Spun 5 rod bearings
02-10-2017, 02:34 PM
#21
Well I've heard that before but after the engine is running some oil gets behind the bearings anyway. But getting assembly lube behind the bearings certainly isn't a good idea. There is something telling in the fact the bearings get worse as you go back...........I have to think on this.
Long long time ago back in the 70's I built a engine SBC and being a novice I dipped all the bearings before installing them. I didn't have any trouble with failure BUT the engine did turn very tight by hand. For sure I never did it again.
Long long time ago back in the 70's I built a engine SBC and being a novice I dipped all the bearings before installing them. I didn't have any trouble with failure BUT the engine did turn very tight by hand. For sure I never did it again.
Also, when everything was together, the rotating torque/resistance was pretty low. Everythign felt great and smooth
02-10-2017, 04:42 PM
#22
Also being overfull with oil can cause aeration or foaming and lead to that bearing demise even though everything checked or felt fine
Lastly. New rods are usually on the low limit for sizing Most every new, no matter the brand, I've had the pin bushing clearance doubled from .0004" to .0008" and the big ends always get a few licks once the bolts have been cleaned, new ARP lube on just the threads and EPL (extreme pressure lube) on the underside of the bolt head. This way your torque spec is met with fastener stretch and NOT resistance to rotational twist. Always check for repeatability with rod bolts and big end size so bearing crush is consistent
Lastly. New rods are usually on the low limit for sizing Most every new, no matter the brand, I've had the pin bushing clearance doubled from .0004" to .0008" and the big ends always get a few licks once the bolts have been cleaned, new ARP lube on just the threads and EPL (extreme pressure lube) on the underside of the bolt head. This way your torque spec is met with fastener stretch and NOT resistance to rotational twist. Always check for repeatability with rod bolts and big end size so bearing crush is consistent