Rocker Arms Ordering Information

 

If you’re not sure or don’t know which Crower Shaft Rocker System will fit your cylinder head, or the type/ model of head you have and need help, follow these simple procedures:

If you’re not sure or don’t know which Crower Shaft Rocker System will fit your cylinder head, or the type/ model of head you have and need help, follow these simple procedures:

Rocker Body Identification

To order replacement rockers and insure correct fit you’ll need to provide your Crower technician with the following info.

1. You’ll need to provide us with some critical information and dimensions.
  1. Cylinder head manufacturer
  2. Engine type
  3. Intake and exhaust valve distances from cylinder head centerline.
  4. Rocker stud spacing from cylinder head centerline.

Here’s how you do it.

Measure the distance from the outside diameter of the two inboard exhaust valves. Record the value. Subtract the diameter of the valve (Example: .341) from your recorded value and divide this measurement by 2. Now you'll know the distance from the cylinder head centerline to exhaust valve centerline.

Now measure the distance from the outside of the intake valve to the outside diameter of the exhaust valve diameter. Subtract .341" from that to get the centerline distance from exhaust to intake valve.

Note: .341" diameter is based on 11/32" intake and exhaust valves. Some cylinder heads have different size intake stems. Make sure you measure valve stem size before measuring valve centerline.

Rocker Body Identification

To order replacement rockers and insure correct fit you’ll need to provide your Crower technician with the following info.

Rocker Bodies without I.D. numbers:
  • Rocker arm Ratio
  • Rocker arm Offset
  • Which valve the rocker actuates (intake or exhaust)
  • Which cylinder the rocker is mounted on (2,4,6,8–1,3,5,7, etc.)
  • Name/brand of cylinder head
  • Stand Number
  • Shaft Diameter
Rocker Bodies with I.D. numbers:
  • Rocker arm Body I.D. number
  • Rocker arm Ratio
  • Rocker arm Offset
  • Stand Number
  • Shaft Diameter
 

For technical support call 619-661-6477 or visit www.crower.com

Please note:

Crower current design 5/8 shaft Stainless Steel & Steel Billet Rockers are rebuildable.  We no longer have components to rebuild our 11/16 shaft rockers. 

Aluminum rockers are not rebuildable.