By
Randy Bolig August 23, 2018The week is almost over, and once again, another Thursday has arrived. I don’t know about you, but since the weekend is getting close, I have already planned what I’ll be working on in the garage. If your garage plans involve choosing or installing a camshaft in your hot rod or classic, we can help with that. No, we are not going to change the stick for you, but we can help make sure you understand everything there is to know about those required valve actuators. Once again, we celebrate another editorial look-back, and jump into the way back machine to open the
Power Automedia vault that houses our vast collection of articles and revisit another great informational piece.
Early cam grinders could not have pictured the overlapping of timing events, the amount of lift in the cam lobes, or the steep ramps on either side of the cam lobe like the camshaft pictured above. They didn’t have to – the engines for which they ground cams were low-RPM engines.
In this
Throwback Thursday, we’re taking a small jump back to August 2013. That’s when we reached out to the folks at
Lunati,
Comp, and
Crane camshaft companies to put together,
Camshaft 101: The History And Substance Of Camshafts.The original article wasn’t one that discussed the best camshaft for a given application. There are way too many variables between every engine to do that. But, the sole purpose was to take a brief look at the history of camshafts, the men and companies that started grinding camshafts for increased performance, and lastly, talked about the current trends and where the future of camshaft design was heading.
Roller camshafts require a cam follower that incorporates a roller bearing where the follower makes contact with the cam lobe. The ramps on roller camshafts are too steep for flat-tappet cam followers to ride, without digging into the cam’s lobe.
Comp Cams’ camshaft specialist, Jay Adams said, “Most of the time, it is easier to move the torque throughout the RPM range with a custom cam – in race applications – because the intended operating RPM range is significantly more narrow than we’d find in a street car. Because you’re custom tailoring the camshaft to a more narrow RPM range, changing where the cam is degreed will tend to make more of a dramatic effect, and the results tend to be more immediate and more easily felt with a custom grind.”
Most camshaft grinds cannot be measured by the naked eye. The manufacturer’s specification card that comes with each camshaft gives you the necessary information.
is full of many more quotes from specialists, and Smokey Yunick even gets to deliver some input. Steve Slavnik of Lunati Cams even added some important information, like, “The biggest mistake is not appreciating the fact that a flat-tappet does need a break-in. Light springs used to be the standard in the industry for break-in, but if you’re not an engine builder and don’t have the facilities, it’s a pain to change the springs.”There is a lot more information in the original article, and lifters are even discussed in great length. If you’re looking for some insightful suggestions from multiple, professional sources, check out
Camshaft 101: The History And Substance Of Camshafts. You’ll be glad that you did.