Piston Top Aprox. Comp. Ratio:
-12cc Flat Top Oldsmobile
| Chamber | Comp Ratio |
|---|
| 72 | 11.89 to 1 |
| 75 | 11.56 to 1 |
| 77 | 11.35 to 1 |
For accurate Comp Ratio info use the calculator below.
Engine Brand: Oldsmobile
Engine Family: Big Block Oldsmobile
Engine Size: 481 Stroker
Cylinder Bore Size: 4.185 in , 106.215 mm
Ring Groove Width: 1/16-1/16-3/16"
Compression Height: 1.260"
Pin Diameter: 0.990"
Connecting Rod Length: 7.100"
Crankshaft Stroke: 4.500"
Cylinder Head: Oldsmobile
TDC Assembly Height: 10.610" ( Zero Deck Height )
Download Piston Instructions
| Features: |
Piston Series |
|
| |
E series
|
SX series |
1-FX series |
2-FX series |
3-FX series |
| Broached pin oiling slots |
x
|
x
|
|
|
|
| Drilled, forced wrist pin oiling |
|
x
|
x
|
x
|
x
|
| Forged drain-back windows |
x
|
|
|
|
|
| Drilled bottom ring land intersecting oil groove drain-backs |
|
x
|
x
|
x
|
x
|
| Slightly larger, deeper valve reliefs than OEM |
x
|
|
|
|
|
| CNC machined valve reliefs for moderate performance heads and cam combinations |
|
x
|
|
|
|
| Larger, deeper CNC valve reliefs for more aggressive cylinder head and cam combinations |
|
|
x
|
x
|
x
|
| Premium Aircraft spec. 4032 low expansion alloy |
x
|
x
|
x
|
|
|
| Premium Aircraft spec. 2618 alloy |
|
|
|
x
|
x
|
| Blower, Turbo, NOS ready |
|
x
|
x
|
x
|
x
|
| Brushed piston crown |
|
|
x
|
x
|
x
|
| Turned dishs |
x
|
x
|
|
|
|
| Max Quench milled dishs |
|
|
x
|
x
|
x
|
| Additional CNC milling for weight reduction in non-critical areas |
|
|
x
|
x
|
x
|
| Patented “X Groove” skirt for superior cylinder and ring life |
|
|
x
|
x
|
x
|
| Thinner/shallower Ring grooves for maximum ring seal and land strength |
|
|
x
|
x
|
x
|
| Low volume contact reduction grooves |
|
|
x
|
x
|
x
|
| 2nd ring land accumulator groove prevents ring flutter |
|
|
x
|
x
|
x
|
| 3rd ring land scraper relief |
|
|
x
|
x
|
x
|
| Oil ring groove relief reservoir |
|
|
x
|
x
|
x
|
| Inner and outer pin boss weight reduction radiusing |
|
|
x
|
x
|
x
|
| Tighter control of crown thickness yields consistently lighter parts |
|
|
x
|
x
|
x
|
| Dynamic skirt milling controls skirt thickness for consistently lighter parts |
|
|
x
|
x
|
x
|
| Diamond-turned high strength skirts |
x
|
x
|
x
|
x
|
x
|
| High-strength piston pins |
x
|
x
|
x
|
x
|
x
|
| Extreme Duty XR wrist pins |
|
|
|
|
x
|
| Horizontal Gas Ports enhance ring seal |
|
|
|
|
x
|
| Forged and machined in the USA |
x
|
x
|
x
|
x
|
x
|
|
Piston Specs
Piston Top Aprox. Comp. Ratio:
-12cc Flat Top Oldsmobile
| Chamber | Comp Ratio |
|---|
| 72 | 11.89 to 1 |
| 75 | 11.56 to 1 |
| 77 | 11.35 to 1 |
For accurate Comp Ratio info use the calculator below.
Engine Brand: Oldsmobile
Engine Family: Big Block Oldsmobile
Engine Size: 481 Stroker
Cylinder Bore Size: 4.185 in , 106.215 mm
Ring Groove Width: 1/16-1/16-3/16"
Compression Height: 1.260"
Pin Diameter: 0.990"
Connecting Rod Length: 7.100"
Crankshaft Stroke: 4.500"
Cylinder Head: Oldsmobile
TDC Assembly Height: 10.610" ( Zero Deck Height )
Download Piston Instructions
Piston Series Comparison Chart
| Features: |
Piston Series |
|
| |
E series
|
SX series |
1-FX series |
2-FX series |
3-FX series |
| Broached pin oiling slots |
x
|
x
|
|
|
|
| Drilled, forced wrist pin oiling |
|
x
|
x
|
x
|
x
|
| Forged drain-back windows |
x
|
|
|
|
|
| Drilled bottom ring land intersecting oil groove drain-backs |
|
x
|
x
|
x
|
x
|
| Slightly larger, deeper valve reliefs than OEM |
x
|
|
|
|
|
| CNC machined valve reliefs for moderate performance heads and cam combinations |
|
x
|
|
|
|
| Larger, deeper CNC valve reliefs for more aggressive cylinder head and cam combinations |
|
|
x
|
x
|
x
|
| Premium Aircraft spec. 4032 low expansion alloy |
x
|
x
|
x
|
|
|
| Premium Aircraft spec. 2618 alloy |
|
|
|
x
|
x
|
| Blower, Turbo, NOS ready |
|
x
|
x
|
x
|
x
|
| Brushed piston crown |
|
|
x
|
x
|
x
|
| Turned dishs |
x
|
x
|
|
|
|
| Max Quench milled dishs |
|
|
x
|
x
|
x
|
| Additional CNC milling for weight reduction in non-critical areas |
|
|
x
|
x
|
x
|
| Patented “X Groove” skirt for superior cylinder and ring life |
|
|
x
|
x
|
x
|
| Thinner/shallower Ring grooves for maximum ring seal and land strength |
|
|
x
|
x
|
x
|
| Low volume contact reduction grooves |
|
|
x
|
x
|
x
|
| 2nd ring land accumulator groove prevents ring flutter |
|
|
x
|
x
|
x
|
| 3rd ring land scraper relief |
|
|
x
|
x
|
x
|
| Oil ring groove relief reservoir |
|
|
x
|
x
|
x
|
| Inner and outer pin boss weight reduction radiusing |
|
|
x
|
x
|
x
|
| Tighter control of crown thickness yields consistently lighter parts |
|
|
x
|
x
|
x
|
| Dynamic skirt milling controls skirt thickness for consistently lighter parts |
|
|
x
|
x
|
x
|
| Diamond-turned high strength skirts |
x
|
x
|
x
|
x
|
x
|
| High-strength piston pins |
x
|
x
|
x
|
x
|
x
|
| Extreme Duty XR wrist pins |
|
|
|
|
x
|
| Horizontal Gas Ports enhance ring seal |
|
|
|
|
x
|
| Forged and machined in the USA |
x
|
x
|
x
|
x
|
x
|
|
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