home | tech | search | checkout | contact | email | forum   

 

 

 

 

 

 

 

 

Classic Inlines
603 W Pecos Ave
Mesa, AZ 85210
(602) 708-6650
9am-5pm (PST)
Monday-Friday
INTERNET-PHONE SALES ONLY

NO WALK-INS
Sorry We don't have a store front







 
C/R Charts - 250ci with a .120 Deck Height

The charts below were calculated using Virtual Engine 2000's Cam Utility Program. The charts list both Static and Dynamic C/R's for a 250ci engine with a .120 deck height, using varied chamber sizes and valve timing (intake close). Calculations were computed using a Felpro head gasket which has a .050 compressed thickness and a 3.81 gasket bore. The columns to the left use dished pistons (6.5cc), the columns to the right use flat top pistons. You can use the links below for the bore size, or just scroll down.



Not Suggested
Regular 87-89
Supreme 90-92
Premium 93-95
Race Only
below 7.0
7.0-7.7
7.7.0-8.4
8.4-9.1
above 9.1
The ideal DCR range for a performance motor on pump gas is 7.5 to 8.5

250ci Engine
.120 Deck Height - Felpro Gasket
Chamber Size, and Valve Timing vary
Dished Pistons - Bore: 3.680 (stock)
Flat Top Pistons - Bore: 3.680 (stock)
Chamber
IVC
SCR
DCR
Chamber
IVC
SCR
DCR
46
50
9.15
8.08
46
50
9.93
8.77
46
55
9.15
7.85
46
55
9.93
8.51
46
60
9.15
7.59
46
60
9.93
8.24
46
65
9.15
7.32
46
65
9.93
7.94
46
70
9.15
7.05
46
70
9.93
7.65
48
50
8.96
7.91
48
50
9.70
8.57
48
55
8.96
7.68
48
55
9.70
8.32
48
60
8.96
7.44
48
60
9.70
8.06
48
65
8.96
7.17
48
65
9.70
7.77
48
70
8.96
6.90
48
70
9.70
7.48
50
50
8.78
7.75
50
50
9.49
8.38
50
55
8.78
7.53
50
55
9.49
8.14
50
60
8.78
7.29
50
60
9.49
7.88
50
65
8.78
7.03
50
65
9.49
7.60
50
70
8.78
6.77
50
70
9.49
7.31
52
50
8.60
7.60
52
50
9.28
8.20
52
55
8.60
7.38
52
55
9.28
7.97
52
60
8.60
7.15
52
60
9.28
7.71
52
65
8.60
6.89
52
65
9.28
7.44
52
70
8.60
6.64
52
70
9.28
7.16
54
50
8.43
7.45
54
50
9.08
8.03
54
55
8.43
7.24
54
55
9.08
7.80
54
60
8.43
7.01
54
60
9.08
7.55
54
65
8.43
6.76
54
65
9.08
7.28
54
70
8.43
6.51
54
70
9.08
7.01
56
50
8.27
7.31
56
50
8.90
7.87
56
55
8.27
7.11
56
55
8.90
7.64
56
60
8.27
6.88
56
60
8.90
7.40
56
65
8.27
6.64
56
65
8.90
7.14
56
70
8.27
6.39
56
70
8.90
6.88
58
50
8.12
7.18
58
50
8.72
7.71
58
55
8.12
6.98
58
55
8.72
7.49
58
60
8.12
6.76
58
60
8.72
7.26
58
65
8.12
6.52
58
65
8.72
7.00
58
70
8.12
6.28
58
70
8.72
6.74
60
50
7.97
7.05
60
50
8.55
7.56
60
55
7.97
6.85
60
55
8.55
7.25
60
60
7.97
6.64
60
60
8.55
7.12
60
65
7.97
6.40
60
65
8.55
6.87
60
70
7.97
6.17
60
70
8.55
6.61
62
50
7.83
6.93
62
50
8.38
8.38
62
55
7.83
6.74
62
55
8.38
7.21
62
60
7.83
6.52
62
60
8.38
6.98
62
65
7.83
6.29
62
65
8.38
6.74
62
70
7.83
6.07
62
70
8.38
6.49
Dished Pistons - Bore: 3.70 (+.020)
Flat Top Pistons - Bore: 3.70 (+.020)
Chamber
IVC
SCR
DCR
Chamber
IVC
SCR
DCR
46
50
9.22
8.14
46
50
10.00
8.83
46
55
9.22
7.90
46
55
10.00
8.57
46
60
9.22
7.65
46
60
10.00
8.30
46
65
9.22
7.37
46
65
10.00
8.00
46
70
9.22
7.10
46
70
10.00
7.70
48
50
9.02
7.97
48
50
9.77
8.63
48
55
9.02
7.74
48
55
9.77
8.38
48
60
9.02
7.49
48
60
9.77
8.11
48
65
9.02
7.22
48
65
9.77
7.82
48
70
9.02
6.95
48
70
9.77
7.53
50
50
8.84
7.81
50
50
9.55
8.44
50
55
8.84
7.58
50
55
9.55
8.20
50
60
8.84
7.34
50
60
9.55
7.93
50
65
8.84
7.08
50
65
9.55
7.65
50
70
8.84
6.81
50
70
9.55
7.37
52
50
8.66
7.65
52
50
9.35
8.26
52
55
8.66
7.44
52
55
9.35
8.02
52
60
8.66
7.20
52
60
9.35
7.77
52
65
8.66
6.94
52
65
9.35
7.49
52
70
8.66
6.68
52
70
9.35
7.21
54
50
8.50
7.51
54
50
9.15
8.09
54
55
8.50
7.29
54
55
9.15
7.86
54
60
8.50
7.06
54
60
9.15
7.61
54
65
8.50
6.81
54
65
9.15
7.33
54
70
8.50
6.56
54
70
9.15
7.06
56
50
8.33
7.37
56
50
8.96
7.92
56
55
8.33
7.16
56
55
8.96
7.70
56
60
8.33
6.93
56
60
8.96
7.45
56
65
8.33
6.69
56
65
8.96
7.19
56
70
8.33
6.44
56
70
8.96
6.92
58
50
8.18
7.23
58
50
8.78
7.77
58
55
8.18
7.03
58
55
8.78
7.55
58
60
8.18
6.81
58
60
8.78
7.31
58
65
8.18
6.57
58
65
8.78
7.05
58
70
8.18
6.32
58
70
8.78
6.79
60
50
8.03
7.1
60
50
8.61
7.62
60
55
8.03
6.91
60
55
8.61
7.40
60
60
8.03
6.69
60
60
8.61
7.17
60
65
8.03
6.45
60
65
8.61
6.91
60
70
8.03
6.21
60
70
8.61
6.66
62
50
7.89
6.98
62
50
8.44
7.47
62
55
7.89
6.79
62
55
8.44
7.26
62
60
7.89
6.57
62
60
8.44
7.03
62
65
7.89
6.34
62
65
8.44
6.79
62
70
7.89
6.11
62
70
8.44
6.54
Dished pistons - Bore: 3.71 (+.030)
Flat Top Pistons - Bore: 3.71 (+.030)
Chamber
IVC
SCR
DCR
Chamber
IVC
SCR
DCR
46
50
9.25
8.16
46
50
10.04
8.86
46
55
9.25
7.93
46
55
10.04
8.60
46
60
9.25
7.67
46
60
10.04
8.33
46
65
9.25
7.40
46
65
10.04
8.03
46
70
9.25
7.12
46
70
10.04
7.72
48
50
9.06
8.00
48
50
9.81
8.66
48
55
9.06
7.77
48
55
9.81
8.41
48
60
9.06
7.52
48
60
9.81
8.14
48
65
9.06
7.25
48
65
9.81
7.85
48
70
9.06
6.98
48
70
9.81
7.55
50
50
8.87
7.84
50
50
9.59
8.47
50
55
8.87
7.61
50
55
9.59
8.23
50
60
8.87
7.37
50
60
9.59
7.96
50
65
8.87
7.10
50
65
9.59
7.68
50
70
8.87
6.84
50
70
9.59
7.39
52
50
8.70
7.68
52
50
9.38
8.29
52
55
8.70
7.46
52
55
9.38
8.05
52
60
8.70
7.22
52
60
9.38
7.79
52
65
8.70
6.97
52
65
9.38
7.51
52
70
8.70
6.71
52
70
9.38
7.24
54
50
8.53
7.54
54
50
9.18
8.11
54
55
8.53
7.32
54
55
9.18
7.88
54
60
8.53
7.09
54
60
9.18
7.63
54
65
8.53
6.84
54
65
9.18
7.36
54
70
8.53
6.58
54
70
9.18
7.09
56
50
8.37
7.39
56
50
8.99
7.95
56
55
8.37
7.19
56
55
8.99
7.73
56
60
8.37
6.96
56
60
8.99
7.48
56
65
8.37
6.71
56
65
8.99
7.21
56
70
8.37
6.46
56
70
8.99
6.95
58
50
8.21
7.26
58
50
8.81
7.79
58
55
8.21
7.06
58
55
8.81
7.57
58
60
8.21
6.83
58
60
8.81
7.33
58
65
8.21
6.59
58
65
8.81
7.07
58
70
8.21
6.35
58
70
8.81
6.81
60
50
8.06
7.13
60
50
8.64
7.64
60
55
8.06
6.93
60
55
8.64
7.43
60
60
8.06
6.71
60
60
8.64
7.19
60
65
8.06
6.47
60
65
8.64
6.94
60
70
8.06
6.24
60
70
8.64
6.68
62
50
7.92
7.01
62
50
8.48
7.50
62
55
7.92
6.81
62
55
8.48
7.29
62
60
7.92
6.60
62
60
8.48
7.06
62
65
7.92
6.36
62
65
8.48
6.81
62
70
7.92
6.13
62
70
8.48
6.56
Dished pistons - Bore: 3.72 (+.040)
Flat Top Pistons - Bore: 3.72 (+.040)
Chamber
IVC
SCR
DCR
Chamber
IVC
SCR
DCR
46
50
9.29
8.19
46
50
10.07
8.89
46
55
9.29
7.96
46
55
10.07
8.63
46
60
9.29
7.70
46
60
10.07
8.35
46
65
9.29
7.42
46
65
10.07
8.05
46
70
9.29
7.15
46
70
10.07
7.75
48
50
9.09
8.03
48
50
9.84
8.69
48
55
9.09
7.80
48
55
9.84
8.44
48
60
9.09
7.54
48
60
9.84
8.17
48
65
9.09
7.27
48
65
9.84
7.87
48
70
9.09
7.00
48
70
9.84
7.58
50
50
8.91
7.86
50
50
9.62
8.50
50
55
8.91
7.64
50
55
9.62
8.25
50
60
8.91
7.39
50
60
9.62
7.99
50
65
8.91
7.13
50
65
9.62
7.70
50
70
8.91
6.86
50
70
9.62
7.42
52
50
8.73
7.71
52
50
9.41
8.32
52
55
8.73
7.49
52
55
9.41
8.08
52
60
8.73
7.25
52
60
9.41
7.82
52
65
8.73
6.99
52
65
9.41
7.54
52
70
8.73
6.73
52
70
9.41
7.26
54
50
8.56
7.56
54
50
9.22
8.14
54
55
8.56
7.35
54
55
9.22
7.91
54
60
8.56
7.11
54
60
9.22
7.66
54
65
8.56
6.86
54
65
9.22
7.39
54
70
8.56
6.61
54
70
9.22
7.11
56
50
8.40
7.42
56
50
9.03
7.98
56
55
8.40
7.21
56
55
9.03
7.75
56
60
8.40
6.98
56
60
9.03
7.51
56
65
8.40
6.73
56
65
9.03
7.24
56
70
8.40
6.49
56
70
9.03
6.97
58
50
8.24
7.29
58
50
8.84
7.82
58
55
8.24
7.08
58
55
8.84
7.60
58
60
8.24
6.86
58
60
8.84
7.36
58
65
8.24
6.61
58
65
8.84
7.10
58
70
8.24
6.37
58
70
8.84
6.84
60
50
8.09
7.16
60
50
8.67
7.67
60
55
8.09
6.96
60
55
8.67
7.45
60
60
8.09
6.74
60
60
8.67
7.22
60
65
8.09
6.50
60
65
8.67
6.96
60
70
8.09
6.26
60
70
8.67
6.71
62
50
7.95
7.03
62
50
8.51
7.53
62
55
7.95
6.84
62
55
8.51
7.32
62
60
7.95
6.62
62
60
8.51
7.08
62
65
7.95
6.39
62
65
8.51
6.83
62
70
7.95
6.15
62
70
8.51
6.59
Dished pistons - Bore: 3.74 (+.060)
Flat Top Pistons - Bore: 3.74 (+.060)
Chamber
IVC
SCR
DCR
Chamber
IVC
SCR
DCR
46
50
9.35
8.25
46
50
10.14
8.95
46
55
9.35
8.02
46
55
10.14
8.69
46
60
9.35
7.76
46
60
10.14
8.41
46
65
9.35
7.48
46
65
10.14
8.11
46
70
9.35
7.20
46
70
10.14
7.80
48
50
9.16
8.08
48
50
9.91
8.75
48
55
9.16
7.85
48
55
9.91
8.50
48
60
9.16
7.60
48
60
9.91
8.22
48
65
9.16
7.32
48
65
9.91
7.93
48
70
9.16
7.05
48
70
9.91
7.63
50
50
8.97
7.92
50
50
9.69
8.56
50
55
8.97
7.69
50
55
9.69
8.31
50
60
8.97
7.45
50
60
9.69
8.05
50
65
8.97
7.18
50
65
9.69
7.76
50
70
8.97
6.91
50
70
9.69
7.47
52
50
8.79
7.77
52
50
9.48
8.37
52
55
8.79
7.54
52
55
9.48
8.14
52
60
8.79
7.30
52
60
9.48
7.88
52
65
8.79
7.04
52
65
9.48
7.59
52
70
8.79
6.78
52
70
9.48
7.31
54
50
8.62
7.62
54
50
9.28
8.20
54
55
8.62
7.40
54
55
9.28
7.97
54
60
8.62
7.16
54
60
9.28
7.71
54
65
8.62
6.91
54
65
9.28
7.44
54
70
8.62
6.65
54
70
9.28
7.16
56
50
8.46
7.48
56
50
9.09
8.03
56
55
8.46
7.26
56
55
9.09
7.81
56
60
8.46
7.03
56
60
9.09
7.56
56
65
8.46
6.78
56
65
9.09
7.29
56
70
8.46
6.53
56
70
9.09
7.02
58
50
8.30
7.34
58
50
8.91
7.88
58
55
8.30
7.13
58
55
8.91
7.65
58
60
8.30
6.91
58
60
8.91
7.41
58
65
8.30
6.66
58
65
8.91
7.15
58
70
8.30
6.42
58
70
8.91
6.88
60
50
8.15
7.21
60
50
8.73
7.73
60
55
8.15
7.01
60
55
8.73
7.51
60
60
8.15
6.78
60
60
8.73
7.27
60
65
8.15
6.54
60
65
8.73
7.01
60
70
8.15
6.30
60
70
8.73
6.76
62
50
8.01
7.08
62
50
8.57
7.58
62
55
8.01
6.89
62
55
8.57
7.37
62
60
8.01
6.67
62
60
8.57
7.14
62
65
8.01
6.43
62
65
8.57
6.88
62
70
8.01
6.20
62
70
8.57
6.63

Other related articles:
Understanding Lobe Centers - Static vrs Dynamic Compression
Cam Installation Tips - Adjusting Your Valves





[ home ] [ index ] [ products ] [ search ] [ checkout ]

Copyright 2012 - Classic Inlines - All Rights Reserved