plugging an engine hole or passage

[grumpyvette]

once you start building engines you'll find theres dozens of locations that need small expansion or threaded pipe plugs, inspect each carefully and ask questions some applications like a spare dip stick hole can use a small brass or steel expansion plug and never have a problem, many oil passages can use expansion plugs but a great deal more security is gained thru tapping threads and using a brass threaded plug, but be aware that in some cases theres a limit on plug depth or you'll restrict oil flow rates, some blocks have both sides cast with dipstick holes nothing brings home the need for carefull inspection and plug installation like starting your first engine and having oil shoot 20 feet across the shop from a forgotten plug in an oil passage....don,t ask! you can bet that only happened ONCE
http://www.superchevy.com/how-to/engines-drivetrain/83818-block-plug-basics/

heres one place where a good dial or digital caliper comes in extremely handy

RELATED THREAD
viewtopic.php?f=57&t=869&p=1357&hilit=brass+freeze+plug#p1357

viewtopic.php?f=27&t=1262&p=6142&hilit=taps#p6142

http://www.ehow.com/video_2327501_plug- ... ngine.html

http://www.summitracing.com/parts/GAR-J9015/

Chevrolet Performance 14091563
Left (Driver Side) Dipstick Plug
Chevrolet Performance 9421743
Right (Passenger Side) Dipstick Plug

obviously high pressure plugs should in many cases be thread plugs with a good sealant on the threads,
but look closely at the picture above, notice the oil pressure passage that would be blocked if the seal plug extended too far into the passage? its not unheard of for beginners to engine builds to screw that up and block off cross feed passages

 

[grumpyvette]

http://www.dormanproducts.com/catalog/h ... _Part1.pdf

look thru the linked info theres a great deal more types and sizes listed

http://freezeplugfactory.com/expansion-plug-size-chart/


Brass Cup Plugs
PART NO SIZE MILLIMETER PART NO SIZE MILLIMETER
102 5/16 7.939
146
1 1/2
38.1
103 3/8 9.525 147 1 9/16 39.69
NOTICE THESE TWO SIZES ABOVE FIT MANY DIP STICK HOLES
104
13/32
10.32
148
1 5/8
41.28
106
27/64
10.72
149
1 41/64
41.68
107
7/16
11.11
151
1 11/16
42.86
108
29/64
11.51
152
1 45/64
43.27
109
1/2
12.7
153
1 3/4
44.45
111
1/2
12.3
154
1 49/64
44.86
112
33/64
13.1
155
1 47/64
44.05
113
17/32
13.49
156
1 25/32
45.24
114
9/16 14.29
157
1 51/64
45.65
116
19/32
15.08
158
1 13/16
46.04
117
39/64
15.48
160
1 7/8
47.63
118
5/8 15.88
161
1 29/32
48.42
119 41/64
16.27
162
1 59/64
48.83
120
21/32
16.67
163
1 15/16
49.21
121
45/64
17.86
165
1 61/64
49.62
123
11/16
17.46
166
1 31/32
50.01
124
3/4 19.05
167
1 63/64
50.42
125
13/16
20.64
170
2
50.8
126
7/8 22.23
171
2 1/64
51.21
128
29/32
23.02
172
2 3/64
52
129
15/16
23.81
173
2 1/16
52.39
130
1
25.4
175
2 3/32
53.19
131
1 1/64
25.8
176
2 7/64
53.59
132
1 1/16
26.99
177
2 1/8
53.98
133
1 1/8
28.58
178
2 9/64
54.38
135
1 3/16
30.16
180
2 5/32
54.78
136
1 7/32
30.96
181
2 3/16
55.56
137
1 1/4
31.75
182
2 13/64
55.97
138
1 5/16
33.34
183
2 7/32
56.37
139
1 21/64
33.74
184
2 1/4
57.15
140
1 3/8
34.93
185
2 3/8
60.33
142
1 25/64
35.33
186
2 1/2
63.5
143
1 7/16
36.51
187
2 9/16
65.09
144
1 31/64
37.71