[Lynn]

Ron,

For every day use and in the short run, there is probably very little difference. I think that, when needed, the main savings is in heat. I was somewhat surprised that most of the NASCAR engines, that run for any length of time, run spray bars on their valve springs just to pull the heat out of them. The heat, they say, leads to high variation in spring pressures, at best, and broken springs, at worst. So the friction of the non-roller rocker can add significantly to the heat buildup in the valve spring combo that they would go to great lengths to avoid. The spring pressure variation leads to valve float which is like public enemy number one for those guys. I would imagine that all of this holds true for just about any kind of racing engine, especially endurance racing, but I just learned about it from the NASCAR engine builders.

Regards,
Lynn