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Electric Fan Installation

3K views 15 replies 7 participants last post by  George Vlado 
#1 ·
I have seen a few threads here on installing an electric puller fan to replace the clutch fan. I have just done this on the 5.0 SLC and thought I'd share the build process for reference.

Here, I used an electric fan and shroud from a 1995 Volvo 940. It is a perfect fit on the car using a later alloy radiator from a 560SL; with some slightly different mounting techniques this should also fit on the earlier 107 cars just fine.

Cost for parts, less than $75.

Part 1 - install

https://slc4dirt.wordpress.com/about/building-the-beast-part-3/electric-cooling-fan-part-1/

Part 2 - connection

https://slc4dirt.wordpress.com/about/building-the-beast-part-3/electric-cooling-fan-part-2/
 
#2 ·
Kevin excellent write-up! Volvo's are a dime a dozen at the two pap's I go to so sourcing the fan, shroud and relay should be easy. One caveat however if trying to use a different fan. A friend of mine tried this and kept frying alternators...too much amp draw. He ended up having a custom high amperage alternator made and the problem was solved. Not an issue with your setup however...
 
#3 ·
Thanks - amperage load of the fan is a big deal, many fans available (both aftermarket and OEM from the yard) draw a lot of amperage. One fan that is popular for this sort of thing on other cars and hotrods is the Lincoln Mark VIII fan, but that draws a lot of amperage (~50 I've read) and is probably too thick to fit. The Volvo fan is perfect, and draws 15 low and 25 high. Plus the added advantage of a simple 2-speed control that is already on the same car and wired in. And yes, you will trip over these in the junkyard every day.
 
#4 ·
as I'm stripping all the ancillaries off so that

I can change the timing chain and tensioners, I've been looking at electric fans and shrouds as well, mainly courtesy of all the posts here. I decided against after-market ( although Mishimoto do a Mustang shroud and fan that would be an almost perfect fit for my rad cowl mountings), as I don't know how many cfms I need . In fact, I need cubic metres, but that's just a transatlantic annoyance.
I have an SLK 320 as a daily hack. It throws out 218bhp. My 500SL throws out 231 ( allegedly). So for a head scratcher, I measured the SLK cowls and fan. Blow me, it's close enough to easily modify to fit the SL mountings. So i punted £20 on a used one on ebay. Less than the cost of the top hose. All i have to do is work out how to wire it up. and I bet someone here has already done that. I could just go the the gorilla on/off from the cockpit via a suitable relay ( caution, requires driver paying attention to temp gauge)
Or maybe just clean up the old viscous set-up and refit. I run Evans waterless coolant in there any way, so i am less worried about it getting 'warm' than I used to be, as there is no pressure build-up to scare me.
 
#10 ·
I can change the timing chain and tensioners, I've been looking at electric fans and shrouds as well, mainly courtesy of all the posts here. I decided against after-market ( although Mishimoto do a Mustang shroud and fan that would be an almost perfect fit for my rad cowl mountings), as I don't know how many cfms I need . In fact, I need cubic metres, but that's just a transatlantic annoyance.
I have an SLK 320 as a daily hack. It throws out 218bhp. My 500SL throws out 231 ( allegedly). So for a head scratcher, I measured the SLK cowls and fan. Blow me, it's close enough to easily modify to fit the SL mountings. So i punted £20 on a used one on ebay. Less than the cost of the top hose. All i have to do is work out how to wire it up. and I bet someone here has already done that. I could just go the the gorilla on/off from the cockpit via a suitable relay ( caution, requires driver paying attention to temp gauge)
Or maybe just clean up the old viscous set-up and refit. I run Evans waterless coolant in there any way, so i am less worried about it getting 'warm' than I used to be, as there is no pressure build-up to scare me.
You mention Evans Waterless coolant.... Obviously you use and must have faith in it. Any thoughts?
 
#6 ·
That's a tight fit - what type of fan did you use on the 280?

On mine, I didn't have to alter the pulley, and the photos may make the clearance look like less than it is. I would say that I have between 1/2" and 5/8" of clearance where needed. Part of what helped here with the Volvo fan is that the fan is not centered in the shroud, it is on the right-hand (passenger) side, such that the motor is offset from the water pump pulley. This was magical, something I didn't fully appreciate until I had the fan and shroud test-fitted. I was thinking mostly of the overall thickness of the assembly and the width of the shroud compared to the radiator.
 
#7 ·
Nicely done. I bought a 16" Flex-a-lite fan, same size as the original, that's controlled by a Megasquirt. I probably
could have gotten more pulley clearance by moving the fan closer to the radiator itself
but was worried about vibration noise. I used the original shroud reinforced to support the fan
but centered the fan on the radiator. My armchair quarterback friends of course said
you should have mounted a bigger or double fan in front as a pusher and had no clearance problems
ala the mid 80's Benz sedans but hopefully there will be a Turbo intercooler there someday.
 
#9 ·
From the rear face of the radiator (a Behr from a 560SL), the rear of the fan motor extends approximately 4 3/4 inches, including the shroud which is the factory one from the Volvo 940. I would guess that if you removed the fan from the shroud and attached it directly to the radiator, it would fit within 2 to 2 1/5 inches, something like that.

Using the Volvo 940 shroud, the fan is offset from center, so there are no clearance issues. It would probably fit if centered, but barely. Here is a photo that shows the separation, as best I could.
 

Attachments

#11 ·
love it to bits. but then I would, I paid £300 for the treatment ( you need flushing fluid, for two flushes, and then enough coolant 13 litres, to fill the system). The old girl would run hot in traffic, even on 70/30 coolant water. On warm-up she would race past 100 Celsius past 110, then the cool water from the rad would come in and she'd settle down ( i hear a lot of v8s do that). I recpred the rad, put in a new stat, and nothing changed. She could fly down the motorway, sitting at 92 or so, but when the traffic slowed to crawl, it was crack the windows and put the heater on and blower as well. i even fitted a new visco, no change.

I was at a car show, and so was Evans trade stand. we got talking. a few hours later, I was loading up the boot with a lot of \evans product ( and the gave me a hat as well, and two mugs).

Since the swap to Evans, no real trouble at all. She still 'burps' over 100 on warm up, but only just. she settles down just fine in slow traffic, runs at about 98, and storming around at speed is no issue, sits at about 95. But the best bit is, NO COOLANT PRESSURE. You can, and I often do, remove the filler cap ( suitably thermally protected of course) at fully-warm heat, and not a lot happens. A tiny hiss, and that's it. So that alone has to be a major benefit. And it's a lifetime fluid. so over time, it will pay for itself. If I'd put it in when I bought the car 12 years ago, I would be quids ahead by now.

I honestly think it's worth it for anyone who will be keeping their SL.
 
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