Schrick Camsafts: Renault

Schrick Camshafts and Adjustable Timing Gears for Renault Engines.

What is the difference between a sport camshaft and a standard camshaft?

Standard camshafts offer a good compromise between the daily requirements from an automotive engine; sustained high speed on open roads, smooth engine idle at low rpm and low exhaust emissions.

If the importance of one or more of these parameters are reduced, the camshaft can be designed to function better in the remaining parameters.

Racing camshafts offer a substantial power increase at high rpm but smooth engine idle at low rpm is not possible any more with this type of cam. This is why Schrick offer a Sport road cam which has a smooth idle and good middle to top end power.
Schrick Sport camshafts increase the valve lift, valve opening duration and the inlet/outlet valve overlap, improving the cylinder filling at high rpm.

Why are Schrick Audi camshafts so special?

• They are manufactured by highly qualified specialists, who also supply the automotive industry.
• They are machined to precise tolerances, using the latest CNC machines.
• They are usually made from expensive, extremely ware resistant "chilled" cast iron.
• Warranty: 1 year with out kilometre limitation.
• The only manufacturer to design camshafts with the "Swing-boost" effect.

What is the "Swing-boost" effect?

After long experimental - and test procedures, we have developed a method of high acceleration to the inlet - and exhaust valves. This causes an intensive resonance amplification of the gas column in the inlet tract, resulting in a very good cylinder filling.

The difference to other manufacturer's camshafts: we reach similar or better max. power figures, but with much smaller opening duration's.

Smaller opening duration's means substantially better torque delivery in the mid- to lower rpm range and a smoother, stable engine idle.

 

Which camshafts are good for street tuning?

If the vehicle is intended for normal street use. i.e. with a stable engine idle and the ability to pass an emissions test (idle to lower rpm range), it is important to consider a small valve lift at TDC.

This table gives a guideline for valve lift at TDC.

2 Valve engines with solid lifters 2.3mm

4 Valve engines with solid lifters 1.5mm

2 Valve engines with hydraulic lifters 1.9mm

4 Valve engines with hydraulic lifters 1.1mm

When these values are exceeded, the engine idle will become increasingly unstable and the torque delivery in the lower rpm range be noticeably weaker.

Camshafts with larger valve duration's, and a resulting higher valve lift at TDC, should only be considered for racing applications, or when each cylinder has it's own butterfly valve i.e. 2 twin-choke carburettors on a 4 cylinder engine.

Schrick Vernier Cam Timing Gear

 

What precaution must be taken with valve springs?

When recommended the use of special valve springs, it is advisable to do so. SCHRICK camshafts usually have an increased valve lift. If the standard valve springs are used, it is important to increase the springs installed hight, so that the increased lift will not overly compress the valve springs (possibly causing spring breakage or unacceptable cam/follower loads).