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Enhancing Rolls-Royce and Bentley Road Holding

R.A. Chapman Brake Discs

Suspension Bearing Pin Bushes

Petrol Hits $2 a Litre!


I am often asked about the cost of a complete handling kit for Rolls-Royce and Bentley by owners who feel that their cars could handle and corner more precisely than they currently do.

When I ask which aspect of their cars handling they feel could be improved, the answer inevitably is "reduce the body roll when cornering".

Delving a little further I find that what the majority would really like is the car to be tightened up slightly and a considerable reduction in body roll.

My usual suggestion is to first try the least expensive component that will give a dramatic reduction in body roll without compromising ride comfort.

This is our up- rated front sway bar with special bearing bushes (reduced deflection and non binding) in conjunction with our connecting links that transfer the full benefit of the up-rated bar to the chassis.

I would also recommend having the shockers /dampers tested (on car) and replaced if required with our Comfort Plus range of shockers.

  In the vast majority of cases this will produce the results the owner really wanted, a smooth comfortable ride quality with minimum body roll.

Minimising body roll and therefore reducing camber change on the front wheels drastically reduces tyre edge wear by keeping the tyre flatter on the road. This also gives increased tyre contact area with the road and therefore greater grip. This in turn reduces understeer, the characteristic that tends to want to make the car go straight ahead when negotiating a corner or drift out to the centre of the road on longer faster corners.

In the case of the owner who really likes to drive his car in a sporting fashion and is willing to except or prefers a firmer ride, then the full kit including up-rated springs and our Sorts Plus range of shockers are available .

The up-rated front sway bar and links components in conjunction with our Comfort Plus range of shockers are available for road test appraisal (along with many other RA Chapman Automotive components) on our product proving car, by appointment.



R.A. Chapman automotive has developed a replacement vented front brake disc for Rolls-Royce and Bentley cars.

The design and manufacture of this disc was brought about by the failure of very badly rusted original discs, mainly experienced on imported cars.  

The original design is a two piece construction, the centre section (the part that is attached to the wheel hub) is connected to the outer section (this is the part that the brake pads act on) by a crimping method simular to that used on a lock washer.

The problem is that when the crimped parts rust, they start to become loose relative to each other. Once there is any movement it is increased on every application of the brake as the two parts become progressively looser until the crimping shears off completely.

When this happens on one wheel only, the results can be very dangerous. I have experienced this total failure on one wheel on two occasions, once during emergency brake testing and once during slowing down at traffic lights. On both occasions the steering wheel spun violently to full lock.

Our disc is also of a two piece design but rather than being a crimped together connection it is bolted together, a design simular to that used by high performance car manufactures and competition vehicles.

This method of connection is extremely strong and enables the outside rotor section (the part the brake pads act on) to be removed and replaced separately. This is a great advantage as it means only the part that wears need be changed when worn below minimum limits. This of course represents a great saving over the original disc design which has to be replaced as a complete unit.

R.A. Chapman Automotives discs comply with Australian design rules.

The other advantage is that they cost considerably less than originals in the first place.  

These discs can be road tested (along with many other RA Chapman Automotive components) on our product proving car, by appointment.



The suspension bearing pin bush is fitted to all Shadows, early Spirits and Bentley derivatives.

The early Shadows /Bentley T (non compliant suspension) uses three different sizes of the bearing pin bush, (UR13211) upper control arms, (UR 10489) lower front and
(UR10490) lower rear. A total of EIGHT per car.
Later compliant suspension cars use two sizes, (UR10489) lower front and (UR10049) lower rear. A total of FOUR per car.

The rubber bush on all three types of these parts is affected by oil, heat and of course normal wear and tear.

The problem is that to replace the worn or oil soaked rubber bush, means replacing the complete pin bush assembly. The genuine price of these parts is $650.93, $387.50 and $344.16 respectively.

Since the steel pin very rarely, if ever is worn, it is only the rubber bushing that needs to be replaced and that is worth about five dollars. This means that a perfectly good very high quality forged pin gets thrown in the bin, for the sake of five dollars worth of rubber bush.

If an owner of an early Shadow or Bentley T was unfortunate enough to require a full set of these pin bushes, then they could be facing a bill of $4067.64 in parts alone!

Further if the car suffers with engine oil leaks at the rear of the engine and they are not rectified, the owner may find that the left hand lower rear pin bush will soon again be destroyed. Perished by the oil and then fried by the heat of the exhaust pipe running just below it.

Thankfully there is a simple and inexpensive solution that retains the original forged pin, replaces the rubber bush with a material that is not affected by the heat of the exhaust or engine oil, fits all three types of pin and costs only $30.00 each.

The replacement process is simple, remove the old rubber from the pin with a Stanley knife and buff pin on a rotary wire wheel, inspect the pin for any damage (which is most unlikely) lightly grease the inside of the new sleave and push onto the pin.

Another advantage is that the new bush material has memory, in other words, unlike rubber that when compressed in a particular position for a period of time, will not return to its original shape, the new material will always return to its original shape.

The advantage is that the new bushes will hold suspension geometry settings more accurately and far longer than rubber, which in turn helps minimise tyre wear.

R.A.Chapman Automotive has been making and using these bushes since 1990 with great success

These parts are available for road test appraisal (by appointment) on our product proving car.




Would you like to reduce your fuel bill by up to two thirds? - and be able to enjoy the pleasures of driving your proper motor car more often? The savings could be between $75 and $100 per fill.  All cars benefit from regular use (as they say, "use 'em or lose 'em").

Would you like to increase the life of your engine?   - a benefit not widely recognised or seriously considered by many owners.  Removing the necessity to start on petrol is a major wear reduction consideration in itself, negating the damage caused by fuel wash from the necessarily rich choke mixtures that cause high wear rates on cold starts.  Combine this with a reduction in contamination of engine oil, and engine life can be considerably extended. Currently the cost of a R-R engine overhaul is in the region of $A15, 000 - $A20, 000.

Would you like to drastically reduce harmful emissions released into the atmosphere by your engine?   Studies suggest that 90% of vehicle pollution is contributed by 10% of vehicles. Engines manufactured before pollution equipment was mandatory if now converted to LPG will significantly reduce all of the three major polluting gases: Carbon Monoxide, Hydrocarbons and Oxides of Nitrogen.

Would you like to increase the long term saleability and value of your car? As the price of fuel increases, the value and saleability of vehicles with intrinsically high fuel consumption decrease proportionately. As currently experienced with other prestige makes of vehicles, those fitted with dual fuel operation are in far greater demand and command a premium resale value.

The Royal Rolls-Royce Phantoms V and V1 were equipped for dual fuel operation with the addition of LPG equipment in 1988. Clearly the main incentive here was not simply about saving money, but rather to help clean up the environment by the use of the greener LPG fuel and to extend the useful life of these valuable cars.  Interestingly, the very latest addition at the Royal Mews (and now the Queen's principal ceremonial car) - the Bentley Limousine - is LPG equipped.

Consider having your Rolls-Royce or Bentley motor car enhanced by dual fuel operation with the addition of L.P.G and experience the benefits above.

Some questions answered:

Q: Will the engine feel less powerful when running on LPG?

A: No. We have 15 years experience tuning and developing this system, and as the Dynamometer Graph below clearly shows, there is no discernable difference in either Torque or Horsepower. In fact owners have described the pulling power (Torque) delivery as "much smoother" than when running on petrol and are only aware that the car is running on LPG because the idle quality is superior.

Q:Will it change the under bonnet appearance of my proper motor car?

A: Yes, but as Rolls-Royce and Bentley specialists, we are very mindful of the importance of appearance and we install the system to factory standards. That is, we ensure that it has the appearance of being factory fitted. Owners have commented favourably that the installation is very neat, unobtrusive and completely in keeping with original under bonnet appearance (please see picture, below).

Q: How much boot space will be taken up by the tank and where will the filler cap be fitted?

A: In the case of a Rolls-Royce Silver Spirit or Bentley derivative, none. This is because the tank fits in front of the boot "forward vertical panel".

In the case of a Rolls-Royce Silver Shadow or Bentley derivative, the tank is fitted fully forward in the boot and the intrusion simply depends upon the size of tank requested. Even with the largest tank fitted (as requested by the majority of owners) it still leaves a reasonable sized luggage space

The filler cap is fitted discreetly inside the petrol door - adjacent to the petrol filler (pictures below) .

Q: How easy is it to change from petrol to LPG and back again?

A: Changing from one fuel to another is as simple as flicking a switch - the same switch incorporates the LPG fuel gauge. This compact, yet easily visible unit is conveniently situated in a position to suit the driver.

Q: Can my car be equipped to run on LPG only? Is there any advantage in this? Is it true that the engine has to be tuned for either petrol or LPG as the same tune will not suit both?

A: Yes, they can be equipped to run LPG only and for some recently imported second-hand Rolls-Royce and Bentley cars, this is the only way they will meet Australian emission standards . However it is hard to see any reasons for not having the benefits and convenience of dual fuel operation if available.

With the octane rating of LPG having been reduced to that of petrol, different ignition advance curves are no longer necessary and the same tune applies for both petrol and LPG . Again this is clearly demonstrated by our Dynamometer testing, shown in the graph below.

Q: Will it be necessary to replace any internal engine parts to make the engine suitable to operate on LPG?

A: No, this will not be necessary as the later 6cyl and all V8 engines were designed to run on unleaded fuels and are equipped with hardened valves and seats. Rolls-Royce engines have travelled many hundreds of thousands of miles running on LPG with no problems whatsoever.  In fact, LPG has undoubtedly prolonged the life of many such engines.

Q: Will the fuel consumption be higher on LPG than petrol?

A: As LPG has lower specific heat energy than petrol, some engines' actual fuel consumption will be approximately 10%-15% higher when operating on LPG. But when a true cost-per-kilometre comparison is calculated, LPG is still considerably ahead.  For example with petrol at $1.40 per litre and LPG at $0.50 per litre, a car that achieves 17 litres/100 km on petrol, would still cost 2.45 times less to operate for that same distance covered on LPG.  In addition it could considerably extend the life of the engine.

Some engines - such as those fitted to Rolls-Royce Silver Clouds (both 6cyl and 8cyl), early Silver Shadows and Bentley derivatives (all of which were not fitted with fuel weakening systems) could actually achieve even better economy operating on LPG than shown above .   This is simply because the LPG equipment automatically "leans off" the fuel mixture under light throttle cruise conditions. It should also be appreciated that in respect of greater engine longevity, these older engines would benefit from the more accurate mixture control.

Our proving car is available for road testing and inspection - please call for an appointment.