electric radiator fan on S1 coupe

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mike gillies

electric radiator fan on S1 coupe

Unread post by mike gillies »

I would like to hear anyone's experiences in fitting a Series 2-3 radiator with electric fan and shroud to a series 1 Fulvia coupe. Any modifications needed for them to fit? Any advice/tips most welcome.

thanks
Mike
S1 Fulvia Rallye 1.3
Huib Geurink

Re: electric radiator fan on S1 coupe

Unread post by Huib Geurink »

They should fit. You may have to put a dent in the pot for the right main beam headlight.

What is the reason that you want to fit one?

I sometimes hear arguments that the mechanical fan takes away 5HP. If this is the case it is time to put new bearings in the fan. I can turn the mechanical with my little finger, perhaps even by blowing against it. The power it takes does not even come near 1HP.

The S1 Fulvia can still drive for many daylight hours if the dynamo fails. In fact all day long if you take out one of the brake lights and don't use wipers or other electrical things. Not so, if an electric fan switches on often. I notice that in rally circles, people often put in electric fans and electric fuel pumps. I would not for the simple reason given above.
If you have to drive through tunnels or during the night with a defective dynamo, pull fuses 1 and 3, and you still have 3 or 4 hours of driving in the battery.

People with electric fans often put switches on the dashboard so they can run the fan all the time. They better put in an S1 mechanical fan, which runs all the time and does not load the dynamo or alternator.

I even know people who replace the fan of an S1 Fulvia with an electrical fan and then mount a switch so they can run it all the time. This is beyond my comprehension.

The fan and its mounting are beautifully made pieces. Very typical Fuvia.

If you gave cooling problems, your radiator is most likely blocked. If you replace the core, better replace the core of the heater too. The higher the outside remperatures, the more important it is (for the car) that your heater works perfectly so you can open the windows and switch on the heater in emergency situations. Replace all hoses at the same time, so that sludge is removed as much as possible in one sweep.
jay hinton

Re: electric radiator fan on S1 coupe

Unread post by jay hinton »

Huib, as usual, is making very good points about S1 fan systems and electrics. But of course, I have to differ with him on this.

for my 3 different S1 Fulvias, I have installed electric fans and electric fuel pumps, and the cars have never been better than this.

for the electric fan, the S2 unit can be installed, with a relay and appropiate wiring, the fan will operate as a S2 does, only intermittently. One serious benefit of this is far more rapid warm ups without a continuously operating fan. Then, reduced noise, its much more interesting to hear a Fulvia engine working than hearing the overly loud fan working. Finally, there is the issue of horsepower, though this seems most affected at high revs, yet, a lot of Fulvias frequently experience high revs.

for the electric fuel pump, I have found a replacement unit for VW bugs that fits well, very close to the fuel cell. Again, with careful wiring, it performs very well on several counts. First, there is a immediate fuel flow to the carbs, greatly reducing starter cranking time, saving that rare starter. Not to mention, not running down the battery. Second, if you can buy a appropiate unit with a pressure regulator, then the fuel flow pressure will be correct, about 2.5-3 lbs. I have often found that the original mechanical units supply well over 4 psi, which causes a rich running condition. Your engine will acquire a much nicer state of tune and economy, with correct fuel pressure. If you doubt this, then measure the incoming pressure and use a adjustable regulator and experiment.

Finally, all my rare dynamos are still functioning, but when they do quit, I will adapt a modern alternator to power the electrical systems. The turn signals, headlamps, interior fan, will all perform better as well.

Oddly, I never see any S2 Fulvia owners retrofitting S1 mechanical fans, no matter how nice the initial fan assemblys were, which indeed, they are.
Brian Hilton

Re: electric radiator fan on S1 coupe

Unread post by Brian Hilton »

From a purely asthetic point of view I wouldn't change the mechanical fan on my 2c Berlina, it is an absolute work of art, and for me to replace it with an electric fan would seem criminal, however much much it would reduce noise, it's part of the overall Fulvia music.

On the other hand, the fuel pump would be welcome for starting purposes, There is no pressure regulator on my early 2c and it seems to crank over for ever although it is probably only a few seconds.
Is it possible to fit an electric pump just to initially prime the Dellorto's?

Regards

Brian
Huib Geurink

Priming the carbs

Unread post by Huib Geurink »

A pressure regulator is a passive device and can only reduce the pressure. The Dellorto's have a beautiful spring loaded float needle which results in a smoothly regulated float level when going over bumps or cornering fast. It is however a bit pressure sensitive. A good pressure regulator is recommended. I use the King Fuel Saver which is made in Seregno, Italy like the Dellorto's. Also consider to use Viton tipped float needles.

For the pressure regulator to operate properly the pressure from the fuel pump should be a bit higher than the required pressure. Assuming the pump, the fuel lines and the air inlet into the tank are in 100% good condition, the pressure from the pump may be raised by reducing the thickness of the thermal spacer.

The mechanical fuel pump is a sort of bellow with two tiny valves, an inlet and an outlet valve. Functionally it is exactly like the foot pump used to inflate air matresses. If there is dirt on the seats of the valves the efficiency is reduced.
Once upon a time there was a fuel filter at the bottom of the tank where the fuel is picked up. This copper mesh filter will have turned to dust. Also there is a small fuel filter in the inlet chamber of the pump. These have usually also become ineffective. I solve this by putting a simple plastic fuel filter just before the pump. At the same time I clean the pump thoroughly and replace the hoses by new ones to get rid of any deposit in the hoses. I also blow compressed air through the fuel line to the tank. Remove the filler cap first.
If there is a lot of dirt in the tank, there is nothing to prevent the fuel line from becoming blocked. You would have to put a new filter at the bottom of the tank overcome this. Unfortunately I have not been able to find these. Clean the tank too.

Get yourself a Gunson pressure gauge (about euro 25) or a manometer. Put it in the fuel line just before the carbs and start the engine. The needle should be just inside the green arc (0,25 to 0,3 bar). Vary the engine rpm. The pressure should remain virtually constant (with a pressure regulator it is constant).

If you have a pressure regulator, then connect the pressure gauge also just before the regulator. The needle should be in about the center of the green arc (0,30 to 0,4 bar). If you use the car very seldom, you may increase the pressure of the fuel pump to the end of the green arc (0,5 bar) so that it fills up the carbs quicker. I find the priming time very acceptable with the pressure from the pump at 0,3 to 0,35 bar when everything is in 100% good condition.
The advantage of priming the carbs by cranking the engine with the starter motor after a long time if inactivity is that engine oil is also pumped around.

Of course the startermotor, wiring, battery and dynamo (to load the battery again) should also be in good condition as everything else on a Fulvia.

If you still want to prime the carbs without using the startermotor you may consider inserting a hand pump. These look like a rubber ball. Insert it in the fuel line at a practical low point. Squeeze the ball a couple of times before starting.

If you still want the electrical pump, make sure it does not give more pressure than 0,4 bar if you have a pressure regulator or not more than 0,3 bar if you have no pressure regulator. So far I have seen electrical pumps connected in parallel with the mechanicall pump through through T pieces. I see no reason why it can not be connected in series which saves the T pieces. However, you then want to make sure that they can never operate at the same time. This can be achieved by inserting a relay (operated by the plus wire of the iginition coil) in the electrical supply wire to the pump. It is a good idea to insert the relay anyway (thus also when the pumps are connected in parallel).

Note that the pressure values given are for the Dellorto's. The required pressure for the Solexes depends on the version. The data is in the Data and Specification book which is on the Fulvia CD's available on this site.
Brian Hilton

Re: Priming the carbs

Unread post by Brian Hilton »

Hi Huib.
Thank you for that extensive information, I shall have a look at your recommendations, As for the filter for the Tank, try Omicron as that is where I got one from, not too long ago.

Regards
Brian
Huib Geurink

Re: Priming the carbs

Unread post by Huib Geurink »

Thanks for the tip, Brian. I will contact Omicron monday and order a few.

I did some more measuring of fuel pressure on several S1 cars. Most of the fuel pumps that are for sale nowadays are different from the original ones. To my surprise they all were around 0,35 bar just like the original pumps. Old or new pumps did not matter. Dellorto's run best at 0,25 bar.
Thus it is best to either put a pressure regulator or fiddle around with the thickness of the gasket of the fuel pump. I would go for the regulator. It will guarantee correct pressure if you have to replace the pump or perhaps temporarily mount an electric one. Among the spares I have on board during a long trip there usually is an electric pump.

Huib
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