Quagmire Posted January 2, 2010 Share Posted January 2, 2010 Guys, Quick question for anyone running an x-fan switch on a 3.5 v8... I got one for Christmas and am very happy with it, it makes the engine bay much sexier to look at than the kenlowe knob thing, and has eliminated the annoying weeping i got with the kenlowe capillary jobby. Due to the fact that my top hose is two pieces anyway i decided to put the switch in the top hose and wire it up using the existing kenlowe "jetboost" wiring. i have a single 16" fan that is dual speed. When the first temp is reached on the switch the slower fan speed is triggered. At the same time an illuminated "on/on" rocker switch on the dash lights up to let me know that all is well. At this point i have gained some functionality over the kenlowe switch. Originally the fan would trigger at the lower speed, and then i could manually select a higher speed with the rocker switch if i wanted. I have now got it setup so that this functionality is retained but if the water temp strays into the second range on the x-fan switch then the faster speed will be automatically triggered anyway. Hope that makes sense. Anyway, here's the rub. The lower temp range with the standard 88-83 / 92-87 switch causes my fan to run continuously! The temp gauge is never allowed to reach the halfway point where it used to sit before. Even when cruising at 60mph in this colder weather i am finding that the fan is still on! Using only the higher range of the switch seems to give much better results, with the gauge reaching just above halfway, then the fan coming in and bringing the needle back to below half. So has anyone got any recommendations on using a different switch? Based on the list below i was thinking of going with a 50215 or a 50113... Thanks! Jamie 50100 82-68 50101 84-79/88-83 50250 86-76 50012 86-77 50090 86-81 50120 88-79 50296 88-79/110-102 50271 88-83 50217 88-83/92-87 50240 90-80 50113 92-82/95-80 50170 92-87 50215 92-87/97-92 50011 93-88 50102 93-88/97-92 50035 95-85/102-92 50130 95-86 50030 95-90 50092 95-90/100-95 50104 97-92 50103 97-92/101-96 50214 97-92/102-97 50190 100-95 50198 100-95/110-105 50000 103-98 50191 120-115 Quote Link to comment Share on other sites More sharing options...
Aragorn Posted January 2, 2010 Share Posted January 2, 2010 Most cars have a switch that will kick in around 95-100c, ie about 5-10c above the stat temp. If your stat is 88 (i think most LR stats are 88), and the switch is 88-83, it will run constantly. I'd go for something like the 50092, or 50102. The only prob with the 102 is that even with a 88c stat you'll find the engine will run around 90c, so the 092 is probably better choice. The other option is to move the current switch to the bottom hose, but i personally think the top hose gives a better idea of the engines temperature, and therefore more consistant operation. If you floor it up a hill for instance, the outlet temperature in the top hose will climb rapidly, but the bottom hose will climb much slower, as the heat from the engine needs to heat the entire rad up first. This means the top hose switch will respond much quicker to increases in temperature than the lower hose, and keep the engine temp better controlled. Quote Link to comment Share on other sites More sharing options...
simonr Posted January 2, 2010 Share Posted January 2, 2010 One or two people have said 50113 is a good choice. If you have trouble finding them, X-Eng buys the 50091's from Unipart. Si Quote Link to comment Share on other sites More sharing options...
MECCANO Posted January 2, 2010 Share Posted January 2, 2010 Stick it in the lower hose : P and all your problems will be solved. Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted January 2, 2010 Share Posted January 2, 2010 Sounds like the switch you have will work fine in the bottom hose. The top hose gives a better idea of what the engine's doing, but if it dumps a load of heat to the rad and there's sufficient ambient cooling (ie on the motorway) then the fan's not needed. Top hose is "better safe than sorry" but means the fan will run more often (and also neater/easier to install), but bottom hose is probably more efficient. Quote Link to comment Share on other sites More sharing options...
zardos Posted January 2, 2010 Share Posted January 2, 2010 On a 3.9 V8 I'm using the aircon temp switch in it's original hole (I don't have aircon) to trigger the relay for twin kenlowes. This is not in the top hose but in the metal pipe the top hose connects to (so a bit closer to the engine). It is a single temp switch at 100C (50190) and this seems to be a good balance between the fans permanently running with the standard X-eng switch and engine getting too hot. Quote Link to comment Share on other sites More sharing options...
GBMUD Posted January 2, 2010 Share Posted January 2, 2010 You have a thermostat to regulate engine temperature and a radiator to cool the coolant so that the thermostat can allow hot water out (into the top of the rad) and cold water in (from the bottom of the rad) as appropriate. It should come as no surprise that the only water the thermostat lets out of the top of the engone, through the top hose and into the top of the radiator is hot water. It will be more than 88 degrees. Assuming it is doing it's job, the water coming from the bottom of the radiator, back into the engine, is cooler. If the radiator should fail to cool the water then you have a problem. The usual problem is lack of air flow through the radiator, and in this case the fan needs to run to create air flow and to cool the water. Enter the fan switch. It detects that the water coming from the radiator is too hot, thus the radiator needs the fan to run and so it switches the fan/s on. If the X-eng supplied switch sensor is fitted to the top hose it will always make the fan run. Generally, one should only expect to hear the fan/s come on in heavy traffic, when stationary, when travelling very slowly under load, or when the radiator is obstructed or has no air flow for some other reason. Think about most modern saloon cars, generally you only get the fans coming on in heavy traffic or when stationary waiting for the wide to be '2minutes'.* If you check the instructions for the X-fan, the very first line is 'The adaptor should be fitted in the bottom radiator hose.'. Of course, the customer is always right. * Curiously, after a few years working for X-eng at shows and chatting with customers, it seem that many customers like to hear their fans running frequently - rather like a puppy being comforted by it's mother's heartbeat perhaps? Or to justify their modification? Same thing IMHO... Chris Quote Link to comment Share on other sites More sharing options...
Aragorn Posted January 2, 2010 Share Posted January 2, 2010 simon: 50113 has a low speed cut out of 82c according to the above table.... That means once its started it would never stop again, assuming it was placed in the top hose? Quote Link to comment Share on other sites More sharing options...
Quagmire Posted January 2, 2010 Author Share Posted January 2, 2010 Thanks for the replies chaps, i will try it in the bottom hose and see what happens then. Will give me a chance to wire the thing up properly anyway as i had used all the same colour wire in my excitement to get it fited *smack on the wrist* Will report back with results Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 2, 2010 Share Posted January 2, 2010 50092 looks like it would sort you out nicely TBH.... if retaining it in the top hose Quote Link to comment Share on other sites More sharing options...
Quagmire Posted January 4, 2010 Author Share Posted January 4, 2010 I should comment on another thing i have noticed- and its a good thing. Using the higher range of the switch so that the fan is switching normally (i.e. only when stationary etc) I have noticed that the engine is running slightly cooler when cruising (fan not on ). I guess that having the big torpedo capillary job in the top hose must restrict coolant flow slightly, accounting for the higher running temp when using the Kenlowe stat? Quote Link to comment Share on other sites More sharing options...
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