Update time.
NOTE: This update covers the last of the modifications, it is also a sum up of everything done thus far so is quite lengthy so grab a coffee and a sandwich and get yourself comfortable, I welcome any and all comments/observations/questions.
As per my last post I was looking to keep the 80 C (176.0 F) switch as it worked as near perfect as could be expected except for the hysteresis in the switch on/off temperatures.
This was explained in my last post but the issue is once the fan is on it was necessary to lower speeds to around 70 MPH and switch off the A/C to get the coolant cool enough to switch the fan off. I needed to increase airflow through the condenser/radiator combination, this has been spoke about before in previous threads about cooling problems by other contributors, and in fact the 80 left the factory with pieces of sponge strategically placed around the radiator assembly, this prevents air bypassing the radiator core. I wanted to try something that would due to time constraints (five airport runs in 5 days and another two by the weekend), be quick and easy to install and if it did not work could be pulled out at the side of the motorway if need be.
The holes in the front bumper are definitely there to aid cooling and not just to make it look pretty, if you look closely enough they are shaped to allow air into the lower radiator area, this it seems was deemed to be necessary by Toyota along with the optional electric fan to help with high temperatures. Unfortunately there are large gaps below and between them and the radiator. So whilst closing gaps around the radiator I plugged the bumper vents/condenser gaps up as best as I could, if it was to be done properly you would have to remove the bumper, fabricate the baffles and then refit, I simply did not have the time to do that. Also of note, the typical European number plate actually covers around 25% of each of these openings, I could have simply lowered it down but that would have left an edge of the plate exposed where the lower part of the bumper folded under, easy for the brushes of the car wash to pull off, so I thought an easy and tidy way out would be to have a plate made up similar in size to the one used on the front of the Alfa Romeo, much shorter than the standard one, this should fit right in between the cooling slots, tomorrow (Saturday) will see me in the shop
Back to the gaps, I had thought about heavy card, aluminium/tin sheeting but, whilst wandering around the various stores I came across the perfect material..... polystyrene! Advantages are it is easy to cut/squeeze/wedge into place, easy to remove if need be and if I was stupid enough to bump into something it would simply fall apart as opposed to cutting through the radiator or condenser. About one and half inches thick, long and wide enough to cut to shape between the bumper and the lower front cross member, a few quick cuts with a modelling knife and some duct tape had most of the gaps around the two components sealed up. I had blocked off and filled as many spaces as possible without dismantling, I could not cut a thin piece of the polystyrene to go in the gap between the header tank as it would have fallen apart, I have a plan for that tomorrow. OK, it is now Friday and off I go on another four hour round trip with my polystyrene and duct tape ‘baffles’, similar time of day with similar temperatures to earlier in the week, and of course I kept around the 80 MPH most of the time. The route taken today meant climbing my favourite test hill, and low and behold a measurable improvement! The first fan speed came on later than normal but of more importance the second speed did not come on at all! We already know the first speed comes on at 80 C (176.0 F) and we know the second speed comes on at 87 C (188.6 F) which was happening in my previous tests, this is clear evidence that even a hasty blocking of the spaces around the radiator will lower temperatures by at least 7 degrees C (44.6 F), a credible improvement with minimal outlay for testing purposes.
The rest of the journey was pretty much as per earlier in the week but, the first speed fan definitely took longer to come on and was not as sensitive to gentle increases in workload, when it did come on it would go off sooner, the increased air flow bringing the temperatures down quicker. I say bringing temperatures down but they are really not high at all, I am quite mechanically sympathetic when it comes to heat/lubrication and thus my quest to mimic the OE set up as near as possible is being a little complicated by the switch temperature variations but I am sure I am close...very close but, I am still seeing the fan come on, I would also guess I am trying to keep the engine temperature a little too low?
So to this morning (Saturday) and I am at the shop to have a shorter number plate made up, easy huh......yeh right!!
The guy behind the counter said no way! He explained, "sorry sir can’t do that, you have to apply under the ‘homogolado rules". Arrrrrrgh!!!!!! So that is out of the question, if I fit it I leave myself open to a fine as would the shop owner for breaching the fabrication rules. I will have to lower the standard plate to clear the holes or, if I can have a plate without the ‘Euro’ logo this will make the plate a little shorter so I need to investigate that avenue.
I also picked up some door sealing rubber, the stuff that fits over the frame edge with a nice squidgy rubber tube that conforms to different shapes, it is almost identical to that used around the top of the battery enclosures and seals against the bonnet to help with battery temperatures. I fitted a piece along the top of the radiator, the gap to small to fit polystyrene, there are gaps down the side of the radiator that were not accessible with the door edging, ideally the radiator needs to be removed to fit the edging moulding around it to make it truly effective, something for a later date when the car is not being used so much. And talking about radiators, mine is not a Koyo or any other known brand name, the guy in the shop (March 2010) told me it was a well made plastic/aluminium radiator for my model. I had only just purchased the car at the time the radiator condition was noted to be very poor, and I had a ferry to catch to get to Spain and grabbed the first radiator I could get my hands on. The replacement is still in there unless when reading further on you see different, I suppose it could be changed for a better version, not too concerned at the moment though, I simply added that to prove you do not need to have the most expensive ‘all singing all dancing’ item out there to achieve effective cooling, no doubt a better quality and heavier duty version will help keep temperatures in check but thus far all is looking good with a basic stock unit. I also took advantage of having a bright lamp with me and shone it through the radiator/condenser fins to check all was clear, easy with an electric fan.
Whilst checking my handiwork I remembered seeing a picture many moons back of an 80 that had two large spotlights, the grill and the bumper removed at the same tine and you could clearly see the lamps had been blocking the airflow by the shading of dust and bugs on the condenser face, so I then turned my attention to my two horns. These are not the original, they are two quite large (and loud) round units I had fitted when the originals started acting up, they were clearly obstructing some of the passage of air to the radiator, for the moment I loosened the mounting bolts and rotated them up towards the slam panel and almost out of the airflow. Next step was to change the first fan speed switch for the alternative 82 C (179.6 F) ON and 74 C (165.2 F) OFF, I know this is an increase of only 2 degrees C (35.6 F) but this is about slowly homing in on the optimum set up.
That brings me nicely to Saturday evening, six people on board with plenty of luggage, I am sure the girls simply screwed a handle to the side of their wardrobes and called them cases! I just managed to squeeze it all in and away we went to the airport again, and straight away another improvement, despite the switch for the first fan speed needing just two degrees of extra heat to activate, the fan did not come on....not once. I have to allow for the fact that the temperatures had dropped towards the afternoon from the 38 C - 41 C (100.4 F - 105.8 F we have been seeing to a cooler 33 C (91.4 F) The temperature gauge also indicated that not only was the engine running cooler but there was less overall movement, remember the standard gauge has been modified to recognise true temperature variations within the engine. Despite running at 80 MPH for most of the journey on the way there was not much movement from the gauge, so that is good, on the return journey I run up to an indicated (alleged) 110 MPH for a short period of time the amount the needle climbed was minimal probably two needle widths but still not enough to trigger the fan switch. I always say ‘make alterations/modifications one at a time’ so you can measure ‘real world’ improvements or failures but, I broke my own rules by:
Increasing the fan switch ‘on’ setting.
Blocking the gap around the top of the radiator.
Moving the horns out of the airflow, three modifications in one go. This means I cannot tell which one made the most difference, the truth is I guess each made a small contribution?
Adding the fan switch may seem odd as it would not affect the early climb in temperatures but, what if when the fan comes on early, and the airflow from moving at speed was now being impeded by the fans rotation? This may explain why I had to lower speed slightly and on occasions switch off the A/C?
As I am now close to completing the testing of the electric fan installation, with just minor tidying of wiring and fitting of the dash indicators (still waiting on LED’s) I will draw the following conclusions:
Without a shadow of a doubt the electric fan (1st speed) matches the the stock offering at idle, never running for more than 22 seconds before shutting down, remember the outside temperatures inland during this test were 44 C (111. F), I have never seen the second speed come on during idle, the engine simply does not get that hot period.
The A/C is more efficient at idle, the A/C compressor able to stay ‘engaged’ longer as the electric fan draws more heat off the condenser, thus cooling the interior quicker from first start up, and there is less 'rise and fall' of interior temperatures as the compressor stays engaged longer than when the condenser is being cooled by the standard VC driven fan.
The 2nd speed of the fan easily outperforms the viscous coupling at idle, I have little doubt about this, even assuming the fan clutch was fixed (which it never is) the slow 600 rpm speed of the engine means the fan is probably turning around 1,800 rpm, a comparable size fan turning at around 3,000 will match the VC in performance but, see the caveat towards the end of this article about simply bolting on a fan. As a test with the engine idling if I switch on the AC the 2nd fan speed comes on within 4 - 5 seconds? Remember the electric fan is responding to the pressure change inside the A/C system, there is no way the viscous coupling is going to respond that fast, this in effect means the A/C again is quicker at cooling the interior. With the A/C on and at speed the fan is of course off but, as forward motion of the vehicle slows and approaching speeds of around 25 - 30 the A/C line pressure starts to rise and the electric fan comes on instantly, this exposes the condenser to strong airflow more or less as the vehicle comes to a stop, the stock viscous coupling has yet to warm before it starts to pull any significant air through the condenser, the result is again felt with the more even and efficient A/C function.
To cooling.
I had always assumed on all vehicles that the movement of air at speeds over about 20 MPH was enough to cool the engine....which it 'normally' is but there is a caveat at work here as well.
As the speed increases thus does the workload which is obvious but, many people do not realise how much the workload increases, in fact it is IIRC around a factor of eight? So if we assume the airflow at say 20 MPH is adequate to cool the engine then if we move the speed to 40 MPH i.e.8 times increase in the workload then the airflow must increase through the cooling system by the same amount. There are of course variables, I am no expert in airflow dynamics but even I can see the breeze block shape of the 80 is going to be very hard work to move at my ‘controlled’ 80 MPH tests. Years ago I observed my V12 Jaguar with twin electric fans, got hot enough at speeds approaching 140 MPH (French trip to the Le Mans 24 hour race) to bring on the fans, the A/C having been removed on that car as it was used in ‘unofficial’ competition so this was purely a result of cooling system function, the Jaguar looking and undoubtedly was more aerodynamic that the 80. If my figures are wrong on the workload please feel free to correct me I am getting old. OK, this means that as much air as humanly possible hitting the front of the 80 must be utilised and directed through the condenser/radiator. I would surmise that at speeds over about 70 - 80 MPH the VC fan detecting the heat coming from the radiator (increased workload) starts to drive the fan with more force but, not necessarily moving enough air to cool the engine but, by creating a negative or lower pressure signal behind the radiator, thus allowing more cooling air to enter the core as opposed to going around it, this is me surmising here as mentioned above I am no expert. My own fan triggering at speed indicates that this theory could in fact hold water however, I am sure there is no way my fan could move as much air as the vehicle could at 80 MPH, so why do they come on and manage to cool the engine at that speed, lower air pressure behind the radiator? Are bonnet vents more of an advantage than we realise?
My quick and somewhat amateurish attempts of plugging the gaps around the radiator seems to have netted excellent results at speed, add in that any obstructions will disrupt airflow aimed directly at the radiator, we are all familiar with what happens when you put your hand out of the window but with the door mirror shielding it from the airflow when driving at speed, the force your hand meets when moved out from the protection from the force met is quite dramatic, this very force IMO is what is being blocked or at least disrupted by large spotlights that many owners fit, and of course the higher mounted winches, is it a coincidence the the Toyota OE winch is narrow in design and mounted low down between the chassis rails out of the airflow?
OK, to the way forward, my plans are as follows:
Over the next four weeks this area of Spain will see it’s highest temperatures of the year so more testing wherever possible, I hope to make a run to 'Seville', known as the 'frying pan of Spain' 48 C (118.4 F)!!
Permanently move the horns away from the radiator area.
Purchase a new fan motor, my testing is with an unknown mileage second hand one.
I ‘may’ return to the lower temperature switch having apparently fitted it prematurely to be decided upon.
Fit the fan/shroud combination a little tighter to the radiator, very close now though.
Refit the radiator while ensuring the moulding to block escaping air as much as possible is used to good effect.
Remove the bumper (it has a small dent anyway and needs replacing/repairing) and make the baffles out of something a little more easier on the eye, perhaps with aluminium or even fibreglass so they can fitted/removed with a couple of self tapping screws.
Resolve the number plate blocking the air intakes on the bumper.
Fit the low water sensor in the top hose.
Complete the dashboard warning lights/buzzer install.
Consider a digital controller but way down the list at the moment, research shows they are not as tough as the manufacturers would have us believe.
To all of this I would add, on the 80 you cannot just bolt in an electric fan and expect it to work, it did on my old Granada, Capri, Jaguar, Discovery (used as a DD AND competitions) but not on the 80, I mentioned the caveat earlier to such a simple assumption. Some have tried and from comments received just as many have failed, I am unsure why but suffice to say it is possible. Manufacturer's have for many years recognised the advantage of fitting an electric fan but, it was during the design stage, i.e. Jeep running their fans from power steering pumps was an early idea, Land Rover recognising the viscous coupling performance could be improved by fitting an electric ‘lock up’ so the A/C would be better at idle and finally Mercedes running an electric system in their ML class 4x4, it can be done. For it to be effective and reliable you need to be careful with your fan choice, (so much BS out there about fans it is untrue!), rugged switching mechanisms, decent wiring, decent batteries and an alternator capable of matching the amperage needed to run a powerful fan fast enough to cool the engine.
Unless anything significant happens then the next post related to this electric fan install will simply be a couple of shots/explanation of the dashboard indicators and shots of the permanent baffles I will fit later in the year.
Finally, some of my faster runs on Friday and Saturday saw speeds (allegedly) of 100 - 110 MPH, most of the time at 80 MPH, and over the test the LC returned 21.98 MPG averaged out over 800 miles
, you guys across the pond are probably not interested but I thought I would throw it in anyway.
Thanks for your time reading and 'likes' of this thread, they are appreciated.
Regards
Dave
the car only having stood for three days. The normal mode is the two batteries are parallel when driving/parked up, the alarm and other parasitic drains coming from both batteries. When the battery voltage starts to drop the Blue Seas isolator does it's job and splits the batteries. The right hand battery then taking over alarm duties, the left hand being saved for the starter. After a week or two of standing it is not uncommon to find they have been separated but the voltages are still very close to each other showing 100%, this morning showing the right hand one down to 75% within three days raised an eyebrow.
The batteries have been in there 4 years and were ridiculously cheap for marine use so have done their job. 
