Re: Having a bummer day..... (crankshaft)

Posted by Jack Vines On 2017/7/17 10:30:51

Hi, Fred,

Over the years, we've had the running discussion about the oil pump dip tube modification, the oil pump pressure relief modification, the cam retainer plate and spacer modification and the rocker arm modification.

What has never been proved is how these relate to the vacuum pump, the lifter clicking and which relate to the main bearing problems.

The one thing which is certain is it is common to find Packard V8s which had problems requiring the crankshaft mains to be turned .010" or .020" undersize, while retaining the standard rod bearings.

It is also common upon teardown of core engines to find the center #3 main totally trashed and #2 and #4 worn into the copper.

Of course, the problem is documenting how the engine was operated and maintained before becoming a core for rebuild. These were often orphan cars, sold cheap to large families and used until the transmission failed. Burning regular grade fuel, no oil changes, no tune-ups, all exacerbate failure modes.

jack vines