The Proper Camshaft For Your Application

Common Usage: Mild street performance to mild race Key Benefits: Modern, aggressive roller profiles, reduced friction, low maintenance, reduced valve train noise, more power than conventional hydraulic flat tappet camshafts Limitations: Increased cost, limited rpm range Select a camshaft for your application?

Frequently used in today’s OEM factory engines and mild to moderately aggressive performance engines, hydraulic roller cams use lifters equipped with a roller wheel that tracks along the camshaft lobe, reducing wear and friction, and enabling faster lobe ramp rates than flat tappet cams. These quiet operation lifters feature the same internal design as hydraulic flat tappet lifters with internal cavities and pistons but do not rotate within the lifter bore. Suited for typical street or moderate race engine speeds, the lifters are pre-loaded and do not require a lash setting. Most OEM hydraulic roller camshafts are limited to 6200 rpm and performance aftermarket systems to approximately 6800 rpm. Hydraulic roller lifters require an appropriately selected valve spring to maintain control and avoid lifter float at higher engine rpm. Hydraulic roller lifters can be re-used with multiple camshafts, however they are more costly than any form of flat tappet lifters.

Common Usage: Mild street performance to mild race Key Benefits: Modern, aggressive roller profiles, reduced friction, low maintenance, reduced valve train moise, more power than conventional hydraulic flat tappet camshafts Limitations: Increased cost, limited rpm range, profile limitations Select a camshaft for your application?

These cams contain all of the same benefits and limitations as a standard hydraulic roller cam; however they include a specialized base circle to accommodate the taller hydraulic roller lifters in blocks that were factory equipped with a flat tappet valve train set-up.

Common Usage: Mild street performance to mild race Key Benefits: Minimal maintenance, little or no valve train noise and economical cost Limitations: Long-term wear, limited rpm range, lobe profile limitations Select a camshaft for your application?

A popular street camshaft used with pre 1985s original overhead valve OEM engines, the hydraulic flat tappet cam is commonly used in up to mildly aggressive performance profiles. The flat tappet lifter has a flat appearing base (this surface is actually slightly crowned) that rides on the cam lobe face, rotating slowly within the lifter bore to promote proper oiling. Internally, the lifter features a cavity that fills with oil and a piston that is depressed by the pushrod (and valve spring). This “hydraulic chamber” provides a cushion of fluid to soften the impact on the valve train, creating room for expansion as the engine reaches operating temperature. Hydraulic flat tappet camshafts deliver quiet operation at street to mild racing engine speeds. The biggest advantage to hydraulic flat tappet lifters is that they do not require constant maintenance to ensure proper valve lash. Hydraulic flat tappet camshafts/lifters are pre-loaded at initial start-up and require little, if any, maintenance from that point forward. Flat tappet lifters can only be used once per camshaft and must be replaced due to wear patterns created by the direct contact of the cam with the lifter base.

Common Usage: Moderate street performance to serious race Key Benefits: Increased engine rpm and profile aggressiveness vs. economical cost of hydraulic flat tappet Limitations: Long-term wear, limited rpm range, periodic valve adjustment required Select a camshaft for your application?

The original race engine lifter, solid (also referred to as mechanical) flat tappet camshafts feature a more aggressive street performance or racing profile and are capable of higher engine rpm than hydraulic flat tappet camshafts. As with the hydraulic flat tappet camshaft, the flat appearing lifter bottom follows the contours of the camshaft to operate the valve train components at the appropriate time, rotating within the lifter bore in a similar fashion to the hydraulic flat tappet lifter. The solid lifter does not have the internal cavity and piston found with the hydraulic lifter and does not expand or contract with engine temperature. Because of this feature, the solid lifter requires an initial cold valve lash setting and then adjustment after the engine has reached operating temperature (hot lash setting) to deliver the engine’s top performance potential. Solid flat tappet lifters also feature a signature performance “ticking” sound, particularly when cold, that many performance fans find attractive as well. The lash setting is adjusted by using a set of feeler gauges to set the proper distance between the rocker arm tip and top of the valve stem when the lifter is on the base circle of the camshaft. Solid lifter camshafts require a certain level of valve lash maintenance at regular intervals. Flat tappet lifters can only be used once per camshaft and must be replaced due to wear patterns created by the direct contact of the camshaft with the lifter base. Special Note: Flat tappet camshafts require a special break-in process to allow the lifters and camshaft to properly mate. These steps include (but are not limited to) using a suitable engine oil with high Zinc (ZDDP) content and reducing valve spring pressure during break-in. For a complete step-by-step break-in procedure, please consult the Flat Tappet Tech Bulletin.

Common Usage: Serious street performance to all-out racing Key Benefits: Maximum performance, reduced friction, most aggressive profiles Limitations: Increased cost, periodic valve adjustment required, not well suited for extended low rpm operation Select a camshaft for your application?

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.

Camshaft Families

Understanding the COMP Cams® camshaft families is a great first step in determining which camshaft is right for you

Today, there are a huge number of aftermarket performance camshafts available. Your challenge: find the right one for your engine application. As you start to research the right cam for your engine, you’ll need to take into account the application and vehicle. Other important details include the engine, transmission, rear gearing, fuel induction system, weight of the vehicle, type of vehicle and all the rest. As any knowledgeable technician can tell you, selecting a camshaft solely based on the fact that it fits your type of engine is a sure recipe for disaster.

Within the COMP Cams® camshaft family,, there are several different types of camshafts available for most popular domestic engines ranging from the Xtreme Energy Cams™ to Nitrous HP™ Cams. So, which one is right for your application? While a simple call to the COMP Cams® CAM HELP® tech line (1-800-999-0853) and short discussion with one of the highly informed tech line personnel will always get you the right answers, having a little personal knowledge on the topic is always a good idea. Any time you are making this kind of important decision about your engine, it’s smart to understand the reasoning behind the selection.

All in the family

While it is important to understand the attributes of the various camshaft families, it is equally important to note that camshaft selection is a individual as the personalities of a customer and his engine. What is perfect for one buyer, regardless of the engine platform, may be totally incorrect for another. In essence, the camshaft family is a good place to begin, but you could end up with a camshaft that is very different from what you originally planned.

Fanning through the COMP Cams® catalog can be a fun endeavor, and while many of the camshafts are categorized by a camshaft family name, more often that not the key determiner is the end usage. Drag racing, pulling/towing, oval track, marine, Nostalgia Plus™, factory muscle or even something like the Tri-Power Xtreme™ are all categories you will discover. It can be confusing for the novice cam buyer – but that is to be expected of a highly technical product such as a camshaft. That’s why a quick call to the COMP Cams® CAM HELP® tech line can help clear the air.

In addition to the CAM HELP® tech line call, you can also shop for your camshaft with our online application CamQuest™, which is available at www.camquest.com. This powerful tool will not only recommend the best camshaft for your engine and application based on the information you provide but will also give you alternative selections to consider. Best of all, the CamQuest™ online application will run a virtual dyno test of your engine with the new camshaft you select so you can see the power and torque you will achieve once installed.  Want to know just how much torque you generate at 2500 rpm? It’s all there.

Regardless of how you ultimately select a camshaft, the key is doing your homework. Research your camshaft online with  CamQuest™ – and then call our CAM HELP® line for verification and suggestions.

Click here to try CamQuest™ Online

Consult with your engine builder and COMP Cams® to determine proper application as these are extremely specialized components.