1980 Austin Princess mild custom - 1951 Lanchester LD10

solex was a french company, I guess that would mean they favoured metric like Webber?

Without wishing to sound soft, it was really nice to see you both so positively fired up about the car.

And don’t worry about “priorities”. Better to tailor your garage/parking situation to your fleet than the other way around.

Your physical location is also great. The “end of the road” plot lends itself really well to doing something that won’t look out of place. You could easily have a 3-bay garage there with apron parking in front of each bay.

I think you'll find with the Princess the more you use it the better it will get, cars are designed to be used not parked, one of my dad's mates had 3 in a row as a sales car he used to do hundreds of miles a week in them. (mind you he did burn the clutch out towing a 3 ton fin keeled Yacht behind it)

Just take whatever the Lanchester throws at you as a new learning experience, it doesn't really matter how long it takes as long as you are making progress and enjoying it.

With respect to the garage yes more space is great but the trouble I've found is that as I make more space I(and my son) tend to fill it with more projects or equipment!
What you do with the garage really depends on funds, flattening it all and building a new brick built one would be great but need proper foundations etc and cost tens of thousands, I would be inclined to take the roof and one side off what you have then build a lightweight timber framed extension on the side and top it with a lightweight pitched roof, you can always pretty the front up and tie it all in with boarding some nice doors and few plants.

M12x1.25 is quite common for banjo bolts.

But as it's a solex carb we may well be talking about France in the 1950's, I don't think the french have ever used anything except metric?

You'll all (maybe not melle) be surprised to learn the thread on that banjo bolt is indeed 12mm x 1.25 I'll do a proper thread later, just snatching a moment between work e-mails here. It must be the Solex connection, I can't think of any other reason for it, it even has some metric measurements in the manual alongside the Imperial (I'll post a pic of that in the next proper post, it's interesting in its own right) so it looks like Lanchester were early adopters for decimalisation in the UK.

Today has been a busy one so I've not had any time until now to get some scribblings down, so here we go. The first thing is a little photographic evidence of the purpose of the mystery thing, courtesy of readers identifying it as the fuel reserve mechanism. I don't know what the rest of this assembly should look like having never seen one and it's slightly disappointing that its no longer there, especially since the cable does still seem to operate it.


The other item is that contentious banjo bolt. The thread pitch gauges arrived today and, after a tip off from another reader about standard Zenith sizes, I just went straight for the 1.25 comb on the metric side.


That looks like a match to me and 12x1.25 is a standard size that's easy to get a helicoil kit for so I've already ordered one of those. I used a different tool for measuring the width of the bolt threads and confirmed it is indeed 12mm so I'm reasonably confident it's going to be correct. The other thing I'm reasonably confident of is that it should be a metric fitting, not just because of the list of metric numbers given for standard Zenith carburettors, but also Zenith's connection to Solex. The third factor is the information on the carburettor in the original handbook I have for this car which lists all of the carburettor dimensions in m/m (funny how we now just go mm for the same). Hopefully that's case closed on this one.


We're in that spot where we're waiting for things to arrive so it's a case of looking for busy work to tinker with throughout the week to make progress on items that make the car a little nicer when the big jobs are done. We were both somewhat disappointed that the horns are silent and, since we weren't sure if it were the horns, the wiring, or the button at fault it made sense to pull the horns and test those separately first since that's easier. The paint on the horns is very thick, we were going to leave them as is but when we realised there's so much paint it's difficult to even see the fixings in places it might be a good idea to restore these. In all, the paint stripper had to cut through four different layers of grey enamel before it got down to the original black finish. Due to the shape of the parts I opted to adopt the technique used on some diecast restoration channels I follow and switch from the initial method of blobbing the stripper on with a brush and instead just set up a stripping tub. This Bartoline stripper is very good, it's just also very slow. It's certainly better than the Nitromors equivalent.




One of the horn domes has already been done and given a splash of paint. Although the horns were black originally, we're making a minor change by doing them black with red domes since the horns are fairly prominent in the engine bay and a bit of colour is always welcome. this red goes nicely against the grey of the engine and the black bodywork.


To dismantle the horns it's a variety of flat headed screws, the domes themselves have one in the top where that dimple is which goes into a bracket that slots into the plate the electromagnet is attached to. Underneath the dome is the wiring, the electromagnet, and the diaphragm. These horns are quite simple, so far as we can work out the problems they usually have is bad connections and badly adjusted diaphragms.


An initial physical inspection revealed nothing untoward beyond dirty contacts. The green wire is moderately new, the bullet connector on the end is well crimped and there's no obvious sign of damage so we're leaving that be for now. The connectors are just sort of clamped in place, they're not terribly secure, the design in this area isn't fantastic. First job was to dismantle, carefully, the points so we could clean them. In the above picture, simply undo the bolt and then the stack of items above the plastic isolator block can be unstacked and laid out for inspection and cleaning.


The points don't have any pitting, though they are slightly discoloured, the camera makes them look blacker and more burnt than they do in person and after a work over with some suitable abrasives we had them nice and shiny again.




Much of this work was done by the other half, he's more comfortable with electrical things than I am and derives more enjoyment from fiddling with them. They checked the various solder points and wires for physical damage and then checked for continuity where appropriate with the multimeter. All checked out fine so it was reassembled and ready to test.


That's when we found out that while everything checks out, we couldn't get so much as a squeak out of the horn. The only other thing it could have been amiss, so far as we could tell, was the diaphragm being out of adjustment. There's a nut and a slot in the thread it goes onto that should be easy to turn to adjust the diaphragm and allow the noise the horn makes to be tuned. It was very, very stuck. For fear of damaging the slot in the thread we opted to dismantle the item down again to tackle it separately. In the following picture you can see the diaphragm on the left, a small activating rod, and the electromagnet on the right.


The rod sits under the arm of the points, and our understanding is that this is pushed against the diaphragm when the electromagnet is energised, which breaks the contacts, which then pulls the diaphragm back, quite rapidly in succession. The shaft and the hole it goes through are free of corrosion and it moves freely, so we're moderately confident that's not the issue. You can see the hole the shaft goes through a bit easier when we flip the parts over.


The problem item is the nut in the middle of the diaphragm. there's a threaded spindle that goes through the diaphragm, the side with the slot is accessible from the outside of the horn by prising out a rubber bung and you should, in theory, be able to just tighten or loosen this with a screwdriver. The other side of the spindle is what the little polished shaft pushes against.




It required a lot of effort to undo the nut that holds this all together, so much so we questioned if it was even supposed to come undone at one point. Once the nut was undone it could be unwound from the thread as could the diaphragm. Some cleaning of the thread and parts later and they all move freely on the threaded portion of the spindle now and the nut can be used to lock things in place properly. Unfortunately, we ran out of time to test the horn again, the batteries are in the car and our neighbours are certainly not going to appreciate a horn toot test at gone 10pm, so this is a job for tomorrow. The paint stripper will have done its magic by then too, so providing the storm clears we should be able to get all the parts of the horn repainted and ready to be reassembled properly.

Sounds like you came to the right conclusion, but now try a 20tpi thread gauge, with the naked eye it will be a perfect fit too. Your measurement at least confirms it's not 1/4 BSP, because that's 19tpi (and 1/4 NPT is 18tpi). Sometimes the best test is to try an unknown bolt in a known size nut or vice versa.

Many years ago I helped a friend restore a mid 30s Morris Eight Saloon. The block was stripped and cleaned we then decided to run a tap in the blind holes in the block to ensure the threads were clean of any gunk or thread sealants from previous strip downs. we were confused to say the least thr bolt and nut heads were imperial ( I don't remember if they were Whitworth or AF probably a combination of both. we came across some very odd thread sizes, not sae, Whitworth but metric. Measured all the fastenings and found metric threads, WTF was the conclusion somebody must have re tapped the threads! but as we later discovered the engine / tooling was a French apparently an Anzani connection and that William Morris' engineers had decided that metric nut and bolt heads would have been rather confusing for the average British mechanic. I must add this was in pre internet days late 1980's and no Haynes manual for this car.