FORD'S ZETEC-R; MAKING THE BEST EVEN BETTER
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Ford and Cosworth were faced with a major challenge for
1995: to ensure the Zetec-R retained its winning ways.
Ford's brand-new Formula One engine was the dominant force
of the 1994 season, powering Michael Schumacher to victory
in eight Grand Prix and making the young German the 13th
driver in 26 years to have won the World Championship with
Ford power.

For the coming season, however, motorsport's governing
body, the FIA, has introduced a number of significant
changes to the Formula One technical regulations. These
include a reduction in engine capacity, from 3.5-litres to
3.0 litres. It was therefore back to the drawing board for
the engineers who had developed Ford's 1994 engine.

As might be expected, the new Zetec-R has been based on
last year's successful engine. The external appearance
remains very similar to the 3.5-litre V8, although there
are small, noticeable differences to allow for the new
"stepped floor" regulations. Inside the engine, however,
the story is quite different.

The 1995 Zetec-R has a new crankshaft, connecting rods,
pistons, cylinder liners, cylinder heads, front cover,
valves, air-valve spring assemblies and inlet system. In
addition, there are modifications to the cam drive
arrangement and some of the auxiliaries, all of which are
dictated by the need to run the engine at higher speeds.

The result is a 3.0-litre V8 which will begin its racing
life with a maximum engine speed limit of over 15,000 rpm.
That equates to 250 revolutions per second. Despite the
severity of the task, however, the new Zetec-R has already
successfully completed a number of simulated race distances
on Cosworth's transient dynamometer, running to maximum
revs in all the gears.

In terms of technical details, the 3.0-litre Zetec-R shares
the same 75-degree vee angle and external dimensions as the
3.5-litre version. Internally, it incorporates titanium
connecting rods and valves plus special alloy pistons. As
in the previous version of the Zetec-R, ceramics are
incorporated in the cylinder heads and a great deal of
attention has been paid throughout the design process to
minimising heat rejections and maximising the stiffness of
the engine in the car.

From a performance standpoint, it is not valid to compare
the new engine with its predecessor. Since the beginning of
the 1994 season, a number of changes have been legislated
by the FIA to reduce vehicle performance, including the
venting of airboxes to prevent pressurising engine air at
high speed and the requirement to use pump fuels instead
of special blends.

The effects of these two changes alone reduced the engine
power on fast straights by about 7 per cent, and these
losses cannot be recovered. In addition, the reduction in
swept volume of 14 per cent will, at constant engine speed,
result in a 14 per cent power loss, which equates to over
100 horsepower in the case of a current-specification
Formula One engine.

Despite this constraint, however, by incorporating lessons
learned from the 1994 Zetec-R program as well as from a
number of ongoing research projects, Ford and Cosworth
engineers have already substantially exceeded their
performance goal of reaching 86 per cent of the power
output of the 3.5-litre Zetec-R.

In fact, the 1995-specification engine already boasts the
highest horsepower per litre figure of any naturally
aspirated engine the company has ever produced. Despite
this drive for power, however, it was not the primary
consideration of the engineers.

"Peak horsepower has never been our objective," says Peter
Gillitzer, Ford's Director of European Motorsport. "We have
always sacrificed peak power for mid-range torque. The
majority of European circuits respond to driveability and
consistenfiy progressive torque. We think this will be of
even greater importance in 1995, when all teams will suffer
from reduced downforce."

In short, then, the 1995 specification Zetec-R is already a
better engine for a given. capacity than it was in 1994.
That has got to be good news for the Sauber-Ford team, but
a worrying development for the rest of the Formula One
grid.


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Source: PP Sauber AG
Scan & ocr by Tero Virta
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