Engines and Components

A crate engine is a new, complete engine from the manufacturer that offers reliability and warranty coverage. A rebuild involves refurbishing your existing engine, which can be more cost-effective but requires a qualified builder and has no warranty.

Camshaft selection depends on your engine combination, intended use (street vs track), and power goals. Consider duration, lift, and lobe separation angle. A mild street cam improves performance without sacrificing drivability, while aggressive cams require supporting modifications.

After initial startup, vary engine speed between 2,000-4,000 RPM for 20-30 minutes to seat the piston rings. Avoid prolonged idling. Change oil and filter after break-in, then drive moderately for the first 500 miles before full-throttle operation.

Signs include cracks between valve seats, excessive warpage, damaged valve guides, and corrosion from coolant leaks. A pressure test and visual inspection by a machine shop can determine if heads are serviceable or need replacement.

Street engines with pump gas typically run 9:1 to 10.5:1 compression. Higher ratios (11:1+) require premium fuel and careful tuning. Boosted engines need lower compression (8:1-9:1) to prevent detonation. Match compression to your fuel and intended use.