Friday, 26 October 2018

Looking at what we've got...

With the engine on the bench we can have a good look at what we have.



First issue: one of the primary case bolts is broken in the crankcase. We probably won't be using these cases (I have the original crankcases elsewhere, these are not them!) I may not worry about this - but I will probably remove the bolt just for the fun of it. What's worse is the state of those splines:


Nothing untoward here - that hole is for a blanking plug (thanks to Simon Gardiner, AOMCC, for that bit of information)


The sump plate, filter and studs are all missing:


Looks like it has most of it's original screws:


Long magneto bolt:


Unfortunately it appears we have a broken fin on the front of the cylinder head. This may have been caused in a shunt since this is where the head steady bolts on I think.


Bird's eye view of the rocker box:


General views of the engine:







Avoiding injury...

Planning the FH rebuild I could see i was going to have a problem with lifting the engine onto the bench and having no wish to impose any pain on my long-suffering wife by enlisting her help, or injure my back by not enlisting her help, I decided that a hoist was in order. I bought this 1000 kg chain hoist from eBay and fastened it to a heavy piece of pipe in my roof beams. The hoist will do a 2.5 metre lift:


After finishing the chair repairs you see in the picture above, I lifted the engine onto the bench to start work using the hoist, which made short work of the lift and saved my back. I lifted it using the top gearbox stud which put the centre of gravity more or less in the right place for a level lift:


Some while back I bought an engine stand and described it in this blog post:

http://ariel-square-four.blogspot.com/2015/09/engine-stand.html

It's quite flexible. I decided to use one of the lower front engine mounts and one of the rear engine mounts; I made sure the stand was aligned with the engine centre line to keep it balanced. Using the hoist, it was easy to get the engine upright once the stand was in place:


Here it is, ready for some inspection & a bit of dismantling:


Saturday, 20 October 2018

Oil, socks and misfires...

Some of you may know that I have been troubled by misfires just recently to the effect that the good old Solex has been stripped more times in the last month than in the 70 or so years since it was manufactured, and the distributor is not far behind.

Link in the oil line modification I did a while ago, and the calorific nature of the engine's energy-conversion activities and a pattern might start to emerge, especially when a lot of those misfire-ridden journeys occurred when we were blessed with warmer weather.

Lo and behold, one day I was working through the ignition system and removed the HT leads, to check them over and apply some heat-shrink numbers to the cables. It was then that I found the oil, sitting in the five little pots on top of the distributor cap and manfully attempting to insulate the distributor from the HT leads, and succeeding some of the time.

Since I cleaned all this out, I have not suffered a misfire (but the weather has turned colder, so no pre-natal poultry accountancy services required just yet).

Ariel knew about this problem, providing a rubber sock to protect the distributor connections from oil and water:

Distributor sock 5239-49


As you can see, its a curved tubular cover which envelops the whole distributor cap and leads in one conical tube. Here's one, fitted to  'barn find' machine.


And another - though this one looks like heatshrink to me:


No, this is not the Sorting Hat from the Harry Potter movies. It's a shroud I've attempted to make from a very large piece of heat shrink:


It looks marginally better in this picture:


Here are some close-ups. It goes right up under the tank, passing over the tank mounts:



I'd really like an original one, but for now this is doing the job sufficiently well to prove the case for the cause of the misfire.

Wednesday, 17 October 2018

Rule of Nine

Many moons ago, I had a burning interest in classic cars, many with British Motor Corporation 'A' Series engines. One of the useful tips I learned working on these was the Rule of Nine, a way to easily make sure your engine was in the correct position when adjusting valve clearances.

The thing is, when you adjust the clearance in a particular valve train you need to make sure the cam follower or tappet is on the base circle of the cam, or the clearance will be excessive. You do this by checking the clearance on both valves in a cylinder when that cylinder is at TDC. The thing is, wild valve timing or quietening ramps in the cam profile means you have to be accurate when positioning the engine.

But there is an easier way. Have a look at this camshaft:


That's a spare camshaft for my Square Four - a lot less worn than the one in the engine. On the right hand side of the picture, you see the thread retaining the cam chain sprocket, and that first cam is the exhaust cam for number one cylinder - notice it is pointing straight up and the valve will be fully open.

Here's a Stormy Petrel's eye view of the rockers, so you can see what I am talking about:


Move to the left hand end of the camshaft and we are looking at the last or eighth cam, the cam for the exhaust valve on number three. It's pointing straight down, which means the valve is fully closed and the tappet is on the base circle.

Now look at this picture. The cam that is pointing up is the inlet cam for number two cylinder - it's the fourth cam on the shaft.



The one pointing down is the fifth cam on the shaft, the inlet cam for number four cylinder, so

4 + 5 = 9

Remember the first example where we looked at the first cam and the eighth cam? Well:

1 + 8 = 9

Guess what? It works on the other valves too! So, if the valve on the second cam is fully open (which is very easy to discern) then you know that the valve on cam seven (the exhaust valve for number four) is on the base circle and can be adjusted.

Easy. The Rule of Nine.

By the way, I found that after 1000 miles, most of the clearances needed adjusting - maybe because I didn't do it very well last time.


Finish off with replacement of the rocker box gaskets with Threebond. The fibre gaskets specified by Ariel are not suitable for the sorts of temperatures the cylinder head sees.

Wednesday, 26 September 2018

A new day and a new project

So today is a new day: this morning, we hoisted my Bantam into the back of a van for it to start it's journey to a new home in Teeside:

A Bantam, waiting for a van
It's been a brilliant little bike, attracting a lot of attention and getting me back into a hobby which I love and which I had missed for almost 20 years. It started me off on this writing lark, lots of blog posts, magazine articles and the Bantam Restorer's Guide, if it ever gets published...

But what now? Time for the FH to come down from the loft. It's going to become my fast road bike, possibly replacing the Square Four. My thoughts are:
  • Fully restored - it's in bits, in multiple colours, and several key items are missing. In short, it's got no patina.
  • It's going to be finished in export paint colours, because I like that and because there are a lot of maroon Huntmasters out there
  • I'm going to replace the rims with stainless, with stainless spokes and plated brass nipples - I thought about getting these built at CWC, and ask them to polish the hubs, but I'll probably build them myself as usual
  • I'll use stainless fasteners throughout. I believe Ariel's of this vintage would have had zinc plated (and not phosphated) fasteners, so in view of the proximity of the sea, dull stainless is the way to go
  • It's got a new Mk1 concentric already
  • It's currently got a 2 into 1, though I have two silencers - I think I will keep the 2 into 1, at least for a while
  • I'll tear the engine down before I decide what to do with it, but it will be rebuilt to standard specification
  • The magneto will be rebuilt by Tony Cooper
  • I need to get it built, inspected and dated to retain the original registration number. I'll do a dry build first.
To get moving, I am going to start with the frame and cycle parts. There is quite a lot of welding to do before we get to sending out for painting, so perhaps I will do this:

  1. Strip the top end and timing side off the engine, to release the head, barrel and engine plates for the dry build and to release the magneto and dynamo for reconditioning.
  2. Put the frame on the bench, and assemble the gear box and empty cases into it
  3. Start welding the mudguards, chain guards and seat pan to trial fit tinwear and frame components
  4. Dry build, with fasteners from stock and no engine internals, wiring or cables.
  5. Register, photograph and develop the 'missing & broken parts' list
  6. Send black items (cycle parts) out for powdercoat 
  7. Send the wheels out for rebuild
  8. Send the levers and handlebars out for plating
  9. Send the tanks, toolbox, and mudguards out for paint
  10. Start the engine and gearbox rebuild
  11. Reassemble when it's all back...
  12. Wiring and cables
  13. Shakedown!
We'll see what happens!

Another Tommy Bar??

Hunting around for tools for the FH, I realised that I needed a tommy  bar to double as a tyre lever from the Ariel parts list, but I have no idea what it looks like as Ariel stopped illustrating their parts lists in 1951. Triumph used something like this:


 I needed to make one, as they were either very expensive when available or just not available. I could either start with a tyre lever and turn the end, or start with bar stock, turn it and forge it to shape. The second is undoubtedly the better approach, but I didn't fancy the forging element in my small workshop so I bought a ready made tyre lever:



I had to slim the spoon end down to get it in the hollow spindle on my lathe - one element which raises a question about my approach. I turned the plastic handle off to reveal as much plain shank as I needed for the screwdriver section.

Turning the end to suit the tommy bar holes in a typical box spanner was easy, as was grinding the screwdriver shape in the end:


The spoon end needed reshaping, and is still too thick:


Monday, 24 September 2018

Ariel Bikes

Here's an interesting web site on the Leader & Arrow - one I had not seen before:

https://arielbikes.wordpress.com/

Saturday, 8 September 2018

Portable Power Supply

Some of you may know that I tinker around with solar power from time to time and that in fact my workshop is 'off-grid'. One of the features of a lifetime spent tinkering with stuff is a lot of spare bits lying around, so when a friend was looking for a lighting system for her allotment shed and summer house I thought I could come up with something quite easily.

I had a 86W panel and a small car battery knocking about (as you do - they were part of the evolution of my workshop solar power system), so I would not have to spend much money. I also had a simple panel controller, which essentially sense battery voltage & connects the panel if the voltage is below a set point and disconnects it when it goes above the set point - pretty basic; no MPPT here.

What I needed was something to unite it all into a simple portable unit. This came in the form of a bit of an old kitchen unit and some pine offcuts:


I used the little router to cut a slot at the back:


This accommodates the foot of the battery. I sized it to suit the largest battery I had, to 'future proof' it a little. You can see how the foot of the battery is trapped in the groove:


The other foot is trapped under this little bar, made from 3 mm cold rolled sheet and retained with two M6 wing nuts:


Here's the battery in place with the controller:


Here I've added a simple modified sine wave inverter. It gives 200 W at 220 VAC, so you can charge your phone from it.


Here it is with the wiring completed. The six terminals top left are for the solar panel and for two 12V outputs. Lower down, there is a higher current termination for main battery cable, voltage sensor and feed to the inverter.


The inverter provides 200W at 220 VAC - that's about an amp, which translates to about 20 A on the DC side; I can run a 60Ah battery for 36 minutes at that rate, assuming my maximum allowable discharge is 20% - with a deep cycle battery I could increase that, and the frame will carry larger batteries.

Wednesday, 5 September 2018

Charlie's Shed - Free the Nipple

We have to make a new set of cables for the W/NG's new handlebars, using the techniques shown in my Cable Making post here. Unfortunately, the lovely Czech levers I have appear to be a little under size for the clutch and brake cable nipples so we are going to need some non-standard nipples.

This presents yet another mini-lathe opportunity. Starting with a bit of brass (10 mm OD) we turn a suitable length to provide two nipples to provide an easy running fit in the lever - about 8.8 mm.


This done, we need to drill the holes. The inner cable diameter (for the clutch in this case) is about 2 mm, so we'll need a through hole for that and a shallow hole, maybe 5 mm, for the birds nest and solder bucket. We'll start with a centre drill, with the bare nipple in a tailpost V block:


The centre drill is followed by a through hole drilled 2 mm, and this is followed by a 5 mm hole to a depth of 5 mm for the 'birds nest' that we will form when we fit the cable.




Here's the bar after drilling for the first nipple:


The next job is to part off to the desired length, in this case 10 mm. The finish leaves alot to be desired - I was running the lathe too slow for brass.


Deburring next; notably the cable hole on the reverse of this picture. I use a centre drill to open that hole out a little to catch the open, unsoldered wire ends on the inner cable.

So that's it. I made three out of the bit of bar I had turned to size, to avoid wasting it. One for the front brake, one for the clutch and one for the box of nipples & ferrules. I wonder if I can make ferrules...