How to ?
Melting Slicks
Joined: Mar 2009
Posts: 2,300
Likes: 115
From: Odessa FL
St. Jude Donor '10-'12-'13-'14-'15-'16-'17
Instructions for the ATI kit:
Crank Pin Drill Fixture Kit for LS1
Part# 918993
Using ATI's crank pin drill fixture kit, you can install 1 or 2 dowel pins in the LS1 crank to eliminate the damper twist on the shaft - a must for engines used for circle track racing or supercharging!
Note: All drilling and reaming dry - no lubricants or cutting oils are necessary!
1. Remove the damper
2. Install the fixture to the crank and position 1 bushing hole for best drill access
3. Using the old crank bolt, lock the fixture to the crank so it can not move
4. Install the 11/64 bushing in the adapter and snug the holding screw
5. Using the 11/64 drill bit, drill through the crank to the center bore
6. Change the bushing to the 3/16 bushing and ream the 11/64 hole to 3/16 with one pass in and out at low RPM.
7. For a second pin at 180^, rotate the crank. Do not loosen bolt!
8. Repeat steps 4, 5, and 6 on the opposite side if you are installing 2 pins
9. Blow the outside and center bore clean of all chips before removing adapter. Then remove adapter.
10. Install the 3/16 pin , allowing it to protrude above the crank surface .093" to fit the keyway in the hub.
11. Install the damper and pull it tight to 200 ft/lbs with the old bolt
12. Install a new bolt (GM Part #12557840) with red #262 Loctite and torque the bolt to 240/250 ft/lbs.
Note: All ATI LS1 dampers have one 3/16 keyway in the hub or ATI can key your existing damper.
Crank Pin Drill Fixture Kit for LS1
Part# 918993
Using ATI's crank pin drill fixture kit, you can install 1 or 2 dowel pins in the LS1 crank to eliminate the damper twist on the shaft - a must for engines used for circle track racing or supercharging!
Note: All drilling and reaming dry - no lubricants or cutting oils are necessary!
1. Remove the damper
2. Install the fixture to the crank and position 1 bushing hole for best drill access
3. Using the old crank bolt, lock the fixture to the crank so it can not move
4. Install the 11/64 bushing in the adapter and snug the holding screw
5. Using the 11/64 drill bit, drill through the crank to the center bore
6. Change the bushing to the 3/16 bushing and ream the 11/64 hole to 3/16 with one pass in and out at low RPM.
7. For a second pin at 180^, rotate the crank. Do not loosen bolt!
8. Repeat steps 4, 5, and 6 on the opposite side if you are installing 2 pins
9. Blow the outside and center bore clean of all chips before removing adapter. Then remove adapter.
10. Install the 3/16 pin , allowing it to protrude above the crank surface .093" to fit the keyway in the hub.
11. Install the damper and pull it tight to 200 ft/lbs with the old bolt
12. Install a new bolt (GM Part #12557840) with red #262 Loctite and torque the bolt to 240/250 ft/lbs.
Note: All ATI LS1 dampers have one 3/16 keyway in the hub or ATI can key your existing damper.
