The highest of all performance level camshafts; solid rollers are designed for both high performance street through all-out racing applications. They feature the most aggressive camshaft lobe profiles and withstand the highest valve spring pressures. As with their solid flat tappet camshaft cousins, they are noisier than hydraulic camshaft systems, particularly when cold, yet they deliver more performance and throttle response, especially when adjusted to "tight" lash settings of 0.010" - 0.012". The solid roller camshaft also uses roller lifters that do not include an adjustment for valve train component expansion due to internal engine heat and requires regular lash adjustment service to deliver top performance. Solid roller lifters can be re-used, however are more costly than flat tappet lifters.