Engine Mechanical (H4SO): General Description: Specification

2007 Subaru Outback Limited, 4D Sedan, StandardSECTION Specification
GENERAL SPECIFICATION

  Model 2.5 L
Engine Cylinder arrangement Horizontally opposed, liquid cooled, 4-cylinder, 4-stroke gasoline engine
Valve system mechanism Belt driven Single overhead camshaft 4 valve/4 cylinder
Bore x Stroke mm (in) 99.5 x 79.0 (3.917 x 3.110)
Piston displacement cm3 (cu in) 2,457 (150)
Compression ratio 10.0
Compression pressure (at 350 rpm) kPa (kg/cm2 , psi) 1,020 - 1,275 (10.4 - 13.0, 148 - 185)
Number of piston rings Pressure ring: 2, Oil ring: 1
Intake valve timing Constant Open BTDC 0°
Close ABDC 58°
Low speed Open BTDC 0°
Close ABDC -50°
High speed Open BTDC 14°
Close ABDC 62°
Exhaust valve timing Open BBDC46°
Close ATDC 14°
Valve clearance mm (in) Intake 0.20±0.04 (0.0079±0.0016)
Exhaust 0.25±0.04 (0.0098±0.0016)
Idling speed [at neutral position on MT, or "P" or "N" position on AT] rpm MT 650±100 (Noload)
850±100 (A/CON)
AT 700±100 (No load)
850±100 (A/CON)
Ignition order 1 → 3 → 2 → 4
Ignition timing BTDC/rpm MT 10°±8°/650
AT 15°±8°/700
NOTE: US: Undersize OS: Oversize
GENERAL SPECIFICATION

Belt tension adjuster Protrusion of adjuster rod mm (in) 5.2 - 6.2 (0.205 - 0.244)
Belt tensioner Spacer O.D. mm (in) 17.955 - 17.975 (0.7069 - 0.7077)
Tensioner bushing I.D. mm (in) 18.00 - 18.08 (0.7087 - 0.7118)
Clearance between spacer and bushing mm (in) Standard 0.025 - 0.125 (0.0010 - 0.0049)
Side clearance of spacer mm (in) Standard 0.20 - 0.55 (0.0079 - 0.0217)
Valve rocker arm Clearance between shaft and arm mm (in) Standard 0.020 - 0.054 (0.0008 - 0.0021)
Camshaft Bending limit mm (in) 0.025 (0.0010)
Thrust clearance mm (in) Standard 0.030 - 0.090 (0.0012 - 0.0035)
Cam lobe height mm (in) Intake Constant Standard 40.075 - 40.175 (1.5778 - 1.5817)
Low speed Standard 35.182 - 35.282 (1.3851 - 1.3891)
High speed Standard 40.315 - 40.415 (1.5872 - 1.5911)
Exhaust   Standard 40.088 - 40.188 (1.5783 - 1.5822)
Camshaft journal O.D. mm (in) 31.928 - 31.945 (1.2570 - 1.2577)
Camshaft journal hole I.D. mm (in) 32.000 - 32.018 (1.2598 - 1.2605)
Oil clearance mm (in) Standard 0.055 - 0.090 (0.0022 - 0.0035)
Cylinder head Surface warpage limit (Mating surface with cylinder block) mm (in) 0.035 (0.0014)
Grinding limit mm (in) 0.1 (0.004)
Standard height mm (in) 97.5 (3.84)
Valve seat Seating angle 90°
Contacting width mm (in) Intake Standard 0.8 - 1.4 (0.03 - 0.055)
Exhaust Standard 1.2 - 1.8 (0.047 - 0.071)
Valve guide Inside diameter mm (in) 6.000 - 6.012 (0.2362 - 0.2367)
Protrusion above head mm (in) Intake 20.0 - 21.0 (0.787 - 0.827)
Exhaust 16.5 - 17.5 (0.650 - 0.689)
Valve Head edge thickness mm (in) Intake Standard 0.8 - 1.2 (0.03 - 0.047)
Exhaust Standard 1.0 - 1.4 (0.039 - 0.055)
Stem outer diameter mm (in) Intake 5.950 - 5.965 (0.2343 - 0.2348)
Exhaust 5.945 - 5.960 (0.2341 - 0.2346)
Valve stem gap mm (in) Standard Intake 0.035 - 0.062 (0.0014 - 0.0024)
Exhaust 0.040 - 0.067 (0.0016 - 0.0026)
Overall length mm (in) Intake 120.6 (4.75)
Exhaust 121.7 (4.79)
Valve spring Free length mm (in) 55.2 (2.173)
Squareness 2.5°, 2.4 (0.094) or less
Tension/spring height N (kgf, lb)/mm (in) Set 235.3 - 270.7 (24 - 27.6, 52.9 - 60.8)/45.0 (1.772)
Lift 578.9 - 639.9 (59.1 - 65.3, 130.3 - 143.9)/34.7 (1.366)
Cylinder block Surface warpage limit (mating with cylinder head) mm (in) 0.025 (0.00098)
Grinding limit mm (in) 0.1 (0.004)
Standard height mm (in) 201.0 (7.91)
Cylinder inner diameter mm (in) Standard A 99.505 - 99.515 (3.9175 - 3.9179)
B 99.495 - 99.505 (3.9171 - 3.9175)
Taper mm (in) Standard 0.015 (0.0006)
Out-of-roundness mm (in) Standard 0.010 (0.0004)
Piston clearance mm (in) Standard -0.010 - 0.010 (-0.00039 - 0.00039)
Cylinder inner diameter boring limit (diameter) mm (in) To 100.005 (3.9372)
Piston Outer diameter mm (in) Standard A 99.505 - 99.515 (3.9175 - 3.9179)
B 99.495 - 99.505 (3.9171 - 3.9175)
0.25 (0.0098) OS 99.745 - 99.765 (3.9270 - 3.9278)
0.50 (0.0197) OS 99.995 - 100.015 (3.9368 - 3.9376)
Piston pin specified diameter mm (in) 23.000 - 23.006 (0.9055 - 0.9057)
Piston pin Outer diameter mm (in) 22.994 - 23.000 (0.9053 - 0.9055)
Clearance between piston and piston pin: mm (in) Standard 0.004 - 0.008 (0.0002 - 0.0003)
Degree of fit Piston pin must be fitted into position with thumb at 20°C (68°F).
Piston ring Ring closed gap mm (in) Top ring Standard 0.20 - 0.35 (0.0079 - 0.0138)
Second ring Standard 0.37 - 0.52 (0.0144 - 0.0203)
Oil ring Standard 0.20 - 0.50 (0.0079 - 0.0197)
Ring groove gap mm (in) Top ring Standard 0.040 - 0.080 (0.0016 - 0.0031)
Second ring Standard 0.030 - 0.070 (0.0012 - 0.0028)
Connecting rod Bend or twist per 100 mm (3.94 in) in length mm (in) Limit 0.10 (0.0039)
Thrust clearance mm (in) Standard 0.070 - 0.330 (0.0028 - 0.0130)
Bearing of large end Oil clearance mm (in) Standard   0.016 - 0.044 (0.00063 - 0.0017)
Bearing size (Thickness at center) mm (in) Standard 1.492 - 1.501 (0.0587 - 0.0591)
0.03 (0.0012) US 1.510 - 1.513 (0.0594 - 0.0596)
0.05 (0.0020) US 1.520 - 1.523 (0.0598 - 0.0600)
0.25 (0.0098) US 1.620 - 1.623 (0.0638 - 0.0639)
Bushing of small end Clearance between piston pin and bushing mm (in) Standard 0 - 0.022 (0 - 0.0009)
Crankshaft Bend limit mm (in) 0.035 (0.0014)
Crank pin Out-of-roundness mm (in) 0.003 (0.0001)
Cylindricality mm (in) 0.004 (0.0002)
Grinding limit (dia.) mm (in) To 51.750 (2.0374)
Crank journal Out-of-roundness mm (in) 0.005 (0.0002)
Cylindricality mm (in) 0.006 (0.0002)
Grinding limit (dia.) mm (in) To 59.758 (2.3527)
Crank pin outer diameter mm (in) Standard 51.984 - 52.000 (2.0466 - 2.0472)
0.03 (0.0012) US 51.954 - 51.970 (2.0454 - 2.0461)
0.05 (0.0020) US 51.934 - 51.950 (2.0446 - 2.0453)
0.25 (0.0098) US 51.734 - 51.750 (2.0368 - 2.0374)
Crank journal outer diameter mm (in) Standard 59.992 - 60.008 (2.3619 - 2.3625)
0.03 (0.0012) US 59.962 - 59.978 (2.3607 - 2.3613)
0.05 (0.0020) US 59.942 - 59.958 (2.3599 - 2.3605)
0.25 (0.0098) US 59.742 - 59.758 (2.3520 - 2.3527)
Thrust clearance mm (in) Standard 0.030 - 0.115 (0.0012 - 0.0045)
Oil clearance mm (in) Standard 0.010 - 0.030 (0.0001 - 0.0012)
Main bearing Main bearing mm (in) #1, #3 Standard 1.998 - 2.011 (0.0787 - 0.0792)
0.03 (0.0012) US 2.017 - 2.020 (0.0794 - 0.0795)
0.05 (0.0020) US 2.027 - 2.030 (0.0798 - 0.0799)
0.25 (0.0098) US 2.127 - 2.130 (0.0837 - 0.0839)
#2, #4, #5 Standard 2.000 - 2.013 (0.0787 - 0.0793)
0.03 (0.0012) US 2.019 - 2.022 (0.0795 - 0.0796)
0.05 (0.0020) US 2.029 - 2.032 (0.0799 - 0.0800)
0.25 (0.0098) US 2.129 - 2.132 (0.0838 - 0.0839)
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.