FH - Steering Head

 Now that the frame is on the bench I can start to assemble some of it, bearing in mind that I must leave mating parts for the paint to fully cure.

I start by reducing the height of the lift so that I can easily get to the head races in the frame, to clear out the paint and primer with a knife, scraper and emery. This is pretty easy as the paint is relatively soft, not like powder coat.

Next step is to clean and fit the races, which go on easily with a copper mallet and a tubular drift. Then it's 1/4" ball bearings, 20 in each race according to the parts book, retained with grease. There usually appears to be a gap where you could fit one more ball, but you should always go by the parts book - the gap is there to allow the balls to move freely.

The top race is easier to assemble, since the inner retains the balls:

Ariels have a dust cover over the top race. You'll note that I haven't fitted the grease nipples to the frame - I will, but all they do is allow the frame tubes to fill up with grease. There is nothing apart from a missing felt washer to direct the grease to the bearing; the washer is shown in the front fork diagram in the parts book but doesn't appear in the parts list.

Next, you have the rather precarious activity of bringing the lower yoke up through the steering head  and through the top race, hopefully without disturbing the balls. Sticky grease helps, as does a dry fit of all the parts. Remember that the top inner race fits tightly around the steering column so you must remove the paint from the fine thread, making sure the adjustment nuts fit:

Next we will go to the other end and fit the swinging arm. It's not obvious, but this is a time when the bike lift is very useful - you can do all this work at the most comfortable working height.

FH - Painting Update

The blog has been a little quiet lately, as the frame parts are at the painters and I have the engine in pieces - but more of that later. 

Pictures from Damon at DJ Spray Services reveal that the painting is on the way - these are the parts in Damon’s shop, just back from the blaster:

Damon has prepared the oil tank by hand - it’s not been blasted. He’s sprayed on the first coat of epoxy primer the same day as the parts arrived:

Blasting has revealed a few problems, the worst of which is these holes in the already lined tank. There’s a crack in the front mudguard, and two broken welds in the number plate:

A couple of days later, much of the black is done:

I retrieved the damaged bits to bring back to the workshop for repair:

Straightforward for the most part, except for this old braze repair which won’t weld. Brazing with TIG is possible with the right rods (with no zinc, and is technically bronze) but repairing this produces lots of spatter and white zinc oxide. It pressure tested perfectly well after a few attempts.

Returning the repaired bits for painting, I picked up the black parts which were ready packed:

They need a while (months) to cure, so they can sit on the bench while I build the engine:

FH - Engine bottom end

 While the painted parts are away, I've got the engine on the bench. Way back when, I established the state of the bores, mains and big ends and what I want to do now is to trial fit the new large bearing crank into the original cases.

A little while in the kitchen at home saw the main bearings fitted:

It's then no more than an hour's work to assemble the crankshaft and the timing gear; the good news is that the timing gear bushes already in this case are in very good condition with very little play. Shame I already bought a new set.

It was clear that the crankshaft was a bit tight. The setup with the DTI reveals no end float and the crankshaft was mildly stiff to turn, but then it does have a large plain bush at one end:

Investigation revealed that the drive side bearing wasn't fitted fully home against the crankshaft web. With that fixed, we have 0.34 mm end float:

That's about 0.013"; we want a maximum of 0.005", according to BSA Service Sheet 208 - Waller is silent on the subject. Since 0.005" is 0.13 mm, we need to shim 0.21 mm; I've bought 0.25 mm shims which should give us 0.09 mm end float, or 0.003".

More later when bits arrive.

FH - Prepared for paint

Here are the pictures of the Huntmaster bits that I'll use to catalogue the bike for the painter:

VMCC Castle Acre Run

 Sunday dawns and I'm up early to get to the start of the Norwich & District VMCC Castle Acre Run but first, it's a trip on the W/NG to deliver the TS125 tank:

With the tank back on the MZ, son Tom starts the freshly oiled & fuelled SQ4 that he will ride today. I'm on the modern Interceptor, just for a change. 

First stop is at the start of the run, for tea, a chat and to sign on. Lovely barn conversion and outbuildings:

At 11:00, we depart for the 37 mile trip to Castle Acre, following the Tulip route sheets. I make the mistake of relaxing at the back of a line of two bikes who miss a turn and I have to double back, messing up my calculations. We arrive eventually, and I'm not last, though I expect to find Tom and the SQ4 there already. He's not, and it turns out he's stopped to wait for me, witnessed by the missed calls on my phone. He turns up a few minutes later and we have lunch.

Two portions of loaded fries and a chat later we wander out to look at the bikes, and do some more chatting...

The rest of the section will take another 37 mile run back to the start, but since that would be in totally the wrong direction for us we say our goodbyes and head back to North Norfolk.

Totals for the day - 130 miles for me aboard two different bikes; about 100 of those on the Interceptor. The SQ4 is going really well and uses negligible oil, and consumes fuel at 50 mpg!

Have to take it a bit easier next time.

Charlie's Shed - Lining a petrol tank

Regular readers will know that in the past few months I have made weld repairs to two petrol tanks, one of which still has a weep in a very inaccessible place.

Today I'm going to line the tank with Slosh, from Rustbuster. This is a polyurethane sealer, resistant to Ethanol, that cures in air. I've cleaned this tank already with their SP10 Tank Kleen and a selection of nuts and bolts:

Those bolts came out a lot cleaner than they went in!

The sealer comes in two bottles, for two coats. You have to pour it in, rotate it around, wait twenty minutes and repeat twice more.

You let it drain from the tap connection to avoid it pooling in the bottom of the tank.

The reason you don't want it pooling is that it gases off a little when setting, and you don't want voids in the lining:

Three hours later, or when the sealer is dry but still tacky, you do the second coat in the same way. Then you let it cure for five days. Easy peasy.

This 400 ml kit is supposed to be sufficient for a 10 gallon tank, and I'm sure it is. My plan was to seal both the MZ tank and the Huntmaster tank in one sitting, but obviously two tanks have a greater metal surface than one tank (though the two together totalled less than 10 gallons) and I wasn't confident I'd have enough for both, so I ordered some more sealer for the FH.

Now that son Tom has his MZ sparking, he's clamouring to get his tank back...

Charlie's Shed - Points backplate

A plea on the VMCC forum found me a little job this week - local BSA B33 rider Richard was looking for a new points backplate - the old one had a stripped hole at the contact set clamping screw.

I volunteered to help - I do this sometimes, it’s a good way to meet new people, it costs nothing and it’s always nice to practice one’s skills. A quick Google revealed that while you can get contact sets, caps and condensers for these ‘distributors’ - Lucas 18D2 or similar, used by BSA, Norton and Royal Enfield the backplate is not available:

The 2BA hole had no thread left and the screw was in a bad way too. I started by marking the hole position on the back, with a scriber:

Laid on the usual copper bar heat sink, I set the TIG welder to 35 A and filled the hole from both sides.

I ground it flat with the Dremel and a file, drilled it for tapping 2 BA (4 mm) and recut the thread.

I cleaned it up with a wire brush. It took a bit of Googling before I was sure I had it assembled correctly:

Having delivered it back to Richard, and seeing his lovely B33 which he has owned for 16 years I was pleased to learn it started straight away. I must have assembled it OK!

It was great to find a few beers on my doorstep the next day. That’s the kind of fee I like.