CAM AND MAIN BEARINGS SHOT

This summer the engine overheated. The gauge did not bury and probably maxed out at 2/3 of its travel, by the time I shut it down. Some antifreeze and steam came out of the radiator overflow for a few minutes.


When I originally installed this engine I primed it with a drill and I think it had about 60 lbs of pressure on the gauge, that I temporarily installed. But the 69 Swinger only has an idiot light, which I believed worked properly. So, I don’t know what the actual oil pressure was during daily drives.


I temporarily reinstalled the oil pump and oil pan and replenished the oil. I primed the oil pump and a small flow of oil did come out of the holes in the bottom of the bearings. I reinstalled the cam and rotated the cam and the crank in small increments, but no oil came out of the pedestal in each head and it showed no oil pressure on the gauge . But there was a massive stream of oil pouring out from the oil galley behind the No. 8 exhaust lifter bore. And there was no oil in the other bank’s lifter bores. I didn’t think at the time, to reinstall the lifters and see what effect that had. I expect that this is the normal oiling; where the oil goes from the oil pump to the oil galley on the passenger side and is distributed to the rest of the block, if the lifters are in place. Can this be confirmed?


Does anybody have any words of wisdom on the extreme bearing wear? Thanks!
The oil testing described above without the lifters installed is totally invalid. The oil from the pump/filter enters the back of the passenger side lifter gallery and if the lifters are not there, then all the oil dumps out the bottom of the lifter bores. So that testing regrettably did not tell you anything.

IMHO the main bearing wear is not what I would call extreme, but is more than I would expect for 2500 miles. No way to know why for sure... could be infrequent startups, could be the mains bores being off a bit, and all the other things suggested like clearances. The cam bearings could have been too tight to start with; we don't know how the cam and bearings were checked at installation.

Hard to say on the 'overheat'.. the gauge movement is not out of the expected range; and the overflow could be a weak rad cap. But no way to really know without good instrumentation.

Sorry to not be more help.... but the why of bearing wear is as shown could be from quite a variety of issues.