GrahamB

I have never used a fuel supply regulator but this reminds me of a problem we had with a regulated water supply. The equipment needed a supply pressure of 15 psi which was controlled by the regulator. However, when the equipment was turned off, a slight leak in the regulator allowed the downstream pressure to gradually increase upto mains pressure. When the equipment was turned back on, the flow was much greater than the leakage so the pressure returned to 15 psi. If there was a slight leak in the fuel regulator, on stopping the engine, the pressure on the needle valve would slowly increase to the residual pressure in the pump caused by the return spring acting on the diaphragm. This could possibly cause a couple of cc of petrol to flow into the carb. May be relevant if all other causes are eliminated.

My understanding was that modern vehicles had to use approved, E Marked, components including light bulbs. Older vehicles (pre 1986?) could have non E Marked components fitted as they were manufactured before the E Marked regulations were in place. However, older vehicles must still meet the MOT headlight beam cut off requirements, I know as my car Spitfire failed after I adjusted the fit of the bonnet. In theory, I can see no problem with fitting good quality LED headlight bulbs as long as the beam pattern is still acceptable and does not cause dazzle. As previously stated, incorrectly adjusted bulbs of any description can cause dazzle. To continue with the drift, modern peat free compost is usually rubbish and very variable as they use anything that is available at the time. Fortunately it is only half a mile to a local stable.

Reminds me of a friend who had noises from the rear suspension as he drove along. Up on ramps with the hand brake firmly applied, nothing could be found. Turned out to be the slack hand brake cable hitting the boot floor but only apparent when the brake was off. Could there be something slack in the cable or choke mechanism that resonates at a certain engine speed? Again, just fumbling in the dark as the most obvious causes have been eliminated.

The previous post relates to an alternator. If you still have a dynamo, these rely on residual magnetism in the coils to activate the charging system. A relay within the regulator box then closes once the generated voltage exceeds the battery voltage and extinguishes the ignition warning light. Therefore, with a dynamo system, the battery will still be charged whether it is a filament bulb, LED or even missing.

My son was having a problem with the instruments on his Focus so drove with one of the harness plugs disconnected. Started as normal but came to a halt after a few tens of miles as the battery was completely flat. The disconnected circuits included the ignition warning light so there was no current through the bulb to activate the alternator. It may only require a very small current to activate the alternator so you may get away with a LED but there is no guarantee. However, after studying the in-built regulator circuit, if the ignition light, be it a filament bulb or LED, goes out, then the alternator must be activated and generating at least 12 volts.

From what I remember they are in the sides opposite each other. I was removing the steering lock to see if I could get it to work but I cannot remember if I removed the lock and then the switch or the switch and then the lock. The previous owner had replaced the shear bolts with hex sockets so removal of the lock was not a problem once I had realised that they were metric.

On the Spitfire there are two grub screws holding the switch mechanism to the lock part. The GT6 may be similar.

I have experienced misfire when accelerating but runs fine when cruising. As you open the throttle, more air enters the cylinder and the pressure at TDC is greater. A higher pressure requires a higher voltage to spark across the plug gap and the higher voltage can cause the insulation else where in the circuit to break down. My most recent occurrence was on my wife's Toyota due to a faulty coil pack. The previous time was on a Hillman Imp due to over large plug gaps and contamination on the distributor cap. That was nearly 50 years ago but I knew exactly where to look on the Toyota last year when I experienced the same symptoms.

Some years when I was approaching Strabane, NI, the car in front missed his turn off so stopped, reversed a couple of yards, then successfully made his exit. So much easier than completing another circuit!

I only have experience of a J type on my Spitfire. Is it possible to disconnect the 12 volt supply from the D type solenoid? If this cures the problem then you know it is an electrical problem such as an intermittent short in the wiring. If the problem persists then it is mechanical such as a worn clutch or maladjusted solenoid.

I too have used Willow Triumph and was very pleased with the service and standard of work. Just up the road when I lived in Darlington but a long way from Middlesex.

After repairing my inlet manifold using 3/8 fittings as suggested in another thread, I tested the heater but no hot air from the N/S screen vent. I found a large split in the hose from the heater unit which I thought might be repairable with PVC tubing and duct tape. On reaching behind the dash, the tube just crumbled, all the mechanical strength of egg shell. But it was -2 deg C and 45 years old. Now to find a replacement. The vacuum advance tubing is very similar to that in the drip feed irrigation system that I instated in the greenhouse.

When I purchased my Spitfire it was fitted with 175/70 /13 on 4.5Js. Too much sideways flex. Handling improved when fitted with 155/80s. This would suggest a maximum of 165. Waiting for the Wales game to begin.

As mentioned earlier, I used to work in the HSE laboratories where we dealt with compressed oxygen upto 4500psi/300bar. If you open a cylinder valve too quickly you can cause a high pressure shock wave and the sudden compression of the gas can result in a temperature sufficient to cause an ignition, the same effect as in a diesel engine. Therefore you must always keep oxygen systems oil and contamination free. Substances burn extremely violently in an oxygen enriched atmosphere. For example, if you try to ignite a piece of expanded polystyrene, it burns slowly with a great deal of black smoke. However, if you dip a piece of the polystyrene in oxygen enriched liquid air, a small spark will result in a bright flash and no black smoke or residue. Compressed air at 100 psi/7 bar will have an oxygen partial pressure 8 times that in the ambient atmosphere. One reported incident involved applying a gas torch to an HGV wheel without de-pressurising the tyre. The effect of the heat, high pressure and oil contamination on the inside of the rim resulted in a fatal explosion. In this case the source of heat was obvious but in other cases it could be caused by friction etc. Introducing a fuel such as WD40 (XL?) which contains "light end" or volatile fractions of petroleum distillate is not a good idea. We also investigated reports of ignitions in a certain design of oxygen cylinder valves. We built a rig to automatically repeatably open and close the valve but even after introducing contamination, we failed to get an ignition. In the case of the hospital incident, it was probably a combination of unfortunate effects which may not be able to be reproduced.

A little known explosive is pork scratchings. Many years ago I worked in the HSE laboratories and were informed of accidents from the factory inspectorate. The cooked pork skin was dipped in liquid nitrogen to make it brittle before grinding into the small pieces. Unfortunately on this day, the liquid nitrogen had been left to stand in contact to the air. As liquid nitrogen is colder than liquid oxygen, this allows oxygen to be condensed out of the air so that the liquified gases becomes enriched with oxygen. After dipping, the oxygen enriched pork fat, high in calories and hence energy, was into fed into the grinder which subsequently exploded, unfortunately killing one of the operators. Danger abounds when you deviate from your usual procedures; "I can weld a repair panel onto a wing so why can I not weld a patch onto a petrol tank?" We also received frequent reports about gas cylinders flying through walls after being dropped on their valves. Graham

I was driving along the A5 when the fuel gauge suddenly fell to empty event though I knew the tank was nearly full. A little while later the gauge started to read again and worked perfectly from half full to nearly empty when I refilled. The problem was that the resistive element in the sender had worn down so no longer made contact over the sector 1/2 to 3/4 full. Presumably previous owners had kept the fuel mainly in this range so it suffered the most wear as the fuel slopped about as the car drove over bumps. Replaced the sender but now it only read 3/4 full even when the tank was nearly overflowing. Eventually diverted the wiring from the solid state 10V regulator so as the gauge was supplied with 12V and now it is fairly accurate although as yet I have never tested it to see what it reads as I run out of petrol! The temperature gauge continues to operate from the 10V supply. So perhaps a replacement sender in your car has been calibrated to run from a 12V supply as the person placing the manufacturing contract failed to explain the correct operating environment to the Asian factory.

I changed the swing spring on my Spitfire, bought it from Moss when they had a special offer. The old spring allowed the suspension to bottom out on anything but the mildest bump it was so weak. The wheels with the new spring appeared to be vertical or perhaps slightly positive and although I was told it would probably settle, I decided to fit a 1/2 inch lowering block from Canley's to give a slight negative camber. It is still fitted several years later and the negative camber is still quite slight. Every time after I have jacked up the rear, on standing back on its wheels, there is a marked positive camber as shown in your photos. Pushing a few feet back and forwards has little effect but the wheels are back to their correct alignment after a short drive. Graham

I have not followed all of your epic restoration saga so some of these points may have already been covered. I agree that from the clips it sounds like the rocker gear. Once after rebuilding a Ford engine, it soon became very noisy. On re-checking the valve clearance the gaps were far too large. Some how it had bedded in on being run. Re-setting the gaps minimised the noise and after that the gaps remained correct. My car came with shiny gauze filters but would not run correctly, running out of power as the revs rose and the mixture became weaker. This was rectified by fitting standard pleated paper filters direct to the carbs without the air box. There was still a problem in hot weather while idling as the hot air was drawn from over the exhaust manifold. I managed to get a used air box and some tubing to restore the setup to standard which remedied the situation. The screwed plug blocking the manifold vacuum take off point does not look right. Is it sealing? Graham

I had a similar problem. There was so much debris in the petrol tank that it partially blocked the in-line filter that I had installed. I tried cleaning the tank by removing the sender unit but too many ridges to flush it out properly. Then the tank developed a pin hole leak so was replaced with a second hand unit and have had no problems since. Graham

I have a similar issue with my Spitfire 1500. Idles at about 1000 rpm, purposely set high, but when the Kenlow fan cuts in the idle speed drops to about 500 rpm requiring an occasional prod of the accelerator to ensure that it does not stall. The fan is wired via a relay and fuse directly to the battery using wire rated at approximately 20 amps. The alternator is rated at 45 amps. I came to the conclusion that it is the extra load on the engine as the alternator is forced to supply the additional current that slows the idle speed. You also get a lowering of the idle speed when you switch on the headlights which supports this theory. The battery turns the engine over vigorously when starting so this would suggest that the battery is not at fault. The only remedy is to pull the chock out about 1/4" so as to increase the idle speed without enriching the mixture. It is not much of an issue as I do not frequently drive in heavy traffic, preferring the open country roads around where I live. Graham

Welcome, I too have a 1975 Spitfire1500 which I purchased several years ago. Yes, it will run on if you use regular petrol but as you found out, a better quality fuel, such as V-Power, will stop this happening. Used the car today to drive to work down the country lanes. Much more enjoyable than driving along the A1 in the BMW. You might as well combine pleasure with work. Graham

"He says, and I agree, that a drill just won't spin a stone fast enough to cut cleanly and quickly." I wondered why it took me so long. I thought that it was just my inexperience! Graham

Yes you can do basic work yourself. Many years ago I worked on a Mk1 Fiesta. If I recall correctly, I clamped an electric drill in a "Wormate" bench and connected a flexible drive shaft. I used a small grindstone to match the ports to the manifolds and smooth out the major lumps left in the ports by the casting process. I then worked on the chambers to reduce the masking of the valves by the walls but very little metal could be removed because of the restriction imposed by the head gasket. Finally, I contoured around the valve seats and the valves before grinding in the valves. The head was re-assembled with a Weber DGV downdraught and a four branch exhaust. It certainly made a big difference to the performance but how much was due to the head work, I do not know. Given the oppertunity I would do the same again. Graham

The grade of oil specified depends on the ambient conditions. According to the owner handbook, 20W/50 is recommended for operation from 0 to 30 deg C., 15W/40 from -10 to 30 deg.C. If you care to drive around with the top down at -30 to -10 deg.C then you should use 5W/40. I always use a 20W/50 from a reputable supplier and maintain 60 psi cruising on a warm day. If it is -10 deg.C then I probably will not be driving so no need for the 15W/40.