project 1951 Lanchester LD10 - Rear Corner Inspection

[vulgalour]

It's the camera angle, my bad.  I couldn't hold the ruler in the right place and the camera... and I'm not very good with fractions.  Anyway, I'll wait for the thread gauge to arrive and see what it measures at.  I wanted to just go into An Shoppe and get An Manne to look at it and tell me what I need, go into Ye Olde Backe Room and asking me for two shillings happence before handing me a good quality tool wrapped in nice brown paper.  Unfortunately we live in the Now, not the Then.

[Christine]

Go to that kent paint and panel place...(i  did a buyage there last week ,very reasonable !) there's a motorbike restoration place in the  next unit . Bet your life they'll have helicoil kits ? Or further round there are motor engineers workshops ..

[vulgalour]

Okay, that bolt width at the widest point of the threads is actually 12mm.  So it's whatever the Imperial equivalent of that is.

[Angrydicky]

BSP would make more sense, all the fuel fittings I've come across of that era have been BSP rather than BSF.

[vulgalour]

Determined last night that the bolt is 7/16ths and that my ruler is a little fibber.  What's 12mm on one side is not the 12mm equivalent in imperial on the other, but then it's not a precision instrument so I suppose that's to be expected.

[egg]

14 hours ago, vulgalour said:

I wanted to just go into An Shoppe and get An Manne to look at it and tell me what I need, go into Ye Olde Backe Room and asking me for two shillings happence before handing me a good quality tool wrapped in nice brown paper.

You are 'avin' me on, you are definitely 'avin' me on!

[vulgalour]

Proper update later, just snatching a minute between e-mails.  Banjo bolt is 12mm x 1.25, as confirmed by the new thread gauge.  Bit odd that it's metric, but that does line up with the Zenith standard measurements offered on another forum.  Helicoil kit ordered for £reasonable and it's a size I can see coming in useful in the future so not a bad tool to have kicking about.

[somewhatfoolish]

A british carburettor from the 1940s with a metric thread? Is nothing sacred? Napoleon has won! etc.

 

[Angrydicky]

I would imagine the thread got stripped in the ally carb body and the original bolt would no longer seal, so someone forced that M12 bolt in there. Would explain the shonky state of the thread!

[somewhatfoolish]

Possibly; it would be a rattly fit in a 1/4 bsp thread to begin with as there would only be a 0.25mm of engagement, then as it was wound in the disparity between 19 tpi and 20 tpi would become apparent; it would also strip as soon as you put any strain on it because pot metal isn't terribly strong.

[alf892]

I would very much doubt that is an m12 bolt because unlikely it would accommodate that filter gauze so neatly.......

on those horns there is a push rod under the points which oscillates as the points make/break.......it tends to stick and just needs taken out and lubricating. I put up with poorly working horns on my rover for over 10 years before having a look!

[Timewaster]

"Do you sell Whitworth spanners?" 

 

"No Sir, we do Draper and Sykes Picavant" 

 

[vulgalour]

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.

Another item is the banjo bolt which has confused many readers because, in part, I'm using imprecise tools and am, in part, an idiot.  TO CLARIFY:  the bolt measures 12mm across, and the thread is 1.25 which coincides with the information provided by a reader for standard fitting sizes on Zenith carburettors.  It also makes some sense to be metric due to Zenith's connection with Solex, and because the carburettor dimensions are one of the things given in metric in the original handbook I have with this car.  A suitable 12x1.25 helicoil kit has been ordered to hopefully fix the carburettor and get us running again.

Now, I know there will be some deliberation even now on whether or not the bolt should be metric, but it's my opinion that the chances are it is.  Whether it should have been imperial original is neither here nor there, fact is the bolt there is now metric and we're putting a new thread in to accomodate the bolt rather than purchasing a non-metric bolt to accomodate the non-existent threads.  Right.  Moving on.

Horns.  While waiting for things to arrive it's good to do busy work and that's what we determined to do.  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.

 

 

[PhilA]

That should work if it checks out. Recommend hearing protection, Windtones are rather loud.

 

Phil

[somewhatfoolish]

8 hours ago, vulgalour said:

Another item is the banjo bolt which has confused many readers because, in part, I'm using imprecise tools and am, in part, an idiot.  TO CLARIFY:  the bolt measures 12mm across, and the thread is 1.25 which coincides with the information provided by a reader for standard fitting sizes on Zenith carburettors.  It also makes some sense to be metric due to Zenith's connection with Solex, and because the carburettor dimensions are one of the things given in metric in the original handbook I have with this car.  A suitable 12x1.25 helicoil kit has been ordered to hopefully fix the carburettor and get us running again.

 

The best check is to do that with the thread gauge, but hold it up to a light source; if the light shines through a nice even gap then it's a match. If the gap is wobbly then it's BSP as BSP thread has a 55 degree included angle rather than the 60 degree angle of metric thread. The TPI difference matters too but the thread form is much more obvious when you're comparing.

[Mr Pastry]

34 minutes ago, somewhatfoolish said:

The TPI difference matters too but the thread form is much more obvious when you're comparing.

FWIW any plumber's merchant will have 1/4 BSP fittings in stock for comparison.

[vulgalour]

When I put the gauge on the thread it's a perfect match, the shape of the thread aligns absolutely with the shape of the comb.

[Christine]

Looks a good fit to me..

[vulgalour]

Today we learned how the seats come out, courtesy of another forum.  The ends of the seat hinge are not both fixed, one end is spring loaded so you simply push it in and lift the seat out of the bracket.  How silly do I feel not realising that?  At least removing the driver's seat for the cover repairs is going to be considerably easier now I do know how they come out.

Little victories, I suppose.  It means the passenger floor can go back in at least.  The other item on the list has been the horns.  I'd left the parts soaking in the tub of goo and it brought them up fantastically well.  The main body of the horn is cast aluminium, while the dome and trumpet are steel.

The dome got another coat of red because I wasn't as happy with the finish as I could have been, and I did the inside of the trumpet in red too.  I found dropping the trumpet into a plastic tub stopped it wobbling around and made it much easier to paint.

For everything else simple gloss black was the order of the day.  The dents and pitting from rust remain because we decided it would be odd on this car if these looked perfect.  Instead they look tidy and cared for and should weather down nicely so when the newness is worn off they fit right in with everything else.  For the outside of the horn I simply masked it by using its own shape and a bit of paper scrunched up in the open end.  This is a great way to get a smart colour split on items like this with really minimal effort.

Originally there was some sort of sealant on the spiral and around the inlet where the horn goes.  Earlier horns have the horn in cast metal rather than steel, these later ones I assume are constructed this way to save money and possibly a bit of weight.  I cleaned the paint off the mating surfaces and added some fresh sealant where the old rubber seal was around the trumpet, using the smallest amount I could on the spiral so it didn't splurge everywhere.  I'm not sure how necessary this sealant is, in theory I expect it prevents vibration and unwanted harmonics between the parts and probably helps seal things up to force the air out of the trumpet rather than the gaps.

Then it was simple a case of reassembling it all.  The fixings aren't painted at the moment, they might be painted before the horns are refitted, we haven't decided since it looks okay as is.

Certainly looks and feels nice than the other horn which is yet to be started.

We did then try and test the rebuilt horn and all we've succeeded in is sparks at the wires when they touch the battery terminals.  Didn't matter which way around the wires were put either, we got the same sparks regardless and nothing out of the horn.  We assume an adjustment is off somewhere and that's why we're getting sparks instead of beeps.  The horn does have a little plate inside that confirms it is 12v and not 6v, so we don't think that's the issue, and there is continuity, the points appear to be okay and are clean and we do now know the diaphragm can move.  Advice welcome on this one, we're pretty sure it'll be something straightforward and easy to fix once the issue is identified.

In other good news, the new inner tubes arrived so when we next have the opportunity to do so we'll be getting those new tyres on which will make moving the car a lot easier.

[Fabergé Greggs]

The banjo bolt thread type is the most heated debate I’ve seen on Autoshite since one of the great politics debacles of yesteryear. Jolly good. 
 

Great work as ever! Am I allowed to say I preferred the horns in a more muted colour? Sorry ? 

[vulgalour]

You're allowed to say it, absolutely.  I'll defend your right to say what the heck you want, even when you're wrong ;)

[Christine]

But there might be another "thing " under the other floor !

 

[puddlethumper]

You can't beat a good red horn. ?

[somewhatfoolish]

I like the horn, it looks like it belongs on Noddy's little car which as the LD resembles a british big brother of the Topolino seems entirely appropriate.

[Christine]

The guts of the horn remind me of those VW golf superchargers , whatever they were called , I ve forgotten ...

G - larder  ! 

[PhilA]

Re sparks and no parp.. what do the green wires connect to? Normally the horn with have a single supply and ground through the body of the horn to the vehicle. Did someone add a second wire instead of using heavier gauge, meaning green to power and frame to ground?

 

Just a thought

 

Phil

[vulgalour]

Both green wires go to the loom, we assumed one was live, one was earth going off other folks' videos on the slightly different model Windtones.  Likewise with the other horn, both those yellow wires go to the loom, there didn't seem to be an additional earth so maybe they do earth through the body of the horn?  Worth bolting them onto the car to test?

[PhilA]

Or just hold a corner of the horn frame onto a battery post and give a swipe of the wire across the other terminal. If not, sparks and no real harm done. If so, it should attempt to make a noise.

[vulgalour]

Still no joy with the horns.  We've had them apart and back together again, cleaned up all the contacts, tried various ways of earthing the body, and putting power to the connections and all we get is sparks instead of parps.  The only thing we could find amiss at all is that the polished shaft that is fired to open the points is sticking, what we can't fathom is why.  There's not obvious sign of wear on it or the hole it goes through, no signs of corrosion either, and when the horn is disassembled it moves very freely, it's only when you have it all together for testing that it sticks and we're at a loss as to why, or why that might even be a problem with operation of the horn.

In other news, the helicoil kit arrived.  Typically, it wasn't a straightforward job because the drill bit supplied is a smidge too wide for either of the drills we have, so I improvised by using pliers to turn the drill to clean out the damaged threads and then ran the supplied tap through what remained, it was slow going but it did work.  Winding the new helicoil in was much easier and we very soon had the banjo bolt wound back in properly and sealed up tight.  Huge relief that this actually worked and we can confirm 100% that the thread here is 12mm x 1.25 since that's what we've used.

In happier news, with that fixed we actually got the Lanchester to run and idle.  It's still not quite right, timing etc. needs adjusting.  We think we've retarded the timing too far now as there's very little throttle reponse and it sounds a little lumpier than it should.  Now we know it idles we can at least go through and set the other items.  That starter motor is a pain too, we're going to have to pull that off and rebuild/replace it.  We did try to select first and move the car and while you can hear it selecting, we're not getting any drive.  This could just be the timing being off meaning there isn't enough throttle to actually move the car.  It could also be that there something wrong with the gearbox and/or flywheel and that could be why it came off the road.  We'll find out when we get the engine running smoother than it is right now.  Not a bad bad little victory for work breaktime at any rate, we're delighted we've got it running semi-reliably and looking forward to dialling everything in properly so it runs better soon.

Progress is progress, even if it's only small stuff.

 

[JeeExEll]

17 hours ago, PhilA said:

Or just hold a corner of the horn frame onto a battery post and give a swipe of the wire across the other terminal. If not, sparks and no real harm done. If so, it should attempt to make a noise.

Sounds like an exciting experiment. For maximum effect it needs to be carried out in a closed small garage full of fresh petrol fumes and vapour.  

'What's it gonna be, Beep or Boom?'. Tune in next week.