-Appendix A
The most important thing is, KEEP IT SIMPLE.
How many competitors have driven in a long distance rally taking more than 7 days, or had experience of rally car preparation? I am sure that many of you will be asking experts in your particular vehicle to carry out the technical side of the preparation. Apologies to the experts reading these notes but these hints are for everyone, experienced or inexperienced. There may be a number of very early cars entered in this type of event and some of these hints may not apply.
A ENGINE
The engine is the heart of your motor car.
1 A reliable known specification is essential; this is not the time to experiment. If you complete the event with only routine maintenance to the engine, you have succeeded. If you don’t know what specification to use, consult a specialist in your engine. There may be few garages on parts of the route and they will probably not have spare parts for your car. Suspensions can be mended, but engines and transmissions can be more of a problem if a serious failure occurs.
2 The octane value of the available fuel may be as low as 70. Therefore, do not build your engine with a high compression ratio.
3 If there is a choice, fit a camshaft giving a mid-range torque band. You do not want a screaming engine with no torque, particularly if stuck in the mud or climbing a mountain.
4 If the engine is fitted with new pistons, ensure that the engine is run-in before the event which will also give an indication of oil consumption.
5 Core plugs may have become corroded, and should be replaced. Retain the core plugs with a safety plate or plastic metal as severe changes in temperature may cause a plug to pop out, with immediate loss of coolant.
6 Inspect, and renew if in doubt, the engine mountings. Some replacement engine mountings are not to the original specification. Mountings made for a Jaguar Mk 2 failed after 500 miles; it was eventually found that the rubber used in the manufacture was suitable for cushion-type radiator mountings! Damaged or loose engine mountings can cause all sorts of damage within the engine compartment. One way to prevent total failure is brackets/straps to prevent the engine moving forward; this could cause contact between fan and radiator on some models if unlucky enough to hit a pothole or go off the road.
7 The oil filter can be a source of problems if the bowl comes loose and blows the seal. Wire locking the bolt is recommended and ensure the filter is protected if in a vulnerable position.
8 Engine oil can become the source of much discussion. Consult the specialists; use a conventional oil which will mix with the type of oil you may have to use in an emergency. Modern synthetic oils are not suitable for many older engines. Companies such as Castrol can supply classic oils such as XL30 or XXL40 for example.
9 An oil cooler may be desirable for some engines, particularly if a large sump shield prevents adequate cooling. Try not to mount the cooler directly in front of the radiator, and ensure it has an adequate stone guard and is flexibly mounted.
10 Exhaust systems are often a problem. Flexible mountings, safety straps and good ground clearance are essential. Engine movement can break systems over long distances. The noise of a side-exhaust can be very tiring to the crew. If there are joins in the system, fit safety straps between the two parts, which are easily unbolted. A jointed system, with some give in it, is better than a rigidly welded up one. Be sure, though, that there are no carbon monoxide leaks into the cabin - this will knock you out before you’re aware of it.
B FUEL SYSTEM
1 Carburettors Altering the mixture is a problem which may require consideration if long sections are run at high altitude or if numerous high passes are included in the route. Approximately 20% power loss will occur at 6,000 ft, with considerable richening of the mixture.
On the 1970 London - Mexico World Cup Rally (with many miles at 15,000 ft), some cars fitted with SU carburettors had a device fitted which enabled the driver to weaken the mixture from the dashboard. Details of this very simple device can be obtained from Don Law, ex-SU Racing Department, who was involved in the original design.
The alternative is to carry weaker jets or needles and change them for the higher sections of the route. On an SU carburettor, a needle change would take at least 5 minutes per carburettor, if you are not tired or suffering from altitude sickness!
2 Fuel tanks If the estimate of the range required by the cars between refuelling is 300 miles, then a car with a fuel consumption of 15 mpg would require a minimum tank capacity of 20 gallons. Fuel in cans or bags must not be carried inside the passenger compartment.
A larger or additional fuel tank may be required by some cars. If a second tank is fitted, this can cause problems with the layout of the pipework. One way of increasing capacity is to install a secondary tank in the system. A separate electric pump is used to transfer fuel to the main tank. This maintains the original feed to the engine. Drain plugs in the tanks are desirable and would facilitate the removal of dirt or water collected during the event.
If your car has had an empty tank for some time, it is essential to remove the tank and clean out all sediment and rust flakes. It is not unusual for cars which have been laid up for some time to stop with blocked systems. All the rust of the years of inactivity is suddenly washed around inside the tank on round roads and hairpin bends. It will soon be picked up by the pump, and if not blocking the pump or clogging the tank pick-up or filters, will reach the carburettors.
3 Electronic fuel pumps should be fitted away from road dirt and water. A reserve pump is essential. Plumb a second electric pump into the system, with electrical supply. The reliability of some of the ‘solid state electronic’ pumps made in the Far East is questionable. Carry a spare mechanical pump or repair kit.
4 Filler Fit a lock to the fuel filler cap (particularly for overnight security).
5 Fuel lines Consider the run of the fuel pipes. Re-route pipes and run them inside the chassis or protect them with metal. In the engine compartment, try to avoid fuel vaporisation by routing the pipes away from hot areas and make sure adequate heat shields are used between carburettors and the exhaust manifold. Petrol will start to boil at approximately 40oC.
6 Fuel filters Dirty or water-contaminated fuel may inadvertently be supplied during the event. A fuel filter is essential; the type with a clear sediment bowl which allows one to see if dirt or water has been collected is desirable. Take spare elements.
One way of preventing dirt/water getting into the tank is to carry a marine type funnel incorporating filters, and always use it when filling either from petrol station pumps or cans.
7 Bulkhead It is essential to have a fireproof bulkhead or barrier between the fuel tank and passenger compartment (and also between spare fuel containers and the passenger compartment), to prevent the passage of liquid or flame.
8 Air cleaners Take four or five changes of paper element if dusty conditions are expected. These should be fitted, easily removed for cleaning in dusty conditions.
C COOLING
1 Radiator Make sure that the radiator is in good condition. Flush out radiators which have been standing for a long time. If in doubt, renew it or have it checked by a specialist.
If cooling on your car is marginal, consider a larger capacity core or auxiliary radiator. In hot climates a larger capacity is recommended. Auxiliary lamps can reduce air flow through the radiator.
2 Stone guard It is essential to fit a stone guard in front of unprotected radiators.
3 Cooling fans Don’t just throw away the original mechanical fan (you are not building racing cars looking for the last ounce of BHP). Maybe radiator to fan clearance is a worry. Fit stops or restraints to the engine/gearbox mountings to stop engine moving into radiator or move the radiator forward. Remember that the fan can act like a boat propeller when fording deep water, and drag itself into the radiator. Protect yourself against this by removing blades, or fitting stops.
4 Electric fans These improve cooling capacity. If fitted in front of the radiator, this reduces the cooling capacity of the radiator. Some off-the-shelf electric fan fits have very flimsy mountings which can collapse on rough roads, so make sure they are modified and do not use mountings which go through the core.
5 Coolant A 50% Bluecol mixture will raise the boiling point of the coolant by 8 degrees C. Do not increase the percentage over 50% as this will reduce its anti-freezing properties.
A heater can be used as an auxiliary radiator in an emergency, which could be helpful in hot conditions, on a long mountain climb or if you have lost your cooling fan.
6 Fan belts These are critical. Ensure the belt fitted is made by a well known manufacturer. If it breaks and it drives the water pump, the engine will soon overheat. Many modern cars use multi-rib Poly-V belts. Make sure your spare belts are the correct type and length. If fitting a replacement is difficult, consider having a new one clipped to the engine during preparation. Carry one or two spares, near the top of your list.
D IGNITION
1 System Why not use the original system that the manufacturer fitted? The points/contact breaker system is easily fixed. Magnetos are original equipment on some older cars. There are a number of after-market ignition systems available but question their reliability.
2 HT leads Use HT leads with wire in them; the carbon-impregnated type are not too robust.
3 Ignition Coil Fit a spare in situ (not on the engine), with wiring to reach both.
4 Ignition advance/retard mechanism Some cars will already have this facility. If not, ensure the position of the distributor is marked for normal 90+ octane fuel. Then you can see where to move the distributor back to, if you have to retard the ignition when using fuel as low as 70 octane.
5 Weatherproofing Protective rubber caps in conjunction with silicone grease could be fitted to coil and distributor if vulnerable. Do not completely seal a distributor as this can cause heavy burning to the points due to lack of oxygen. If necessary fit a breather pipe to the body of the distributor.
6 Spark plugs Consult the specialists. Mount spare plugs in a rack with the terminals pre-tightened.
E GENERAL ELECTRICS
1 Dynamo/alternator Alternators have a higher output and are more reliable. If acquiring replacement and spare dynamos/alternators, check that they are either new, or have been reconditioned by reputable companies. The cheaper replacement could be just a ‘paraffin overhaul’, of high mileage which will not last five minutes.
The adjuster strap is a weak link on engines with certain in-built vibration frequencies. Fit a new strap, strengthen the original strap or fit a nylon one.
Consider pulley diameter and alignment of pulleys.
On engines with reduced accessibility, consider having a spare drive belt clipped in place when the engine is assembled. Where possible, use original equipment belts to suit your engine; try not to use belts of dubious origin which may not last.
2 Battery Fit a heavy duty battery within the confines of the original cradle. Secure the battery very firmly with a strong frame round the top, making sure it is designed not to be too close to the terminals, and use clamp-type terminals. Insulate the terminals - if one comes loose, you don’t want it touching the bonnet or metal cover!
3 Starter motor This should be refurbished and protected from manifold heat if the exhaust runs close. Most cars don’t really need to carry a spare starter (it’s all weight). Generally there will be someone to give you a tow or push start. Ensure heavy duty cables are securely clipped, and don’t forget to check the earth lead and separate engine-to-chassis earth leads.
4 Wipers/washers Check/renew motor and linkage. Overhaul washer system and consider increasing capacity of reservoir. Twin jets will improve efficiency and give a spray if one jet blocks.
Take spare wiper blades/arms (in some parts of the world these are collectors’ items!)
5 Wiring Harness must be in good condition with security clips and good grommets where cables pass through bulkheads or panels.
Add fuses to vulnerable circuits, which are accessible. Label all fuses before you set out; it can save hours if you have a short circuit at night! Fix or tape your spare fuses in one place, labelling each one.
F TRANSMISSION
1 Gearbox This should be rebuilt and run-in. If you select closer ratios, ensure first gear is not too high - this could be a handicap if you encounter soft going or have to stop on steep climbs or hairpins (the clutch will suffer).
2 Gear linkage Check this and renew joints as necessary. Consider fitting an extra gearbox breather, particularly if a sump shield could cause overheating.
3 Lubrication How do you refill the gearbox? Does it have a dipstick? If the filler cap/plug does not have an access panel, make one, possibly in the gearbox tunnel. You may have to consider carrying a syringe or funnel (or similar) if access is difficult.
Consult specialists if unsure about oil grade to use.
4 Mountings These must be secure and strengthened if necessary. If rubber bonded mountings are not fail-safe, fit safety straps or bolt through the rubber to stop the gearbox falling out.
5 Clutch Heavy duty cover/driven plate. Replace carbon thrust with race if practicable. Operating mechanism - renovate. Cables, rods, hydraulics - protect if vulnerable. Adjustment - is it easy to get at? Spare clutch driven plate is recommended.
6 Propshaft Balanced propshaft, fit new U/J’s, replace fabric type. Fit a safety strap to support propshaft should a U/J break. Carry spare U/J kit(s)?
7 Axle If you have an engine with good torque, the standard ratio should be suitable. If you wish to drop the ratio for improved acceleration and hill climbing, make sure it is not too low to avoid over-revving on smooth/flat sections. An overdrive can compensate for a low ratio at cruising speed. Rebuild with new parts and run-in. I tyre/wheel sizes are changed, consider the RPM of the wheel/tyre before deciding to drop the axle ratio. Changing tyre sizes or axle ratio will require re-calibration of the speedometer and/or distance recorder.
8 Axle oil Consult a specialist to find out the right specification. How do you refill the axle? Is access to filler plug good? Will you require a funnel/syringe? Does the axle have a good breather in the casing? Consider a diff. guard.
9 Axle shafts Fit heavy duty shafts if available - if secondhand spares, ensure you mark the shaft to indicate which side it came off. Renew shafts with known spec. Fit new bearing/seals etc. If hub/flange pressed on shaft, ensure spares have hub/flange already pressed on. Use high melting point grease in hub bearings.
G STEERING
1 Steering box/rack and pinion Check the mountings, and strengthen if necessary. Check steering column brackets/bushes. Check steering arms/rods/joints - renew if necessary.
2 Steering ratio An easy method of reducing ratio is to fit a smaller steering wheel. Try it out first as a smaller wheel may cause the steering to be unacceptably heavy and tiring over long distances. Check lock-to-lock clearances if wider or taller tyres fitted, and wheel-arches for clearance and projections when fully loaded. A bolt sticking through may rip the tyre on rough roads!
H SUSPENSION
1 Weight Keep the weight down! Of all factors, the overall weight of the car will have the most influence on whether you reach the finish! Suspension weakness or failure is the commonest problem.
For various reasons, you may wish to carry a third crew member. Don’t forget that the average person weights about 12 stone (168 lbs/80 kg). This is equivalent to 1.5 cwt before adding the extra luggage of the crew member. This may not be a problem on events with predominantly smooth tarmac roads.
Weight distribution is important. Too many cars start long distance events dragging their backsides on the ground!
2 Leaf/coil springs Generally, ground clearance is influenced by road spring rates/lengths. The extra weight of additional equipment/spares etc can seriously lower the car. Increase spring rates with additional leaves or uprated coil springs. Spacers are sometimes used to alter ground clearance but will not alter spring rate.
3 Bump rubbers/check straps These must be in good condition. Fit heavy duty bump rubbers. Check/renew shackles, bushes, U-bolts etc.
4 Shock absorbers Strengthen the mountings if necessary (it probably will be). Uprate the dampers but ensure the correct stroke unit is supplied. If longer than original for example, on full bump (which will occur on rough roads with a heavily laden car) the shock absorber will come to the end of its stroke, which will damage it or punch out the mountings. Adjustable shock absorbers can compensate for wear.
I BRAKES
1 Drums/discs Drums may be changed for discs, if the regulations permit. Uprate lining/pad material specification. Don’t forget that every mountain climbed has to be descended and this can cause serious overheating/wear. Consider adding cooling ducts to front brakes. Additional holes in brake drums/back-plates will assist dissipation of heat but be sure not to weaken drum by oversize holes. Bolt hydraulic wheel cylinders to back-plates to improve heat dissipation. Hydraulic pipes - protect or run inside chassis. Uprate and/or protect flexible hoses. Check/renew rods/cables.
2 Hydraulic system A dual or twin master cylinder is desirable. An efficient handbrake is essential, although most historic rallies prohibit hydraulic handbrakes.
3 Protection Protect pipes/hoses where they enter backplate or calipers, from stone damage. Heavy duty mud-flaps under chassis can be mounted to deflect stones from vulnerable components such as brake and petrol pipes.
4 Brake fluid Renew with minimum DOT4 spec. Do not use a silicon fluid as this could be a problem if a serious leak occurs and you run out of fluid - it’s difficult, if not impossible, to find local garages (particularly in third world countries) which stock silicon fluid, and it does not mix!
J WHEELS AND TYRES
1 Tyres Consult manufacturers. The best are usually tread, puncture resistant, and fitted with tubes. A taller tyre will give bigger footprint and help ground clearance, but it is not a good idea to fit very wide tyres - older cars will not have much choice, but oversize modern rubber adds to the stresses on wheels and suspensions. Tyres supplied for modern 4x4 vehicles will fit some historic cars.
2 Punctures Punctures must be catered for. Can you change your own tyres or repair a puncture? You should have tyre levers (aluminium ones save weight), puncture repair outfit, tubes, valves, tool for valves, pressure gauge, foot pump (and a small, light 12 volt compressor).
3 Pressures Check pressures daily - this may warn of problems with slow punctures. Increase running pressures with advice from manufacturers.
4 Wire wheels These will require careful preparation. Consult a specialist who will inspect them and advise what needs doing. Consider increasing the number of spokes.
5 Car jack wheelbrace Get heavy duty items. Can you get the jack under the car when the tyre is flat? A board to support the jack on soft ground/mud/snow or a large plate added to the base of the jack is desirable. Make sure you have a good strong wheelbrace. Some spare wheel nuts or bolts (or knock-off spinners - one for each side) are essential.
A high-lift bumper jack can be used if stuck in mud, but you will require strong jacking points on the car for this type of jack. Useful for de-ditching.
K PROTECTION
1 Sump guard Some cars have good ground clearance, but a sump guard is essential. Apart from rocky conditions, if you go off the road, accidentally or to avoid an obstruction, you may wish you had some protection.
One important point which is often missed; make sure there is a pad of high density foam or rubber, filling the gap between the sump and guard. If there is a gap and stones get in, the first time the guard is bashed, a stone can act as a punch and quickly puncture the sump.
2 Exhaust systems These are often a problem. Flexible mountings, safety straps and good ground clearance are essential. Engine movement can break systems over long distances. If there are joins in the system, fit safety straps between the two parts which are easily unbolted. Weld skid plates to the leading edge of silencers on cars with low ground clearance.
3 Vibration Rough roads will loosen parts which never come loose on European roads. The use of locknuts, self-locking or castellated with split pins is recommended. Some components can be wire-locked and careful attention should be paid to engine/gearbox and axle drain plugs. Consider carrying spare drain plugs; if one drops out and you avoid internal damage, it can be almost impossible to seal the hole without the correct plug.
4 Routine checks Be prepared to carry out regular spanner checks during the event. For example, a slightly loose suspension part could be found and tightened, preventing serious damage later on. Prevention is better than cure! You may not feel like it after a long day at the wheel, but it is essential if you want to arrive at the finish. Set yourself a routine to go round so much of the car each time you stop.
5 Waterproofing Position engine air intakes high enough to prevent ingress of flood water (even a large puddle can wreck an engine - water does NOT compress). Protect vulnerable ignition components with a splash guard if in vulnerable position.
If river crossings, flooded roads or flash floods are a possibility, carry an exhaust tail pipe extension which can be quickly attached. Not essential if engine keeps going, but if you stall, will help start engine. Deep water may require removal of fan belt to avoid throwing water over electrics or preventing fan becoming damaged. Alternatively, have a strong plastic sheet available with attachments to fix across the radiator to reduce the amount of water pouring into the engine compartment.
L SAFETY
1 Fit a laminated windscreen. If not available, provision of some form of emergency windscreen in event of breakage. For open cars and cars without laminated windscreen recommended to wear goggles or visor - carry goggles anyway in case you have to run without screen.
2 Seat belts Full harness recommended.
3 Roll-over bar If not mandatory, seriously recommended for all open cars - for saloons you’re probably safer without one if you aren’t wearing crash helmets to protect your skull from the cage.
Consult a specialist supplier such as Safety Devices.
4 Fit safety chain or cable to oil, water and fuel filler caps.
5 Bonnet and boot lid safety straps should be fitted.
6 Fire extinguishers Fit 2 x 2.5 kg hand held, within reach of crew with belts on.
7 First aid kit Essential; seek professional advice.
8 Internal electrical master switch, accessible by crew with belts ON.
9 High intensity or air horns - co-driver button recommended.
10 Strong towing eye front and rear essential, mounted where it is easily accessible, not tucked in too far.
11 Mud flaps At least behind rear wheels
12 Fire and liquid proof bulkhead between engine/fuel tank and passenger compartment.
13 Warning triangle.
14 Strong tow rope.
15 Secure spare parts in strong container (plastic or metal), strapped or bolted down.
16 Secure petrol cans securely in boot.
M ACCESSORIES
1 Night sections may not be planned, but if you break down and are running late, a pair of powerful spot lamps are essential. Outside Western Europe many vehicles (particularly lorries) will be unlit, there are no ‘cats-eyes’, and pedestrians, animals and bullock carts do not usually have reflectors!
2 Consider the following:
3 If a mechanical distance recorder (e.g. Halda) is not fitted, a speedometer which has a trip meter and which has been calibrated to take account of tyre size and axle ratio is essential.
4 If there is a space on the chassis near the exhaust manifold to hold instant meal tins, consider a simple bracket to hold them in place while travelling. It can be quite nice to stop for a hot snack, instantly available if you have a tin opener!
N SPARE PARTS/TOOLS
1 What to take? It is very difficult to decide what to leave behind. It is all too easy to overload the car with spare parts.
2 How to pack? The parts you carry should be packed in plastic or metal boxes; cardboard boxes will turn to ‘dust’ on rough roads.
Ensure the small spares are accessible and the boxes labelled with the contents. All spares/boxes must be secured.
If you decide to take an axle shaft for example, see if it can be secured towards the front of the car, under the seat for example to improve weight distribution. (An entrant on the 1995 London - Mexico rally carried an axle shaft behind the front bumper).
3 Tools Select your tool kit and then go round the car making sure that at least all the spares you carry can be replaced with the tools on board, and you carry the sizes of spanner and socket that you actually need - tools are heavy, so don’t take ones you will never need. Consider if you require a small trolley jack. It may not be practicable to carry large hub spanners etc. because of weight/space limitations.
4 Nuts and bolts If you get the choice, ensure that you use as few sizes of nut and bolt as possible in preparing the car, to simplify work en route and minimise the number of spanners, etc., you have to carry. Some people colour-code nuts, bolts and the equivalent spanners and sockets with dabs of paint.
5 Spares The following is a ‘long checklist’ of spares; do NOT expect to take them all, as the car will break under the load. Concentrate on items that will keep you going if suffering a roadside breakdown (R = recommended, O = optional - mainly on grounds of weight)
6 Conclusion
These preparation hints are for guidance and most of them are not mandatory. The object has been to highlight some of the points which should be considered, particularly as many cars entered in long distance events have not had a hard competitive life and will require some additional preparation to prevent them "falling at the first fence". A shakedown down a smooth main road to Brighton, when you think the car is ready, is not good enough. Load the car as you expect to travel on the rally and compete in a rally or at least drive it hard over rough/bumpy roads, up long hills and see what happens. This may highlight teething troubles before the start.
Many of the preparation hints for historic cars also apply to modern vehicles, and 4x4 owners should read Part One. The following are supplementary notes for 4x4s.
1 Modern systems
Engine Modern engine management systems for petrol and diesel vehicles are electronically controlled. This means that the remote ‘bush’ mechanic will not normally have available the means of diagnosing faults. This would only be available at the franchise dealer of the make of vehicle, which may be hundreds of miles away.
Electronic systems use a number of sensors to send messages to the electronic control unit (ECU) or ‘brain’, to enable the correct fuel mixture to be supplied to the engine for all conditions.
The accelerator cable is becoming obsolete as more manufacturers develop ‘drive-by-wire’ systems. A sensor attached to the accelerator pedal is connected to the engine via the ECU by a wiring harness.
The failure of any one sensor may cause the ECU to revert to the ‘limp home’ mode, enabling the engine to provide just enough power to get the vehicle to a workshop.
Failure of certain other sensors will cause the engine to STOP. Many modern electronic systems incorporate self-diagnosis, where fault codes can be accessed using a diagnostic unit or in some cases, more simply without specialist equipment. If a fault code number can be accessed, this will indicate which sensor has failed.
If a number of vehicles of the same make and type are on an event, it would be sensible for at least one vehicle to carry a diagnostic unit with someone trained to use it.
2 Transmissions
The majority of 4x4 vehicles will have low ratio transfer gearboxes, differential locks, etc. These should be robust enough to cope with most conditions found on rallies of this kind.
3 Suspensions
The suspension will require uprating if 3 or 4 crew members are carried in addition to luggage and spares. Increase of springs rates and heavy duty shock absorbers are recommended. The manufacturers may well have higher spec. items in their catalogue.
4 Chassis protection
The design of the medium to large 4x4 ensures good ground clearance. However, consult the manufacturer for advice on sump guards, ‘bull - bars’, differential shields. In many cases these will be available as accessories, which will have been designed and tested by the manufacturer.
5 Waterproofing
This is not such a problem in diesels but wading through deep water will often require special attention to transmissions etc., and will probably be dealt with in the owners handbook.
6 Tyres
The performance of 4x4 vehicles has ensured that tyre manufacturers have developed weathermaster type tyres capable of high motorway running without overheating. If the route is likely to encounter wet/muddy conditions, consult the vehicle and or tyre manufacturer for advice. The tyre specification supplied for vehicles sent to local markets may be more suitable than the UK showroom tyre.
If you have a puncture, consider the problem of changing a wheel. The wheel/tyre assembly on a modern 4x4 is heavy. The jack in the tool kit may be inadequate. Can you jack a heavy 4x4 up on a soft sandy or muddy surface without the jack sinking in ?. You may require a wheelbrace with a longer handle than standard, and possibly a high lift jack with bumper-level mountings.
7 Fuel
Petrol or diesel fuel in third world countries is more likely to be contaminated with dirt and/or water. Carry a marine type funnel fitted with filters and use it every time.
Fuel pumps on 4x4 fitted with petrol injection engines are often fitted inside the fuel tank. Find out how to change it, and of course carry a spare pump.
Fuel range should not be a problem on most events. A survey of 1996 4x4 vehicles shows an average tank capacity of between 17 & 20 gallons, which should give a range of approximately 400 miles depending on the vehicle - but bear in mind that consumption is often much higher on gravel roads.
8 Altitude
Many modern injection systems (petrol & diesel) use mass air flow or manifold absolute pressure sensors, which automatically compensate for high altitude, although the usual power loss will still occur.
9 Compass
A useful navigational aid. However, the magnetic effect of electronic engine management systems can cause serious deflections and errors to the cheaper versions.
10 Spare Parts
Consult the manufacturer or specialist for advice on essential components to carry. Electronic management system sensors are generally small and light to carry, and are essential.