Thread: General Hemi Info Part 5

Tweet

The crankshaft:

The early Chrysler Hemi’s all come with a steel crank that is more than adequate for street applications. If your going to go racing with one or building the engine to handle a blower/turbo they lend themselves to all the normal race prep procedures of any other quality crank.

One of the things you should spend a few minuets looking at however is the crank flange, primarily the pilot bearing area. I have come across 3 different pilot bearing configurations over the years and think I should bring this up. While the pilot bearing may not be a big deal if you are planning on running an automatic, it is critical if you’re going to run a stick (or if somewhere along the line you decide to convert from an automatic to a manual)

If the engine you are building came from an automatic equipped car chances are the crank has not been drilled for a pilot bearing at all. (See picture 1). The crank going in the 331 is an automatic crank, and while the engine was apart I had it drilled for the standard Chrysler pilot bearing just in case at some point I want a stick behind it.

On some of the industrial engines, the pilot bearing hole is VERY large. The good news is these are set up to use a sealed bearing and all that is required is one with a right inside and outside diameters. (See pictures 2 and 3).

Some of the cranks are just right and will take a standard 60’s-80’s Chrysler pilot bearing. I have also heard of some cranks having a pilot bearing hole that is just slightly larger that the common Chrysler bushing, in this case they do make an oversize bushing that will fit the crank with the proper interference fit (I picked up one of these some time ago “just in case”).

If you’re going with an aftermarket transmission adaptor is should come with the required pilot bearing/bushing.


Finally, when you have your block back and you put in on the engine stand, take a few minuets and make sure the crankshaft will actually go into the block with the engine stand head on. The Early Hemi cranks have a pretty good overhang, and it may be necessary to add some spacers between the engine stand head and the block so the crank will sit in the journals.