Listed below is a group classification for the custom (or high) performance camshafts listed in this catalog - (the durations shown are based on .050 cam lift). The descriptions within each group show the characteristics of the cams in that group as well as any recommended modifications to the car or engine that will help get the desired performance. Good idle quality. Low RPM torque and mid range performance. Will work with stock or slightly modified engine. Manual or auto transmission.
CLASS I (200° - 215°)
Good idle quality. Low RPM torque and mid range performance. Will work with stock or slightly modified engine. Manual or auto transmission. Possibly lower vacuum than stock.
CLASS II (215° - 230°)
Fair idle quality. Good low to mid range torque and horsepower. Will work with stock or modified engine. Manual or auto transmission. Possibly lower vacuum than stock.
CLASS III (230° - 245°)
Rough idle quality. Good mid to high RPM torque and horsepower. For use with manual or high stall auto transmission. May need improved carb, exhaust and ignition systems. Comination street and d rag. Will have lower vacuum than stock.
Rough idle quality. Mid to high RPM torque and horsepower. For serious racing. Need proper selection of rear axle ratio and improvements in carburation and exhaust systems. For use with manual transmission or automatic with a very high stall converter. Will not have enough vacuum for power accessories.
Melling Select Performance recommends using MELL-LUBE Engine Assembly Lube to prevent scoring or galling during engine start-up. MELL-LUBE also contains corrosion inhibitors to prevent rust and pitting to new engines. MELL-LUBE is not for use on cylinder walls or piston rings. MELL-LUBE now has 1,400 PPM zinc for better protection.
- Always install new lifters (followers) with a new camshaft. Installing used lifters with a new camshaft can cause premature failure of both the camshaft and the lifters.
- Do not allow the engine to run under 1500 RPM for the first 20 minutes. The first few minutes of the engine operation are the most critical and tests have shown that if there is no metal pickup or spalling during this period, the camshaft will wear as long as the other engine components.
- With performance camshafts - usually you will have to advance the distributor timing (on the vibration damper) more than stock specifications.
- When installing any high performance or racing camshafts into an engine, check to make sure there is adequate clearance between the valves and pistons and also make sure the valve springs do not compress solid.
- On all engines equipped with roto-coils or valve rotors in either the intake or exhaust positions check for possible coil bind. You might have to change the valve spring and retainer - (using aftermarket high performance valve springs is an alternative).
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