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Post Number: 1
|Posted on Wednesday, 11 January, 2017 - 02:43 am: |
Silver Shadow SRH 17968 owned and loved since new!
I was wondering if anybody has managed to fit an aftermarket electric radiator fan to a Shadow 1. I have tried to find some space, but everything is so tight, I would have to butcher the grill which I would prefer not to.
I find that in the middle of summer (39 Celcius +) when travelleing very slowly, I seem to get fuel vaporisation, and my aircon (converted to 134) gives up the ghost.
This may be due to R134 being a less efficient a/con gas and the modern fuels having a lower vaporisation temperature. Underbonnet temperatures are frightening!
Anybody have a similar experience?
Omar M. Shams
Post Number: 993
|Posted on Wednesday, 11 January, 2017 - 03:23 am: |
Jabal Tariq (or Gibratar) is not as hot as Dubai.
I stop driving my cars when the temperature reaches 40 degrees C.
The shadow can cope well at 40. It struggles at 45 and higher. A clean radiator and a good viscous coupling is all you need. This assumes that you have not done what lots of people do in hot countries - removing the thermostat. Don't consider running the engine without a thermostat. These cars dont work without thermostats.
R134a is good gas. It should work like mine does here in Dubai.
Does the small fan at the front work?
There is no real need to modify anything - it should all work as long as everything is in good order.
Robert Noel Reddington
Post Number: 1262
|Posted on Wednesday, 11 January, 2017 - 04:27 am: |
Removing the stat on any car is a false assumption and merely proves that the mechanic doesnt understand cooling systems.
Post Number: 1552
|Posted on Wednesday, 11 January, 2017 - 05:01 am: |
I did have a problem when I lived in Nevada (35 - 40C most days in summer) but resolved it with a new viscous fan coupling. The Hayden 2706 is a perfect fit and costs around US $40. If you have any doubts about the coupling on your car I would replace it.
An additional option is to fit a heat sink kit. Introcar sell them for 68 UK pounds. It is basically a very thick manifold to carburetor gasket that helps insulate the carb from the manifold.
I have not fitted one of these kits to my car so cannot give a personal recommendation but did read a very positive report about one fitted to a Cloud 3.
I do agree with Omar, a clean rad and effective viscous coupling should be all that's required unless you are hitting the realms of 45-50C ambient, as Omar does.
On very hot days (40C) I do find starting the engine on my car, when it is already hot, can occasionally cause slightly rough running for a couple of miles. I put this down to fuel vaporization in the float chambers. As the cooler fuel pumps through things quickly return to normal. I may at some point fit the heat sink kit to get rid of this problem.
Post Number: 2379
|Posted on Wednesday, 11 January, 2017 - 07:48 am: |
Old bush mechanic trick:-
If the car has been parked in the hot sun for a while, the under bonnet temperature can be extremely high and the aircon refrigerant gas may not condense when passing through the condenser in front of the radiator due to its extremely high temperature after passing through the compressor. The refrigerant will eventually liquefy once the car is moving and the airflow through the condenser removes the excess heat and the system will then start cooling the interior. The system cooling requires liquid refrigerant to be fed into the evaporator and vapourise to extract heat from the car interior. This problem can also arise if the car is in slow-moving stop/start city traffic and the airflow through the grille is insufficient to liquefy the refrigerant in the condenser - this is the reason ancillary electric fans are fitted to increase air flow [and thus cooling capacity] in these circumstances.
To get around this problem, just use a water hose to wet the condenser from the front of the radiator when starting the car until cool air starts to flow from the vents and then drive the car normally. My experience has been this is the best way to expedite cooling in high ambient temperature situations. If no water is available, another technique was to open the hood/bonnet before starting the car and run the engine at a fast idle [1500/2000rpm] to allow the hot air to leave the engine bay as fast as possible to reduce both the under-bonnet temperature and thus the refrigerant gas temperature whilst drawing maximum air flow through the condenser to condense the refrigerant gas. Once the car interior starts to cool, the bonnet/hood is closed and the car driven normally.
The problem is basically one of heat transfer from hot compressed refrigerant gas to the outside environment to liquefy the refrigerant and evaporation of the liquid refrigerant in the evaporator to cool the car. The efficiency of the process is a function of air ambient temperature, engine bay temperature, air flow through the condensor and, to a lessor extent, air flow through the evaporator. It also helps to set the aircon sittings to recirculate initially to reduce the heat load on the system by cooling already cooled air and once the cabin is at a comfortable temperature, the settings can be changed to allow outside air to enter the car.
I encountered this problem on a regular basis whilst travelling in the Pilbara region of West Australia during the summer when ambient temperatures were always 45+deg C - parking under a tree or sheltering roof was automatic during the day and you always carried 20/40 litres of water and a tarpaulin for safety reasons in case of car breakdown. Fortunately, stop/start traffic was never encountered and you could immediately travel at speeds that provided sufficient air flow for the aircon to start cooling the car. This was before the advent of satellite phones and off-highway excursions outside the range of mine site 2-way radio communication meant the RFDS [Royal Flying Doctor Service] radio network was the only means of emergency communication so you always advised properties along your route of your departure and anticipated arrival times so they could start looking for you if you did not turn up when expected - all properties had helicopters/light planes for stock mustering so you would be found quickly provided you stuck to your route. The main exception were city dwellers "doing their own thing" who didn't advise their travel routes and departure/arrival times. The North-West of Australia is a vast unpopulated and very dangerous wilderness that must be given utmost respect otherwise it will kill you.
Post Number: 2
|Posted on Wednesday, 11 January, 2017 - 09:23 am: |
Thank you all for sharing your excellent knowledge. I will order an isolator gasket for starters.!
So nobody managed to squeeze a booster electric fan into a Shadow 1 huh? Does seem close to impossible to me.
Post Number: 894
|Posted on Wednesday, 11 January, 2017 - 09:28 am: |
Welcome to the forum.
One thing I always recommend is to put a torch ( you will need a helper here) behind your radiator (fan side) and shine it through to the grille. If you can easily see the light shining through all parts of the radiator, your cooling fins will be pretty clean and ok.
If the light is very dull or you can't see it, you will need to remove the radiator and reverse flush/wash (back through to front) the cooling fins until you can readily see through the radiator either with a light, or by holding it up,to the sun.
Don't be tempted to use a high pressure blaster, as you may lay all the cooling fins flat, or if they are old, blow them out all together.
Mild pressure from a hose is usually ok.
Of course, you will also need to be sure the internal cooling tubes are not blocked with scale or grime.
Post Number: 895
|Posted on Wednesday, 11 January, 2017 - 09:32 am: |
As Omar correctly states, if the cooling system is in good order running the appropriate coolant, you should not need any additional help.
I don't think any SSI had auxiliary electric fans fitted to the front of the rad, they appeared on SSII, but I may be corrected here.
Post Number: 1553
|Posted on Wednesday, 11 January, 2017 - 11:39 am: |
Here is the comment from Chris Browne from another thread regards the heatsink kit:
A friend of mine has a 1974 Shadow 1 and for the past few months, after a long run in summer temperatures in the UK, (so not THAT hot!) it was difficult to restart the engine from hot and it gave all the symptoms of fuel having evaporated from the carbs. We happened to spot the ad for the isolator kit from Introcar and thought we'd give it a try. I had a spare inlet manifold with carbs from a Shadow 2 which was already fitted with the thicker isolator. The original isolator on the Shadow 1 was only paper thick. We lifted the carbs assembly and replaced the isolator with the thicker one and the longer centre bolt. Since that home made modification, the fuel evaporation problem has disappeared entirely and we have been having temperatures in the low 30's in the UK lately. It would seem that the extra thickness of the isolator insulates the carbs from the heat of the engine just enough to stop the evaporation of fuel. I presume that was the reason the thicker isolator was fitted as standard on the Shadow 2's.
From Chris, this is a good recommendation indeed.
Post Number: 2190
|Posted on Wednesday, 11 January, 2017 - 12:57 pm: |
With regard to cleaning out radiator cooling fins (or AC unit cooling fins whether on a car or not), the best tool I've found is a regular garden hose with a nozzle that has a pin-spray setting. On mine here in the USA, for several brands, this is generally labeled as the "Center" setting, which has about 6 to 8 really sharp pin sprays. It is absolutely amazing how well these can ream out dirt from small spaces while not ever doing damage to delicate structures at the same time.
If you know that you've got a dirt/dust clogged radiator it's also helpful to give the thing a good wet down followed by a thorough spraying (a garden sprayer works well) with detergent and allowing that to sit and loosen the dirt, but definitely not long enough to dry, before you start the pin-spray blast-out step. If you can use warm to hot water for all of this all the better.
Post Number: 1094
|Posted on Wednesday, 11 January, 2017 - 05:16 pm: |
Here in the UK I find that the flys wasps weed seeds etc can be a prob.
Wise words from patrick "Don't be tempted to use a high pressure blaster, as you may lay all the cooling fins flat, or if they are old, blow them out all together."
However always blow out from the reverse of the cars running air flow.
Useing water from the start can make the debri expand and get hard compact and will get stuck further in the cores IMO.
Omar M. Shams
Post Number: 994
|Posted on Wednesday, 11 January, 2017 - 05:34 pm: |
Cooling systems have no filters.
The radiator is one large filter. All the crap in the cooling system ends up in the radiator and clogs up the narrow tubes. If anyone can put their hands on their hearts and claim anything above a 95% efficiency of their radiator - they are a better man than I. Radiators with 60% blockage are not uncommon. People just dont know until an event like the one described above manifests itself.
gordon le feuvre
Post Number: 151
|Posted on Wednesday, 11 January, 2017 - 07:18 pm: |
It is so easy to remove radiator grille- 3 x bolts visable when bonnet open and 2 x bolts facing up from under bumper. This then exposes condenser and allows detailed cleaning with degreaser/water as opposed to trying to aim hose through vanes of shell. It is amazing just how much fins clog up over years. Ii's a sunday morning job. Also great opportunity to really clean vanes/shell etc. Kept my wife quiet for an hour!
Post Number: 37
|Posted on Wednesday, 11 January, 2017 - 07:28 pm: |
The original fan fitted to early Spirits (I assume the same type was fitted to Shadows) is quite unsuitable for the job. It has a "pancake" motor with the commutator formed from the ends of the windings, so very thin. If it is only running occasionally it might be OK, but airflow through the blades makes it rotate while the car is moving (or parked in a breeze) so the commutator wears out fast. Replacing it with the same type is a waste of money.
Post Number: 897
|Posted on Friday, 13 January, 2017 - 01:45 am: |
Great work Gordon.
I'm sure she did a great job.
Post Number: 130
|Posted on Tuesday, 23 May, 2017 - 03:27 am: |
Just to give this thread closure:
Thanks to all for your knowledge and advice - Omar, Robert, Geoff, David, Patrick R, Brian, Patrick L, Gordon and Alan.
I have followed all of it:
Installed the isolator gasket - for good measure
Cleaned the radiator grills water and aircon - they were actually OK
flushed radiator and cooling system - rusty water but no sludge
Changed thermostat - for good measure
New NON ORGANIC antifreeze
cleaned pwr steering cooler whilst at it.
Changed viscous coupling - the real culprit!
You were right in that the cooling system is over engineered and works extremely well so long as everything is in working order.
My main problem was an intermittent fault with the viscous coupling. It was something that I did check, on various occasions, but was always apparently working well. An exhaustive check by covering and uncovering the rad over 40 mins or so, showed that it would occasionally not engage properly - eureka moment.
In Morocco, 5 up with luggage and full aircon, up and down steep hills- cool as a breeze.
The only thing that failed was the high pressure flexihose to the self levelling suspension (covered in another thread).
Thank you all again
Post Number: 1711
|Posted on Tuesday, 23 May, 2017 - 05:16 am: |
You have done a great job there. Thanks for the update.
Robert Noel Reddington
Post Number: 1441
|Posted on Thursday, 25 May, 2017 - 04:12 am: |
This is a good example of fixing what isnt broken and treating the symptoms rather than the cause.
In this case the job was caught before it got done wrong.
A job done properly will last I suspect that a booster fan wouldnt have worked because the engine driven fan shifts a hell of a lot of air.
So well done Patrick.
I always remember that the car definitely worked properly when new so something is faulty and needs replacing not modifying. And remember the first owner probably just drove the car and barely looked under the bonnet.
Post Number: 134
|Posted on Thursday, 25 May, 2017 - 07:38 am: |
Thanks Geoff, Robert.
Problem was that when I could find nothing wrong with the system, I presumed it was the modern fuels and the 134A aircon gas which were the only two "possibles" left!