The two most commonly used methods to break in a rebuilt engine are dynamometer or load bank testing. However, these methods of engine testing aren’t always possible. If a rebuilt engine isn’t broken in correctly issues can arise including high oil consumption, excessive smoking and overall poor engine performance. This blog article looks at how to break in a rebuilt engine without the use of a dynamometer or load bank…
Why Should You Break In a Rebuilt Engine?
The process of breaking in an engine involves forcing rings and cylinder bores to conform to each other, sealing the combustion gasses within the cylinders. Unfortunately, idling the engine for a period of time will not create the pressures needed. Without serious force, piston rings may not seal properly – resulting in poor oil control and diminished engine performance overall.
Dangers of Not Breaking In a Rebuilt Engine
Improper or inadequate breaking in of rebuilt engines causes what is known as ‘glazing’, which prevents piston rings from ever sealing correctly. Glazing refers to how hard oil and fuel deposits collect on the cylinder walls of an engine. Once this happens, the only way to rectify the issue is to dismantle the entire engine again and break it in correctly.
Just Rebuilt an Engine? Here’s How to Break It In:
Apply Make-Shift Loads
Most engine rebuilders agree that to correctly seal the piston rings, you need to focus on getting around 75% of full load on the rebuilt engine for a few hours – keeping idle time to a minimum. Ways of breaking in vehicular engines include:
- Attach a heavy trailer, find a long steep hill, and drive up it once or twice.
- Drive up to the speed limit as fast as you can then, while still in gear, release the throttle and let the vehicle coast to a complete stop.
Utilise Break-In Powders
They might be a little old-school, but many engine rebuilders still swear by them! We’re talking about break-in powders, like Caterpillar’s 7F5225 powder. Here’s how to correctly utilise a break-in powder when breaking in a rebuilt engine:
- Reassemble and start the engine,
- Loosen air cleaner on each bank of cylinders (leaving a gap between flange and inlet manifold),
- Run engine at 800RPM and allow powder to be sucked slowly through gap (1.25 teaspoons per cylinder,
- Tighten air cleaner, idle engine for 30 minutes, and it should be ready for service.
Call the Professionals
Still unsure if you’ve rebuilt your engine correctly and you’re concerned about proper breaking-in procedures? When in doubt, call a certified engine reconditioning specialist and get advice directly from the professionals. They should advise you on the best way forward, ensuring that you provide your rebuilt engine with the careful attention it deserves!
Engine Rebuilding Professionals in Durban
Eagleharm Engineering has been refurbishing engines of all makes and sizes for near on 50 years. We’re held to high standards of service efficiency, and therefore utilise only the most effective techniques to break in our rebuilt engines. Contact us today for more information on the fine art of engine reconditioning!