Thread: Why Mr Lucas?

Excuse me Lionel, you're addressing the manufacturer contemptuously with lack of respect..

The correct form of address is: His Royal Highness Joseph Lucas Prince of Darkness!

Hi Lionel,

The other question might actually be "Why not?". When looking for a power source that is only on when the ignition is on then it is probably not a bad place, one less wire through the firewall. I would be tempted to add a modern touch with one of the automatic cutout switches that will turn the pump off if the engine is not running and maybe an individual fuse but apart from that it doesn't matter where the power sources from.

Cheers,

TimJ.

Also it should be 'why Mr Land Rover'.
Lucas provided the parts but I'm not sure they would have been involved in the wiring layout.


Colin

Originally Posted by Timj

Hi Lionel,

The other question might actually be "Why not?". When looking for a power source that is only on when the ignition is on then it is probably not a bad place, one less wire through the firewall. I would be tempted to add a modern touch with one of the automatic cutout switches that will turn the pump off if the engine is not running and maybe an individual fuse but apart from that it doesn't matter where the power sources from.

Cheers,

TimJ.

Hello Tim,

The wire from the coil to the fuel pump siphons away sparks from the coil to the distributor to the spark plugs. It may not take much, however I like all the sparks from the coil being dedicated towards making the engine work. Oh plus there is no relay in the system and no form of turning off if there is an accident.

It is like they did a count of the posts on the ignition switch and could not add another, so they stole power from somewhere else.

The hotrod circuit also has the issue that the engine needs to have full oil pressure before it turns the fuel pump on. If the car is not used for some time it could take a lot of cranking before the oil pressure reaches the correct level to operate the fuel pump.

The options seem to be either a kill switch on the dash or a tachometric relay that are used in LPG fuelled cars.

Kind Regards
Lionel

Originally Posted by gromit

Also it should be 'why Mr Land Rover'.
Lucas provided the parts but I'm not sure they would have been involved in the wiring layout.


Colin

G'day Colin,

I take on board what you say. I was going to write the title as, "Why Mr Leyland" since it is a Series 3. Then I thought of the Prince of Darkness - Mr Lucas. I am sure the two talked together and conspired in their plot for engineered obsolescence somewhere along the track.

That's right wheel in the Conspiracy Theory model, when things like logic fail. Especially since it was through my own inattention to the full schematic diagram that I disconnected the circuit from the ignition to the coil in the first place anyway

Kind Regards
Lionel

Originally Posted by Lionelgee

Hello Tim,

The wire from the coil to the fuel pump siphons away sparks from the coil to the distributor to the spark plugs. It may not take much, however I like all the sparks from the coil being dedicated towards making the engine work.

Rubbish! Neither the ignition nor the fuel pump draw high currents, and if the wire size is adequate there is no problem whatsoever in this layout. Since the pump and the coil are on the engine side of the firewall, there is a good reason for doing it that way.

Oh plus there is no relay in the system and no form of turning off if there is an accident.

Ignition switch turns it off - as would happen if there were a relay. Adding a relay is adding another failure point for no good reason. G-sensitive switches or relays to kill electrics after an accident are something that was added to car designs many years after the Series 3 was designed, in fact, long after production of it stopped. Expecting a car designed in 1970 to 1990 design features is just plain silly.

It is like they did a count of the posts on the ignition switch and could not add another, so they stole power from somewhere else.

Using a different switch for the six (the four does not have an electric pump) would make even less sense.

The hotrod circuit also has the issue that the engine needs to have full oil pressure before it turns the fuel pump on. If the car is not used for some time it could take a lot of cranking before the oil pressure reaches the correct level to operate the fuel pump.

One of the advantages of the electric pump is that it will fill the carburettor before you even start to turn the engine - can be an important factor if the battery is not too good or it is very cold. Perhaps a case for a kill switch, but I never even thought of it in Landrovers I have owned with electric pumps.

The options seem to be either a kill switch on the dash or a tachometric relay that are used in LPG fuelled cars.

Kind Regards
Lionel

One of the contributors to the decline of UK motor manufacturing was that starting during the 1940s Lucas either drove out of business or bought all of their competitors, by producing products that were cheaper (and nastier), thus getting the contracts with the major manufacturers, so that by the 1960s manufacturers had no choice but to use their products, make them themselves (not practical except for companies like Ford and GM), or import them (not practical with the protection then used in Britain).

It is probably lost in the mists of time just how the electrical system design responsibility was shared between Lucas and Rover/Leyland, but my guess is that most of the design was by Lucas, especially since it involved a change from the generator used in Series 2a to the alternator used in Series 3 (and also in 2a six), which Rover had very limited experience of.

John

Since the pump and the coil are on the engine side of the firewall, there is a good reason for doing it that way.

Hello John,

The electric fuel pump in the 2.6 litre is not on the same side of the firewall as the coil. The fuel pump is located very close to the fuel tank. This is in accordance with the recommendations of manufactures such as Facet electric fuel pumps. Accessed 20th August 2014 from http://www.facet-purolator.com/cube-fuel-pumps.php "mount the pump close to the fluid or fuel tank and below the liquid level".


Relays may provide a source of possible failure and they also supply a less impeded supply of current to heavy draw things like the headlights and the starter motor while only using a small current via the ignition switch itself; or their dedicated switches such as Part number 575383. I have already had to replace the indicator horn stalk because the horn burnt out the wiring when the previous owner had the vehicle. I will be fitting horn relay to protect this from happening again. It is also a case economics: pay as little as $16.85 (AUD) for a genuine Bosch relay - [ame]http://www.ebay.com.au/itm/GENUINE-BOSCH-12V-30A-SPDT-STANDARD-5-PIN-RELAY-0332209150-/141143196985?pt=AU_Car_Parts_Accessories&hash=item 20dcca4539[/ame]

or pay $120 (AUD) + postage for a Land Rover Series 3 Indicator Switch - [ame]http://www.ebay.com.au/itm/Land-Rover-Series-3-Indicator-Switch-Lucas-575383-Blinker-/200994105498?pt=AU_Car_Parts_Accessories&hash=item 2ecc2ea89a[/ame]. The same previous owner rigged up a floor mounted dimmer switch because the original circuit burnt out. I also want to fit driving lights and I will be fitting relays too.


One of the advantages of the electric pump is that it will fill the carburettor before you even start to turn the engine
The description in the hotrod link that I included previously (http://www.how-to-build-hotrods.com/...fuel-pump.html) states that, "The switch will stop the pump whenever the oil pressure in the engine goes away. So, whenever the engine is off, the pump will turn off automatically. This suggests that with the engine off there is no oil pressure and the fuel pump will not start. Within the example presented in the article,this unfortunately removes the advantage of an electric fuel pump wired via the ignition switch/coil.


I would prefer to be able to turn off the fuel quickly if I was in an accident or a fuel line split. Ignition switches can fail so having a full dependency on the ignition switch/coil to turn a pump off makes me uncomfortable. Hence a number of non-ignition switch dependent alternatives such as a kill switch.

You can call me silly for valuing the life of my passengers and myself. To do so I will build in as many redundancies for safety in a vehicle that I can. These are things that can be done without detracting too much from the vehicle. I also upgraded my Series 3 diesel from a single circuit to a dual circuit brake system. I upgraded from 4 cylinder to 6 cylinder sized brake shoes and backing plates. A single circuit brake system may never fail, I would still prefer to have the dual circuit system if things happen to go wrong.

Kind Regards
Lionel

Originally Posted by Lionelgee

Since the pump and the coil are on the engine side of the firewall, there is a good reason for doing it that way.

Hello John,

The electric fuel pump in the 2.6 litre is not on the same side of the firewall as the coil.


Depends on when the vehicle was built - suffix 'A' had the pump mounted on the firewall in the engine compartment unless I am mistaken, which may suggest why power was picked up in this area.

Relays may provide a source of possible failure and they also supply a less impeded supply of current to heavy draw things like the headlights and the starter motor while only using a small current via the ignition switch itself; ...
No arguments at all - and headlights in particular are a place where Landrovers should have introduced relays very early, and horns as well, although I must admit I have rarely heard of horns being a problem. But the fuel pump is not a high power device like any of these.

One of the advantages of the electric pump is that it will fill the carburettor before you even start to turn the engine
The description in the hotrod link that I included previously (Electric Fuel Pump: How to Do It Right) states that, "The switch will stop the pump whenever the oil pressure in the engine goes away. So, whenever the engine is off, the pump will turn off automatically. This suggests that with the engine off there is no oil pressure and the fuel pump will not start. Within the example presented in the article,this unfortunately removes the advantage of an electric fuel pump wired via the ignition switch/coil.


I would prefer to be able to turn off the fuel quickly if I was in an accident or a fuel line split. Ignition switches can fail so having a full dependency on the ignition switch/coil to turn a pump off makes me uncomfortable. Hence a number of non-ignition switch dependent alternatives such as a kill switch.

This is your view, but I suggest that most owners value more highly easy starting and reliability. And it is hardly fair to criticise the design of a 1960s electrical system because it does not conform to twenty-first century hotrod standards. Do you know of any other 1960s designs with this feature?

You can call me silly for valuing the life of my passengers and myself. To do so I will build in as many redundancies for safety in a vehicle that I can. These are things that can be done without detracting too much from the vehicle. I also upgraded my Series 3 diesel from a single circuit to a dual circuit brake system. I upgraded from 4 cylinder to 6 cylinder sized brake shoes and backing plates. A single circuit brake system may never fail, I would still prefer to have the dual circuit system if things happen to go wrong.

I agree entirely that all these are eminently reasonable upgrades, but I do not agree that an oil pressure operated switch on the fuel pump is in the same league as these. And I particularly disagree with criticising the original design on these grounds. Heaven knows, there are enough other things to criticise about the electrics! But go ahead and do it on your S3. As you say it will not be detrimental to it, as long as there is a switch to bypass it to aid starting.


.....

When the Landrover was originally introduced, there appears to have been a conscious effort to keep the electrics as simple as possible. I doubt this was a cost decision, but rather to simplify maintenance and repair and to increase reliability. This extended to almost no fuses!

Unfortunately, expected and mandated electrical gadgets multiplied over the years and were more or less patched on to the earlier simple electrics. By the time the Series 3 was introduced this had resulted in what was conceptually a patchwork electrical system. It should have been redesigned from scratch, but with Landrover being the only profitable part of Leyland, and treated as a cash cow, it did not happen. The 110 did get the system redesigned, although still with a number of shortcomings (still Lucas!).

John