REBUILT Engine BREAKIN
- Thread starter Roadster62
- Start date
Chuck Sea/Tac
Well-known member
Not exactly, they were "burnishing" the bearings until the resistance became in spec.
Does anyone know the procedure for fitting bearings from the factory? In other words, did they just throw the engine together ., counting on precision machine work, and then burnish them in, or were the bearings more "hand" fit?
Does anyone know the procedure for fitting bearings from the factory? In other words, did they just throw the engine together ., counting on precision machine work, and then burnish them in, or were the bearings more "hand" fit?
edmondclinton
BANNED
Many engine rebuilders set the bearings at a light drag. This is possible only because of the oil grooves. Otherwise, without the grooves the bearings would be toast in short order.
New babbitt bearings are often set to a light drag so one can get more miles of wear before needing adjustment.
So, if an engine is set "tight" one would be an idiot to just get in and take off at higher speed or in other words, break in like you're going to drive it. Too much heat and friction would be generated.
So unless one knows otherwise, it's best to putt around, so to speak, at varying lower speeds and loads until the engine frees up some. Unless of course if an engine has been blueprinted and all clearances are on the loose side.
One can easily see if an engine has loosened up just by watching the fan when the ignition is turned off. If the engine is still tight, the fan, and of course the engine, will stop abruptly almost like it locked up.
When the engine is free, it will rock on compression when the ignition is turned off and one can see it in the fan as it stops and changes directions just for an instant. Also, one can hear the familiar cough or hiss that comes out of the carburetor.
New babbitt bearings are often set to a light drag so one can get more miles of wear before needing adjustment.
So, if an engine is set "tight" one would be an idiot to just get in and take off at higher speed or in other words, break in like you're going to drive it. Too much heat and friction would be generated.
So unless one knows otherwise, it's best to putt around, so to speak, at varying lower speeds and loads until the engine frees up some. Unless of course if an engine has been blueprinted and all clearances are on the loose side.
One can easily see if an engine has loosened up just by watching the fan when the ignition is turned off. If the engine is still tight, the fan, and of course the engine, will stop abruptly almost like it locked up.
When the engine is free, it will rock on compression when the ignition is turned off and one can see it in the fan as it stops and changes directions just for an instant. Also, one can hear the familiar cough or hiss that comes out of the carburetor.
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