Why Are Pushrods Bad (by Ruaraidh)

Right then,

"Pushrods are bad as the valvetrain is heavy and so consequently can't be revved."

True.

"Pushrods are bad as the valvetrain is flexible so aggressive camshaft profiles can't be run."

True.

This means that Pushrods are bad as we can't run at higher engine speeds to make power. This means that specific horsepower is poor.

This means to make more power we just throw capacity at the problem.

This means that when we don't want ALL the power the fuel economy is shocking.

Pushrods are bad as they result in inefficient engine designs. However, they are dirt cheap and simple (no complex head casting).

OH NO NOT THIS ONE AGAIN!!!!:

A big V8 shoves you along as it makes loads of torque at low speed. Moderate power.

A smaller engine makes less torque but makes it at a higher speed = same power. Result equal performance. However, you only need a small engine to do it. This means that fuel econ is better.

Psychologically, however, the smaller engine feels like its working harder. Despite the fact that both engines are making the same power......

That's where all this torque myth comes from. Forget torque just think about power.

Low end torque is just power produced at a lower speed........
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Cheers,

Ruaraidh