THIN fans

[discopotato03]

Stamp licker , I didn't realise that airconditioned MY's used two electric fans .
I think I know where one of those is , was looking at it on a massive pile of thermo fans and remembered thinking that looks just like Ellies mechanical fan shroud only with an elec fan in it .

I'm really keen to know how well it works compared to the mechanical one , I reckon a wet sparrow could move more air than the std one at idle .
If it works well then between it and the AC booster fan more than enough air could be pulled through the standard radiator core at idle and low speed .

For EA MPFI/Turbo punters its easy to see why these engines don't run too well when hot . The coolant collector log that feeds hot water from the heads bolts to the back of the inlet manifold and this will always be at coolant temp . The maze of tubing for the injectors is pretty close to the manifold and log so it can get a bit toasty as well . The give away is when you put your hand of the steel fuel filter and it can be very warm in a hot engine bay . When my RX L is not stewing the fuel filter feels luke warm and in cold weather its cool to touch .

The only conclusion I can draw is that every effort needs to be taken to ensure that the radiators water temp is kept as cool as possible . I'd say that above possibly 40-50 Kmh the fans won't do much , but at low speeds or stationary they must be able to pull enough air through the core to keep its water at something like thermostat cracking temperature . If the rad temp keeps rising then it wont mater how far the thermostat opens because the water its letting in isnt cool enough to stop the upwards creep . Also the higher the rad temperature gets the hotter the air is thats getting dumped into the engine bay so if the fans get stuck in before it climbs high everything stayes cooler .

One thing I'm going to try is to bypass the throttlebody water heating set up , all it needs is a longer length of hose to join the inlet and outlet and it can run in front of the throttlebody in the area where the throttle damper is . Someone here mentioned recently that these hoses are 7mm bore and stupid money new ie something like $21 and $23 . I think a couple of short sections of 7mm EFI fuel hose would cope very easily . I also think a non intercooled turbo engine with a hot water pipe bolted to its inlet manifold is not likely to ice up - well in a Sydney summer anyway .

Lastly can anyone suggest a better way of switching the fans other than one of those bulb in the top hose earth reostats ? I'd much prefer a lower temp switch that screwed in to a boss and sensed water temp that way . On the other hand if the bulb job can be relied upon to seal every time in the hose it should be ok . Anyone using these things ?

Cacha all , cheers A .

PS need to find sensible local sites because I need hard data on MY98-00 WRX's . The next Subie will almost certainly be an Impreza and I need to find out which models got which spec engines - heads turbos etc . Ta .

[sven '2']

[quote="discopotato03"] .


The only conclusion I can draw is that every effort needs to be taken to ensure that the radiators water temp is kept as cool as possible . I'd say that above possibly 40-50 Kmh the fans won't do much

Lastly can anyone suggest a better way of switching the fans other than one of those bulb in the top hose earth reostats ? I'd much prefer a lower temp switch that screwed in to a boss and sensed water temp that way . On the other hand if the bulb job can be relied upon to seal every time in the hose it should be ok . Anyone using these things ?
QUOTE]

First point: When I was sorting my last L's cooling issues, i asked the radiator place what use fans were at speed...why do they not turn off? Obvious in traffic / hard low range beach work - needs to maintain airflow. Seems that even in a cross wind the amt air drawn is less.

Thought this was BS myself - stick your head out the window even in a cross wind and there seems to be plenty of air smacking you in the face...

Second: I have used both - both work well, although the bulb thru the radiator hose sealed ok, was a pain out bush when removing the radiator or replacing hoses.

I think DC make a control unit that allowed 2 stage sequencing - mine was a rip off bought in the states. Was a good unit.

Chris: The BMW fans were from a later model, twin headlight, blue - sorry!

[Chris_Rogers]

think I know which one. E36 so 91-97. I'm going past the wrecker in the morn with dimensions so I'll know which one fits.

thanks!

as for switching them on/off. I had a switch on mine that would manually operate them or auto via the OE switch. both were relayed. this car the switching is done via the ECU.