pru426 Posted November 6, 2015 Share Posted November 6, 2015 http://www.dailymail.co.uk/news/article-2960913/Mechanic-fixes-Land-Rover-POTATO.html#comments CES spares for MVs ? :cool2: pekka Quote Link to comment Share on other sites More sharing options...
0 CMP-Phil Posted November 6, 2015 Share Posted November 6, 2015 Hi Now that is a new one, definitely going in club newsletter under tech tips. Wonder how much size and freshness matters? This one that I've got to try. Cheers Phil Quote Link to comment Share on other sites More sharing options...
0 Sean N Posted November 6, 2015 Share Posted November 6, 2015 Ingenious. Wonder how well cooked the potato was when they reached their destination. ISTR the approved REME recovery manual method for condenser replacement was two baked bean cans (or equivalent) with a piece of paper between. Quote Link to comment Share on other sites More sharing options...
0 Tony B Posted November 7, 2015 Share Posted November 7, 2015 (edited) Anyone else read Terry Prattchet's Long Earth and Long Mars series? :cool2: Who needs a De Lorean! Sean, out of intrest, do you have details of the method? Edited November 7, 2015 by Tony B Quote Link to comment Share on other sites More sharing options...
0 fv1609 Posted November 7, 2015 Share Posted November 7, 2015 ISTR the approved REME recovery manual method for condenser replacement was two baked bean cans (or equivalent) with a piece of paper between. Quote Link to comment Share on other sites More sharing options...
0 fv1609 Posted November 7, 2015 Share Posted November 7, 2015 This is an old story that has cropped up Land Rover forums where someone measured the capacitance across a similar potato & was unable to detect any meaningful capacitance. Well I have just selected a similar type & size of potato using test prods that are about half an inch long probably similar to the length of the screws used & measured 0.09 mfd. So this is slightly under half the normal 0.2 mfd used in most distributors. Before penetration I measured the surface resistance from one end of the potato to the other & this was about 100 megohms. After penetration with the same prods the resistance fell to 1.2 megohms but this was with a multimeter at very low voltage. The role of the capacitor is to absorb the Back EMF from the primary which is in the order of 300 volts. The effect of this is to reduce sparking at the points to enable a more abrupt collapse of the magnetic field in the coil. This leads to an improved HT output than if no capacitor is used. I tested the resistance at 250 volts & found that the resistance fell to 0.01 megohms. So at 250 volts a current of 25ma will flow, clearly a useful path for the Back EMF. Apply a rough calculation for 12 volts only 0.01ma would flow & have negligible effect. So it looks as if the potato might be performing two roles. Acting as a crude VDR (Voltage Dependant Resistor) clipping the Back EMF & also providing about half the required capacitance. Quote Link to comment Share on other sites More sharing options...
0 hummermark Posted November 7, 2015 Share Posted November 7, 2015 I was waiting for your knowable response :coffee: Quote Link to comment Share on other sites More sharing options...
0 fv1609 Posted November 7, 2015 Share Posted November 7, 2015 I've been doing a bit more experimentation today :shocked: I repeated the measurements a bit later & found using the same holes, although the resistance remained the same, the capacitance had reduced a bit. Cleaning the prods & inserting them in new areas nearby still produced these new readings. All I can think that the cold potato was now a bit warmer now it had been indoors for a few hours. Anyway I found moving the prod insertion points closer increased the capacitance to such a point that the prods one cm apart had nearly double the capacitance of the prods at the furthest point. So a better result could have been achieved if the AA man had put the screws nearby to each other. The curious thing is that wherever I inserted the prods be it, near to each other, on opposite sides across the width or the length the resistance remained constant. Next I tried a carrot & this behaved in the same way with capacitance being greatest with the prods nearby. But the resistance remained the same here on both measurements as 1.1 megohms. I measured the capacitance as 0.08 mfd with the prods close by then chopped the carrot & it remained at 0.08 mfd So as far as vegetables go, size or even length does not matter :-D Looks like I'll be eating perforated vegetables tonight :shocked: Quote Link to comment Share on other sites More sharing options...
0 GeePig Posted November 7, 2015 Share Posted November 7, 2015 Just make sure you don't drop your condensors in the chip pan when the larder is empty... :-D trevor Quote Link to comment Share on other sites More sharing options...
0 Tony B Posted November 7, 2015 Share Posted November 7, 2015 I do wonder what outsiders think of us. :nut: Quote Link to comment Share on other sites More sharing options...
0 matchlesswdg3 Posted November 8, 2015 Share Posted November 8, 2015 I often wondered what people meant when they told me their engine had been chipped! Now I know why you get Crisp acceleration.............but too much and it can result in a bad Smash. I'll get my coat............:cool2: Quote Link to comment Share on other sites More sharing options...
0 Tony B Posted November 8, 2015 Share Posted November 8, 2015 Just peel off somehwere! Mind you the humble bean tin has solved many problems over the years. And to stop the engine, shove the spud up the other end! Quote Link to comment Share on other sites More sharing options...
0 matchlesswdg3 Posted November 8, 2015 Share Posted November 8, 2015 The versatile spud! On an entirely unrelated subject, early gold miners used to extract fine gold from the concentrate in their gold pans using mercury (artisanal miners still do) and when the mercury started getting lumpy, they knew it was saturated with gold as an amalgam. They would then place the lumpy Mercury inside a raw spud and roast it on a fire. The Mercury would mostly vapourise off, leaving gold (mostly) in a nugget in the potato. Alas, some miners then liked to eat the baked spud, Mercury residue and all. "Gold fever" was not a myth! Quote Link to comment Share on other sites More sharing options...
0 Tony B Posted November 8, 2015 Share Posted November 8, 2015 Many moons ago, I did breack three raw eggs into a cracked radiator as a get you home, and it worked. Needless to say Rad was replaced. There is also the story that porridge oats works. Never tried that. Quote Link to comment Share on other sites More sharing options...
0 fv1609 Posted November 8, 2015 Share Posted November 8, 2015 Tony I think three complete eggs was a little excessive for anyone, the REME manual suggests just the white of an egg. Quote Link to comment Share on other sites More sharing options...
0 Richard Farrant Posted November 8, 2015 Share Posted November 8, 2015 Needless to say Rad was replaced. Reckon you could say your radiator was 'egg bound' :-D ......... or clucked :cool2: Quote Link to comment Share on other sites More sharing options...
0 Tony B Posted November 9, 2015 Share Posted November 9, 2015 It was, I then had to shell out for a new radiator! When I was earning about £9.50 a week that was no yoke! :mad: (I'll take the tablets shall I ?) Quote Link to comment Share on other sites More sharing options...
0 Tony B Posted November 9, 2015 Share Posted November 9, 2015 Tony I think three complete eggs was a little excessive for anyone, the REME manual suggests just the white of an egg. Youthful enthusiasm! Does it say anything about Porridge though? Quote Link to comment Share on other sites More sharing options...
0 fv1609 Posted November 9, 2015 Share Posted November 9, 2015 I think you are in the realms of fantasy there Tony, although it does suggest pea flour or mustard powder. No mention either of a NATO potato. Quote Link to comment Share on other sites More sharing options...
0 Tony B Posted November 9, 2015 Share Posted November 9, 2015 Ah well Porridge must be against the NATO grain. Quote Link to comment Share on other sites More sharing options...
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pru426
http://www.dailymail.co.uk/news/article-2960913/Mechanic-fixes-Land-Rover-POTATO.html#comments
CES spares for MVs ? :cool2:
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