350 chevy 014 block

Small Block Chevy 350 Dimensions

 Small Block Chevy 350 Dimensions

Common info but hard to find them all in one place. I figured I would type them all into one post to make life easier for me if for no one else. Most figures will be in inches where ever possible. All Small Block Chevy 350 Dimensions will be for the standard small block 350 unless other wise noted other engine model to come as i have complete dimensions for them. All Dimensions are for OEM blocks and parts with the amount of aftermarket engine parts for the small block chevy it will not be possible to list even the typical aftermarket specs for most parts. I will try to list some common aftermarket sizes if they are common industry wide.

I will be adding more information to this article as I have them.

Standard Information:

  • 90 Degree v8
  • 350 Cubic Inches
  • 5.7 Liters

Internal Measurements:

  • Rod Length Measured center of the pins = 5.7″
  • Big end rod inside diameter = 2.1000″
  • Early sbc rods were small journal 2.00″
  • Small end of rod inside diameter = .927″
  • Stroke = 3.48″
  • Bore = 4.00″
  • 30 over Bore = 4.030″
  • 60 over Bore = 4.060″
  • Standard Piston Deck Height with pistons at TDC = .025″
  • Head Gasket thickness = .020″ to .049″
  • Block or stack height = 9.025″
  • Piston compression height = 1.56″
  • Piston Pin diameter = .927″
  • Harmonic Balance sizes = 6-3/4″ x 1-3/16″ or 8″ x 1-1/2″ sizes were used on the 350
  • Stock Push Rod Length = Flat Tappet = 7.794″ or OEM Roller = 7.195″ common measurements are 7.800″ and 7.200″

Cam and Lifters

  • Lifter Diameter = .842″
  • The Lifter bore Spec for the block is  .8438″ to .8443″
  • Common oversize Lifter is .874 .875  ford size. These are used if the lifter bores are worn or damaged and also with some larger lift cams in race engines.
  • Large lifters are the .903 these are a mopar size but must be made for chevy engines. But often used in large flat and roller cams with higher lifts aggressive lobe profiles and long duration with fast opening and closing degrees. These allow the lifter to better follow the cam lobe. With roller they also allow for the roller to be much larger and this helps in many ways as above and also in durability. This is a common size for Circle track and drag racing engines.
  • Cams are made in the std  1.868″  and some after market core sizes.
  • Common oversize is big block Chevy cam journals: 1.948″
  • Other Sizes are  50mm (1.969″) for needle bearings
  • Ford 2.124″
  • Cores needle bearings also include 55mm (2.165″) and 60mm (2.364″) But more common for BBC since the cams can be too large for some sbc blocks. Raised core blocks can take much larger cam sizes.
  • Cam Bearing Bore dimensions:
  • Bearing #1  2.0190-2.0210
  • Bearings #2  &  #5  2.0090-2.0110
  • Bearings #3  &  #4  1.9990-2.0010

Crank Shaft Tolerances and Specs

  • Crank Shaft End Play   Std.  .002″ – .006″
  • 350 Rod Large Journal Standard 2.099″ – 2.10″
  • .010″ Under Rod Journal         2.089″ – 2.090″
  • .020″ Under Rod Journal         2.079″ – 2.080″
  • .030″ Under Rod Journal         2.069″ – 2.070″
  • Main Journal 350 Blocks 1-4 Standard: 2.4484″-2.4493″
  • .010″ Under 350 Main 1-4: 2.4384″-2.4393″
  • .020″ Under 350 Main 1-4: 2.4284″-2.4293″
  • .030″ Under 350 Main 1-4: 2.4184″-2.4193″
  • Rear Main Journal 350 Blocks 5th Standard: 2.4479″-2.4488″
  • .010″ Under Rear Main Journal 350 5th: 2.4379″-2.4388″
  • .020″ Under Rear Main Journal 350 5th: 2.4279″-2.4288″
  • .030″ Under Rear Main Journal 350 5th: 2.4179″-2.4188″
  • Main Journal 400 Blocks 1-4 Standard: 2.6484″-2.6493″
  • .010″ Under 400 Main 1-4: 2.6384″-2.6393″
  • .020″ Under 400 Main 1-4: 2.6284″-2.6293″
  • .030″ Under 400 Main 1-4: 2.6184″-2.6193″
  • Rear Main Journal 400 Blocks 5th Standard: 2.6479″-2.6488″
  • .010″ Under Rear Main Journal 400 5th: 2.6379″-2.6388″
  • .020″ Under Rear Main Journal 400 5th: 2.6279″-2.6288″
  • .030″ Under Rear Main Journal 400 5th: 2.6179″-2.6188″

 

Racing engines will often run loose clearance on the rods and mains up to .0003″ – .0006″ is common. Experienced engine builders may run them even looser with proper oil viscosity and pressures. For most engines running 50 w racing oil .0005″ is best.

Taper and run out should not exceed .0005″ on all rods journals and mains.

 

Block Outside Dimensions:

I will try to list just the blocks outside sizes first and look at other dimensions later. These are basic dimensions not factory blue print sizes. Measured with a ruler they are all approximate sizes.

OE Block

  • Block length without crank is = 21″
  • Width = 17″
  • Height from oil pan gasket area 10″
  • Height from crank journal 14″
  • Deck Width = 7 3/4″

OE Cylinder Head

  • Length = 19-3/4″
  • Width = 7 3/4″ – 8″
  • Height without springs and valves = 4-5 “
  • Height with tall valve covers = 8″
  • Valve Spacing = 1.8″
  • Stud Spacing = 1.8″
  • Intake To Intake Spacing = 2.8″

Edelbrock Performer

  • Width=9.75
  • Length=20.75
  • Pad Height=4.25

HEI Dizzy with cap

  • H=7.75
  • D=5

Firing Order

  • Chevy V8 Firing Order: 1-8-4-3-6-5-7-2
  • The Distributor turns Clockwise

Cylinder Heads

Valves

Intake:

Valve Head Diameter   1.720″,  1.824″,  1.940”,  2.00″,  2.020″,

After Market Valve Sizes:  2.050″,  2.080″,  2.1″,  2.125″, 1.625″  Some heads can even use larger valves on 400 cubic inch bores (4.125)

11/32” (0.3415”) Stem Diameter

4.880” Overall Length (Stock) can also be 4.911″ 4.905″

+ .100 Longer valves are 5.011 and are very common in performance heads. 5″ are also common

Exhaust:

Valve Head Diameter 1.500” 1.600”

11/32” (0.3415”) Stem Diameter

4.920”,  4.930″,  Overall Length (Stock)

Port Volume range from 145cc to 175cc depending on the head only the best X heads will have sizes over the standard 160cc range. LT1 aluminum heads are 170cc and LT4 Heads are 195cc but these are not first gen sbc. I would call them gen II sbc.

 

Bolts & Torque Specs

All torqued bolts should have at least (Good) engine oil (Better) Molly lube and (best) would be ARP ultra-torque

  • Main caps bolts (2 bolt mains) 7/16  at 70 ft lbs.
  • 7/16 Main Inner caps bolts 4 (Inner mains bolts) at 70 ft lbs
  • 7/16 Main outer caps bolts 4 (Outer mains bolts) at 65 ft lbs
  • 3/8 Main Inner caps bolts 4 (Outer mains bolts) at 40 ft lbs
  • 3/8 OEM Connecting Rod bolts 3/8″ at 40 ft lbs
  • 11/32 OEM Connecting Rod bolts 11/32″ at 45 ft lbs
  • Cylinder Head Bolts 7/16″ at 65 ft lbs
  • Rocker Studs For oem Screw in studs 50 ft lbs
  • Oil Pump Stud In main 65 ft lbs
  • Oil Pan 12 ft lbs
  • Upper Cam bolts x 3 – 25 ft lbs
  • Front Timing Cover 6 ft lbs
  • Intake Manifolds bolts 30 ft lbs
  • Valve Cover 6 ft lbs
  • Exhaust Manifold 25 ft lbs
  • Flex Plate or Flywheel 60 ft lbs
  • Clutch Pressure plate 35 ft lbs
  • Harmonics Balancer 60 ft lbs
  • Bellhousing 25 ft lbs
  • Spark Plugs  20 ft lbs

 

More to come…