Air Filters
Always start new engines with air cleaner assemblies installed. Anytime the engine is off and a change in the timing, fuel pressure, jets, pills, bypasses, or reinstalled spark plug wires etc… Always install air cleaner as a flame arrestor to avoid a fire from backfiring, and fuel spitting. When an engine belches it can throw flaming fuel on your racecar and you, or light any raw fuel on the intake manifold or rags. The air cleaners can be removed as soon as the engine is started. This is especially important safety precaution for alcohol, injected, or supercharged engines.
Warm the engine up (See oil section regarding preheating). If engine wasn’t dynoed and has a flat tappet cam, add 2 extra quarts of oil and ZDDP cam break-in supplement. Warm the engine up at idle or a little faster idle for 30 minutes minimum. Don’t run at 1500 rpm like they recommend as exhaust temperature will have about 1300 degree temp at that rpm. All that brutal heat on new not carboned(heat isolated ) parts is crazy! You can throttle motor up to set timing and initial tune engine, just don’t hold at a steady higher rpm for extended time (roller cams you don’t need to do this). Always keep an eye on the oil pressure! Dedicate someone to always keep an eye on the oil pressure and water temperature until everything has been successfully verified. This is the opportunity to check header tubes for dead cylinders, look for leaks, set water level, rough tune ignition timing, injector, fuel pressure, and carburetors etc…
After 30-45 minutes shut off engine and change the oil and filter. This is especially important on flat tappet cams because the special cam lubricant that is used on camshaft will plug the oil filter. Pour in more ZDDP cam break-in supplement if using flat tappet cam along with new oil. Re-torque the heads to spec, mark all head fasteners with an alignment mark to verify how far each one moves, fasteners MUST MOVE. If they don’t, back off a little to break the thread set, then torque. They all should move 1/8 to 1/4 of a turn. If using head studs on aluminum heads allow time for engine to cool before re-torqueing. Reset lash, retorque intake manifold, check carb bolts, and headers, etc…