Just small jobs this weekend. The good news is a package of parts from David in the UK arrived. Lots of nuts and bolts and washers and gaskets.
I was able to replace the gasket on my steering box and with that, and some Loctite 515, it now doesn’t leak (I hope). It was a sunny day on Saturday so I was able to paint the back of the instrument panel white.
The white means it’s much easier if you’re working behind there when it’s in the car as everything is brighter and easier to see. Next I need to paint the front crackle black but I need a nice hot day for that (which today wasn’t).
I also looked at modifying the clutch. A7 clutches seem rather complicated! The issue is the toggles that push against the backplate when you press the pedal. Where the toggles press on the backplate the plate wears. Mine had been welded to take out the wear but a better mod is to drill the plate and insert 1/4 inch grub screws to provide a hardened surface for the toggles to rest on. It also allows you to adjust the height of the pivot point. To accurately drill the holes in the centre of the slot I turned up a little punch on the lathe so I could make a punch mark right in the middle of the slot. The punch is the same width as the slot.
Because the plate had been welded (and the welds are hard) and the punch wasn’t hardened it only lasted the three punches then the point was ruined. But it was enough. I used a centre drill to start the holes then drilled them out to the right tapping size for 1/4 UNF. UNF as the threads are fine and the plate isn’t very thick. Also luckily I have a 1/4 UNF tap!
To tap the holes I used the pillar drill. Unpowered and turned by hand of course but that ensured I tapped the holes square. I find that tricky sometimes by hand.
I now need to get some 1/4 UNF grub screws.
I also had another look at the top of the crankcase. There was some pitting so I though why not try filling those with epoxy. I smeared the top with epoxy and have roughly sanded it flat with some paper on top of my glass plate. I still need to lap it smooth with some grinding paste but I ran out! One rear corner at the bell housing end was very pitted so the epoxy built that back up to height.
One mod worth doing is adding o-ring grooves to the front cam bush (there isn’t quite enough space on the rear one). The bush fits into a hole in the crankcase so you can have oil flowing into the gap between the two rather than through the hole and onto the camshaft itself. There is just enough room for a groove between the locking hole and the front of the bush. I ground a tool and cut two suitably sized grooves on the lathe.
The other mod is to restrict the oil flow through the bush. You can see the oil hole (the upper one above) is pretty large. You get way more oil going to the cam than you need meaning you don’t get as much going to the big ends where you want it. A well lubricated big end is a happy big end.
To restrict the flow you can fill the holes in the cam bushes with solder then drill a smaller hole. I filed the inside of the holes to get back to clean metal then used a small butane torch to solder the holes. After filling I carefully scraped and filed away the excess solder then drilled a 1/16th hole in each bush. I believe that’s the correct size.
I’ll put the bushes into the ultrasonic cleaner once I know that is the correct size to get them perfectly clean then bag them up until engine assembly. I won’t fit the o-rings till then. The other thing I will have to do is build up around the rear oil take off with a little epoxy then file it flat. This is so I can use a fibre washer on the rear oil take off to seal it.
The hose barbs I am using are parallel thread so they seal on the face rather than the threads as taper ones do (although some sealer on the threads might not hurt?).
Today I machined up an aluminium plug to block the oil gallery. This is so I can reroute the oil through an external filter. The plug was machined from a little piece of aluminium bar Ian gave me. That was a tight fit and was hammered home into the crankcase. The side of the crankcase was drilled and tapped for a 1/4 bsf bolt which would lock the plug into place. Tapping was tricky since you can’t get a normal tap wrench into the space but I was able to go slowly with a small spanner and do it.
To really make sure it won’t move the locating bolts has a little of the thread on the end turned off to leave a small pip on the end of the bolt. This was 3/16ths in diameter. The block had a small dimple drilled in the side which I used to start the drill. By being extremely careful I was able to drill into the plug through the threaded hole (without damaging the tapped threads). The hole was of course 3/16ths too. With the bolt done up the little pip fits tightly into the hole and now the plug can’t move at all. Loctite on the bolt and a fibre washer should make it all oil tight (if any oil can squeeze around the plug which I doubt).
Lets see, what have I been doing? Not too much unfortunately. But I did strip down a Ruby seat. Not since I plan to use it, more to see how they are made.
Someone had recovered these and had used hundreds of small tacks. It took forever to remove them all. I’ll make a similar seat but shaped to fit my car. The Ruby ones are much to wide to fit.
Joss found me the steel piece that runs from the scuttle to the radiator surround. The bonnet hinge fits above that. One end is missing but we have several loose ones so I can weld that on. I started hammering some of the dents out of it using a handy steel block I got the last time I was at the metal place in Onehunga.
During the week my new throttle spindle and disc arrived from Joe Curto in the states. I’ve taken the body to CSL in Grafton to get them to fit the new bushes and the shaft. You need to drill the body from each side but not all the way through so there is a little edge for the bush to push up against. The two sides need to be perfectly in line of course or the spindle won’t rotate smoothly. It’s a bit tricky for me to manage that at home so the experts can do it for me.
I finished up the repair on the throttle spring lug. I sanded the epoxy and inserted a small piece of brass tubing in the hole as a bush.
I also removed the little instrument panel lights from an old Ruby panel. They are spot welded in place so I drilled those out. The holder is on a little toggle so you can lift the bulb up to replace them.
I gave them a good clean up and repainted the brackets then did some playing about with actual bulbs and a battery to work out the best placement to light up the instruments.
The photo makes the lighting look harsh but it looks more even in real life. The oit gauge might need the plastic diffuser replacing as it lets through a bit too much light. The small oil gauge doesn’t have the clear windows around the face so that one doesn’t light up. I added two small switches on the far left of the panel, one for the lights and one spare, maybe to be used to turn on and off the water pump? The instrument panel can now be painted, gloss white behind (makes working on it in the car much easier later on) and crackle black on the front.
The other small job I did was lapping the top of the cranks case with some grinding paste (miked with kerosene) on a sheet of flat, thick glass. This makes sure the surface is flat so the block will seal onto it nicely (with appropriate gasket goop). There is some pitting on the surface but the aim is to make sure the mounting surfaces are flat rather than making the whole top smooth.
I still need to fit the oil gallery plug then I can take the crankcase off to the engineer for some more work.
The other thing I did was order a bunch fo parts fomr David in the UK so hopefully they’ll arrive soon. All the fiddly little bits I need for the engine, tab washers, oil throwers, centre cam bearing race and so on.
Right, no major progress but I am trying to get small bits and pieces done. I cleaned up the White Lady sign and that’s looking good now.
And I started stripping down my carb for rebuilding. The outside of it looked clean but the internals are a mess. One of the throttle disc screws was stripped so I had to drill it out to remove the spindle. I found it was badly worn.
When worn like that the carbs leak around the spindle and you can never get them set up right. Once I had everything apart I discovered the rebuild kit the SU people sent is the wrong one. It has a 1 1/8 disc and spindle whereas my carb is a 1 1/4. I also had a wee accident and the carb body fell off the bench and I broke off a lug on the body.
One of those lugs is used for the choke lever pivot and the other for the return spring. You can flip over the lever as it works the same on either side. To fix it I drilled the body and inserted a small brass loop then I built up around the wire with JB Weld epoxy. I didn’t get a picture of the brass wire unfortunately.
I then sanded back the epoxy and drilled a new hole. For added strength I inserted a small brass tube as a sleeve which is epoxied in place. Once that dries I can sand everything smooth and it should all be good again. I have ordered a new disc and spindle but not from the Burlen people. They were slow and I find their web site is really hard to navigate. It works great if you know the exact number of your particular carb. If you don’t think it is really hard to find parts on the site. So instead I am getting them from Joe Curto in the states, well known as the best SU rebuilding place in the states.
I came to the conclusion that trying to drill the body to fit the new bushes (the ones in the kit were correct teflon lined ones) at home is asking for trouble so I will get the local carb building people at CSL to do that bit for me.
One other small job was removing the cam shaft centre bearing outer ring. It’s a press fit in so I heated up the crankcase around the bearing with the oxy torch then used a suitably sized socket and long extension to carefully tap the ring out.
I also cleaned up the oil pressure gauge I got off Eddie in the VAR. That was the last gauge I was missing.
Once I got it apart it was easy to clean things then reassemble it. Since it is lit from the back as are most of the gauges I decided to modify my tachometer to make that backlit also. I cut a strip of thin perspex on the scroll saw then used the hot air gun to soften the plastic and I formed that around a glass jar. I scuffed the plastic a bit with a scotch pad to make it a bit more diffuse.
Bulbs behind the instrument panel should now light up the gauges. I tried an experiment with a bulb and battery and it should work (but was damn hard to photograph).
I also realised that I get a better view of the gauges with the steering wheel oriented with one spoke point up and two down. It also looks better on the car that way. All I need to do now is make a hole and mount the lighting switch then I can look at painting the instrument panel in crackle black. The back of it is painted gloss white, a trick I used on my MG. With a white back it is much easier to see what you’re doing if you ever find upside down head under the dash trying to see something.
I also looked at the long stud mod to the crankcase. I machined a point on the 5/16ths rod Glenn gave me and also machined up an old aluminum knob so I could pass the rod through the crankcase and ensure it was square to the top face.
The idea being that with the rod square to the crankcase top I could then see where it would pass through the bottom flange where the oil strainer would usually go. The mode involves bolting a large aluminium bar on that lip that these long studs then screw into. This spreads the load across the bottom of the crankcase rather than having two short studs pulling on the rather thin top part. What I found though is the rod would actually come out into the side of the case itself. I put that aside for a bit so I could ask Ian what he thought about it.
In the weekend, on Sunday afternoon, I went over to Ian’s. There was a North Shore branch VAR club run that finished at Ian’s garage to see his projects. I didn’t go on the run but did go to the end part at Ian’s house. There were quite a few people there and quite a few interesting cars. Mostly Austins of course (being the vintage Austin register) but a couple of Morris’ too! The little blue Chummy replica is nice. I like the paperclip holding the throttle linkage in place.
Ian took a look at my stud mod and he thinks that maybe the top face isn’t flat so the rod might not actually be square to the top of the crankcase. I need to flatten the top by grinding it on a flat glass surface. This will ensure it is flat and also make it much easier to get an oil tight seal there. He also thinks that milling a small amount off the crankcase where the aluminium bar fits will make things much easier. I can’t do that myself at home so I contacted a local engineer and will go see him to get his opinion. This is someone other Austin people have used so he understands what we’re trying to do. He’s fixed up front bearing lips and done other things for people. I will get him to look at my crankcase and also my blower drive setup which will require a few mods.
So tonight I looked at the blower drive setup and how that will work. I need to modify a front cover to provide the extra mounting lugs the Grasshopper drive has. I had a few to choose from and this one seems about right. Everything is just loosely in place for now.
With the Grasshopper drive the blower will be much further forward that I originally planned. In fact a rear mounting lug on the blower would hit the water inlet on the front of the head. But I think I can remove that and mount the blower on a plate mounted to the proper mounting points on the drive (the two holes seen in the middle photo above).
I also looked at the fan mount. There is just enough clearance to run a fan (the wood block is about the same thickness as the radiator) but I think I will not run a fan (since I have an electric water pump) and instead I will probably make a new fan mounting that has my idler pulley on it. To see how that would work I temporarily removed the original fan pulled and slid my V belt one on the drive. You can see how the fan spindle is mounted to block that has a shaft that’s mounted to the blower drive. It’s a bit like half a crank pin. That is how you can adjust the belt tension by rotating the fan spindle.
I can use the same arrangement but since I am using a seal bearing on the idler pulley I don’t need the greasing point the original has. The idler is even on the right side of the belt (the slack side). I am still working out the details but I think I can see how it all works. One thing I am not sure of is what you do with the end of the cam shaft. Normally the big pulley for the fan belt drive goes there but with the Grasshopper drive there is no room for that of course. I wonder what they did on the original cars? There is some fiddling to be done with cam shaft end float so I need to work out how all that works before I go and see Brian the engineer.
And tonight, when fiddling around with nose cones, I went and found the crank handle that came with the car. That always had a horrible bend in it for some reason so I got out the oxy/acetylene again and heated up the shaft and straightened it a bit. It might still need tweaking but at least it’s not got an S bend now!
And finally I got a new tool today. My old vernier calipers got dropped and they then never ever returned to zero the same every time you used them. So I bought some new ones. I was looking about for a while and finally found out that surprisingly RS components locally had a pretty good deal.
These aren’t fancy expensive ones like Mitutoyo but they are good enough for an amateur like me. These are dual metric and imperial (which I didn’t actually know existed) and they seem very solid. Better than my last ones (which lasted 10 or 15 years). I prefer the dial kind to the digital ones since 1. no batteries and 2. when I am mucking about on the lathe I like to see how much actual difference a cut makes. With a digital set (and digital gauges in general) you only get an indication of the actual reading at that time. Analogue gauges and dials not only give you the actual reading, you can see the difference between readings by how far the needles move. It’s why I prefer dial calipers and why I also prefer analogue clocks and watches. The changing position of the needles tell you something as well as the number they point at. I always liked how old fighter aircraft and race cars have their instrument panels arranged so all the needles point up (some gauges are rotated even so this happens) when everything is running right. You can tell at a glance is anything is out of place.
So now I have those I can machine up the oil gallery plug in the crankcase. All these little jobs add up it seems!