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Buick Fireball Eight

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
Buick Eight Torque

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
     Synchromesh - Series 40 Only 6.6 to 1 ---
     Synchromesh - Series 50 Only 6.9 to 1 ---
     Dynaflow - All Series 7.2 to 1 7.5-1
Compression Pressure @ Cranking Speed (psi)
     Synchromesh - Series 40 Only 114 ---
     Synchromesh - 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.
     Synchromesh - Series 40 Only 120 @ 3600 ---
     Synchromesh - Series 50 Only 124 @ 3600 ---
     Dynaflow - All Series 128 @ 3600 168 @3800
Engine Weight, 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″-------------->



Full precision bored bearings first appeared in Buick engines in 1947. In series 40-50 after engine 4918702 and up to engine 4919898 and after engine 4922786 In series 70 after engine 49918703 and up to engine 4919899 and after engine 4922786 (0.094).
Crankshaft Bearings, Flywheel Balancer
Crankshaft Weight (lbs.) 90 116
Number of Crankshaft Bearings 5 5
Bearing Which Takes Thrust <-----------------Center---------------->
Crankshaft Bearing Type <-------------Replaceable 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 Weight, Synchromesh C.I.-36.56 ---
    Material and Weight, 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 <--------------Replaceable 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 <---------------Hydraulic---------------->
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 Gauge <---------Rod in R. Side of Crankcase-------->
Oil Level Pressure Gauge 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.)
     Synchromesh 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”
Fillet Radius
.125"
 
Thrust Width
1.5490"
 
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
---
Connecting Rod Bearing Nominal Diam. x Length
2 1/8" x 1.030”
2 1/4" x 1.306”
Crank pin Journal Diameter
2.125" - 2.126”
2.248" - 2.249”
Crank pin Journal to Bearing Clearance
.0005" - .0016”
End Clearance to Connecting Rod on Crank pin
.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 Length, Overall
3 49/64”
4 9/16”
Piston Diameter, 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-Fit Oil Rings
.186" - .187”
Width of Gap, Ring in Bore -
 -Compression and Upper Oil Ring
.010" - .020”
 Flex-Fit Oil Ring
No Checking or Fitting Required
Side Clearance 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 Length -
 -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”
Valve Head Diameter -
 -Inlet
1 17/32”
1 25/32”
 -Exhaust
1 11/32”
1 7/16”
Valve Seat Angle - Inlet and Exhaust
45º
 Rocker Arm Ratio -
1.45
 
Valve Lift -
 -Inlet
.348”
.347”
 -Exhaust
.342”
.348”
Valve Stem Diameter -
 -Inlet
.3715" - .3719”
 -Exhaust
.3711" - .3719”
Valve Stem Clearance in Guide -
 -Inlet
.0015" - .0035”
 -Exhaust
.0021" - .0039”
Valve Guide Extension from Top of Cyl. Head
1 5/32”
1 5/32”
Inner Valve Spring, Used with Adjustable Valve Lash -
 -Valve Open (lbs. @ length)
48 - 54 @1 5/16”
---
 -Valve Closed (lbs. @ length)
17.5 - 22.5 @ 1 21/32”
---
Outer Valve Spring, Used with Adjustable Valve Lash -
 -Valve Open (lbs. @ length)
74 - 80 @1 19/32”
---
 -Valve Closed (lbs. @ length)
29.5 - 34.5 @ 1 15/16”
---
Inner Valve Spring, Used with Hydraulic Lifters -
 -Valve Open (lbs. @ length)
49 -55 @1 5/16”
 -Valve Closed (lbs. @ length)
22 - 26 @ 1 21/32”
Outer Valve 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 valve lifters.
Valve Lash at Road Operating Temp.,
Inlet and Exhaust -
.015”
---
Valve Lash using Shop Procedure
.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°

Blue Print Specifications
 
248
263
320 
Bore
3 3/32””
3 3/16””
3 7/16””
Stroke
4 1/8”
4 1/8”
4 5/16”
Cylinder Head Volume
 
98cc 
116cc
Piston Dome Volume
 
9.5cc
14cc
Deck Clearance
 
.0012” - .0018”
.0014” - .0020”
Deck Height
 
Rod Length
7.625"
7.375"
8.250" 
Rod/Stroke Ratio
1.848"
1.787"
1.913" 
Bore/Stroke Ratio
0.750"
.773"
.798"
263 Bore pitch: cylinders #1-2, 3-4, 5-6, & 7-8 are 3.725" apart, cylinders #2-3, & 6-7 are 3.750" apart and cylinders #4-5 are 4.185" apart
320 Bore pitch: cylinders #1-2, 3-4, 5-6, & 7-8 are 4.075" apart, cylinders #2-3 & 6-7 are 4.290" apart, and cylinders #4-5 are 4.545" apart.

Contributors: bob k. mando, pmuller9