504 with no fan

Doush_504

Active member
Fellow Frogger
Joined
Nov 1, 2010
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Location
Cairo, Egypt
G'day everyone
Just sharing thoughts, what do you guys think of that ?
Winter has started and I feel that having the fan spinning at all time (directly with the engine) is quite useless. I am thinking of removing it and see how the car will react. I am expecting a great reduction in noise and maybe little better performance :rolleyes:
As a backup I have the A/C fan which has a temp sensor at the bottom of the radiator that activates it in case the temp goes over 90 C and I also have an under dash override button.
Has anyone tried this ? Guys with electric fans, do you hear them engage in winter ?

Cheers,
Chadi
 
Most of us here use only electric with 82C - 68C valves. For a street car an 85C - 80C valve may be sufficient. You will notice quite a bit of difference in power, especially at the upper rev range.
 
G'day everyone
Just sharing thoughts, what do you guys think of that ?
Winter has started and I feel that having the fan spinning at all time (directly with the engine) is quite useless. I am thinking of removing it and see how the car will react. I am expecting a great reduction in noise and maybe little better performance :rolleyes:
As a backup I have the A/C fan which has a temp sensor at the bottom of the radiator that activates it in case the temp goes over 90 C and I also have an under dash override button.
Has anyone tried this ? Guys with electric fans, do you hear them engage in winter ?

Cheers,
Chadi

Seems like a reasonable proposition. My 505 has a fully shrouded twin electric fan setup. In combination with the front air dam but more importantly the bit of trim that goes from the front air dam to the chassis I never need to switch the second fan on unless I have the air-conditioning on and it's 35+. A 504 won't be quite as efficient but I would think you'd be able to get away without the viscous fan.

If your viscous fan is working properly, it shouldn't really make much of a difference to fuel economy or noise except when the engine has just started and the fluid in the viscous coupling is cold. If you have an electromagnetic clutched fan I wouldn't bother removing it.
 
On my old 505GTI I had the A/C fan as usual on the out side and fitted a single fan on the inboard side after deleting the fan.
Hooked it up to the low speed temp switch for the A/C on the radiator using a redundant relay.
I should have put in a manual over-ride for traffic/hot days inside the cabin, (a good idea).
 
504 fan

G'day everyone
Just sharing thoughts, what do you guys think of that ?
Winter has started and I feel that having the fan spinning at all time (directly with the engine) is quite useless. I am thinking of removing it and see how the car will react. I am expecting a great reduction in noise and maybe little better performance :rolleyes:
As a backup I have the A/C fan which has a temp sensor at the bottom of the radiator that activates it in case the temp goes over 90 C and I also have an under dash override button.
Has anyone tried this ? Guys with electric fans, do you hear them engage in winter ?

Cheers,
Chadi

My engine driven fan still cuts in during winter in traffic after 4 or 5 minutes at idle.
I can remember years ago that the fan always cut in when I nipped up the gutter lane to blow someone off at the lights!!!:mad:


I read somewhere that the engine driven fan takes 12bhp off the 504 engine power to drive it at max revs (approx. 13%!).

If you do disconnect the engine driven fan I suggest you fit wider tyres to the back. You may get wheel spin!!!:wink2:
 
The viscous fan in our GTi and SRD works perfectly in the worshop when the cars are hot at idle and both seems to fail when you need them out on the road on extremely hot days. My old 504 injection behaved the same.

I'd change over in a flash to electric fans if I could trust myself to get it right.
 
The 504s do not have a fixed fan. Sometimes people with no clue lock the fan in so it is 'fixed' and on all the time. The fan has an electromagnetic clutch (I cannot believe nobody has pointed this out) so the fan comes in when the water temperature is hot; it is thermostatically controlled.

Ignore anybody who tells you to run an electric fan IN PLACE of the Peugeot fan. You're losing efficiency by doing so. Just get the electromagnetic fan working how it was intended.
 
I read somewhere that the engine driven fan takes 12bhp off the 504 engine power to drive it at max revs (approx. 13%!)

Here are the hard numbers with one of my earlier 504 rally engines. Back to back dyno runs, the first with the electromagnetic fan on, electric switched off, the second with the electromagnetic fan removed and the electric fan switched on. The sequense is: rpm, bhp ATW with electromagnetic, bhp ATW with electric. The power loss ATW is from the work it takes to rotate the water pump pulley with the fan attached, clearly the higher the rpm, the higher the loss.

4000 rpm, 101 bhp, 105 bhp
4500 rpm, 111 bhp, 116 bhp
5000 rpm, 120 bhp, 127 bhp
5500 rpm, 122 bhp, 130 bhp
6000 rpm, 114 bhp, 124 bhp
6500 rpm, 102 bhp, 113 bhp

IMHO it makes no sense to keep the electromagnetic fan (especially if it is fixed) when you can get efficient cooling with an electric one.
 
Electric fan

For the last few years in my outback travels, I have fitted a 505 SR or GR radiator to the Breavan and my 404 wagon, taken away the engine fan and fitted a 16 inch thermo fan in front of the radiator. It is controlled by the fitting in the bottom of the radiator and has an overide switch on the dash as well as a bright light which comes on with either switch. For most driving the temp gauge sits on under a half and the fan seldom comes on. It is reasonably boisterous when it comes on though.

When I come to a water crossing, I will turn the fan on for a short while to get the temp right down , then cross without any chance of the fan cutting in while crossing. With the standard set up it would be wise to remove the belt on the engine fan as if can pull itself into the radiator, or splash water over the electrics causing the car to stop. On the recent Cape York trip there was one day when we crossed 5 or 6 creeks - no fun taking the fan belt off each time.

My set up is also good for hillclimbs etc ensuring that no power is lost through the event by the fan cutting in as you have been able to run the fan up until you start.
 
Ok Thanos, it's good to have those figures. I'm still going to stick with the electromagnetic fan for my own use but I would have thought that converting energy from mechanical to electrical and then back again would be less efficient. Clearly there is more to it, however, such as how much air the fans push per HP etc. as clearly the electric fan funs at a constant speed and the original fan does not. Though if electric works for you, excellent, as I see how it would be an advantage in rallying.

For everyday use though the electromagnetic fan makes sense as it is generally only on in traffic or hot weather. In light of this I may consider wiring my electric fan to come on earlier than my electromagnetic fan though since it's there already for air conditioning.
 
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...I have fitted a 505 SR or GR radiator to the Breavan and my 404 wagon, taken away the engine fan and fitted a 16 inch thermo fan in front of the radiator. It is controlled by the fitting in the bottom of the radiator and has an overide switch on the dash as well as a bright light which comes on with either switch... It is reasonably boisterous when it comes on though...

My configuration is nearly identical; my fan is a bit smaller (I matched the height of the fan to the height of the radiator) and I am using the 504 radiator with an extra row of cooling fins. Still, the cooling is very efficient, even in all-out rally stages, with an engine that puts out more than 150% the power of the standard engine. Be that as it may, the 505 cross-flow radiator is more efficient at removing heat than a standard 504 radiator and a good upgrade if you can get it.
 
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Most of us here use only electric with 82C - 68C valves. For a street car an 85C - 80C valve may be sufficient. You will notice quite a bit of difference in power, especially at the upper rev range.
That's encouraging enough :)
My water thermostat opens at 82C that's why the radiator temp sensor works at 90 (80C-90C), I think 82C-68C in my case would be unable to cool the car because it will be working against the water pump thermostat, right ?
I do have a spare one that opens at 75C but I feel the car runs better at 82C.
Peugeot504-505thermostat.jpg


Seems like a reasonable proposition. My 505 has a fully shrouded twin electric fan setup. In combination with the front air dam but more importantly the bit of trim that goes from the front air dam to the chassis I never need to switch the second fan on unless I have the air-conditioning on and it's 35+. A 504 won't be quite as efficient but I would think you'd be able to get away without the viscous fan.

If your viscous fan is working properly, it shouldn't really make much of a difference to fuel economy or noise except when the engine has just started and the fluid in the viscous coupling is cold. If you have an electromagnetic clutched fan I wouldn't bother removing it.
Problem is I have neither viscous nor electromagnetic fan, it was removed more than 25 yeas ago. People are scared that those fans might fail in hot weather and damage the cylinder head so everyone fixes them for the peace of mind. I would greatly appreciate it if you could explain the difference between the 2 please.

On my old 505GTI I had the A/C fan as usual on the out side and fitted a single fan on the inboard side after deleting the fan.
Hooked it up to the low speed temp switch for the A/C on the radiator using a redundant relay.
I should have put in a manual over-ride for traffic/hot days inside the cabin, (a good idea).
My temp switch only has 2 terminals, no high/low speed option. And a manual override button is always a peace of mind.
The 504s do not have a fixed fan. Sometimes people with no clue lock the fan in so it is 'fixed' and on all the time. The fan has an electromagnetic clutch (I cannot believe nobody has pointed this out) so the fan comes in when the water temperature is hot; it is thermostatically controlled.

Ignore anybody who tells you to run an electric fan IN PLACE of the Peugeot fan. You're losing efficiency by doing so. Just get the electromagnetic fan working how it was intended.
Mine does, but not from factory of course, here is how it looks
Peugeot504enginefan.jpg


Peugeot504fanhub.jpg

Radiator side


Engine side
Peugeot504enginefanengineside.jpg


Here are the hard numbers with one of my earlier 504 rally engines. Back to back dyno runs, the first with the electromagnetic fan on, electric switched off, the second with the electromagnetic fan removed and the electric fan switched on. The sequense is: rpm, bhp ATW with electromagnetic, bhp ATW with electric. The power loss ATW is from the work it takes to rotate the water pump pulley with the fan attached, clearly the higher the rpm, the higher the loss.

4000 rpm, 101 bhp, 105 bhp
4500 rpm, 111 bhp, 116 bhp
5000 rpm, 120 bhp, 127 bhp
5500 rpm, 122 bhp, 130 bhp
6000 rpm, 114 bhp, 124 bhp
6500 rpm, 102 bhp, 113 bhp

IMHO it makes no sense to keep the electromagnetic fan (especially if it is fixed) when you can get efficient cooling with an electric one.
All this loss comes only from just removing the fan !!
This is using a normal Peugeot water pump, right ?
 
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No, it comes from ADDING the fan :wink2:

Oops :D

Yes

As to your previous comments, the 504 runs better (and produces more power) with the lower temp thermostat.
Thanks Thanos :)
Does the 75C fit in the 505 pump ?
Are there any differences in efficiency between 504/505 pumps ? People seem to prefer the older style 504 pumps (that have no thermostat housing, and wider hose diameter on one end) over the 505 units (like the one shown) and I don't know why :rolleyes:

IMG_4139.jpg


IMG_4141.jpg
 
The electromagnetic clutch fan is run by the pulley on your water pump. When the temperature gets hot and the switch (usually in the radiator) turns on, it sends power to the electromagnetic clutch, magnetising it, and the fan engages and uses the power of the engine to turn it. The loses that Thanos described are due to the fan spinning faster as engine speeds increase, thus robbing more power from the engine. (There may very well be an engine speed [below about 3,500] where the motor makes more power with the electromagnetic fan engaged than the pure electric fan, which draws it's power from the alternator). This isn't a big concern, as when the fan engages you are usually stuck in traffic. Getting some road speed and the engine will cool down, the fan will disengage and you'll be honey dorey.

PRV engines being fitted with viscous fans them. I don't know much about them except they use a fluid, when the fluid heats up it engages the fan. Maybe someone else could fill in the blank.
 
504 running temperature.

"I feel the car runs better at 82C."

The Peugeot 504 Ti workshop tuning manual instructs that mixture settings must be carried out at 80C though no lower than 75C, so 80C sounds right to me.:)
 
"I feel the car runs better at 82C."

The Peugeot 504 Ti workshop tuning manual instructs that mixture settings must be carried out at 80C though no lower than 75C, so 80C sounds right to me.:)

with warm plugs, low compression and leaded fuels

But be that as it may, a 80C to 90C thermostat will have the engine running above 75C-80C, even at less than full chat.

The 82C to 68C thermostat was used by the works cars and temperatures stay at 80C to 85C for short stages, several degrees higher at longer stages.

We see loss of power at the dyno once the temp goes past 85C and this loss becomes very significant at 95C.
 
The electromagnetic clutch fan is run by the pulley on your water pump. When the temperature gets hot and the switch (usually in the radiator) turns on, it sends power to the electromagnetic clutch, magnetising it, and the fan engages and uses the power of the engine to turn it. The loses that Thanos described are due to the fan spinning faster as engine speeds increase, thus robbing more power from the engine. (There may very well be an engine speed [below about 3,500] where the motor makes more power with the electromagnetic fan engaged than the pure electric fan, which draws it's power from the alternator). This isn't a big concern, as when the fan engages you are usually stuck in traffic. Getting some road speed and the engine will cool down, the fan will disengage and you'll be honey dorey.

PRV engines being fitted with viscous fans them. I don't know much about them except they use a fluid, when the fluid heats up it engages the fan. Maybe someone else could fill in the blank.
If I understood correctly, both fans (when engaged) would be running at idle speed in a traffic light, which might be insufficient. An electric fan would be running at full blast in a traffic light and then shuts up once you hit an open road (where you actually need power).
In my case, I mostly do highway driving so the fan would be functioning against common sense, very slowly during traffic (when you need it most in a hot summer) and roaring when at speed (when it is useless since it cannot bring in more air that what is already entering).
Maybe Thanos would have the power numbers with the electric fan ON.

with warm plugs, low compression and leaded fuels

But be that as it may, a 80C to 90C thermostat will have the engine running above 75C-80C, even at less than full chat.

The 82C to 68C thermostat was used by the works cars and temperatures stay at 80C to 85C for short stages, several degrees higher at longer stages.

We see loss of power at the dyno once the temp goes past 85C and this loss becomes very significant at 95C.
There are two settings of thermostats that I know of, 75C and 82C (the mechanical ones that go inside the water pump, see attachement) and I currently have the 82C fitted. The electronic thermostat/temp sensor (fitted at the bottom of the radiator ) with wires going to the electric A/C front fan has many ranges. When I was buying a new one a couple years ago, I had a choice between "80C-90C" and "68C-82C". I figured that if I buy the lower one, the electric fan would be running all the time since the mechanical thermostat (valve) would always keep water temp at 82C so I bought the 80-90C. During those two years, I never heard the A/C fan engage except for once after a 170kph run and it engaged after I had almost reached my destination (a couple of minutes after leaving the highway). So I am pretty sure that my water temp never gets past 90C even in hottest summer days and the A/C fan just ensures a piece of mind.

"I feel the car runs better at 82C."

The Peugeot 504 Ti workshop tuning manual instructs that mixture settings must be carried out at 80C though no lower than 75C, so 80C sounds right to me.:)
I don't know if there are 80C thermostats :rolleyes:
Check attached pics

A cold engine delivers more power than a warm engine, but a warmer engine provides better fuel economy than a cold engine.
The 2nd part is fairly logic, but wouldn't better fuel economy mean better combustion/efficiency and therefore more power ?
 

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If I understood correctly, both fans (when engaged) would be running at idle speed in a traffic light, which might be insufficient. An electric fan would be running at full blast in a traffic light and then shuts up once you hit an open road (where you actually need power).
In my case, I mostly do highway driving so the fan would be functioning against common sense, very slowly during traffic (when you need it most in a hot summer) and roaring when at speed (when it is useless since it cannot bring in more air that what is already entering).
Maybe Thanos would have the power numbers with the electric fan ON.

He does, what he didn't show was the power with no fans on, this would be very interesting.
Graham
 
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