Finishing Touches.

‘Finishing’ is a very welcome concept. The car has taken just under 3 years to build and, the pleasure and challenges it’s given me aside, I’m glad there’s now not much to do but get out there and drive.

New linings

The new brake linings, despite there being a slight hitch in that they’re a tiny bit thinner than the old woven ones, are brilliant. Even when I hadn’t adjusted them properly and went for a spin round the yard, it was immediately noticeable that they had far better grip on the drums when applied and, they were silent! After adjustment I went down to the local brake people and asked about reducing the volume of the slave cylinders in order to reduce the pedal travel. This was Awkward’s idea and he demonstrated its effectiveness by closing off one side of the brakes which then reduced the pedal travel by half. So, in theory, if the cylinders were half the current bore size…. My inquiries determined that 3/4″ was probably the smallest available for the casting size I’ve got (I’ve no intention of re-modelling the brake back plates and cylinder mountings at this stage of the game) and the existing bores are 7/8″ (22mm). More anon.

Lower friction damper mounting block

The lower friction damper mounting blocks at the back of the car had worked a bit loose in the 130 or so miles the car had gone so Chumley counter-bored the bolt holes for me and the bolts now go all the way into the threaded hole at the back of the axle – they didn’t quite make it all the way before.

Cheat line

I was a bit nervous of adding the aluminium bead to make the cheat line along the length of the car. I’d got the levels a bit wrong and so there would be a step just behind the windscreen pillar. As it turned out, it didn’t matter in the slightest and the step added to the general effect. I bolted a wing mirror to the pillar which also helps with the look. The nearside is taken care of by the various bits of the door which takes the eye away from the step in the beading. The ash cap strips are now attached to the cockpit sides.

Cap strips

The next job was to connect the lighting. This took a bit of time because when I switched them on for the first time, one sidelight blew itself to pieces and one headlight refused to cooperate. I checked the wiring – there was continuity. I ran 12 volts through the wire – nothing. What? Do that again…. same result. Where were my volts going? It wasn’t until about 7 o’clock in the evening when Angus the Electric popped his head round the door that things became clear – everything was illuminated – so to speak. There’s a small machine screw in the back of a Marchal headlamp whose purpose is to provide a connection to ground the body of the lamp to the chassis; this wasn’t doing its job properly ( the sidelight worked for some reason but not the headlamp).

Lights

Anyway, by 9.00pm I had the whole lot up and running and, because they seem to be pretty good, I’m going to make up some stone-guards for them with the rest of the stainless steel mesh I have left over from the radiator grill.

That’ll be a nice touch.

Advertisements

3 comments on “Finishing Touches.

  1. Doug Gordon says:

    You should be wary of messing with slave cylinder bore sizes. What you lose in pedal travel will, theoretically, result in significantly increased pedal pressure required to produce the same braking effort. Master cylinders are always a smaller bore than slaves for a reason – to amplify the pedal effort – just like a jack. That’s just simple hydraulics – a coefficient of the area of the bores and the relative displacement of fluid – that’s how you get a mechanical advantage. Are you sure you have properly bled out all the air??…and ADJUST the shoes up a bit tighter, with MINIMAL clearance, before you do anything drastic.
    You could also consider changing the leverage point on the pedal before changing cylinders? This will also affect pedal travel.
    Are your current master and slave cylinders from an ORIGINAL integrated system or are they an arbitrary collection of parts?

  2. What I’m trying to do is reduce the pedal travel. I take your point about the slave cylinder bores and I’ve since sourced a 1″ bore master cylinder. I know that will increase the effort required at the pedal but the travel will be reduced. The master and slave cylinders are not from an existing integrated system.
    I hadn’t thought about changing the leverage point on the pedal – I’ll investigate that before doing anything else.
    The brakes work as they would have worked in 1927 and are satisfactory provided that the car – like a lot of vintage cars – is driven accordingly. I had though hoped that the introduction of hydraulic assistance might make them a bit sharper than the old cable system. The shoes have yet to bed in so some of my anxieties might yet dissolve.
    Thank you for your timely input; I’ll hold off messing about with the slave cylinders and look at the simpler stuff first.

  3. renaud says:

    Doug, Nigel is using the original cable brakes stuff. He’s using hydraulics to push on the brakes levers exactly like in an hydraulic clutch.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s