The Ford Lotus Twin cam, the legendary high-performance engine of the 1960s era. The Mk1 Twin Cam was introduced as a test bed engine in the Mk1 Cortina in 1963 and followed by the Mk II which powered the
Mk II Lotus Cortina – The same engine that was also fitted to the 1968 Escort Twin Cam.
The Lotus Cortina and Twin Cam Escort were instant winners both on the track and in many rallies held around the world. It is often said that the 1960s were the golden years of motorsport, and the Lotus firm and its highly competitive cars were held in high regard. But the Lotus elan, which was unveiled publicly at the 1962 Earls Court Motor Show, was the sports car that set the motoring world on fire, the elan earned a reputation as a point-to-point fast engine, as well as amassing Hit after hit on racetracks around the world. Lotus world was quick to build on that success with the launch of the lotus elan 26R, the racing version, which was based on the elan S2 model, the factory only produced around a hundred elan 26Rs.
The mill running ford four cylinder cast iron engine block provided the base on which the twin overhead cam engine was built, the cylinder head was a Harry Mundy designed twin overhead cam alloy head incorporating transmission by chain to the double overhead cams, which actuated all eight valves. The engine was normally aspirated and fed by twin forty-millimeter Weber carburettors, which are characterized by the distinctive cluck they make when the throttle butterflies are opened.
But despite the high power output of this little four-cylinder engine, this engine has two Achilles problems, the first being a reputation for water pump failure, which is mainly due to the engine being left sitting for long periods of time. long periods without coolant in the block, on the first engine run, the dry seal tears during the first turn.
Many elan and escort owners have also upgraded the original dynamo to a modern alternator for the electrical system, the high tension on the belt required to run the alternator creates excessive side loads on the water pump which can lead to premature failure… Replacing the standard water pump requires the alloy dual-cam cylinder head to be removed first, which can result in a very expensive mechanical repair for the non-practical dual-cam owner.
The best solution to this problem is to install the newer modular type water pump, which makes it much easier to remove and replace. The other problem with the twin cam lotus engine is the engine’s constant habit of losing oil pressure in tight right hand turns, many owners choose to ignore this problem at their own peril, lotus twin cam
Drivers have been known to simply listen for bearing rattle and then stand back and wait for the oil pressure to return…if you hear bearing rattle, the engine is only seconds away from a possible engine blowout,
From a cold start, you can tolerate bearing chatter in an engine because it only lasts a second or two while the engine is idling, but it’s a whole different story when the engine is revving from four to seven thousand revolutions per minute. . Where even a short period of oil starvation can have a devastating effect on engine bearings, bearing failure is not an if, but rather a question of when engine bearings seize on the crankshaft.
But you will be pleased to know that there is a solution. But there are really only two options;
1: If you like circuit racing then dry sump lube is a given, it can be expensive and time consuming to set up and get right but most racers wear out on dry sump lube.
2: Install a gated wet sump oil control system.
Sounds technical but it is not, the closed sump system is to design and build a unique apparatus that mounts to the standard double cam sump or oil pan, it is not expensive to build or difficult to manufacture, it is not complex and most home mechanics would be able to build the deflector if they enjoy fabricating with sheet metal and also know how to do a small amount of brazing.
No one but you will ever know that there is a special anti pressure rise oil control system installed in the sump of your lotus twin cam engine. But the difference is that with the gated deflector installed, you can take any corner at high speed in your Ford escort, Lotus Cortina or lotus elan and not have the slightest worry about rising oil, the oil gauge will tell you that it is running. Supplying the correct oil pressure to your legendary twin cam lotus engine, it’s all about peace of mind and confidence with a high performance engine. Build it once, build it right, and you’ll be fine.