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I am not a very experienced long time Lagonda man (only ten years now) but engineer and I think much of these overheating problem (see also the M45 stuck in London traffic on the way to “the one show”, equipped with electric fan) is due to restrictions in water circulation. I think this goes in line with most of the previous posts on this topic.
I had this on my V12. The car would boil at low revs e.g. driving on the highway and then get into stop and go in a traffic jamm or at the end of a mountain climb. The water temperature at this point still beeing acceptable. Electric fan or new radiator does not help much in this case because the water is still cooled well but does not reach the hot areas at sufficient rate. The reasons are:
1. Problems in the design at first (was still ok when the car was new)
2. Water pump with less performance due to corroded rotor
3. Corroded water passages plus lime depositThe cure is: solve the above 3 problems, at least the last 2, especially if you do a complete engine overhaul. Or put an electric water pump as temporary cure for the problem. I did the last (in series to the existing water pump), I switch it on when I anticipate it will be needed (slowing down after strong going, traffic jams) and it works. And if I forget to switch it on then I have the boiling, quite reproducably.
Things would be different if the true water temperature (measured with a correctly reading device) goes to high, then I would go for radiator clean, electric fan, new readiator.
I prefer water as coolant, when it boils=evaporates it cools extremely well and this boiling indicates the problem early. I will not try waterless coolants.
The radiator does not look like 16/80 but is hidden behind a stoneguard. In the film “The adventure of Johnnie Waverly” the car is braking down (Hastings later finds out it was because he ran out of fuel). He opens the bonnet and tinkers around with the carburettors and you can perfectly see the 2ltr engine.
No Lagonda appeared in the show yesterday. Received the Information from Colin that the car did not make it to the show because they got stuck in London traffic.
This job took me much longer than I thought but finally the solution and explanation for the problems:
On the sketch the upper diagram shows how an original (3 connector) tank sender (a potentiometer) would have worked with the still original fuel gauge in my car. The fuel gauge, when connected to 12V and ground only, shows half full. The signal from the sender is between negative (ground) and +12V. (Works accordingly on cars with positive ground). This pulls the needle up or down accordingly. It seems all modern available tank senders only have 2 connections: one is ground and the second signal, no connection to +12V. Might be for safety reasons not to have power from the battery directly on the sender if it shortcuts by fault.
The sender I found in my car is of the modern type: a tunable resistor (potentiometer) against ground only. This would work fine with other fuel gauges like the one from MGA and other cars but not with the one in my Lagonda. Connected directly to the original Lagonda fuel gauge it would display from half full to empty only when it goes from top to bottom in the tank. But there was another problem with this sender: mechanically when in low position the tank would be still half full because the drop arm is so short and a longer one can not be fitted because the fuel tank is divided in compartements leaaving not much space for the sender drop arm. And the tank was not grounded properly, so the signal would be erratic.
The solution: I found a universal tank sender where the potentiometer can be adjusted to sit in the middle of the fuel tank. This allows to have a total travel of the 26cm needed with a drop arm length of only half of that. It came with a fuel gauge that would work fine with it but looks to modern (see parts not needed on the right side of the image “fuel gauge replacment”). So it needed an electronic that converts the signal to fit to the old gauge. This is shown in the lower part of the sketch: an operation amplifier with adjustable gain (defined by the 100k resistor and 10k potentiometer). The gain is set once to match the sender unit to the fuel gauge reading. The current through the sender is only 2.5mA and limited by the 5k resistor. I prefer to have low currents in the tank. I also have put a fuse of 32mA in the connection to the tank sender, just in case something goes wrong. I also had to make a new holding plate for the new sender because the one that came with it has 5 holes not six like on my fuel tank.
It works fine tested on the bench, the reading should now quite well correspond to the real fuel level. Also works in the car but I have not tested it yet under real driving conditions.
I will not tell you how many hours this took me but I now understand why so many drivers are using a wooden dipstick to check the fuel level.
A Lagonda friend has sent me this photo of the sender unit on his 3ltr. It has 3 wires connected! I assume it is +12V, ground and the signal to the gauge. With such a sender unit my gauge would work correctly. My conclusion so far: the gauges like on the MGA are standard and work with a sender unit that has only the signal and ground. And there are the (more unusual) gauges like on the 2 and 3 ltr Lagonda (and may be others) that require a different sender. Somebody has replaced the sender of my Lagonda with a new (wrong) one. If nobody has other solutions or can tell me I am wrong, I will probably have to built a little eletcronic converting my signal to the one needed.
I mentioned I had recently trouble with the magneto ignition (BTH GA4) on my 2ltr LC. During a drive it failed and only gave some rare misfiring. I did put my spare coil ignition in instead (I now also have the adaptor piece to be able to use the clamp of the magneto without change). It has no advance-retard options but worked fine to bring me home. The complete unit (without the distance piece adaptor which I made from wood and painted black) is supplied by club member John B29.
Later with the magneto on the living room table I found the simple and stupid reason: the contact breaker distance had become to small (below 0.2mm) and the cam-ring which is operated by the advance-retard lever had some play and probably had tilted a bit (a fraction of a mm). So the spark was erratic. Bringing the gap back to 0.3mm (12 thou) it is working perfectly well again. When playing with the magneto, I saw that the spark when turning it slowly by hand was much stronger than from the coil ignition. I like the magneto and keep the coil in the car just in case.
Moved your post to the right section. Unfortunately flat broke is completely right about value. The value of the car is about the value of the engine plus gearbox. Value depends on the exact condition of the engine, completely restored with new parts during the last decades or only still running in 2000 and still free now ? The probability that it sells in parts is high. SRD knows the market best.
The part indicated in the image after a second inspection was found to be only some slight restrictor, it has not a full bore but is half open but a wire can be pushed through. And it was not the reason for the whining sound.
I also checked the axial alignment of the exhaust camshaft, first trying with the adjustment screw on the front of the “P” plate, with no effect. Then I removed and refited the brass gear which drives the rev counter on the rear side of the exhaust camshaft. (On other 2ltrs this sits on the inlet camshaft and there is a thrust pad on the exhaust one instead). But at the same time I tightened some screws on the carburettor flanges. The noise was gone ! But I can not tell which of the two was the reason. Club member John (B29) helped much again with suggestions. Other discussed source of a whining sound was the dynamo.I have put it back in without mesh so far. I increased that one hole by about 2mm in diameter, then it is about the inner diameter of the suction tube to the oil pump. I asked a company for a quote for a custom built metal edge filter tube (as an alternative to a simple mesh) with 0.2mm gap (as an example), this would cost 135 EUR per piece when ordering 3, quite reasonable price. But finally I decided it worked well before without and I might improve for the worse. At the moment I have to reduce the spring of the oil pressure relieve walve a bit (pressure cold with a 20/50 oil is 55psi and when hot in fast idle above 40)
Dear oakley, yes please mail it to me, always good to learn, you also can attach it (like a photo but as pdf) to your post if it is small enough (<200kB)
I was looking for a 2 or 3ltr LC for a long time and I fell in love with this one (especially the red leather..) compression problems or not. There was quite some work to do on the cylinder head and I was very happy that a good friend and Lagonda Club member did this for me. The car came with 2 cylinder heads, the one mounted is downdraught but the standard one came with the car. Both needed new seats, valve guides, valves etc. There should be thimbles on the valves which were missing too. Putting them in changes the timing so this had also to be redone (front cover of engine off). It runs good and strong now, with good oil pressure. There will be some more little things to do and you will certainly find now some more contributions in the 2ltr section !
Spot on Colin ! 110k for the barnfind M45
the other 2 Lagondas at this auction were a 2l Continental with quite some work to do, incorrect front wings, estimated 45-55 and reaching 46 (the barnfind dust and rust was missing to reach more) and a very nice Rapier supercharged Ranalagh bodied tourer stopped at 40k (estimate 50-70). May be the seats looked to new..
Conclusion: barnfinds sell well at auctions
Really surprising ! must have been somebody with the initials F.L.D.
Picture has been removed now, wait and see how it really looks
I am no specialist in magnetos but you can remagnetize the magnets to bring them up to old strength (that is what I would do) and I think your magneto service workshop should be prepared for this. Here is one company I found on the internet, there are certainly many more: http://www.brightsparkmagnetos.com/services/index.htm. You see this remagnetizing job on their list and it costs 18GBP. Certainly your magneto service will check the coils and rewind if necessary.