Thread: General Hemi info part 4

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Balancers, Water pumps, Pulleys and Brackets

Many of the early HEMIs did not come with a harmonic balancer, just a pulley built on the end of a hub. Additionally many of the original balancers you find are questionable. While the originals can be rebuilt and Fluidampr also makes an approved one, HOT HEADS sells a modified 318/340 unit that can also be used. The modifications include re-cutting the internal Key way to fit the wider key used on the HEMI crank and remarking the timing marks (which may be things you are capable of doing yourself, however when you consider the cost of a new stock 318/340 balancer the HOT HEADS unit is pretty attractive).

Many people opt for the BB Chevy water pump conversion. If you are going to use the short version of the BB pump, you have to go with a thinner (aftermarket) timing cover. What you are not normally told with this conversion is that if you use the long water pump the stock timing cover can be retained.

There are a fair amount of high dollar pulleys available for the early HEMI. If a steel painted pulley is OK for you, the Chrysler crank pulleys are a bolt on for the Chrysler Early HEMI. (They were a direct bolt on to both my 331 and 354, although I have read that there might be 1 bolt hole that will not line up on some applications). Personally I think the stock early HEMI WP pulley is just plain ugly, I also have concerns that with the use of the Chevy water pump it would turn the pump to slowly to prevent the engine from overheating. All I did for the upper pulley was go through my pile of pulleys until I found one that lined up and fit the pump. One word of caution if you use the Chrysler 4 groove lower pulley, the outer 2 grooves are just slightly smaller than the inner groves, which mean that the belts on the inner groves move at a different speed than the ones on the outer grooves. Belts on the on the inner and outer grooves cannot run on a common 2 groove pulley that has the same size inner and outer grooves (such as a water pump pulley).

The picture below shows (from top left); the windage tray I found in the trunk of a car, stock lower crank pulley (without balancer), stock early HEMI water pump pulley, 72 and earlier 318 balancer, mid-70s BB Chrysler 4 groove lower crank pulley, unidentified 2 groove water pump pulley and very lower part of picture, 70’s Chevrolet SB Alternator bracket.