4. How does increasing or decreasing duration affect my engine performance?

Duration has a tremendous amount of affect on engine behavior -most notably, the rpm at which its peak torque is produced. Shorter duration camshafts (or “mild” cams) produce more low rpm torque, while camshafts with larger duration (or “bigger” cams) will tend to increase upper rpm horsepower at the expense of low rpm torque. In general, for every 10° increase in duration, the torque peak of the engine moves up by 500 rpm.

5. I currently run a solid flat tappet cam. Is it worth the investment to upgrade to a solid roller cam?

The simple answer to this question is yes -if it’s in your budget. Solid roller designs use the latest and most advanced profiles that we offer. Among the benefits are reduced valve train friction, higher engine rpm capability, and use of faster ramp profiles, which generate higher power and torque by snapping the valve open and closed more quickly.

Solid roller camshafts and related component technology has come a long way in the last 10 years. Today, a solid roller setup can be durable and offer incredible performance. COMP Cams® offers a high quality, Endure-X™ lifter which features a tool steel axle, EDM Oil Injection and precision sorted needle bearings. Endure-X™ lifters are available for a variety of engines with different offsets and lifter body heights.

6. How does compression ratio affect camshaft selection?

The key factor to consider here is cylinder pressure. If you have a lower compression motor, say 9.5:1, and you use a camshaft that is fairly large (increased overlap between lobes –which allows both the intake and exhaust valves to be open at the same time) then you will bleed off cylinder pressure and in effect – horsepower and torque.

On the other hand, if you’re running a high compression race motor and your camshaft has a minimal amount of overlap, the cylinder pressures can go sky high. This is far less of a problem for race engines than it is for street-bound engines, but it should be considered and factored in at the time that you choose your cam. In addition, the type of cylinder heads that you’re using and the quality of available fuel should be taken into consideration. If you have to stick with pump gas, the rule of thumb is to limit compression to 10:1 with cast iron heads and 11:1 compression with aluminum heads.

7. I have heard stories about people having issues with flat tappet break in. What does COMP Cams® offer to help reduce the chances of flat tappet failure?

Due to federal legislation, motor oils no longer contain certain anti-scuffing agents that played a critical role in flat tappet camshaft break in. While incorrect valve spring pressure and not following proper break-in procedure are often the culprits, the changes in oil formulation have brought about a need for additional steps to be added to the break-in process.

COMP Cams® has two ways to ensure proper break-in of flat tappet cams. COMP Cams® Engine Break-In Additive (part #159) ensures that the camshaft will have the lubricants that it needs to seat the camshaft journals and lobe/lifter surfaces. This lubricant is poured into the engine crankcase after the camshaft and lifters have been coated with the initial break-in lubricant supplied with the camshaft.

Another option for increasing flat tappet cam longevity is nitriding. Recently COMP Cams® invested in a nitriding machine, the first of its kind owned by a major U.S. aftermarket camshaft manufacturer. Nitriding actually hardens the surface of the camshaft and tappet face by injecting nitrogen “needles” into the metal. The result is an ultra-hard surface on the face of the camshaft lobes and lifter face, which greatly improves the performance and break-in process for flat tappet cams. This process is an additional charge for COMP Cams® camshafts, but for many extreme duty applications, it virtually ensures proper break-in and increased durability.