General Specifications for the 263 and 320 straight eight Buick engines. The following information has been directly complied from the original 1952 Buick service manual.
| BOLT TORQUE SPECIFICATIONS |
| LOCATION |
THREAD SIZE |
TORQUE |
| Spark Plug |
14MM |
22-28 |
| Crankcase Drain |
28MM |
30-35 |
| Lower Crankcase |
5/16-18 |
6-15 |
| Flywheel Housing to Upper Crankcase |
7/16-14 |
55-60 |
| Timing Gear Cover |
3/8-16 |
15-20 |
| Valve Push Rod Cover |
5/16-18 |
4-5 |
| Valve Rocker Arm Cover |
5/16-24 |
4-5 |
| Water Pump Mounting |
3/8-16 |
25-30 |
| Manifold Stud |
3/8-24 |
25-30 |
| Cylinder Head |
7/16-14 |
65-70 |
| Con. Rod Bolt - Series 40-50 |
3/8-24 |
40-45 |
| Con. Rod Bolt - Series 70 |
7/16-24 |
60-65 |
| Piston Pin Clamp |
5/16-24 |
25-30 |
| Crankshaft Bearing Clamp |
1/2-13 |
90-100 |
| Balancer Retaining |
3/4-16 |
100-110 |
| Flywheel to Crankshaft, Synchromesh |
3/8-24 |
35-40 |
| Flywheel to Crankshaft, Dynaflow |
7/16-24 |
50-55 |
| Rocker Arm Shaft Bracket |
3/8-16 |
30-35 |
| Rocker Arm Shaft Bracket Stud |
3/8-24 |
30-35 |
| Generator to Bracket Bolt |
3/8-24 |
25-30 |
| Generator Mounting Bracket to Crankcase |
3/8-16 |
30-35 |
| Front Engine Mounting Bracket to Frame Bolt |
3/8-24 |
30-35 |
| Front Engine Mount Stud |
3/8-24 |
30-35 |
| Transmission Mounting Pad to Rear Bearing Retainer |
3/8-16 |
30-35 |
| Transmission Mounting Pad to Transmission Support Bolt |
3/8-24 |
30-35 |
| Transmission Support to Fame Cross Member Bolt |
3/8-24 |
20-25 |
| Thrust Pad to Transmission Support and Thrust Plate |
3/8-24 |
30-35 |
| GENERAL SPECIFICATIONS |
| General Information
Items |
Series 40-50 |
Series 70 |
| Type |
<------------Valve in Head-----------> |
| Cylinders and Arrangement |
<---------------8 in Line-------------> |
| Bore and Stroke |
3 3/16" X 4 1/8” |
3 7/16"X 4 5/16” |
| Piston Displacement |
263.3 |
320.2 |
| Compression Ratio |
| Syncromesh - Series 40 Only |
6.6 to 1 |
--- |
| Syncromesh - Series 50 Only |
6.9 to 1 |
--- |
| Dynaflow - All Series |
7.2 to 1 |
7.5-1 |
| Compression Pressure @ Cranking Speed (psi) |
| Syncromesh - Series 40 Only |
114 |
--- |
| Syncromesh - Series 50 Only |
118 |
--- |
| Dynaflow - All Series |
<-----------------120----------------> |
| Firing Order |
<----------1-6-2-5-8-3-7-4----------> |
| Taxable Horsepower |
32.51 |
37.81 |
| Max B.H.P. @ RPM. |
| Syncromesh - Series 40 Only |
120 @ 3600 |
--- |
| Syncromesh - Series 50 Only |
124 @ 3600 |
--- |
| Dynaflow - All Series |
128 @ 3600 |
168 @3800 |
| Engine Wieght, Less Clutch and Mountings (lbs.) |
746 - 749 |
833 |
| Number of Mounting and Material |
<----------3 Synthetic Rubber---------> |
| Cylinder Crankcase and Cylinder Head |
| General Information
Items |
Series 40-50 |
Series 70 |
| Cylinder Crankcase Type |
<---Black Cast Integral with Crankcase---> |
| Cylinder Head Type and Material |
<----------One Piece, Cast Iron---------> |
| Combustion Chamber |
<---------------Cast in Head------------> |
| Head Bolts, Number and Diameter |
<----------------22, 7/16″--------------> |
| Crankshaft Bearings, Flywheel Balancer |
| Crankshaft Wieght (lbs.) |
90 |
116 |
| Number of Crankshaft Bearings |
5 |
5 |
| Bearing Which Takes Thrust |
<-----------------Center----------------> |
| Crankshaft Bearing Type |
<-------------Replacable Liners----------> |
| Crankshaft Bearing Material |
<---------Steel Backed Durex 100A-------> |
| Provision for Bearing Adjustment |
<-----------------None------------------> |
| Bearing Cap Bolts, No. and Diam. |
| Rear Bearings |
Two 1/2” |
Four 1/2” |
| Other Bearings |
Two 1/2” |
Two 1/2” |
| Flywheel |
| Material and Wieght, Syncro-mesh |
C.I.-36.56 |
--- |
| Material and Wieght, Dynaflow |
Steel - 9.23 |
Steel - 12.21 |
| Number of Teeth on Ring |
146 |
156 |
| Crankshaft Balancer Type |
<--Laminated Steel Flywheel on Steel Leaf Springs--> |
| Balancer Location |
<---------Front End of Crankshaft---------> |
| Connecting Rods, Pistons and Rings |
| Connecting Rod Bearing Type |
<---------Steel Backed Durex 100-A--------> |
| Connecting Rod Bearing Material |
<--------------Replacable Liners------------> |
| Provision for Bearing Adjustment |
<------------------None-------------------> |
| Number and Diam. of Cap Bolts |
Two 3/8” |
Two 3/8” |
| How are Rods and Pistons Removed |
<-----------From Top of Cylinder-----------> |
| Piston Type |
<----------------Full Skirt----------------> |
| Piston Material and Surface Treatment |
<--------Aluminum Alloy - Anodized-------> |
| Compression Rings Per Piston |
2
| |
2
| Type |
<--------------Inside Bevel---------------> |
| Oil Rings Per Piston |
2 |
2 |
| Type, Upper |
<-------Channeled - Oil Return Slot-------> |
| Type, Lower |
<----------------Flex-Fit-----------------> |
| Location of All Piston Rings |
<------------Above Piston Pin------------>
|
| Camshaft and Valve Mechanism |
| Camshaft Drive |
<-------------Link Belt Chain------------>
|
| Number of Camshaft Bearings |
5 |
5
|
| Camshaft Bearing Material |
<----------Steel Backed Babbitt--------->
|
| Camshaft Thrust Control |
<-----------Plate at Front End----------->
|
| Camshaft Sprocket
|
| Material and Width |
<------------Cast Iron, 13/16″----------->
|
| No. of Teeth |
38 |
38
|
| Crankshaft Sprocket
|
| Material and Width |
<--------------Steel, 13/16″------------->
|
| No. of Teeth |
19 |
19
|
| Timing Chain Width |
13/16” |
13/16”
|
| Valve Lifter Type
|
| Series 40, Synchromesh only |
Plain Sleeve |
---
|
| Series 50, All Dynaflow |
<---------------Hydrualic---------------->
|
| Valve Type |
| Inlet |
<--------------Streamlined--------------->
|
| Exhaust |
<---------------Mushroom---------------->
|
| Valve Seat Angle, Inlet and Exhaust |
<--------------45 Degrees--------------->
|
| Valve Spring Type |
<--------------Dual Helical--------------->
|
| Valve Guide Type and Material |
<---------Removable, Cast Iron----------->
|
| Engine Oiling System |
| Oiling System Type |
<---------------Forced Feed----------------> |
| Oil Supplied to Bearing Surfaces - |
| Crankshaft Bearings |
<-----------------Pressure------------------> |
| Connecting Rod Bearings |
<-----------------Pressure------------------> |
| Pistons and Pines |
<------------------Spray--------------------> |
| Camshaft Bearings |
<-----------------Pressure------------------> |
| Timing Chain and Sprockets |
<-----------Metered Jet and Spray-----------> |
| Rocker Arms and Valves |
<---------------Low Pressure----------------> |
| Valve Lifters |
<---------------Low Pressure----------------> |
| Location of Oil Filter |
<---------In Valve Rocker Arm Cover---------> |
| Location of Oil Drain |
<-----------Plug in Lower Crankcase----------> |
| Oil Reservoir Capacity - Quarts (add 1 1/2 qts for dry oil filter |
| Dry Engine |
6 |
8 |
| Refill |
5 1/2 |
7 |
| Oil Level Guage |
<---------Rod in R. Side of Crankcase--------> |
| Oil Level Pressure Guage Make |
<--------------------A/C--------------------> |
| Normal Oil Pressure |
<-------------35 lbs. at 35 mph.-------------> |
| Oil Pump Type |
<----------------Helical Gear----------------> |
| Oil Pump Location |
<-------Suspended in Lower Crankcase-------> |
| Oil Screen Location |
<--------On Float Attached to Pump---------> |
| Oil Pressure Regulator Type |
<------Non-Adjustable Spring and Valve------> |
| Engine Cooling System |
| Cooling System Type |
<-----------------Pressure------------------> |
| Water Temperature Control |
<--------Thermostat and Fixed Bypass-------> |
| Cooling System Capacity - Quarts (Add 1 1/2 qts. for Dynaflow) |
| Less Heater |
12 |
18 |
| With Heater |
13 1/2 |
19 1/2 |
| Location of Drains |
<-Cocks in Rad. and in R.H. Side of Crankcase-> |
| Water Pump Type |
<----------------Centrifugal-----------------> |
| Water Pump Location |
<----------Front End of Crankcase-----------> |
| Water Pump and Fan Drive (With Generator) |
<----------Single Vee Belt-------------> |
| Water Pump to Crankshaft Speed Ratio |
<-----------------0.9 to 1-----------------> |
| Water Pump Bearing Type |
<----------Sealed Double Row Ball------------> |
| Water Pump Seal Type |
<----------Spring Loaded, Packless-----------> |
| Fan Diameter |
<-------------------18"---------------------> |
| Number of Blades |
4 |
5 |
| Radiator Make |
<-------------------Harrison-----------------> |
| Core Type |
<----------------Vee Cellular--------- -------> |
| Core Material |
<-------------------Copper------------------> |
| Core Frontal Area (sq. in.) |
| Syncromesh |
415 |
--- |
| Dynaflow |
484 |
484 |
| Core Thickness |
2” |
3” |
| Radiator Pressure Control |
<--------------Valve in Filler Cap-------------> |
| Radiator Pressure |
<-------------------7 lbs.-------------------> |
| Radiator Thermostat - Make |
<------------------Harrison------------------> |
| Thermostat Location |
<--------In Housing Above Water Pump-------> |
ENGINE DIMENSIONS AND FITS NOTE:Dimensions and limits for fir of parts apply to new parts only. Where limits are given, "T" means tight and "L" means loose. *A11 Measurements in Inches Unless Otherwise Specified.
Crankshaft and Connecting Rod Bearings |
|
Series 40-50 |
Series 70 |
Crankshaft Bearing - Nominal Diam. X Length |
|
|
-Front |
2 9/16" x 1 17/64” |
2 9/16" x 1 9/32” |
-Front Center |
2 9/16" x 1 1/32” |
2 5/8" x 31/32” |
-Center |
2 9/16" x 1 35/64” |
2 11/16" x 1 15/32” |
-Rear Center |
2 9/16" x 1 1/32” |
2 13/16" x 2 15/32” |
-Rear |
2 9/16" x 1 25/32” |
2 13/16" x 2 15/32” |
Crankshaft Journal Diameter |
-Front |
2.5625" - 2.5632” |
2.5605" - 2.5615” |
-Front Center |
2.5625" - 2.5632” |
2.6235" - 2.6245” |
-Center |
2.5625" - 2.5632” |
2.6855" - 2.6865” |
Center Rear |
2.5625" - 2.5632” |
2.7485" - 2.7495” |
-Rear |
2.5625" - 2.5632” |
2.8105" - 2.8115” |
Crankshaft Bearing to Journal Clearance |
.0006" - .0018” |
.0006" - .0020” |
Crankshaft End Play at Center Bearing |
.004" - .008” |
Fit to Main Drive Gear Pilot Bearing in Crankshaft |
.004"T to .0012"L |
--- |
Conecting Rod Bearing Nominal Diam. x Length |
2 1/8" x 1.030” |
2 1/4" x 1.306” |
Crankpin Journal Diameter |
2.125" - 2.126” |
2.248" - 2.249” |
Crankpin Journal to Bearing Clearance |
.0005" - .0016” |
End Clearance to Connecting Rod on Crankpin |
.005" - .010” |
Connecting Rod Length, Center to Center |
7 3/8” |
8 1/4” |
Cylinders, Pistons, Pins and Rings |
Cylinder Bores, Standard Size |
3.186" - 3.189” |
3.436" - 3.439” |
Piston Lenth, Overall |
3 49/64” |
4 9/16” |
PistonDiameter, Top of Skirt, at 90° to Piston Pin - |
-Standard |
3.1860" - 3.1872” |
3.4358" - 3.4370” |
-.005" Oversize |
3.1916" - 3.1922” |
3.4414" - 3.4420” |
-.010" Oversize |
3.1966" - 3.1972” |
3.4464" - 3.4470” |
-.020 Oversize |
3.2066" - 3.2072” |
3.4564" - 3.4570” |
-.30" Oversize |
3.2166" - 3. 2172” |
3.4664" - 3.4670” |
Piston Clearance in Cylinder Bore at Top of Skirt |
.0012" - .0018” |
.0014" - .0020” |
Piston Fit @70º F., using Feeler Gauges, Allowing
Piston to Drop on its Own Weight |
.0015" GO - .002" NO GO |
Piston Pin Length |
2 11/16” |
3 1/16” |
Piston Pin Diameter |
.8124" - .8129” |
.8744" - .8749” |
Piston Pin Fit in Piston at 70º F. |
Finger Push Fit (.0003" - .0005") |
Width of Compression Rings |
3/32” |
3/32” |
Width of Channeled Oil Rings |
3/16” |
3/16” |
Width of Flex-Fite Oil Rings |
.186" - .187” |
Width of Gap, Ring in Bore - |
-Compression and Upper Oil Ring |
.010" - .020” |
-Fles-Fit Oil Ring |
No Checking or Fitting Required |
Side Cleraance of Rings in Piston Grove - |
-Compression Ring |
.0015" - .0035” |
-Upper Oil Ring |
.0015" - .003” |
-Flex-Fit Ring |
.001" - .003” |
Camshaft and Valve Mechanism |
Camshaft End Play |
.004" - .009” |
Camshaft Bearings - Diam. x Lenth - |
-No. 1 |
2 5/32" x 1 1/8” |
-No. 2 |
2 1/8" x 3/4” |
2 1/8" x 1 1/8” |
-No. 3 |
2 3/32" x 1 1/8” |
-No. 4 |
2 1/16" x 3/4” |
2 1/16" x 15/16” |
-No. 5 |
1 3/4" x 31/32” |
Camshaft Clearance in Bearings |
.0015" - .004” |
Valve Lifter Diameter |
.9975" - .9985” |
Valve Lifter Clearance in Crankcase |
.0005" - .0025” |
Rocker Arm Shaft O.D> |
13/16” |
13/16” |
Rocker Arm Clearance on Shaft |
.002" - .004” |
Vavle Head Diameter - |
-Inlet |
1 17/32” |
1 25/32” |
-Exhaust |
1 11/16” |
1 7/16” |
Valve Seat Angle - Inlet and Exhaust |
45º |
Vavle Lift - |
-Inlet |
.348” |
.347” |
-Exhaust |
.342” |
.348” |
Vavle Stem Diameter - |
-Inlet |
.3715" - .3719” |
-Exhaust |
.3711" - .3719” |
Vavle Stem Clearance in Guide - |
-Inlet |
.0015" - .0035” |
-Exhaust |
.0021" - .0039” |
Vavle Guide Extension from Top of Cyl. Head |
1 5/32” |
1 5/32” |
Inner Vavle Spring, Used with Adjustable Vavle Lash - |
-Valve Open (lbs. @ length) |
48 - 54 @1 5/16” |
--- |
-Valve Closed (lbs. @ length) |
17.5 - 22.5 @ 1 21/32” |
--- |
Outer Vavle Spring, Used with Adjustable Vavle Lash - |
-Valve Open (lbs. @ length) |
74 - 80 @1 19/32” |
--- |
-Valve Closed (lbs. @ length) |
29.5 - 34.5 @ 1 15/16” |
--- |
Inner Vavle Spring, Used with Hydraulic Lifters - |
-Valve Open (lbs. @ length) |
49 -55 @1 5/16” |
-Valve Closed (lbs. @ length) |
22 - 26 @ 1 21/32” |
Outer Vavle Spring, Hydraulic Lifters - |
-Valve Open (lbs. @ length) |
96 - 104 @ 1 19/32” |
-Valve Closed (lbs. @ length) |
49 - 55 @ 1 15/16” |
Valve Lash - Series 40 Synchromesh
NOTE: Does not apply to engines equipped with hydraulic vavle lifters. |
Vavle Lash at Road Operating Temp.,
Inlet and Exhaust - |
.015” |
--- |
Valve Lash using Shop Proceedure |
.017”Go-.018”No Go |
--- |
Engine Oil System |
Pump Shaft to Bearing Clearance |
.0005" - .0020” |
Pump Idler Gear Bearing Clearance |
.001 - .0025” |
Pump Drive Gear Backlash |
.003" - .005” |
Pump Drive and Idler Gears Backlash |
.003 - .006” |
Pump Drive and Idler Gears End Clearance |
.003 - .006 |
Oil Pressure Valve Clearance in Body |
.003" - .006” |
Engine Cooling System |
Fan Belt Adjustment |
5/16” |
Fit of Bearing in Water Pump Body |
.0006T to .0009"L |
Pump Bearing Shaft Diameter |
5/8” |
5/8” |
Fan Hub Fit on Bearing Shaft |
.001"T - .0025"L |
Fan Hub Position on Bearing Shaft |
13/64" from end |
Radiator Hose Inside Diam. and Type |
1 9/16" Elbow |
Bypass Hose Inside Diameter |
3/4” |
Standard (151° ) Radiator Thermostat Calibration, @Atm. Press. - |
-Start to Leave Seat |
148° to 155° |
-Fully Open |
Not over 176° |
Standard (182° ) Radiator Thermostat Calibration, @Atm. Press. - |
-Start to Leave Seat |
178° to 185° |
-Fully Open |
Not over 211° |
|
|
