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| BMW
Performance Engines of the Past & Future |
If you're reading this website, you're probably
enthusiastic about performance. |
| The '70's |
| In the 70's, "Performance" usually meant side draft carburetors,
a hot cam, headers and a loud exhaust. If the engine made a lot of induction
and exhaust noise, the customer thought he had a hot car (noisy cars seems
to produce the illusion of going fast). |
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| The '80's |
| By the '80's, fuel injection was definitely in, plus quiet exhaust,
fuel economy and emissions. By this time all BMW's were equipped with
catalytic converters and fuel mileage was up. By the mid '80's, performance
was in. The 3 series cars got the 2.7 liter "Baby Six" and the
5 series cars got the 3.3 liter "Big Six", but not without sacrificing
fuel economy and emissions. |
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| The '90's |
As we look to the future of the automobile, it is becoming more and
more apparent that these three elements must exist in harmony;
- Performance
- Emissions
- Economy
At Metric Mechanic, the formula for building a high performance engine
does include emissions and economy. Since 1987, our philosophy has been
not to sacrifice economy & emissions, just for the sake of performance.
Now, more than ever, we find ourselves aligned with this thinking. As
we look to the '90's, our objective is to build engines that are Clean,
Lean and Mean! |
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| The Balance of Horsepower & Torque |
| At Metric Mechanic, all our engines are designed to have a balance of
horsepower and torque. We feel this is the key to good driveability. Our
engines, in general, produce peak horsepower at about 5800 rpm and peak
torque at about 4000 rpm. When this happens, horsepower and torque will
be equal. Engines that have quite a bit more torque than horsepower tend
to feel strong on the bottom end but dead on the top end. High Horsepower
engines that are low on torque feel just the opposite. |
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| How We Build a Balance of Horsepower and Torque |
Horsepower
The horsepower increase in our engines comes from our head design. The
HiFlo ST Sport head has an 18% flow increase over stock for better breathing.
Surface Turbulance™ has been added for increased fuel economy and
lower emissions, but it also reduces detonation and allows for an increase
in breathing with a minimal effect on emissions and fuel economy. |
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Torque
The torque that our engines produce comes from the block. Because torque
is directly related to displacement, all our engines are made larger.
We do this by boring and stroking. Stroking also adds more leverage to
the crankshaft (more torque). Reciprocating mass has been greatly reduced
inall our engines. Although our head and block perform two different functions,
when coupled together as a unit, they produce a balance of horsepower
and torque. |
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| Mechanical Upgrading Before we embark on redesigning
a particular BMW engine, we first take a hard look at it's reliability
problems. All our enginesm even the least expensive models, have been
mechanically upgraded. Longevity is planned for first, then performance.
We combine a traditionally proven design with creative engineering
to make our engines up-to-date performers. |
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| Defining the Metric Mechanic Engine Models |
* 2200, 2500, 3200, 3500, 3800 & 4000 - Equals the approximate engine
size in cc.
* HiFlo - A head ported for approximately 18% airflow increase.
* ST - Surface Turbulance™ which results in fuel efficiency and
emissions.
* Sport - If Sport is listed in the name, the engine has a Sport Cam.
If Sport isn't listed, then the engine has the stock cam. |
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