[PCHARGED70]

Had the car out last night and was having some fun, I heard a noise from the engine when at idle and further investigation I found that the harmonic balancer spun with the engine off . I took the car apart and I have sheered the keyway on the crank. I want to do the upgrade now that I have it apart so what do you guys suggest for a dual keyway set-up and harmonic balancer for a 406sbc with a D1SC.

 

[72much]

This is what I did, but you have to get the crank double keyed.

Supercharger Damper Hubs & Timing Covers

Supercharger Super Dampers

Supercharger Super Pulley

Supercharger Damper Hubs and Timing Covers

V-belt to Serpentine Conversion Kit

Y-Body, F-Body, & C/K-Body Serpentine Conversion Kits for LS1 & LS2 Engines The early small block Chevrolet and the later LT1 and LS1 engines all present problems when supercharging. The original Small Block and the LT1 have a shaft size of 1.245” and a seal diameter of 1.760 leaving the hub wall thickness at .257” or just over 1/4”. Many engine builders put a 1/4’ key in the crankshaft leaving just 1/8” of material between the groove and the seal surface. The result is a failed hub that destroys the damper and the nose of the crank shaft. The later LT1 and LS1 are even worse with just a press fit and no keys; a total disaster when you try to supercharge and drive the blower from the damper. To remedy this situation, ATI now manufactures a variety of Small Block Chevrolet hubs for supercharging.

Big Block 2.331” Seal Diameter
For the serious racer with high boost requirements, ATI offers a small block Chevy crank hub with the big block 2.331 seal diameter increasing the wall to .562; a whopping 220% increase that totally eliminates failure at this point. A new timing cover and seal are required. For small blocks up to 1992.


Applications

Part #​

Price​

HUB FOR SBC, 6 BOLT, CHRYSLER FRONT, (1) 3/16, (1) 1/4 KEYWAY*

916135​

$141​

HUB FOR SBC, 6 BOLT, CHRYSLER FRONT, (2) 3/16 KEYWAYS*

916136​

$141​

HUB FOR SBC, 6 BOLT, CHEVY OEM FRONT, (2) 3/16 KEYWAYS

916172​

$130​

TIMING COVER FOR SB CHEVY, WITH BB SEAL, CAST ALUMINUM

925500​

$150​

HUB FOR SBC WITH BB SNOUT - CHRYSLER FRONT - 3/16" & 1/4" KEYWAY

916134​

$141​

*Room in front of damper for ignition trigger wheel located on hub

 

[PCHARGED70]

I am running the Procharger accessory drive kit for the water pump and alternator, will this kit^^^^^
affect the pulley alignment with the bigger snout?

 

[72much]

I don't think it should but might check with other sources to find out for sure.

 

[PCHARGED70]

What about pinning the crank, has anybody tried that kit and have any success with it ?

 

[f_o_a_d]

You will need to check the crankshaft snout diameter. It may have been damaged when the damper spun. If the snout is undamaged and a proper interference fit can be achieved the crank can be saved. Adding dual keyways and adding a good damper with a steel hub is the correct way to fix it. What damper do you have now?

 

[PCHARGED70]

I have the ATI 7 inch for a standard SBC crank.