General Hemi info part 4

[Mike P]

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.

[Mike P]

I have used the SB short water pump alternator bracket with various modifications on a ton for custom applications. These brackets were found on 70’s Chevy SB powered trucks and Corvettes. I usually keep a couple sitting on the shelf. It’s been about 10 years since I bought one new from the Chevy dealership, but at they time they ran about $12. They should still be available new or easily found at most wrecking yards. All I did was shorten the bracket, re-drill the lower hole, find a spacer for the back side so it would mount flush and use an off the shelf chrome alt adjustment arm (I had to put a slight “S” bend in it so it would line up. I have less than $25 tied up in it. You can buy an aftermarket mount that mounts the alt in this location shown below it’s about $75.

You can also see another bracket set up I built (for a Chrysler alternator) if you look closely at the picture in this post. http://www.clubhotrod.com/forums/sho...threadid=15088

Yes I wimped out and bought the AC compressor bracket.

[Mike P]

If you are doing a 331/354 or 392 HEMI you do have some aftermarket alternatives available to include magnetos, converted Chevy units, and even billet units. If your running the Dodge or Desoto’s you also have some options (check the Hot Heads web site).

Chrysler made distributors real confusing for the Early HEMIs. Although they all used the same cast iron housing, the shaft lengths were different even within the same Division. Chrysler is a good example, the 331-354 Dist have the same shaft length but the 392 uses a longer shaft due to the raised block design. The length of the Chrysler distributor shafts is different than the Dodge and Desoto and also different than the latter 318 Poly/LA and the B and RB engines.

If you happen to have the correct distributor for your early HEMI and don’t want to mess with the points, a lot of people seem to have good luck with the Pertronix conversion.

My solution to get electronic ignition was to convert the original distributor to electronic using Chrysler parts. All the upper parts from a Mid 70’s MOPAR SB will fit the cast iron housing (to include vacuum advance). You must use the SB parts and not the BB as the distributors rotate in different direction and the advance will not work with the BB pieces. Simply replace the breaker plate and point cam with the electronic ignition breaker plate, pick-up and reluctor (you can find the how to in almost any 70’s shop manual). If I remember correctly you may have to drill or enlarge one hole for the breaker plate attaching screw. This set up uses the latter style rotor and early cast iron distributor cap (original style HEMI cap).

If you happen to have a hard time finding the original style cap, you are in luck. It is the same cap used on Mallory’s dual point and unilite distributors.

Finally, the early HEMIs used a long insulator on the spark plugs. These are usually missing or broken. You are not necessarily stuck buying a new set of HEMI spark plug wires with the insulators or checking E Bay to get these parts. Nor do you HAVE to buy a set of 426 sparkplug-well boots if you are not running the original wire covers. Many of the foreign 4 and 6 Cyl cars were a hemi head design and used the long insulators and boots. You can usually find these at a salvage yard for next to nothing. Buy a set of universal plug wires so you can cut them to the correct length, thread the new wire through the boots and insulators, crimp on the sparkplug terminal and pull back into the insulator, instant cheap HEMI wire set.

Shown below are from top to bottom; my cheapie set of HEMI plug wires, 331/354 HEMI distributor converted to electronic ignition (also the HEMI cap and late rotor) and some OE ceramic insulators

[Dave Severson]

Great stuff, Mike!!! Had to save a copy of all of them. Thanks much for the edjamication on the Hemi!!! Cleared up a lot of things I was cloudy to partly cloudy on!!!!

[Mike P]

Thanks Dave, I really did just start out to put together a couple of points on the old engines.

I put all the posts in the 426 HEMI section so they would be easier to find if I or anybody else needed to reference them.

[Dave Severson]

Works great for me, filed it in the hi performance "library" on the old 'puter. Thanks again.

[FFR428]

Mike this is some really cool stuff. You are a weath of HEMI knowledge. Very interesting reading and pics. I never knew there was so much to the early HEMI's. Fantastic job! I'm a long time Ford guy but have been caught at times lusting over the HEMI. Like now! LOL, G.