Many older engines use flat-tappet camshafts, where the lifters slide on the cam lobes. The first minutes of running are critical, because this is when the lobes and lifter faces wear in together. A poor break-in can wipe a lobe and send metal debris through the engine.
Before Startup
- Always install new lifters with a new camshaft. Used lifters are worn to the old cam and should not be reused on a new one.
- Coat the cam lobes and lifter faces with the assembly lubricant recommended by the camshaft manufacturer.
- Use an oil with adequate anti-wear additives, or a break-in oil or additive, for flat-tappet break-in.
- Prime the oil system and confirm oil pressure before the first start.
- Check that the lifters rotate freely in their bores and that valve spring pressure is appropriate for the cam.
During Break-In
Start the engine quickly, without long cranking, and avoid idling. Many camshaft manufacturers recommend running the engine at a moderate speed, often around 2,000 to 2,500 RPM, for about 20 to 30 minutes while varying the speed slightly. Follow the instructions supplied with the camshaft. Monitor oil pressure and coolant temperature throughout.
After Break-In
Change the oil and filter after the break-in period to remove assembly lube and wear particles. Continue to use an oil suitable for flat-tappet engines.
Common Causes of Lobe Failure
- Reusing old lifters.
- Excessive valve spring pressure during break-in.
- Extended idling or long cranking on the first start.
- Insufficient lubrication or the wrong oil.
Evergreen Camshafts and Lifters
Evergreen offers camshafts and lifters by engine application. Use the Evergreen eCatalog to find the matching camshaft and lifter set.
