<NEW> To engines without camshafts

["Mike Theuri" <mikesoft@xxxxxxxxxxxxxx>]

Sorry for the repetition if you've already heard about 
BMW's new engine currently under development that 
will eliminate the use of the camshaft. I read this in a 
Nov. 98 issue of Popular Science pg 45 edited by Dan 
McGosh. Paraphrased as is necessary :

The article says that the objective of eliminating the
camshaft would be to attain higher levels of fuel 
efficiency through using new methods of actuating 
valves. What is being developed therefore are fully
variable mechanical valve-trains including electrically
actuated valves which would make the camshaft 
redundant. 

The article goes on to say that BMW's ultimate goal 
would be to use the valves to control airflow directly
through the engine thus eliminating the need for 
the throttle completely.

There are two systems available. The first is an 
enhancement of the current variable valve timing 
mechanism. A system that allows a variable lift is
enabled by having a lever placed between the camshaft
and the pair of inlet valves of each cylinder. The lever's
position is adjusted by an electronically controlled 
rotating eccentric. 

The second system doesn't use the camshaft at all. 
"A spring-loaded armature at the end of the valve moves
between two magnets that hold the armature in the end
position -- valve open or closed." This cycle is watched
over by a sensor and controlled by a controller that allows
the valve to have a gentle landing as it seats.

The new valve system hopes to improve fuel efficiency
by accurately filling the cylinder with fuel and air more
efficiently. The two systems the article mentions have a 
greater level of effectiveness when used alongside direct
injection. In addition variable-lift improves fuel efficiency
by 10% while the electrical system improves torque 5%.

- -----------END------------------

Now to other interesting stuff in the same magazine. 

The magazine also has a section a 5-Year New Car Preview.
Interestingly enough BMW has nothing listed for 2001-3. 

For 1999 : Squarebacked 2-seat coupes join Z3 lineup in 240
and 190-hp. 3 series coupe and sedan redesigned; 408-hp
hot-rod M5 5 series due late in year. 

2000 : 5 Series sedan-based SUV due for US production; 
production version of Z07 2-seat super roadster added to 8 
series.

Range Rover '99 : 4.0 SE/4.6HSE upgrade to BMW 4.0 liter
V8 engines likely.

Rolls-Royce '00 : New BMW powered Silver Seraph due to 
be introduced in the US.

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End of bmw-digest V9 #324
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