Tony_C Posted October 5, 2009 Share Posted October 5, 2009 I have dropped a 2.5TD 19J into a series 3. All going well so far - runs well (short periods only as currently no fans) and everything now fits (eventually) I have removed the viscous fan, and fitted twin fans off a renault people carrier (actually these fit perfectly - little cutouts in the plastic match exactly with the rad) I am now going to set about wiring the fans up, does anyone know optimum/ideal or best guess temps for a pair of temperature switches (one for each fan) on this engine? Defender 19J 2.5TD? Thanks Tony Quote Link to comment Share on other sites More sharing options...
Aragorn Posted October 6, 2009 Share Posted October 6, 2009 It depends where they are fitted, but most manufacturers go with ~100C at the radiator inlet, or sometimes they'll do two stage with one fan coming in at 95 and the other at 100 (or one fan with two speeds) Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 6, 2009 Share Posted October 6, 2009 Use a two-temperature single switch (they have three pins instead of two), that way you can just use one fan at the lower temperature, and two when it gets really hot, there's a huge range of temps available, but personally I would go with something just above the thermostat temperature, and then say 6-8C above that. If you're running an 88C thermostat then say a 92C for the first switch, and 98C for the second. I personally don't like running an engine over 100C for long, it's just stressing everything unnecessarily IMHO, especially on older designed engines. Quote Link to comment Share on other sites More sharing options...
reb78 Posted October 6, 2009 Share Posted October 6, 2009 I'd agree with Bowie. Quote Link to comment Share on other sites More sharing options...
errol209 Posted October 6, 2009 Share Posted October 6, 2009 I'd agree with Bowie. Me too - the gap between the white bit and the red bit on the standard gauge is at about 900C give or take typical LR tolerances. Somewhere in this area would be about right. Quote Link to comment Share on other sites More sharing options...
Tony_C Posted October 6, 2009 Author Share Posted October 6, 2009 Thanks for the responses, looking at the stat housing there are two 'blanks'. i guess i can drill and tap one (furthest (slightly) away from the body) of them to suit whatever dual rated switch i source. I have no idea what stat is in there - suppose i will find out when i remove it. A couple of relays (60A i think for these fans). (the guage is a different matter - S3 guage and currently a standard sender on a 19J2.5TD (not looked or wired that bit yet) Thanks for your help Cheers Tony Quote Link to comment Share on other sites More sharing options...
Aragorn Posted October 6, 2009 Share Posted October 6, 2009 I would suggest fitting a proper guage that reads in C and its appropriate sensor, rather than messing with the rubbish landrover sensors/guages. Personally i wouldnt want the fans coming in at stat temperature, at speed the radiator is generally more efficient without a fan as the fan creates a lot of turbulence immediately behind the rad which can begin to hinder cooling, so i suggested 5c/10c above it. Most vehicles run at 88-90c, hence my suggestion of a 95/100c sensor, if the engine normally runs at 82c, then an 87/92ish fan switch would be fine. Quote Link to comment Share on other sites More sharing options...
TD5 power Posted October 6, 2009 Share Posted October 6, 2009 hi just a quick thought shouldn't the fan switch be placed in the bottom hose to tell you when the radiator can no longer sufficiently disperse the heat and needs the aid of the fans. As for temperature i would think the first fan needs to come in by 95c and the second by 100c, also a lot of these switches i think disengage at a lower temperature ie 90c to prevent them flicking on and off this might need to be considered when choosing a switch. i would suggest looking at X eng as their fan switch is proven to work well with land rovers. HTH matt Quote Link to comment Share on other sites More sharing options...
Aragorn Posted October 7, 2009 Share Posted October 7, 2009 The problem with using the bottom hose is that you have no idea how much cooling the rad needs to have done. If you use for instance a 90c switch, your assuming the engine is going to warm it up by no more than 10c before it hits the rad again, which may or may not occur. However if your getting 95c out of the thermostat housing, then you know that regardless of the temperature of the water leaving the rad, its not cold enough. Regulating the bottom hose temperature could work, but you'd need to select a much lower rating for your fan switch, and even then there will be a bit of a delay. I'm sure someone on here posted about a similar setup recently, and with a 90 or 95c switch in the bottom hose, the engine was up over 110c before the fans would kick in. Quote Link to comment Share on other sites More sharing options...
markyboy Posted October 7, 2009 Share Posted October 7, 2009 hi just a quick thought shouldn't the fan switch be placed in the bottom hose to tell you when the radiator can no longer sufficiently disperse the heat and needs the aid of the fans. In a word, yes. Have a look where they're fitted by the vehicle manufacturers. Invariably towards the bottom of the radiator, about 1/3rd up from the bottom usually. If you fit it into the top hose, you aren't allowing the radiator to do it's job. You can fit the switch in the top but it needs setting up carefully. It's simpler to fit it in the bottom hose. Mark. Quote Link to comment Share on other sites More sharing options...
Tony_C Posted October 7, 2009 Author Share Posted October 7, 2009 The Citroen i took the fans off had the temp switch about 1/3 the way up the rad (i should have used that rad). Some pics i found on here had the temp switch (x-eng switch) in the bottom hose. (i have no idea - which it the normal direction of flow through a rad?) I guess from the comments above it flows (when hot, stat open) engine -> top hose -> rad -> bottom hose -> engine. not that it will make any difference, but, these are pusher fans mounted in front of the rad - i expect they will hinder airflow slightly when not running. Oh, i also took the fuse box and relay box off the same car - a bit of jiggling with the internals of these two and you can fit fuses and relays in the same splash proof box - quite neat (battery is now under passenger seat so new relay box will be mounted on inner nearside wind up front near the rad.) Cheers Tony Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted October 7, 2009 Share Posted October 7, 2009 Some pics i found on here had the temp switch (x-eng switch) in the bottom hose. X-Eng reccomend putting it in the bottom hose as per their fitting instructions here: http://www.x-eng.co....tions/X-Fan.pdf not that it will make any difference, but, these are pusher fans mounted in front of the rad - i expect they will hinder airflow slightly when not running. My fan is mounted behind the rad at a spacing of around 1". This allows the air free passage through the rad during normal ram-air cooling Quote Link to comment Share on other sites More sharing options...
gasket Posted October 8, 2009 Share Posted October 8, 2009 Hi, i know there are different strokes for different folks and all that, but i was advised to put the sensor in the top hose before the rad as it is the engine temperature your fan is responding to and you dont want everything to be running at maxi chat temp wise before your fan kicks in (Also the top hose was easier access). but either way as long as it functions and stops any overheating :-) also You may wish to consider wiring through a relay? apparently electric fans draw a lot of current, this was another grape vine recommendation i heard. good luck with it. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 8, 2009 Share Posted October 8, 2009 Definitely use relays, one 30A (at least) per fan. Even on 30A relays I found one of them managed to welds it's contact together -waiting to get some 40A ones replace them with, though of course it will depend on the fan specification. Quote Link to comment Share on other sites More sharing options...
TD5 power Posted October 8, 2009 Share Posted October 8, 2009 hi if in one cycle of coolant through the engine you are adding 10c plus to the coolant temp that's a lot, either your working flat out going slow or there may be some other problem. The water cooling system is aided by the lubrication system which disipates a large amount of heat especially with the TD engine as they all have oil coolers. although land rover didn't really get the engine design right they compensated for that by over specifying the cooling package its not a high performance petrol engine producing loads of heat running at high rpms. matt Quote Link to comment Share on other sites More sharing options...
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