Going And Stopping.

On closer examination of the front brake shoes I discovered that one of the ends was half the thickness of the rest and in consequence that shoe wasn’t contributing at all. I can’t think why I missed that in the assembly but I’ve since built it up with a steel plate welded to the shoe and, because the linings were a touch thin, I’ve introduced a 1mm saddle to the operating cam.

Brake shoe shim

That gives me enough extra diameter to get the shoes to just touch the drum at the minimum adjustment. What it hasn’t done is improve the pedal travel. Besides the air in the system, my next discovery was that the master cylinder wasn’t 7/8″ bore as I supposed, but 3/4″. Hence the slaves at 7/8″, are bigger than the master – not helpful in my efforts to reduce the pedal travel. I’ve ordered a 1″ master cylinder with the same mounting holes and, at the same time, a modern plastic reservoir that will take a pressure (rather than a vacuum) bleeding system. Everyone seems to have a different opinion on how to reduce the pedal travel but the advice to look at the simpler things first before getting into deep water seems logical; I shall first do the pressure bleeding and secondly look at the position of the actuating rod on the foot pedal and see where that takes me. I’ve got reasonably effective brakes – no worse than they were originally – but what I’ve learnt is that simple though hydraulics may appear in theory, their application is more complex. If they look right, they may not necessarily fly right; you’ve got to do the maths. As breakfast in Holt was on the cards, I clamped each of the pistons at the bottom of their respective cylinders and then re-bled the brakes. The results of this exercise were encouraging enough to proclaim the car roadworthy.

 

Trip to Holt

We met up with Awkward and his Avon Special at Mundford at 7.15 on a chilly Saturday morning but by the time we got to Holt the sun was out and we managed to park right outside the cafe.

Holt

There I discovered that a certain amount of the diff oil had worked its way down the half-shaft casing and was dripping out of the drain hole provided for just such an event. That was the only snag on the trip and on the way back we bowled along happily at an indicated 50-55mph stopping briefly at Awkward’s workshop to have a quick look at the diff oil. We drained out what was there (only just enough) and then added the same quantity of engine oil as a get-us-home gesture which revealed that the diff oil might have been too thick in the first place and, after being flung about by the crown wheel and pinion, wasn’t falling back to the bottom of the diff casing. There hasn’t been any sign of a leak since.

Trip to Holt

Breakfast in Holt brought the total mileage to 313 with a slight improvement in mpg at 16.8. Some more tweaking is called for and I must get down to the rolling road. The Morris Six returned at least 24mpg and this prompted me to get Counsel to come and help with the calcs again. We determined the following:

In top gear (1:1) 1000rpm equates to 19.2mph. 2000rpm gives 38.4mph, 3000rpm, 57.6mph and 4000rpm, a heady 76.8mph. That’s fast enough for me.

 

 

 

 

 

 

 

 

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9 comments on “Going And Stopping.

  1. asciimation says:

    You’re almost done and I have stalled somewhat. Held up by the fact that I can’t buy 5/16 EN16T steel in New Zealand. No one imports the stuff (or 4140 or 4340)! But there is more I can do in the mean time.Sort out the clutch so I can get all the whizzy bits balanced. Few more mods to the crankcase (fitting an oil filter and windage tray). I have a carb rebuild kit from the SU people finally so I can do that. Little more metalwork on the drivers floor. After moving the steering column over half an inch the holes in the floor don’t match the column and pedal now. And I need to do final adjustment on my brakes too actually. The strings just need a bit of tightening. Should really think about painting the body too then I can bolt that down. I am surprised I haven’t been getting complaints about lack of progress!

    Simon

  2. Hello Simon,
    I’ve been trying to work out why you need a particular grade of steel. The guys down at Wanaka must have a supply of aircraft grade steel, maybe you should try them?
    I was very disappointed with the service from Burlens’ website. You might think that as (apparently) the premier SU people they would have in stock a gasket kit for an H4 carb. Instead, they take your money (no ‘out of stock’ notice on the site) and say delivery will be 6-7 weeks – in the 70’s that was acceptable but not anymore.
    You haven’t been getting complaints about your lack of progress through the usual channels – we’ve been thinking it; that’s why you know.

  3. Simon says:

    The studs hold the block to the crankcase so need to be high tensile. They pass right through it on the cam shaft side down to a ali bar that spreads the load across the flange that usually holds the oil gauze on.

  4. renaud says:

    Hi to you both from the wonderful Pays Basque that maybe Nigel knows? For you Simon it’s in south of France near the Spanish border. No comments or complaints because I was incommunicado.
    “I’ve learnt is that simple though hydraulics may appear in theory, their application is more complex. If they look right, they may not necessarily fly right; you’ve got to do the maths.” I’ll risk being a pest (in fact I don’t mind at all…) and say that “doing the maths” about your brakes is exactly what I proposed to you earlier. Then, trial and error is fine too!

  5. Wiser counsel will always prevail but it’s always worth making your own mistakes. I shall be back working again in the Pays Basque next year – can’t wait.

    • renaud says:

      Yes, Nigel, agreed on all counts. Making one’s own mistakes is my motto too. I practice regularly to get the feeling of it. About the Pays Basque it’s really a wonderful place, very good food and nice people too. I’m near Hasparren for the week.

  6. I know it well. I pass through with Cook on our way from Biarritz to St Palais and Lantabat. Lucky you!

  7. Raphaël ROCH says:

    Hello , very please to meet you in my Restaurant ( le Randonneur ) on monday. Bon voyage à vous 2.
    Raphaël.

    • Very pleased to meet you and your wife too. Your wonderful country has treated us extremely kindly and the car has received a great many compliments. I shall contact you on my return. Thanks again for your hospitality.

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