| General Description
The line of six cylinder engines used in Chevrolet light
and medium duty trucks are very tough and durable. The cylinders are numbered from the front of the
engine to the rear; the forward cylinder always being the #1 cylinder. The firing order for a
4-cylinder L4 engine is 1-3-4-2 and the firing order for a 6-cylinder L6 engine is 1-5-3-6-2-4. The
4-cylinder engine has five main bearing and the 6-cylinder engine has seven main bearings. Both engine
configurations use hydraulic valve lifters and hollow push rods to operate the individually mounted
rocker arms which pivot on ball seats. A gear-type oil pump driven by the distributor shaft provides
full pressure lubrication for each of these engines. The main oil gallery along the hydraulic lifter
area passes oil through drilled passages to each cam and main bearing, through the hydraulic lifters
and hollow push rods to the rocker arms.
Click on the following thumbnails to see an example of
some engines, a cross sectional view showing the flow of oil through an engine and exploded view
illustrations of a typical 6-cylinder engine.
|
Engine
|
Displacement
|
Compression |
Gross HP |
Net HP |
Gross Torque |
Net Torque |
Spark Plug |
|
153 L-4 |
153 |
8.5:1 |
90 @ 4000 |
75 @ 4000 |
152 @ 2400 |
144 @ 2600 |
AC46-N |
|
230 L-6 |
230 |
8.5:1 |
140 @ 4400 |
120 @ 3600 |
220 @ 1600 |
200 @ 1600 |
AC44 |
|
230 L-6 * |
230 |
8.5:1 |
125 @ 3400 |
100 @ 3200 |
210 @ 1600 |
200 @ 1200 |
AC44 |
|
292 L-6 |
292 |
8.0:1 |
165 @ 3800 |
147 @ 3600 |
280 @ 1600 |
262 @ 2000 |
AC42-5 |
|
283 V-8 |
283 |
8.5:1 |
175 @ 4400 |
145 @ 4200 |
275 @ 2400 |
245 @ 2000 |
AC44 |
|
327 V-8 |
327 |
8.0:1 |
185 @ 4400 |
158 @ 4400 |
305 @ 2000 |
280 @ 2000 |
AC42-1 |
|
348 V-8 |
348 |
7.75:1 |
220 @ 4400 |
180 @ 4000 |
325 @ 2600 |
300 @ 2400 |
AC42-N |
|
409 V-8 |
409 |
7.75:1 |
252 @ 4000 |
215 @ 4000 |
390 @ 2400 |
352 @ 2400 |
AC42-N |
|
4-53 Diesel |
212 |
17.0:1 |
130 @ 2800 |
118 @ 2800 |
271 @ 1500 |
263 @ 1500 |
N/A |
|
6V-53 Diesel |
318 |
17.0:1 |
195 @ 2800 |
183 @ 2800 |
423 @ 1500 |
415 @ 1500 |
N/A |
|
|
| 1964 Truck Engine Tune-Up Specifications |
Specifications |
Engines |
|
153 CID |
230 CID |
292 CID |
283 CID |
327 CID |
348 CID |
348 CID |
409 CID |
|
Carburetors |
Carter YF |
Rochester B |
Rochester 2G |
Rochester 4G |
|
Compression (Note 1) |
130 PSI |
140 PSI |
|
Spark Plugs |
Make & Number |
AC 46N |
AC C42N |
AC 44 |
AC 42-1 Com |
AC C42N |
| Gap & Torque |
0.035" @ 20 - 25 Ft. Lbs. |
Ignition
Distributor |
Dwell Angle |
31° - 34° |
28° - 32° |
| Point Gap |
0.019" (New) - 0.016 (Used) |
| Spring
Tension |
12 - 23 in. Oz. |
| Condenser |
0.18 - 0.25Mfd. |
|
Fan Belt |
75 ±5 Lbs. using Strand Tension Gauge |
|
Air Cleaner (Note 2) |
|
|
Valve Lash |
Intake |
Hydraulic - 1 Turn Down from "No Lash" Point |
| Exhaust |
Hydraulic - 1 Turn Down from "No Lash" Point |
|
Ignition Timing (Note 3) |
4° BTDC |
8° BTDC |
4° BTDC |
|
Engine RPM |
Synchromesh |
450 - 500 RPM |
| Powerglide
(Note 4) |
450 - 500 RPM |
|
Fuel Pump |
Pressure |
3½ - 4½ PSI |
5¼ - 6½ PSI |
| Volume |
One Pint in 30 - 45 Seconds |
|
Cooling System Radiator Pressure |
7
PSI & 13 PSI |
9
PSI |
|
|
Notes:
1
At cranking speed w/
wide open throttle - maximum variation between cylinders is 20 PSI.
2 Paper
Element - Service at 12,000 miles initially and then every 6000
miles thereafter.
Oil
Wetted Polyurethane - Service every 12,000 miles
Oil Bath -
Change oil at regular engine oil change intervals
3
At idle speed w/
vacuum advance line disconnected and plugged.
4 In
"Drive" position.
| L6 Truck Engine
Illustrations |
| |
|
 |
|
|
| |
|
230 CID L6 Engine |
|
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|
250 CID L6 Engine |
|
|
|
292 CID L6 Engine |
Many
thanks to Michael "Jolly" Goodfellow for allowing me to use
these engine graphics for my web site. Jolly has an outstanding site
packed with hard to find information about '60 - '66 GMC trucks. Check
out Jolly's site at
http://6066gmcclub.com/gmcguy/ |
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