Making the type four rev higher Options

[Trekkor]

I have a VW Bug race car with a type four motor.

I would like it to safely rev up to 6500-7000 rpms.

What is needed to accomplish this?

thanks

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KT

[stugray]

they bounce off the seat because the springs cant control the weight of the valvetrain any more.

I thought that the problem occurred at the opposite end of the valve travel.
When the valve has enough momentum to "jump" off the top of the cam lobe and travel past full open.
This would cause the valve to travel farther than the cam is trying to open the valve.
The full open point is when the spring is trying to hold the valve back and the spring is at it's greatest force.

At the opposite end of valve travel (the one you are talking about) the valve is closing and the momentum of the valve is pushing against the rocker (and therefore the cam lobe).

Now IF the lifter has not come down to rest on the cam lobe from the overshoot at max open, then I could see that the valve train would be in "freefall" and the valve seat would stop the valve.

Do they really "float" so far for that to happen?

Stu - Maybe confused?

[messix]

they bounce off the seat because the springs cant control the weight of the valvetrain any more.

I thought that the problem occurred at the opposite end of the valve travel.
When the valve has enough momentum to "jump" off the top of the cam lobe and travel past full open.
This would cause the valve to travel farther than the cam is trying to open the valve.
The full open point is when the spring is trying to hold the valve back and the spring is at it's greatest force.

At the opposite end of valve travel (the one you are talking about) the valve is closing and the momentum of the valve is pushing against the rocker (and therefore the cam lobe).

Now IF the lifter has not come down to rest on the cam lobe from the overshoot at max open, then I could see that the valve train would be in "freefall" and the valve seat would stop the valve.

Do they really "float" so far for that to happen?

Stu - Maybe confused?

From the research I have done and what I have seen. It depends on the harmonic rate of the springs.

Yes the momentum of the valve train can and does somethimes by design continue to lift off the lobe. But the problem with the stock springs is age,low lift cams,poor cam design, and heavey valvetrain.

The stock heads don't even use spring dampers. So there fore I assumed the probable cuase of "valvefloat" on his engine to be poor harmonic response and inadequate valve control on a low lift cam.