Re: Dart SHP Cam bearing failure
Posted: Tue Oct 17, 2017 2:33 pm
I have seen the melted Durabond bearing issue in several engines in the past couple years year.
Even with the bearings with a single hole clocked correctly to promote oil wedge they melted.
These were both the std and HP non coated bearings. We switched to the HP coated bearings and the issue went away.
As mentioned there is bearings available with several holes drilled in them but I have had to drill others to provide adequate oiling to the cam journals.
In both stock blocks as well as aftermarket blocks there has been the same issue with melted bearings not specifically #4 but I have seen 3-4-5 have an issue.These were also not heavily loaded with higher spring pressures as well maybe 130/375 at most for spring loads but all have been chevy's
Again the coated HP bearings with 2-3 oil feed holes have provided better protection against the issue todate.
Now I just add the extra holes regardless or groove the bearing back if not available to provide a better oil supply
Even with the bearings with a single hole clocked correctly to promote oil wedge they melted.
These were both the std and HP non coated bearings. We switched to the HP coated bearings and the issue went away.
As mentioned there is bearings available with several holes drilled in them but I have had to drill others to provide adequate oiling to the cam journals.
In both stock blocks as well as aftermarket blocks there has been the same issue with melted bearings not specifically #4 but I have seen 3-4-5 have an issue.These were also not heavily loaded with higher spring pressures as well maybe 130/375 at most for spring loads but all have been chevy's
Again the coated HP bearings with 2-3 oil feed holes have provided better protection against the issue todate.
Now I just add the extra holes regardless or groove the bearing back if not available to provide a better oil supply