Forged from 2618 or 4032 alloy, Premium series include all of the features of FHR pistons with the addition of precision, CNC-machined valve reliefs and crown, pressure fed oiling, and skirt and pin boss struts for added durability. Pistons listed accept 1/16" (top), 1/16" (second), and 3/16" (oil) rings unless noted. Sets of eight include wrist pins and spiral locks
- Piston Head Type:
- Dish
- Bore (in.):
- 4.156
- Bore (mm):
- 105.562mm
- Recommended Stroke (in.):
- 4.250 in.
- Piston Style:
- Step head, with two valve reliefs
- Compression Height (in.):
- 1.750 in.
- Piston Volume (cc.):
- --25
- Piston Material:
- Forged aluminum
- Piston Avg Weight (g.):
- 583
- Piston Ring Thickness:
- 1/16 in. x 1/16 in. x 3/16 in.
- Quantity:
- Sold as a set of 8.
- Notes:
- Step dish design.
- Wrist Pin Included:
- Yes
- Wrist Pin Style:
- Press-fit or floating
- Piston Pin Diameter (in.):
- 0.980 in.
- Wrist Pin Retainers Included:
- Yes
- Piston Pin Wall Thickness:
- N/A
- Piston Pin Material:
- N/A
- Piston Rings Included:
- No
- File Fit:
- N/A
- Gas Ported:
- N/A
- Gapless:
- N/A
- Make:
- Oldsmobile
- Engine Family:
- Oldsmobile V8
- Recommended Rod Length:
- 6.735 in.
- Compression:
- 77cc: 9.5, 80cc: 9.3, 84cc: 9
