heat and my vice folder as well as the slip rollers to make the shape. I did the final shaping around a Riley 9 hub which happened to be about the right diameter.
The bracket was fairly beefy so I used the step drills (which are the best thing ever – if you don’t have any get some!) to make the holes which of course make things go faster. I am saving up all my parts that need painting and will do them all at once the next nice day we have. I mounted the bracket to the firewall.
Speaking of step drills the other thing I did was make some washers to stop a small oil leak on top of the oil filter. For some reason the holes the pipe fittings go into are really countersunk so when I tighten up the fittings the fibre washer was distorted down into the countersink. I used the step drills on the lathe enlarge the hole in the middle of a standard big washer to stop the fibre washer distorting and spread the load onto it more evenly.
The steel washer might need to be slightly bigger still but I will see how this goes.
Another small job was the choke cable. I found an old MGB one in my box of junk and hacked that up a bit. In my junk steel and brass box I found a steel shaft with a hole already drilled through it stripped from an old printer I think. That fitted the slot in the choke control and the hole matched the inner choke cable so I made use of it and soldered the cable into the little steel bar.
I then drilled a hole in the firewall for the cable to pass through. Now this takes some thought. I need various holes in the firewall for choke cable, starter pull, oil line and wiring. For the choke I drilled a hole in the middle under the bonnet support bar as that gives me the straightest run. Again the step drills are invaluable here after drilling a pilot hole. I drilled a hole for a grommet to pass the choke through.
I still need to get the little piece that hooks the cable to the carb but I will order that when I order likages from the SU people in the UK. I did look through my box of random old SUs and didn’t find one (or any linkages or useful levers) but I did find a throttle shaft return spring so I fitted that to the carb. I will add a second though.
I also worked on the starter pull. As far as I can tell this was just a straight wire or cable passing through the firewall to operate the lever on the starter motor. I ended up hunting through my box of junk left over from when I worked at Weta because I knew I had some old steel cable in there about the right diameter. I found that and modified the control itself by soldering a brass wire with a loop in into the end. I don’t like the idea of a bare cable so I decided to make my own style Bowden cable. I am using a net curtain hanging spring thing with the outer plastic coating removed.
The steel wire will pass through the brass loop and then into the springy net curtain outer which will be attached to the firewall to bring the inner wire out opposite the starter. That’s the idea anyway!
The other thing I did was go to Bunnings and bought some rubber matting I will use to make the floor covering. It’s thick and dense so I think it will give a nice non slip surface as well as add some weight to the car to prevent drumming in the footwells.
I had hoped to get some marine ply to make the tool box but they didn’t have it at that branch. I did try ringing another but it turns out there is only one branch locally that stocks it and they aren’t open in the weekend! So that’s no bloody help. I did mock up one in cardboard and hot glue to see how it will look and where I can mount things.
I am going to mount the battery isolator switch in the back of the box poking through the firewall so it is accessible inside the cockpit but hidden from view up under the instrument panel. The battery positive will connect to the switch via a short link then the positive will pass along the back of the box then down along the firewall and down to the starter motor terminal. I’ll box in the back of the switch of course so nothing can short it out.
The earth I haven’t completely figured out yet but I am thinking it will go across the back of the tool box to a stud mounted to the firewall as the main earth on the offside. From the stud will be a heavy lead directly to the engine/starter. The regulator and fuse box will be mounted next to the tool box. I also need to work out a battery hold down but I suspect that will just be threaded rods and a bar across the battery top.
The job I didn’t do was mocking up the throttle linkage. I need to do that so I can order the right length rods and levers from the SU people. Tomorrows job!
The other nice thing is my Innovate unit arrived (the next day)! It looks very flash and will let me measure AFR as well as RPM and other things.
It actually logs to an SD card and connects to a laptop running their special software. I should be able to hook up a TPS sensor as well if I wanted to. It came with all the cables and the O2 sensor as well as a cable to plug into an OBD-II port to read out modern car error codes. As I have no modern cars I don’t have anything I can even test that out on!
I need to weld the bung into the exhaust manifold. But the exhaust needs some thought as my idea of a straight pipe along the side may not work as it will then hit the rear mud guard. If you bend the pipe so it avoids that it would be right next to the passenger! So I might need to angle the muffler down and exit the exhaust in front to the rear wheel. Those are details to be worked out in future!
It runs!
April 10th, 2019Tonight I finally tried firing the engine. And it works! I had pretty much gotten everything ready last night. I just needed to add a throttle return spring.
I filled the float bowl, hooked up the starter battery and a smaller one to run the ignition and tried it. It took a bit of fiddling but I got it to run.
I now need to make everything more permanent. The massive jump in oil pressure is normal for A7s apparently. It should settle down to 2-3 PSI once everything is hot. A few small leaks around the oil filter fittings but that’s easy to fix. I did take off the tappet chest cover and there didn’t seem to be any oil in there which worries me a little but then I am not sure how much there should be after a short run. I want to make sure oil is getting to the jets.
It sounds just like an A7 and the muffler works great. The best thing is it now smells like a proper car. Fuel and oil and exhaust fumes and burnt paint and so on. It smells just like a vintage car which is hard to describe but people who have one will know what I mean.
I need to work out exactly what the timing is. I had the distributor wound much further around advanced that I expected. At TDC on 1 it seems like the trailing edge of the rotor is opposite the terminal. Maybe that’s normal? Once things are all set up permanently I will get a timing light on it.
To actually tune it I splashed out today at work in a moment of extreme boredom and bought an Innovate Motorsports LM2 which will measure and log air fuel ratios as well as RPM and other signals. In theory I could put a throttle position sensor on it and log all that. When that arrives I can tune the carb properly. I was going to get the simplest AFR setup they did and actually looked at simulating their serial protocol to see if I could talk to their (free) software they provide with an Arduino but I never got it working. Some things it’s probably worth just spending the money on up front.