First to clarify it is not a big block hub. It is smaller at only 2.25" dia, the big block hub is 2.331".

I would not recommend using 2 seals. Seals are lubricated by the oil they are trying to retain. The second (outer) seal would starve for oil. On, the larger seals you see with 2 lips, the outer is really a dust shield & does not help the sealing process, buy merely is intended to keep the sealing area clean.

As for spacing, you will definitely need to modify your blower spacer thickness. The extra 3 bolts for pulley mounting are optional.

Hope this helps.

 

Nearing the final assembly of my 396.

It just dawned on me that ATI mentioned using 3/16" key widths, while the stock design is for 1/4" width.

I went to summit and found some of their step-down key stock for making your own keys... but I was wondering if anyone had a source for a 3/16" woodriff key I could just order off the shelf to save time at the dremel.

Anyone?


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Nevermind... found it. (ATI#918992) Guess I'll order 2 for this double-keyed hub.

 

They had hardened woodruff keys at the True Value hardware store near my house.

 

Don't use hardened keys in engine hubs.

 

I don't understand this. You're using two keys but you're not using hardened keys. You don't want them to shear do you?

 

Does the hub you sell work with the balancer shell from other companies? Or even the stock balancers? Thx.

 

It will only work with ATI balancers.

 

No, the hubs are ATI specific.

Stock small block keys are 3/16" not 1/4"

You also should use hardened keys. Why would you double key for strength, only to use a soft key?

The ones you typically find at hardware stores are meant to shear as a safety feature. These are used in lawnmowers etc. to prevent breakage when the engine suddenly stops due to hitting a rock etc. Save these keys for this purpose, not on your car.

 

hardened keys shouldn't have any more sheer strength than a standard steel of the same alloy.

Hardening will prevent scratching/galling/impaction of a metals surface... and it WILL affect Ultimate Tensile Strength I believe... but it shouldn't affect Ultimate Sheer Strength of a steel. If anything it may affect the fatigue life of the metal due to brittleness... especially bad in a reciprocating situation like a rotating engine crank snout.

I may in left field here though... been a while since I looked at modulus and heat treating properties.


Another cavet here is weither the "hardened" keys even use the same steel alloy as the untreated keys use. They may be using a an alloy with higher shear strength. I dunno... just sounded like a bad idea.

 

Hardened keys are made not to shear. Normal keys are made to shear to prevent damage due to sudden stoppage. Like in a lawnmower when you hit a stump.

 

that makes sense... they must use a stronger alloy for hardened keys.