Category Heads

Cylinder Head Compression

April 26, 2010 EngineHeads

The information below reflects the research conducted by Pontiac enthusiast/ author Pete McCarthy, much of which is from his book, Pontiac Musclecar Performance 1955-1977, as well as information gathered from many other Pontiac enthusiasts world-wide. Information about PMD heads is still being gathered. What is apparent is that while Pontiac had policies and specifications, both seemed to fluctuate as need be to build engines and place them in passenger cars.

 

Chamber size of heads is given as an approximate CC as is static compression. When examining any Pontiac head today it requires an open mind. All chamber sizes should not be assumed but cc'd to confirm the chamber size. I wish to point out that

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Cylinder head chamber volume

April 26, 2010 EngineHeads

 


Cylinder Head Chamber Volume, cc's

50

55

60

65

70

75

80

85

90

95

100

105

110

115

303

9.35

9.18

8.67

8.23

7.83

7.47

7.15

6.86

6.60

6.36

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Rocker Arm Adjustment

January 17, 2010 CamshaftEngineHeads

Pontiac Rocker Arm Adjustment

After two decades of weekly hands-on with various Pontiac V8 engines, one area that is always given insufficient attention is the correct setting of the rocker arms.

 

Whether you have decided to stick with the stock type stamped rocker arms or upgrade to Competition Cams Magnum Rollers Rockers (as pictured below), or go for big buck rockers, the correct setting of valve lash is key to getting the best from your valve train . Torquing the adjusting nut per the old Chilton's to 20-25 ft pounds won't work on any heads that have been milled. This is especially true with the high lift cams of today. The valve train needs to be adjustable. Some

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Cylinder Head Volumes

December 8, 2009 EngineHeads

 

Head #

Intake CC's Max

Exhaust CC's Max

4X

156

142

6X

161

148

5C

154

140

46

158

141

16

165

152

62

165

152

66

148

144

31

165

152

670

165

152

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