Engine Break-In. Part 4. Post Flight
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Understanding what happens during the break-in allows us to understand the ideas behind how we should initially operate a new engine.
Generally: Take off at full power and reduce to climb power at the first available safe altitude, all while keeping the climb angle flat and the climb airspeed higher to promote the best cooling possible.
Use between 65% and 85% power at all times when at cruise altitude. Watch CHT's; keep CHTs below 450°F on a JPI EDM engine analyzer. This means step climbing the aircraft if necessary. Periodic climbs at full power act to achieve a higher than cruise B.M.E.P. which helps to seat the rings. Avoid operating at a constant engine power setting for prolonged periods of time. When flying cross country on a new engine, vary your cruise altitude by 2000 feet by climbing at full power, cruise at 75% to 85% power, long descents at 65% power, full power acceleration to cruise speeds then reducing to 75% power, then climbing ..... for the next 30 hours.
I recommend you break-in your new engine (or cylinders) with AeroShell 15W-50. I've been doing it this way since 1991.
Post Flight Test
• Check for leaks at:
-- Fuel and oil fittings
-- Accessory case parting surfaces
-- Engine case parting surfaces
• Check tightness of rocker box cover screws, oil scavenge, intake hoses, and exhaust system.
• Drain oil.
-- Remove oil suction screen (on the bottom of the oil sump). Check for debris or contamination
-- Remove oil filter. Check for debris or contamination
• Compute fuel and oil consumption and compare to limits given in operator's manual
-- If consumptions vary from figures shown in manual, determine the cause before releasing the aircraft for service.
• After all discrepancies have been corrected and the aircraft and engine conform to manufacture's specifications:
. . .
-- The aircraft may be returned to service
Return to service: Owner's responsibilities
• Before each flight: Check
-- engine for obvious leaks
-- baffles and baffle seals for integrity
-- engine oil consumption
-- check engine operations on ground during normal run-up
At 5 hours and 15 hours after engine overhaul
• Change oil, inspect suction and pressure screens or oil filter element
• Check tightness and integrity of:
• rocker box cover screws
• baffle attaching screws and baffle seals
• oil breather tube
• intake hoses and exhaust system
• Remove and inspect lower sparkplugs for oil or oil mist
• Adjust lifter clearances on all engines not having hydraulic lifters per manufacturer's service manual.
At 25 hours and 50 hours after engine overhaul
• Change oil, inspect suction and pressure screens or oil filter element
• Check tightness and integrity of:
• rocker box cover screws
• baffle attaching screws and baffle seals
• oil breather tube
• intake hoses and exhaust system
• Remove and inspect lower sparkplugs for oil or oil mist
• Adjust lifter clearances of all engines not having hydraulic lifters per manufacturer's service manual.
At each 25 hours interval thereafter
• Change oil, inspect suction and pressure screens or oil filter element
• Check tightness and integrity of:
• rocker box cover screws
• baffle attaching screws and baffle seals
• oil breather tube
• intake hoses and exhaust system
At each 100 hour interval or each annual inspection
• Adjust lifter clearances of all engines not having hydraulic lifters per manufacturer's service manual.