Other related articles: Selecting the right Camshaft, Static vrs Dynamic Compression.

I get a lot of e-mails requesting cam recommendations. The biggest confusion is selecting the right lobe center, as most do not understand it. Last night, I typed a response and
post it here. Hopefully it will help explain lobe centers, why they are changed, and will assist some of you when the time comes for making your own cam selection.

The lobe center controls where the power curve is applied.  The higher the lobe center, the lower the rpm range. In general, two degrees is equal to approximately 500rpm. This cam with a 112* lobe center will come on around 2500 RPM. Changing the lobe center to 110* will raise the point where the cam starts working (kicks in) to about 3000 RPM. And changing it to 108* will raise it to approximately 3500 RPM.

Therefore, if a cam with a 112* lobe center performs best from 2500 RPM to 6000 RPM, the same cam with a 110* lobe center will perform best from 3000 RPM to 6500 RPM. While the same cam with a 108* lobe center would perform best from 3500 RPM to 7000 RPM, which is better suited to drag racing, where top end performance is desired over bottom end torque.

However, a cam with a 112 lobe center will idle better than one with a 110* lobe center. And a 110* better than one with a 108* lobe center.  A 112* will generally have a smooth idle, 110* will be a bit lopey, and 108* will be choppy. The 108* cam is fine with a manual tranny, but an automatic may require a matched stall converter (3200-3600 RPM stall) for the best results.

Inches of vacuum may also be of concern if you have vacuum assisted accessories, such as power bakes. This cam with a 112* lobe center will pull 16-20" of vacuum (good for power brakes). With a 110* approximately 14-18" of vacuum (still OK for power brakes), and with 108* about 12-16" (which may be borderline for power assisted accessories). This can vary a few inches one way or another, depending on several other factors, and your individual engine specs. But this will give you some idea of the manifold vacuum they pull, and needs to be considered if using power assist accessories.

You just need to decide which will work best for your application. If you want a smooth idle and do highway driving where passing power is of concern, the 112* might be best. If you do a lot of light-to-light driving, and like a lopey idle, the 110* would be better. But if you want to eat V8's off the line, and don’t mind a choppy idle, the 108* is far better suited. Basically, it comes down to a compromise between performance and idle quality, base on your specific driving requirements.

You asked about a cam with a 114* lobe center, which we would not recommend for a street cam, as you would have no high end performance for highway driving. I hope this is clear and helps you in choosing the right lobe center for your application.

A last word of advise. Once you get your cam and are ready to install it, be sure to pick up a Cam Degree Kit and degree the cam to the manufacturers specs when installing. Many manufacturers suggest installing the cam three or four degrees advanced. This also lowers the power curve of the cam and increases low-end torque. At the same time, it sacrifices top end power, but more is gained on the bottom end, than is lost on the top end. It should also be noted that some manufacturers, such as Comp Cams, grind their cams with a 4-degree advance automatically included. So you need to verify this prior to degreeing the cam.

Other related articles:

Static vrs Dynamic Compression - Cam Installation Tips
How to Degree Your Cam - Adjusting Your Valves
Clay Smith Cam Cards - Clay Smith Cam Profiles