Engine rebuild: rebuild a Lotus Twin Cam

The Ford Lotus Twin Cam, the legendary high-performance engine of the 1960s era. The Mk1 Twin Cam was introduced as a dyno engine in the Mk1 Cortina in 1963 and was followed by the Mk II which powered the

Mk II Lotus Cortina – The same engine that was also installed in the 1968 Escort Twin Cam.

The Lotus Cortina and Twin Cam Escort were instant winners both on the track and at many, many rallies held around the world. It is often said that the 1960s were the golden years of motorsport, and the Lotus signature and its highly competitive cars were held in high esteem. But the Lotus Elan, which was publicly launched at the 1962 Earls Court Auto Show, was the sports car that ignited the motoring world, the Elan established a reputation for its point-to-point driving speed, as well as racking up successes after successes on racing circuits around the world. . Lotus was quick to build on those successes with the launch of the lotus elan 26R, the racing version, which was based on the elan S2 model; the factory only produced about one hundred 26R elans.

The mill’s four-cylinder ford cast iron engine block provided the foundation on which the dual-cam engine was built, the cylinder head was a Harry Mundy-designed dual-cam alloy head incorporating a chain drive to the cams. twins in the head, which operated the eight valves. The engine was normally aspirated and powered by twin forty-millimeter Weber carburettors, characterized by the distinctive clucking sound they make when the throttle valves are opened.

But despite the high power of this small four-cylinder engine, this engine has two Achilles cures, the first being the reputation of water pump failure, which is mainly due to the engine being left idle for long periods of time. periods without coolant in the engine. block, on the first crank of the engine, the dry seal tears during the first turn.

Many elan & escort owners have also upgraded from the original dynamo to a modern alternator for the electrical system, the high tension on the belt required to run the alternator places excessive side loads on the water pump which can lead to premature failure. .. Standard water pump replacement requires the twin cam alloy cylinder head to be removed first, which can lead to a very expensive mechanical repair for the impractical twin 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 issue with the dual cam Lotus engine is the engine’s constant habit of losing oil pressure in tight right turns, many owners choose to ignore this issue at their own risk, Lotus Twin Cam

Drivers have been known to just listen to the rattle of the bearings, then ‘back up and wait for the oil pressure to return … if you hear the rattle of the bearings, the engine is only seconds away from a possible engine explosion,

From a cold start, bearing rattle can be tolerated in an engine because it only lasts a second or two while the engine is idling. But it’s a completely different story when the engine is revving at 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 a yes, but rather a matter of when the engine bearings grab onto the crankshaft.

But you will be pleased to know that there is a solution, but in reality there are only two options;

1: If you like circuit racing then dry sump lubrication is a given, it can be expensive and time consuming to set up and get right but most racers go for dry sump lubrication.

2: Install a gated wet sump oil control system.

It sounds technical but it is not, the gated sump system is about designing and building a unique appliance that installs into 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 baffle if they like to make from sheet metal and also know how to do a small amount of brazing.

No one but you will know that there is a special anti-surge oil control system installed in the crankcase of your dual cam Lotus engine. But the difference is that with the closed deflector installed, you will be able to take any corner at high speed in your Ford, Lotus Cortina or Lotus elan and you will not have the slightest concern about oil rising, the oil gauge will tell you the oil pressure Right is being delivered to its legendary dual cam Lotus engine, it is all about peace of mind and confidence with a high performance engine. Build it once, get it right, and you won’t have a problem.

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