Dynamo & Split Bullets

Time to hook up the dynamo. The split bullets so beloved of Mr Lucas are a crude but effective design. I thought I'd show you how to use them. These came from Feked, though you can get them all over the place.

Strip the cable insulation so that there is a similar length of bare wire as the length of the bullet:

Push the wire into the wider end of the bullet, and fan the wire evenly over the bullet:

You may need to pass one of the wires through the Tufnol retaining piece before you fit the bullet. Push both the bullets into their socket in the dynamo and screw the retaining piece in place firmly. You will see the bullets slide into their slots:

Then you are done. Fit the dynamo end cover, making sure you don't trap the flexible brush wires in it, and screw the cap down:

Loose Ends

Well, its been an active and enjoyable weekend tidying up loose ends. Thanks go to Patrick Huthwaite who came by yesterday to do the inspection for the Dating Certificate - nice to meet you Sir.

On with the oil tank - the secret to fitting it, is to get it inboard enough to allow the clearance built in the top of the tank to accommodate the frame tube; the secret to allowing this to happen is to remove the nut on the gearbox top bolt.

Next problem is getting the oil lines in. I've realised that most of the struggle I have with this is down to the fact that the strainer I made is way too long, with the result that you have to bend it to get it in and it always catches on the threaded boss in the tank. I cut it down and re-soldered it:

So now, the oil lines go in easily.

I've also fixed the rocker feed oil lines:

And the rocker shafts are sealed:

What else?

O Lucky Man

Well, there are advantages to being a bit of an eBay vulture...

Gauge, oil line, solder nipple and union nut

My latest purchase is this original Ariel oil pressure gauge, of exactly the right type for the Square Four. This is connected into the double oil line above the cylinder head with a short pipe that comes down through a tube welded into the fuel tank.

You can just see it in the top of this picture. The short line is made from parts from Draganfly - 17" of 1/8" copper tube, two 1/8" solder nipples and appropriate 1/8" BSPP union nuts. You can see the conical nose to the nipple, and the conical seat in the gauge - together these form a metal to metal seal. The nipple is soft soldered to the tube using Baker's Fluid, lead solder and a small blow torch.

That 2 BA stud on the back of the gauge passes through a welded bracket in the petrol tank.

Slippin' and slidin'

Moving swiftly on...

Not a huge amount to report today, but the gearbox is now filled with a 50/50 mix of Castrol LM grease and 20W/50 engine oil.

Access to the gearbox filler entails removal of the oil tank, which I don't have the knack for yet. The oil tank is very tight to the frame tube, can't be tilted forward because of the distributor and the frame seat tube, can't be tilted back because of the toolbox and the mudguard and is generally a pain...

However, the gearbox is now filled with about 450 ml of oil/grease mix and the oil lines have their hose clips in place - modern ones unfortunately.

Tomorrow we will have a major step forward - we are having a visit from a local AOMCC member, Patrick Huthwaite, whose inspection is the next step in the registration process.

Hopefully it won't rain.

Mighty Morgo

Today I fitted the Morgo oil pump made by Autovalues Engineering from Bradford.

The Morgo is a gear type pump, and is very nicely manufactured, well packed and is provided with a comprehensive set of instructions. While there are several Morgo rotary pumps for other Ariels & Triumphs, the fitting kits and instructions are bespoke to the model you are fitting. Very nice quality, well thought out.

The pump comes with a fitting kit, consisting of the left hand drive nut, a set of shims, a gasket, two tab washers and two mounting bolts

This is the drive side of the pump, showing the Oldham coupling used to drive the pump from the camshaft.

And here is the drive nut for the pump. Those slots are closely toleranced to prevent rattles and wear

Here it is in place. I've got it fitted with the original studs at the moment, since I don't like the idea of wearing threads in the soft crankcase to remove a service item but in practice you have to engage the pump coupling before bolting up - it is close fitting in its slots, as it needs to be, and this makes the bolts supplied with the pump the only practical way of fitting it.

I need to prime the pump - so I will refit it with the bolts supplied with the pump.

Throttle Cable

I've had the throttle cable set up like this for a while:

As a few folk on the AOMCC forum have pointed out, it doesn't work very well. First off the cable outer doesn't have a good abutment in the stainless steel bracket; secondly, the volute spring (granted it is the wrong one) has way too much internal friction to return the throttle successfully; thirdly, the cable run is poor, both due to the bracket and the volute spring.

But mainly, with the Solex carburettor and its butterfly throttle valve, the cable return spring is the only method of closing the throttle - so if it is not working well, you are going into the back of the braking car in front (and I have done that before) or that expensive rebuilt engine is going to disappear in a mass of tangled aluminium.

So, now I have this:

I have removed the volute spring entirely, and I have a stiff coil spring in its place. It's attached to the dynamo strap with a stiff wire link, and it has a little brass sheet link to attached it to the carburettor cable clevis pin. The throttle returns beautifully now.

I need to adjust the cable path by bending that bracket a little more, and I'll plate that spring later.

Great strides...

Masses done this weekend.

I started by trimming up the HT leads and setting the distributor position, followed by the ignition timing - easy with the timing cover still off.

Next I stripped the primary drive & the clutch, pinning the engine shock absorber and bolting up the inner case.

I pulled the outer cover off the gearbox, and removed the gearbox mainshaft. I wanted to check that I had greased the sleeve gear, which I had - too many stories of those bushes seizing! I thoroughly greased the gearbox change mechanism and the kick start parts, before bolting everything up and fitting the clutch.

For some reason the new clutch centre nut does not fit - tight on the thread. I'll have to use this old one, for extra 'patina'...

Next, the clutch cover. This has never been fitted with the exhaust in place and, as predicted by several AOMCC forum members, the exhaust fouled the clutch cover.

This was easily remedied with a little metal work, and I produced a professional looking dish in the cover with a hardwood block and a deep socket.

I fitted the rear chain and chainguard too, using my usual ty-wrap method:

Next, the smaller oil lines. These are very soft copper and are easily bent by hand.

Time to admit I made a mistake...

This, I have to admit, is a KH tank. It is a shame that I painted and lined it but it does look very nice!

This however is a Mk1 Square Four tank, which I bought from Jorgen Andersen of the AOMCC; it too will be very nice once it has had some treatment from a nice man with a welder and a can of Sureseal - oh, and a gritblaster, some lead, and some paint in various colours

 It has the bonus of being fitted with a better filler cap than my one

But it does have some dents, a mounting that is full of either weld or chemical metal, some holes around the edges, and some rather dicey looking threads. Its got the right tap (though it is in poor shape) and it has the crossover pipe.

It has some original red paint underneath, which happily looks very like the red I used on the wheels.

This is not so nice but it will add to the experience!

Next steps

The build so far has shed light on a few issues, so I'm going to make a list of what I have to do next:

• finish the valve timing. I need to get the DTI on the engine again to ascertain where the cams are going me peak lift - I currently believe this is about 15 degrees early, so I need to measure that precisely and adjust it
• when that is done, the Morgo oil pump can go on
• I have no hose clips on the oil lines - I need to take the oil tank out to fit them, and I need to fit the rocker oil line
• whilst the oil tank is out I will fill the gearbox. I also want to make sure the sleeve gear is properly greased, so I will remove the clutch and mainshaft to do that, and I can finish off the primary case (sealing) and shock absorber (split pin) followed by the chain and chain guard.
• Then I will fit the oil tank and prime the oil system, and fit the sump plate
• Connect up the HT cables (so i know which distributor connection is #1) and time the ignition
• Sort out the carburettor throttle return spring and fit the throttle cable properly
• flash the dynamo to change to negative earth
• finish the earth cables in the headlamp
• commission the electrical system
• fit the fuel tank and fuel lines
• turn the engine on the power drill

And then the moment of truth will be upon us...

It's been a while...

About a month actually. Ariel time in the last 4 weeks has been spent on a number of fronts: 

• welding cable guides inside the rear mudguard 
• finishing the wiring 
• messing about with the valve timing 

the latter item has been the most frustrating. I have a good set of guidance notes from Draganfly, written by Bruce Longman which I have followed religiously.

I assembled the head using only cylinder number 1, as I thought I would make it easy on myself and avoid having to turn the cam against four sets of valve springs.

Initially I tried the Waller-style method of aligning timing marks.

Having done this I turned the engine over to see the exhaust valve opening half way down the power stroke. Bruce says that sometimes the factory timing marks don't give the correct timing, so I tried again... and again... and again... eventually getting the timing discs and dial test indicator out to do the job the long way, all the while getting more and more proficient at releasing tension on the cam chain, removing the nuts, drawing off the crankshaft pinion before I could remove the cam shaft pinion... Always the same result.

Eventually I started doing this more scientifically, drawing the valve event charts and calculating overlaps & durations. This is what it is supposed to look like:

Frustrated with Cylinder #1, and confused by the fact that #1 runs backwards, I changed to #3 and drew another diagram:



This revealed that #3 was about 180 degrees out; while #1 inlet valve was correct and #1 exhaust valve was about 180 degrees out too. Confused, I thought about looking at #2, which was doubly frustrating because one of the pushrods would not go in the tunnel.

I set and reset valve timings for about a week, and then one day, looking at the rockers, pushrods and convincing myself that #1 inlet must somehow be on the wrong cam, I started looking at the #2 inlet pushrod problem when I happened to glance down the #1 inlet pushrod tunnel - to see the pushrod going off at a weird angle.

I now know it is possible to get a SQ4 pushrod in it's neighbour's tappet. #1 inlet was in #2 inlet's tappet, so it was operating from #2 inlet's cam! Now that I realise what I am looking at, it's obvious.

Ho hum. we live and learn. At least I found it before I pulled the head off again!