Rover8FFR Posted June 29, 2010 Share Posted June 29, 2010 Correct. Although there was an upgrade for Saladin to fit a 75 amp dynamo it was quite a lot larger & the further limitation was the carbon pile regulator to control the field winding. That was as about as big as a vehicle dynamo could get in practical terms. Until the advent of silicon diodes, alternators in AFVs were not practical. The 24v AC system introduced into Land Rovers in 1961 was originally limited to 40 amps as the only solid state rectifiers at the time were selenium. These performed reliably only if the temperature was kept below 80 deg C. Cooling was achieved by cooling fins on the rectifier which had to be mounted in a flow of cool air, this was not practical in an AFV. Silicon diodes changed all this, not only are they smaller & more efficient but they can withstand temperatures of up to 200 deg C & in some systems were oil cooled. There was an EMER issued in 1978 to replace the Gen No.2 (ie 2-speed 25 amp dynamo) with Gen No.10 (ie the 90 amp alternator) which is what happened to your Ferret. The programme was later abandoned due to the shortage of components. Clive I am interested in this. Are you suggesting that it would be possible to replace a 40amp gen with a 90amp one in an old landrover mk 8FFR without massive issues...??? Curious thats all my friend. Regards:-\ Quote Link to comment Share on other sites More sharing options...
fv1609 Posted June 29, 2010 Share Posted June 29, 2010 Clive I am interested in this. Are you suggesting that it would be possible to replace a 40amp gen with a 90amp one in an old landrover mk 8FFR without massive issues...??? Curious thats all my friend. Regards:-\ Wayne I'm sure it could be done but I'm not sure why you would want to do this as it would destroy the originality & character of the Rover. It is always a delight to see a Rover with a 40 amp system in place, still connected & actually working. The vast majority that I see have been converted down to 12 volts although some retain the selenium rectifier for display purposes. The date of introduction of the 40 amp system looks to be April 1961 when GS Rovers Mk 3 & Mk 5 were converted to FFW role. Anyway haven't you got enough on your plate with the forthcoming additions? Quote Link to comment Share on other sites More sharing options...
Rover8FFR Posted June 29, 2010 Share Posted June 29, 2010 (edited) Wayne I'm sure it could be done but I'm not sure why you would want to do this as it would destroy the originality & character of the Rover. It is always a delight to see a Rover with a 40 amp system in place, still connected & actually working. The vast majority that I see have been converted down to 12 volts although some retain the selenium rectifier for display purposes. The date of introduction of the 40 amp system looks to be April 1961 when GS Rovers Mk 3 & Mk 5 were converted to FFW role. Anyway haven't you got enough on your plate with the forthcoming additions? I was purely curious and I don't wish to remove the 40amp gen. Keep it real as they say! If there ever came a time that the 40amp gen fell over and died and couldn't be replaced I would want to look at what alternatives I could apply to prevent the dreaded 12v alternator replacement..... I took my rectifier off the front panel carefully the other day and wondered how sensitive they are to being disassembled as the paint has been flaking off. Appears to be a miriad of plates washers/ spacers with electrical contacts etc........... Ooops sorry we are detracting from the B60 temp probe thread, which of course I now have an interest in........:cool2::cool2: PS did you meet Alan last week at Evesham???? I need to pop around and see him and would be nice to collect ATU parts. Edited June 29, 2010 by Rover8FFR Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted June 29, 2010 Share Posted June 29, 2010 The official reason is given as "to improve operational performance" which could include all of the above. It was not an immediate modification but to be done only during a Base Overhaul. The EMER was suspended in 1983. Clive, Not all of these mods were done on base overhaul. We did a number at Comd Wksps, and I thought the reason for fitting was when Clansman was introduced. Quote Link to comment Share on other sites More sharing options...
fv1609 Posted June 30, 2010 Share Posted June 30, 2010 Richard, you must be right then, I wasn't there (I'm far too young:D). But did this apply to both Ferrets & Saracens? I was surprised when I read the EMER that no time had been quoted. But I see I was reading from the Saracen EMER, most of my Ferret ones are in fiche. Quote Link to comment Share on other sites More sharing options...
fv1609 Posted June 30, 2010 Share Posted June 30, 2010 PS did you meet Alan last week at Evesham???? I need to pop around and see him and would be nice to collect ATU parts. Wayne, yes he has your items. Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted June 30, 2010 Share Posted June 30, 2010 Richard, you must be right then, I wasn't there (I'm far too young:D). But did this apply to both Ferrets & Saracens? I was surprised when I read the EMER that no time had been quoted. But I see I was reading from the Saracen EMER, most of my Ferret ones are in fiche. Clive, You were too young then? If thats the case I should have retired by now :-D. Actually, I do not recollect the mod being done within Wksps on Saracens. Perhaps it was embodied on Ferrets when a dynamo was faulty and needed replacing...........or at Unit's request, so that outstanding Mods were up to date. Quote Link to comment Share on other sites More sharing options...
griff66 Posted June 30, 2010 Author Share Posted June 30, 2010 now does having a alt fitted make getting hold of belts easier? Quote Link to comment Share on other sites More sharing options...
fv1609 Posted June 30, 2010 Share Posted June 30, 2010 No difference really. If you are going to get brand new ones, which I would recommend, you'll need just take it along to get measured up for a modern equivalent. Quote Link to comment Share on other sites More sharing options...
Rover8FFR Posted June 30, 2010 Share Posted June 30, 2010 Wayne, yes he has your items. Spoke to him today.... Thank You very much.... I went to see Alison today and met Ashley as well. Lovely people who are very Helpful in light of their recent loss! Ashley took me into the garden.........OH MY GOD!!!!!:shocked::shocked::shocked::shocked::shocked::shocked::shocked::shocked::shocked: I will say no more but as and when Alison, you and Ian get round to that area it will be an Aladins Cave. I could have bought another 2 special landrovers there and then. Quote Link to comment Share on other sites More sharing options...
griff66 Posted September 4, 2010 Author Share Posted September 4, 2010 after changing quite a few items turns out over heating prob was all down to valve on top of rad not closing which was stopping cooling sytem pressurising now temp never goes above 195 f even on longest hills . all good learning curve!!! Quote Link to comment Share on other sites More sharing options...
Diana and Jackie Posted October 6, 2010 Share Posted October 6, 2010 Hi, Were you able to fix it it did you have to replace it? Our ferret gushes water out of the valve (Overheating) when it comes up the hill outside our home- maybe the revs are too low, but I'm suspicious of the valve. Only recently fixed the temperature guage so not yet able to see the overheating situation as the vehicle is off road having a beauty treatment on its brakes - driving with brakes on 3 wheels as the previous owner was doing is not good for ones health. :shocked: Diana and Jackie after changing quite a few items turns out over heating prob was all down to valve on top of rad not closing which was stopping cooling sytem pressurising now temp never goes above 195 f even on longest hills . all good learning curve!!! Quote Link to comment Share on other sites More sharing options...
griff66 Posted October 7, 2010 Author Share Posted October 7, 2010 (edited) ended up fitting nos rad ass but i bet u could get new valve from richard bannister now after a very good run once sytem cooled down it might take quarter of pint versus before new valve couple of pints! run your ferret for a good twenty mins at least get it nice and hot have your hand over rad outlet makes from temp rise you can feel thermostat has opened run for another ten mins turn eng off, wait twenty mins ish and carefully release rad cap u should with valve operating correctly hear a release of pressure .be ready though to put cap back on quickly if coolant wants to come out as well as pressure realease!!!! Edited October 7, 2010 by griff66 Quote Link to comment Share on other sites More sharing options...
Toolman Posted October 7, 2010 Share Posted October 7, 2010 I once got 2nd degree burns trying that on an MGB. I'd "carded" some of the rad off to help the warm up in winter and as it was overheating once I thiought I'd check the coolant level....... Schoolboy error.... Ouch! Quote Link to comment Share on other sites More sharing options...
griff66 Posted October 7, 2010 Author Share Posted October 7, 2010 like i said u got ta be carefull!!:cool2: Quote Link to comment Share on other sites More sharing options...
Diana and Jackie Posted October 27, 2010 Share Posted October 27, 2010 The problem ended up being the cooling system filler cap. The previous owners must have know there was a problem since they gave us quite a few spares, one of which was a filler cap. Cap and attached pipe changed - problem solved! Diana and Jackie ended up fitting nos rad ass but i bet u could get new valve from richard bannister now after a very good run once sytem cooled down it might take quarter of pint versus before new valve couple of pints! run your ferret for a good twenty mins at least get it nice and hot have your hand over rad outlet makes from temp rise you can feel thermostat has opened run for another ten mins turn eng off, wait twenty mins ish and carefully release rad cap u should with valve operating correctly hear a release of pressure .be ready though to put cap back on quickly if coolant wants to come out as well as pressure realease!!!! Quote Link to comment Share on other sites More sharing options...
griff66 Posted October 28, 2010 Author Share Posted October 28, 2010 pleased u got it sussed always worth going for the basic stuff first be it bad earths , rad caps, or vacum release valves on top of rads!!:-) Quote Link to comment Share on other sites More sharing options...
tankdiver Posted October 28, 2010 Share Posted October 28, 2010 If temp gauge goes to hot when switched on it is going to ,,earth change sender unit check leads ,finally replace sender unit ,gauge and leads laurencde Quote Link to comment Share on other sites More sharing options...
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