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WW1 Thornycroft restoration


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Thanks Chaps. Just what I wanted!

 

Cast iron is lovely to machine but the swarf is filthy. I shall have rusty handkerchiefs for a week!

 

Steve :)

runs lovely does cast...no water needed either....

another one is a good toolsteel....will machine stainless lovely will toolsteel....much better than ceramic/carbide tips...

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If anyone is wondering why the difference in the clearances, an Aluminium piston will expand slightly more rising to the same temperature as an iron one would - assuming you are using a cast iron block in both cases.
but they (aluminium) loose heat

better as well....through the oil.....

thats why manufacturers started to use ally pistons...

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Steve has had a go at straightening the steering worm in his press. It would not go cold so he had to heat it in the end and there are some marks in the surface. Nothing serious and, although not perfect, the steering column moves only about an 1/8” from centre when rotated between the lower centre and the bearing surface. He will make further adjustments later on if necessary.

 

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The other thing he did was to sort out the lower bearing surface. As you can see, the bearing has ‘worked’ and rather chewed up the surface.

 

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Steve’s solution was to bore out a sleeve and skim the end of the shaft to fit before pressing it on.

 

 

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Then he mounted it back between centres and skimmed it back to size.

 

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.That’s something else which should live to fight another day.

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Regular readers may remember the water pump inlet casting which had had the inlet flange broken off. Steve made up a pattern and had a replacement flange cast which our friend Adrian kindly welded on. Unfortunately, the joint was slightly pin holed and Adrian offered to take it away to seal it up.

 

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This he has done and on completion, it held a pressure of 30psi (hydraulic) for 20 hours without weeping.

 

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We were expecting him to weld it but he says not. Apparently, he put it in the Rayburn oven for a month to start with ( I must thank the long-suffering Fay for her patience and tolerance at this point!). He then took it outside and squirted it with a 95% aqueous solution of urea 9.3 g/l, chloride 1.87 g/l, sodium 1.17 g/l, potassium 0.750 g/l and creatinine 0.670 g/l. each day for another month simply leaving it to corrode between doses. He finally washed it off, sand blasted it and gave it a coat of paint. Job done!

 

You learn something new every day in this hobby! Many thanks Adrian.

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He then took it outside and squirted it with a 95% aqueous solution of urea 9.3 g/l, chloride 1.87 g/l, sodium 1.17 g/l, potassium 0.750 g/l and creatinine 0.670 g/l. each day for another month simply leaving it to corrode between doses.

 

Tim, are you saying he pee'd over it? Not worked out the formula but the largest part of it gave me a clue ...

could be wrong of course ;)

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Apparently BMW formula one teams used a similar trick to strengthen engine blocks in the early eighties.

 

Some of you might wonder how did the engine block resist to such immense detonation inside the combustion chamber. This may not be the answer you were looking for – and most of you might not believe it – but it seems BMW was in fact using seasoned inline 4 cylinder blocks – picked up from several junkyards – for their F1 operations. The interesting part about it was that the blocks were kept out in the cold and urinated upon in order to strengthen their composition.

 

While some may laugh at this strange solution by the German manufacturer, the urinating process is based on nitridization (a process which introduces nitrogen into the surface of a material and is widely used in automotive, mechanical and aeronautical engineering, having the property of a case hardening treatment of predominantly steel but also for titanium, aluminium and molybdenum). Why are we talking about nitridization? Because urine seems to contain numerous waste compounds, many rich in nitrogen. We can't yet figure out how the German engineers found this particular method to strengthen the cylinder blocks – and not use a more technological measure – but it makes for some interesting stories to tell out grandsons.

 

From here http://www.autoevolution.com/news/turbocharged-engines-in-formula-one-18108.html

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My Land Rover wheels must be missile proof by now having for years had the daily attentions of half a dozen dogs all determined to be the last to leave his mark :D

 

I don't think Degsy should be too confident about the strength of his Land Rover wheels, for here is a picture of a 4mm thick box section post which has had the daily attention of one of our dogs. Maybe it is the breed, - so avoid Belgian Shepherds!

 

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Barry.

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I don't think Degsy should be too confident about the strength of his Land Rover wheels, for here is a picture of a 4mm thick box section post which has had the daily attention of one of our dogs. Maybe it is the breed, - so avoid Belgian Shepherds!

 

[ATTACH=CONFIG]77930[/ATTACH]

 

Barry.

:wow:

No Belgian Shepherds, just sheepdogs and an American Akita ;)

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The completed Gearbox had been standing upside down on a mobile table for painting for the last few weeks and with the bottom part now completed in that upside down position, it was time to turn it right way up so that the job can be finished with the top to be done.

 

The pictures are quite self explanatory – but it was necessary to lift the gearbox – put it on the ground to be rolled over and then lifted again onto the table, but now the right way up.

 

 

We have managed to find some old style wing nuts now with “Mickey Mouse” ears, and those shown in the picture which are the modern type will be replaced.

 

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We have not posted anything for a little while but work has been going on! Steve has completed the first stage of the machining of the new pistons and they are now with our friend Andy W who is boring them for the Gudgeon Pins – his Milling Machine has greater capacity than our modest ones and he will also shorten the old gudgeon pins by 3/16” so that they can be used again in the new narrower pistons. They are of extremely hard material but again, Andy has the facility to machine them. When Andy has completed that job they will come back to us for the final machining here.

 

We have been looking at the flexible coupling that goes between gearbox and engine. This consists of a leather disc, 7” in diameter with a 5” hole in it. It has six, 5/8” diameter holes in it for securing bolts so that it can be coupled to the two forks – three bolts to each fork. We had one original leather coupling which is beyond redemption with just one of the original steel “washers” still attached to it. But this provides us with sufficient information for us to replicate.

 

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Another of our great friends is Mark D – a former Submariner and Museum Technician and Restorer – and a man of many great skills – including leatherwork! We asked him for advice on making the leather ring and he immediately offered to make it, but not only the one but two others as there is a similar arrangement at the ends of the prop shaft – so we shall need three in total.

 

Mark rescued a roll of Pump Leather from a Skip some time ago and it has been awaiting a use! The final ring is about an 1 1/4” in thickness and four layers of the leather sewn together – by hand – provide this! The six 5/8” holes remain to be put in the leather and Mark tells me to do this with a sharp 5/8” drill!

 

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The one recovered washer provided the pattern for 36 to be laser cut – sufficient for all three couplings, at just a very modest cost and saving a tremendous amount of work in having them made this way.

 

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These three pictures will give some idea of how the finished assembly will look! The 5/8” Holes are still to be drilled and the washers attached.

 

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Hi,

 

The whole thing will become clear when there are holes drilled in leather. The washers go on the leather so that The two forks will be coupled by the leather. Six holes in the leather will be bolted to one of the six holes in the two forks, the forks won't touch each other.

 

Give me a shout if I'm not clear!

 

Regards, Matthew

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Question i understand the purpose of the big hole in the washer but where is the small one used for ?

The way I see it is the shaped washers are backing strengtheners for the holes drilled in the leather, which acts the same as a modern rubber coupling, simelar to a Hardy Splicer unit! The centre hole does nothing except look pretty...! (as with everything else on this vehicle!!!):cool2:

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Question i understand the purpose of the big hole in the washer but where is the small one used for ?

 

 

If I had to guess I'd say the small holes were just for rivets to keep the thing aligned while it was being stored, until it was assembled.

 

Gordon

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rivets.JPG

 

rivets 2.JPG

 

As you will see, the superior Dennis product has 3 rivets to hold the washer in place to aid alignment whilst the bolt is pushed through. It must be so dispiriting working on a Thornycroft after the magnificence of a Dennis!

 

Barry.

Edited by Asciidv
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