Home » Racing Engines » Chevrolet Small Block Gen III LS1 345
Specifications
Chevrolet Small Block Gen III LS1 345ci (5.7 lt), 4 stroke
Introduced in 1997
5665cc
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Dimensions
Cylinders arrangement: V8 (90o)
Strokes: 4
Bore x Stroke: 3.898 in (99.06 mm) x 3.62 in (91.9 mm)
Capacity: 5665 cc
Compression ratio:
Construction materials
A319 T5 (production) or A357-T6 aluminum alloy block with 234.7mm deck height and 111.8mm bore spacing
A356 T6 aluminium head
nodular iron crankshaft with 5 main bearings 65mm diameter
connecting rod length between centers 154.9mm, big end bearing diameter 53.3mm
Cylinder-head
crossflow design
OHV
camshaft in block with overhead valves (OHV), 2 valves/cyl - 16 valves total
Aspiration
Νatural with multipoint electronic Fuel Injection
Ignition
ECU
firing order 1-8-7-2-6-5-4-3, with Driver side 1 3 5 7, Passenger side 2 4 6 8
Animation
Cooling and lubrication
water cooled, Reverse flow water cooling
wet sump
Torque values
Models used and Output
Year | Model | Induction | Compression ratio | Power | Torque |
---|---|---|---|---|---|
2001 | Mosler MT900R | MPFI | 430 bhp / 321 KW |
Service info (street engine)
Source
LS1/LS6 Engine Dimensions & Clearances
Production = (P), Service Limit = (SL), Out-of-Round = O-o-R
Run Out = RO, Inside Dia. = ID, Outside Dia. = OD
CAMSHAFT:
Base Circle Dia.:
'97-'04 LS1 = 19.7mm / 0.776"
'01 LS6 = 19.3mm / 0.760"
'02 -'04 LS6 = 19.0mm / 0.748
End Play: 0.025-0.305mm / 0.001-0.012"
Journal Dia.: 54.99-55.04mm / 2.164-2.166"
Journal Dia. O-o-R: 0.025mm / 0.001"
Intake Lobe Lift: 7.04mm / 0.277"
Exhaust Lobe Lift: 7.13mm / 0.281"
Poller Lifter Dia.: 17.78mm / 0.700"
RO @ Intermediate Journals: 0.05mm / 0.002"
Lobe Base Circle Radius:
'97-'04 LS1: 19.7mm / 0.776"
'01 LS6: 19.3mm / 0.760" (reduced for ^ valve lift)
'02-'04 LS6: 19.0mm / 0.748 " " " " " "
CONNECTING ROD:
Bearing Bore Dia.: 56.505-56.525mm / 2.224-2.225"
Bearing Bore O-o-R (P): 0.004mm / 0.00015"
Bearing Bore O-o-R (SL): 0.008mm / 0.0003"
Bearing Clearance (P): 0.015-0.063mm / 0.0006-0.00248"
Bearing Clearance (SL): 0.015-0.076mm/0.0006-0.003"
Bearing Width: 24mm / 0.9449"
Side Clearance: 0.11-0.51mm / 0.00433-0.02"
Center to Center: 154.89mm / 6.098"
Piston Pin Bore Dia.: 23.97mm / 0.9436"
Piston Pin Boss Width: 24mm / 0.9449"
Piston Pin Press Interference:0.020-0.043mm / 0.0008-0.0017"
Rod Bolts: M9 x 1" (replace with ARP/Katech if > 450HP)
CRANKSHAFT:
Rotation = Clockwise (looking at front of block)
Bearing Clearance (P): 0.018-0.054mm / 0.0007-0.00212"
Con Rod Journal Dia. (P): 53.318-53.338mm / 2.0991-2.0999"
Con Rod Journal Dia. (SL): 53.308mm Min. / 2.0987" Min.
Con Rod Journal Taper (P): 0.005mm / 0.0002"
(Maximum for 1/2 Journal length)
Con Rod Journal Taper (SL): 0.01mm Max. / 0.0004" Max.
Con Rod Journal O-o-R (P): 0.005mm / 0.0002"
Con Rod Journal O-o-R (SL): 0.01mm / 0.0004"
Con Rod Journal Width: 48.37mm / 1.902"
End Play: 0.04-0.2mm /0.0015-0.0078"
Main Journal Dia. (P): 64.993-65.007mm / 2.558-2.559"
Main Journal Dia. (SL): 64.993mm Min. / 2.558" Min.
Main Journal O-o-R (P): 0.003mm / 0.000118"
Main Journal O-o-R (SL): 0.008mm / 0.0003
Main Journal Taper (P): 0.01mm / 0.0004"
Main Journal Taper (SL): 0.02mm / 0.00078"
Main Journal Width: 22.99mm / 0.905"
Reluctor Ring RO: 0.25mm / 0.01"
(Measured @ 1.0mm/0.04" below tooth Dia.)
Crank RO : 0.05mm / 0.002" (Measured at rear flange)
Flywheel Bolt Base Circle: 78.99mm / 3.110"
Stroke: 92mm / 3.622"
Rear Seal ID: 114.99mm / 4.527"
Thrust Wall RO: 0.025mm / 0.001"
Thrust Wall Width (P): 26.14-26.22mm / 1.029-1.032"
Thrust Wall Width (SL): 26.32 Max. / 1.036" Max.
CYLINDER BORE:
Bore Dia.: 99.0-99.018mm / 3.897-3.898"
Bore Taper Thrust Side: 0.018mm Max. / 0.0007" Max.
Bank Angle = 45 degrees
Cylinder Bank Offset: 24.10mm / 0.949"
CYLINDER HEAD: A356 T6
Block Deck Flatness: 0.11mm / 0.004" (within a 6" area)
Block Deck Flatness: 0.22mm / 0.008" (length of head)
Exhaust Manifold Deck Flatness: 0.22mm / 0.008"
Intake Manifold Deck Flatness: 0.22mm / 0.008"
Height: 120.2mm / 4.732" (Deck to Rocker Cover Surfaces)
Valve Angle: 15 degrees
Valve Guide Material = Sintered Iron (Press IN)
Valve Guide Seperation: 48.6mm / 1.913"
Valve Seat Angles: 30/45/60 degree blend into chamber
Valve Stem Dia.: 8.001mm / 0.315"
ENGINE BLOCK: A319 T5 / 107#'s
Length: 519mm / 20.43"
Width: 460mm / 18.11"
Deck Height: 234.57-234.82mm / 9.235-9.245"
Cylinder Bank Angle = 45 degrees
Cylinder Bank Offset: 24.10mm / 0.949"
Center Main = Crank Thrust Wall #3
Indexing = Crank CenterLine
Camshaft Bearing Bore Dia.: 55.063-55.088mm / 2.168-2.169"
Block Deck Flatness: 0.11mm / 0.004" (measured within 6")
Block Deck Flatness: 0.22mm / 0.008" (length of Deck)
Main Bearing Bore Dia. (P): 69.871-69.889mm / 2.750-2.751"
Valve Lifter Bore Dia. (P):21.417-21.443 / 0.843-0.844"
FUEL INJECTION:
LS1 Static Flow Rate = 3.6 gal/sec.
Cranking Fuel pressure = 53 to 63 psi
IGNITION:
Coil Output = 60mJ
Sparkplug Wire length = 219mm
Sparkplug Type = AC 41-931 / Beru Silverstone S1K
Sparkplug gap = 1.5mm / 0.060"
INTAKE MANIFOLD;
Head Deck Flatness: 0.5mm / 0.02" @ gasket mating surface
LS1 MAF ID = 75mm
LS1 Throttle Body ID = 75mm
LS6 MAF ID = 80mm
LS6 Throttle Body ID = 80mm
OIL PAN & FRONT/REAR COVER Alignment:
Oil Pan to Rear of Block: 0.0-0.25mm / 0.0-0.01"
(@ Bellhousing Surface)
Front Cover: 0.0-0.5mm / 0.0-0.2" (@ Oil Pan Surface)
Rear Cover: 0.0-0.5mm / 0.0-0.2" (@ Oil Pan Surface)
OIL PUMP:
Dia: 89.99mm / 3.543"
Gear Thickness: 10.69mm / 0.421"
Pressure Relief Setting (Factory): 60 psig @ 5,000 RPM
PISTONS: Cast Eutectic Aluminum, +'03 have coated skirts
Weight = 434 grams
Piston OD: 98.964-98.982mm / 3.8962-3.8969"
Piston to Bore Clearance(P): 0.018-0.054mm/0.0007-0.00212"
Piston to Bore Clear. (SL): 0.018-0.054mm / 0.0007-0.00212"
(Maximum)
Piston Deck Height in Operation: 0.203mm / 0.008"
(Above Deck Surface)
Top Land Thickness: 34mm / 0.177"
PISTON PINS:
Pin to Piston Bore (P): 0.01-0.02mm / 0.0004-0.00078"
Pin to Piston Bore (SL): 0.01-0.02mm / 0.0004-0.00078" Max.
Pin Dia.: 23.997-24.0mm / 0.9447-0.9448"
Pin Fit in Con Rod: 0.02-0.043mm / 0.00078-0.00169"
(Interference)
PISTON RINGS:
Top Comp. Thickness: 1.500mm / 0.59"
Top Comp. Gap Clocking: None Required
Top Comp. End Gap (P): 0.23-0.38mm / 0.009-0.0149"
Top Comp. End Gap (SL): 0.23-0.38mm / 0.009-0.0149" Max.
Top Comp. Groove (P):0.04-0.085mm / 0.00157-0.003346"
Top Comp. Groove (SL):0.04-0.085mm/0.00157-0.003346"Max.
2nd Comp. Thickness: 1.500mm / 0.59"
Top Comp Gap Clocking: None Required
2nd Comp. End Gap (P): 0.44-0.64mm / 0.0173-0.0251"
2nd Comp. End gap (SL): 0.44-0.64mm / 0.0173-0.0251" Max.
2nd Comp. Groove (P): 0.04-0.08mm / 0.00157-0.003149"
2nd Comp. Groove (SL):0.04-0.08mm/0.00157-0.003149"Max.
Oil Cont. Rail Thickness (2): 3.00mm / .188" (EACH)
Oil Cont. Top Rail Gap Clocking: 25 degrees from Top Ring
Oil Cont. 2nd Rail gap Clocking: 25 degrees from Expander
Oil Cont. End Gap (P): 0.18-0.69mm / 0.007-0.0271"
Oil Cont. End Gap (SL): 0.18-0.69mm / 0.007-0.0271" Max.
Oil Cont. Groove (P): 0.01-0.22mm / 0.0004-0.00866"
Oil Cont. Groove (SL):0.01-0.22mm / 0.0004-0.00866" Max.
VALVETRAIN:Hydraulic Roller
Rocker Arm Ratio = 1.70:1
Valve Lash Net Lash: No Adjustment
Valve Face Angle = 45 degrees
Valve Seat Angle = 46 degrees
Valve Seat RO: 0.05mm / 0.002" Max.
Valve Seat Width (Intake) = 1.02mm / 0.04"
Valve Seat Width (Exhaust) = 1.78mm / 0.07"
Valve Stem:
Clearances:
Intake (P): 0.025-0.066mm / 0.001-0.0026"
Intake (SL): 0.093mm / 0.0037" Max.
Exhaust (P): 0.025-0.066mm / 0.001-0.0026"
Exhaust (SL): 0.093mm / 0.0037" Max
Oil Seal Installed Height = 18.1-19.1mm / 0.712-0.752"
(Measured from VS Shim toTop Edge od Seal Body)
Valve Stem Dia. (P): 7.955-7.976mm / 0.313-0.314"
Valve Stem Dia. (SL) 7.9mm / 0.311 Min.
Valve Spring:
Free Length = 52.9mm / 2.08"
Pressure (Closed) = 340 N @ 45.75mm / 76# @ 1.80"
Pressure (Open) = 980 N @ 33.55mm / 220# @ 1.32"
Installed Height (Intake) = 45.75mm / 1.800"
Installed Height (Exhaust) = 45.75mm / 1.8"
Valve Guide Installed Height = 17.32mm / 0.682"
(Measured from Spring Seat Surface to Top of valve Guide)
Roller Lifter Dia.:17.78mm / 0.700"
Valve Material: Stainless Steel, Hollow Stems, Na filled Exhaust
Cams
1997-2000
0.472/0.479, 202/210 on 117
2001 LS1
.500/0.500, 198/208 on 115.5LSA
2001 LS6
0.525/0.525, 204/211 on 116
2002 LS6
0.551/0.547, 204/218 on 117.5