La Sarthe - Technical specification and build information.

Here we will outline the car's technical specification, show you how we build La Sarthe and tell you about some of the sympathetic modifications and upgrades.

An original genuine Bentley chassis.


Starting with a carefully selected Mk6 or R-Type, the chassis is completely rebuilt to the highest standards with the latest modifications.

The chassis pictured above is a LHD car. These are rare but can be found in suitable condition. We are not in the business of removing bodies from good cars.


Technical specification




Whilst we retain the original steering wheel, this is reduced in size from 18 to 16 inches. The large wheel in its original form is no longer needed due to the fitment of power steering. The reduction in size allows for more leg room and assists in entering and exiting the vehicle. 

Power steering



The power steering is an EZ Power Steering unit. It is the top of the range version which allows us to maintain the ride control lever which passes through the centre of the steering column. On automatics the gear selector mechanism is modified to pass over the power steering drive. This unit electronically adjusts the amount of assistance, as required by steering load inputs. 




The 4.5 litre engine is uprated to 4.9 litre. Every component is checked and meticulously rebuilt. Engines are fitted with lightweight Omega pistons. An alternator is fitted to replace the original dynamo. We fit electronic ignition with carbon HT leads. An efficient stainless steel exhaust system with a 6 branch manifold is fitted as standard. 



The gearbox is a 4 speed auto with kick down and also includes option to manually select 2nd and 3rd or a 4 speed manual with synchromesh in 2nd, 3rd and 4th. We keep the gearbox with its original chassis, all numbers match the chassis record cards. 



The differential is completely rebuilt in-house to final factory specification and a higher 3.08:1 Continental axle ratio is fitted. This will allow 80mph motorway cruising at 3000rpm. We are one of only a few companies in the UK with the skills to rebuild these complicated differentials.



We always strive to retain originality. The Bijur chassis lubrication system is retained on all our cars, and all brass pipework is replaced. This system, operated via a foot pump under the dashboard, provides all moving components on the steering and suspension with the correct 20SAE oil. 



When air conditioning has been requested, we use our tailor made system. We modify the crankshaft pulley with an additional drive and mount the air conditioning unit in a discreet area so not to detract from the aesthetics of the engine bay. 



The braking system also retains its originality and is driven from a mechanical servo drive on the gearbox. New wheel cylinders and brake drums are fitted. 

Brake fluid check


On the Bentley R-Type, the only way to check the brake fluid level was to withdraw the driver’s seat base and remove the cap of the master cylinder below a cover in the floor. We have overcome this by modifying the cap and fitting a remote, glass reservoir from a later model Bentley, in the engine compartment, enabling easy checking of level or replenishment of fluid. 

The coachwork

La Sarthe is built on possibly the most substantial piece of tooling of any car manufactured in such low volume. Even though, due to its hand built nature each car is slightly different, the final finish of the panel work and shut gaps using this tooling is second to none.


The interior of La Sarthe has been designed to be flexible. Different veneer and dash board design, sound systems, fitted luggage, rear seats and more can all be accommodated.

Instrument panel.


The instrument panel in La Sarthe is CNC machined from a single block. This allows our in house CAD team to easily make changes. The construction also creates a very quiet and solid instrument panel that is very stable, eliminating noise and protecting the veneers that will be the show piece of the interior.