"Fan delete mod"

[3bvert]

the fan used was from a 960 volvo, wiht shroud, wires up near direct, installed with a lower thermoswitch
its set up as a puller opbviously, got rid of the bmw aux fan pusher
that with delete of p/s and a/c now only run 1 belt
really cleaned up front of engine

[graphikg]

This mod should be safe to do on the M50 powered e34s right?

[flyboyx]

so far this is my first winter with an electric fan only, and it has not kicked on in days and days. I think in winter another side benefit might be that the engine warms up faster, thus the heater does too

that setup is really cool, but it will not clear the accessory belt of a 24v engine. i was trying to figure out why you had so much clearance between the engine and radiator until i noticed the engine in your photos is an m42. my tbird turbo coupe has an electric puller setup. it works fine, but again there is lots of 4 cylinder clearance on that car too.

[flyboyx]

the fan used was from a 960 volvo, wiht shroud, wires up near direct, installed with a lower thermoswitch
its set up as a puller opbviously, got rid of the bmw aux fan pusher
that with delete of p/s and a/c now only run 1 belt
really cleaned up front of engine

obviously, the purpose of this thread is to discuss methods to keep 24v cars from overheating. with an m/s series 6 cylinder engine, the aux e30 pusher is generally inadequate to provide ventilation across the radiator at a stop on a warm day. assuming what you mentioned above accomplishes this function, you are good to go.

however, from an engineering standpoint, i'm not sure why you would want to get rid of the aux pusher fan. (since you have deleted a/c and ps, i can only assume you are trying to save weight off the front of the car forward of the wheels for racing purposes). my 750i aux pusher is very effective. it is absolutely awesome in my opinion that the factory bmw fans come with two speeds. i don't think i could overstress the importance of this feature. most of the time mine runs on the lower speed and the sound it produces is unnoticeable. below is a photo of my engine bay with a stock s52 radiator. i know you have stated above that you are not running a/c. that will only save you about an inch of space or so. as you can see my a/c clutch clears my rad by about 5/8ths of an inch. it is pretty tight. without a/c, there will be less than two inches of clearance for a puller fan because of the water pump pulley, radiator hoses, etc. the volvo fan in the photo is thicker than that. the power steering delete doesn't have relevance to this conversation because it runs in the path of the main serpentine belt.

also, as mentioned in an entry above, the engine and ecu are designed to run somewhere in the 90c range. the engine needs to be at this temperature in order for the ecu to allow it to produce optimal power. i think guys swap in a lower temperature thermostat because they get a warm fuzzy by seeing the needle on the temp gauge in the lower third of the arc. the lower temp thermostat will not prevent over heating, all it does is lower the point at which the valve opens up to allow coolant to circulate in the system. if there isn't adequate ventilation present(ie: ram air, fan, etc), the car will overheat just the same. changing the radiator temp switch to the one from an e36 m42 will allow the fan to come on a few degrees sooner, but altering the operational temperature of the engine doesn't really accomplish anything.

[Cronus]

Someone had mentioned earlier if these fans are freewheeling at higher rpm. Which I'm not sure of. However that would seem to be the reason i would want to do this mod.

If you are spinning the fan when you are at 7000 rpm thats a lot of parasitic power loss. Think about all that extra resistance the engine is having to overcome. You take that fan off and you no longer have as much wind resistance while revving high.

[graphikg]

Flyboy, so is what you are suggesting is to keep the tstat the same when doing the fan delete mod, yet swap the stock fan with a better one while keeping the 2 speed option?

[flyboyx]

Flyboy, so is what you are suggesting is to keep the tstat the same when doing the fan delete mod, yet swap the stock fan with a better one while keeping the 2 speed option?

graphikg, this is what i am suggesting. the issue is not having enough cfms flowing across the heat exchanger(radiator) thus causing the engine to overheat. if you are sitting in traffic on a hot day with very little air flow through the radiator, it doesn't make any difference (within reason) what temperature your t-stat opens. the radiator won't be able to get the engine heat out of the water unless you have a way to blow lots of air across it. the two speed fan isn't a requirement so much as an inherent convenience already built into the factory fans. since the feature is there, it is would be a travesty not to make use of it. as i mentioned above, the low speed kicks on pretty quickly after the engine warms up for a couple of minutes. i don't remember the details, but i think the e36 m42 switch is set to 170 low and 190 high. the low speed fan runs pretty much continuously and the high cycles in and out every few minutes or so idling on a hot day. i can watch the temp gauge in the car rise and fall with the fan cycle. i would say it the gauge fluctuates between 2/3rds down to 5/8ths.

not exactly related to this thread, but another factor in avoiding an overheat situation is the radiator size. many of us with 24v swaps have a tendency to run the m42 radiator out of convenience due to the integral reservoir. my e30 came with this radiator and the donor car came with the stock s52 radiator so i own both of them. i can say that comparing the two, the m42 rad is about 20% smaller than the m3's. i am having a dilemma deciding how to finalize my cooling system. i have a real problem using the m42 rad because it is so small, but i also have a problem trying to figure out what to do with the coolant reservoir because my supercharger kit interferes with its placement on the driver side inner fender. the higher horsepower associated with forced induction will further compound my coolant problem. i have yet to see anyone who has come up with an acceptable solution. i could possibly run the old style overflow tank on the passenger side. i think i am going to get a v8 or v12 coolant reservoir and see if i can find a place to mount it on the firewall. if anyone has a better idea, please let me know.

[graphikg]

Why dont you use the 88 e30 style radiator with the expansion tank? I think that might give you more room.

[dude8383]

graphikg, this is what i am suggesting. the issue is not having enough cfms flowing across the heat exchanger(radiator) thus causing the engine to overheat. if you are sitting in traffic on a hot day with very little air flow through the radiator, it doesn't make any difference (within reason) what temperature your t-stat opens. the radiator won't be able to get the engine heat out of the water unless you have a way to blow lots of air across it. the two speed fan isn't a requirement so much as an inherent convenience already built into the factory fans. since the feature is there, it is would be a travesty not to make use of it. as i mentioned above, the low speed kicks on pretty quickly after the engine warms up for a couple of minutes. i don't remember the details, but i think the e36 m42 switch is set to 170 low and 190 high. the low speed fan runs pretty much continuously and the high cycles in and out every few minutes or so idling on a hot day. i can watch the temp gauge in the car rise and fall with the fan cycle. i would say it the gauge fluctuates between 2/3rds down to 5/8ths.

not exactly related to this thread, but another factor in avoiding an overheat situation is the radiator size. many of us with 24v swaps have a tendency to run the m42 radiator out of convenience due to the integral reservoir. my e30 came with this radiator and the donor car came with the stock s52 radiator so i own both of them. i can say that comparing the two, the m42 rad is about 20% smaller than the m3's. i am having a dilemma deciding how to finalize my cooling system. i have a real problem using the m42 rad because it is so small, but i also have a problem trying to figure out what to do with the coolant reservoir because my supercharger kit interferes with its placement on the driver side inner fender. the higher horsepower associated with forced induction will further compound my coolant problem. i have yet to see anyone who has come up with an acceptable solution. i could possibly run the old style overflow tank on the passenger side. i think i am going to get a v8 or v12 coolant reservoir and see if i can find a place to mount it on the firewall. if anyone has a better idea, please let me know.

There's a guy running a turbo setup with a stock m42 radiator and he hasn't complained of any overheating...I too have an m42 radiator and live in NY, the traffic here can get pretty awful. I installed two fan's to get air moving, a 14" slim fan radiator side and a 16" spal fan on the condenser side. The 14" fan acts as the low speed and when things get hot, the 16" kicks on and brings temps back into check. I think you just need to have a powerful aux fan to be safe with a supercharged setup.

*EDIT* found the link:

http://r3vlimited.com/board/showthread.php?t=130093&highlight=fan+radiator+cooling

[3bvert]

flyboyx
sorry I guess I did not relize this thread was for 24v conversions, and I thank you for my comments and your thoughts, even though I run a m42
1) ac was deleted because it did not work, being a vert in rural oregon, would only need ac maybe twice a summer
2) pusher vs puller fan thoughts
one , the stock pusher made noise, a volvo puller was cheaper then finding a replacement pusher
two , I grew up in the olden days when mg-td's and triumph Tr-3's were the hot track cars. the school of thoght back then was not to stick anything in front of the radiator. yes it is an old school of thought, and the bmw engine bay looks cleaner with the fan in front of the radiator, but for me, in this application, it did not matter
since the install I have gotten a parts car, and if I had had that early on, I would have stayed with a pusher fan

thanks again for your thoughts,.........Ill try harder to pay attention to the threads original intent and focus

[nando]

the stock aux fan is pretty loud regardless. a puller may in fact be quieter, but the 16" curved blade pusher fan I'm using isn't very loud at all, and it's wired to only run at high speed.

and I don't think it matters too much what motor or car you're talking about here. The premise is still the same. You're basically removing the clutch fan and using an electric fan to cool the car in cases where you are sitting still. Once you are moving airflow over the radiator is all that is really needed.

[motorsports_3]

So If I wanted to use the stock fan in front, and the spal on engine side, should I splice into the stock wiring and run them both, or do you think that would pop the fuse too often?

I will be runing a stock e30 t-stat, and m42 temp switch (the cooler one)

The reason I want both fans, is that I will be using the A/C

[nando]

You couldn't really run them both off the same thermoswitches/relays, because they would both turn on. you'll need a seperate fan controller circuit.

[SamE30e]

It's on my list!

[motorsports_3]

So the stock aux fan is set to come on when the A/C comes on also when the motor gets past a certain temp right?

Where could I find info on wireing both fans? Should I splice into the stock harness then run it to a relay, then into the fan?

Or Do you think I will be fine with the above mentioned mods (lower temp t stat, lower temp switch, and water wetter) along with a Spal fan in place of the stock fan on the condensor.