griff66 Posted June 27, 2010 Posted June 27, 2010 (edited) has any one got a workshop manual figure for temp probe resistance at set temp , thanks. Edited June 27, 2010 by griff66 Quote
fv1609 Posted June 27, 2010 Posted June 27, 2010 At "room" temperature its about 200 ohms. Did you just want a ball park figure? Not sure if there is a defined resistance/temperature corelation published. It either is about that resistance or if it goes open circuit the temperature needle goes right up the very hot end. Quote
haybaggerman Posted June 27, 2010 Posted June 27, 2010 Mine is open circuit, just went straight up to top temp from the start. Now, though, it stays there even when the batteries are disconnected. Where to start though, just another job on the list Paul Quote
griff66 Posted June 27, 2010 Author Posted June 27, 2010 temp still wants to sit at 205 f on a run have fitted a new 78 f thermostat flushed cooling system twice blasted rad cooling fins correct anti freeze percentage , wondering if my temp bulb just over reads by 10/15 f ? couple of questions should ferret cooling system hiss ie audible release of pressure when cap undone like a car system ?wondering if prv on top of rad is stuck open all the time Quote
Richard Farrant Posted June 27, 2010 Posted June 27, 2010 temp still wants to sit at 205 f on a run have fitted a new 78 f thermostat flushed cooling system twice blasted rad cooling fins correct anti freeze percentage , wondering if my temp bulb just over reads by 10/15 f ? couple of questions should ferret cooling system hiss ie audible release of pressure when cap undone like a car system ?wondering if prv on top of rad is stuck open all the time Check your fan belts are not slipping. I had to go out to one last year, he had suffered overheating on a road run. Belts sitting low in pulley vees, which means they were not gripping on the flanks. Quote
fv1609 Posted June 27, 2010 Posted June 27, 2010 Consider fitting brand new ones not NOS ones. On a run with hills the Pig would usually creep into 190 F. Having fitted brand new ones it doesn't go above 180 F. Quote
fv1609 Posted June 27, 2010 Posted June 27, 2010 Mine is open circuit, just went straight up to top temp from the start. Now, though, it stays there even when the batteries are disconnected. Where to start though, just another job on the list Paul Paul I would very carefully dismantle the right angled connector that goes into the sensor & check that the wires that are soldered onto the 2-pin connector are still intact. Check the resistance of the sensor directly on its terminals. Quote
griff66 Posted June 28, 2010 Author Posted June 28, 2010 would any one know fan belt pt no and where to source 3 off Quote
haybaggerman Posted June 28, 2010 Posted June 28, 2010 Paul I would very carefully dismantle the right angled connector that goes into the sensor & check that the wires that are soldered onto the 2-pin connector are still intact. Check the resistance of the sensor directly on its terminals. Thankyou, I'll do just that. Its a bit disconcerting not knowing what temp the engine is running at. Cheers Paul Quote
fv1609 Posted June 28, 2010 Posted June 28, 2010 I'm not sure that you actually need 3 belts. All in service installations I have seen used just 2 although there is clearly provision for 3, quite why I am not sure. Hornet actually had 5 belts but that was a bit different. In my list of civilian equivalents I have built up over the years I have down: Ferodo V250D I note that I fitted Fenner AI200/A46 13x1168LI to Hornet 15 years ago. When I went to these people, http://www.eriks.co.uk/belts/ these numbers meant nothing to the girl srving me. You will see they have branches all over the place. So I went back with a NOS belt & a pulley to get measured up. There was no direct modern equivalent anymore. But they could provide one about 5mm shorter or 10mm longer. I opted for a pair of the longer ones (C1350-FEN). They had to be ordered but arrived the next day. You need to watch the pricing structure as they are £35.47 + VAT each. I was lucky to achieve a 65% discount & the pair cost me £29.18 all in. Although slightly longer, fitting was a bit easier & there is still plenty of spare adjustment. I know someone who has fitted 3 belts to his Humber & ordered them through a tractor spares company (Baker & daughters) the numbers he used were: C1308 LD/22X250 L1 C49 Optibelt VB Quote
fv1609 Posted June 28, 2010 Posted June 28, 2010 Thankyou, I'll do just that. Its a bit disconcerting not knowing what temp the engine is running at. Cheers. Paul Yes I once got badly caught on the motorway suddenly when it went into overheat. I pulled in & walked to the nearest service area. They had no petrol cans there that I could fill with water. I managed to borrow a watering can & a bucket & proceeded on my return journey a mile up the motorway. Needless to say it wasn't long before I got apprehended for behaving in a very stupid way on the motorway. After the error of my way was pointed out to me. I was given a lift back to the Humber. As it happens I had been returning from a private function at Police HQ & this crew had earlier been playing in the band there. So they were familiar with the vehicle. Anyway, by now the radiator had cooled sufficiently to top it up with this hard won water. To my surprise I found I was not shortage of water at all. It was at this point I got my multimeter out & I soon learnt that an open circuit temp sensor equals maximum temperature reading! Quote
griff66 Posted June 28, 2010 Author Posted June 28, 2010 ok three belts are fitted at the moment Quote
griff66 Posted June 28, 2010 Author Posted June 28, 2010 and when you have no water at all in the system the needle will read cold ! been there for that one:cool2: Quote
fv1609 Posted June 28, 2010 Posted June 28, 2010 and when you have no water at all in the system the needle will read cold ! been there for that one:cool2: Yes we live & learn! Quote
Richard Farrant Posted June 28, 2010 Posted June 28, 2010 ok three belts are fitted at the moment Just had a thought, perhaps you have a modified Ferret, with 90amp alternator (as the old 24v petrol Land Rovers), seem to recollect they had three, but quite narrow in comparison to the normal belts on B range units.. Measure the width of a belt, or better still take a photo of the engine. Quote
griff66 Posted June 28, 2010 Author Posted June 28, 2010 just had a look and is a 90 amp alternator fitted , is that more than unmoded ferrets? what output are they? Quote
fv1609 Posted June 28, 2010 Posted June 28, 2010 just had a look and is a 90 amp alternator fitted , is that more than unmoded ferrets? what output are they? 25 amps Quote
keefer1236 Posted June 28, 2010 Posted June 28, 2010 has any one got a workshop manual figure for temp probe resistance at set temp , thanks. Hi my temp probe was open circuit....i cut open the brass tube and found a wire broken inside...i resoldered the wire to the terminal....soldered the outer brass tube in place....havnt had any trouble since..takes bout 20 mins to do...hope this helps..Ps i have a spare probe ..i could do some resistance test at various temps if it would help regards Keith Ferret MK2/3 03 CC 29 Quote
griff66 Posted June 29, 2010 Author Posted June 29, 2010 keith if you could do one 20 c and 25 c ambient that would help thanks ,a jump from 25 amps to 90 amps quite a margin. Quote
Richard Farrant Posted June 29, 2010 Posted June 29, 2010 a jump from 25 amps to 90 amps quite a margin. That is because the original generator was a dynamo Quote
griff66 Posted June 29, 2010 Author Posted June 29, 2010 are dynamos unable to give a equivalent amperage output for a similar physical size then? Quote
fv1609 Posted June 29, 2010 Posted June 29, 2010 are dynamos unable to give a equivalent amperage output for a similar physical size then? 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. Quote
griff66 Posted June 29, 2010 Author Posted June 29, 2010 with the 1978 emer was more equipment fitted to take advantage of this increased ouput Quote
fv1609 Posted June 29, 2010 Posted June 29, 2010 with the 1978 emer was more equipment fitted to take advantage of this increased ouput I've no idea, but I think the demands of the vehicle & radios already far exceeded the available 25 amp output. Just consider the time taken to recharge the batteries having boiled up for a cup of tea! The other factor might have be the reliabilty of the alternator system & there may have be less radio interference. A small factor may have been that although the alternator is giving more output it has less torque than the 2-speed dynamo. You can judge this by turning the alternator fairly easily by hand but the dynamo is very stiff to rotate, that is all extra load for the engine to provide. 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. Quote
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