Subaru BRZ FA20D Head Bolt Torque Sequence and Angles
2013 Subaru BRZ/Scion FR-S FA20D head-bolt guide: 20/100 N·m prestress, 360° release, 20/42 N·m reseat and staggered angle stages.
For the naturally aspirated FA20D in the cited 2013 Subaru BRZ and Scion FR-S, clean the six head-bolt threads and oil the threads and washers. Tighten all six in the bank-specific order to 20 N·m (15 lb-ft), then 100 N·m (74 lb-ft); loosen all six 360 degrees in the shown order; retighten all to 20 N·m, then 42 N·m (31 lb-ft); add 100 degrees to all six; add another 100 degrees to the two center bolts; then add 50 degrees to the four outer bolts. Use an angle gauge and the correct LH/RH factory figures. This page does not claim that the same sequence covers the turbocharged WRX/Forester FA20DIT.
‘FA20’ is used casually for both naturally aspirated BRZ/FR-S engines and turbocharged WRX/Forester engines, but that shorthand is unsafe for internal assembly. This page is deliberately limited to the FA20D/4U-GSE joint documented in the 2013 rear-drive coupe manuals.
Its clamp method has a high-load seating cycle, a full one-turn release and a lower final baseline before three angle operations. The last two operations split the six bolts into a center pair and an outer group. Calling the procedure simply ‘42 N·m plus angle’ hides the earlier 100 N·m prestress and invites a serious assembly error.
Left and right banks use their own illustrated order. The controller below helps log stages but cannot identify the center pair or physical orientation by itself. Keep the matching bank figure open and label the engine-front direction before beginning.
Interactive FA20D eight-stage controller
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Tracks six numbered positions and center/outer final groups. It is not a physical LH/RH map; use the BRZ/FR-S manual figure to assign every number and group.
Subaru Fa20 Head Bolt Torque Sequence Diagram
| APPLICATION / ITEM | SPECIFICATION | NOTES |
|---|---|---|
| Prestress stages | 20 N·m → 100 N·m | All six in bank-specific order |
| Release stage | Loosen 360° | All six in published order |
| Reseat stages | 20 N·m → 42 N·m | All six in sequence |
| First angle stage | +100° all six | Use angle gauge SST or equivalent |
| Center-bolt finish | +100° two center bolts | Only factory-identified center pair |
| Outer-bolt finish | +50° four outer bolts | Only factory-identified outer group |
The BRZ and FR-S share the FA20D long-block procedure, but Subaru's FA20 family also includes turbocharged direct-injection engines with different combustion, induction and service contexts. Verify the VIN, year, market and engine hardware. The interactive six-position controller is a pass log, not a scaled bank drawing.
How to use this specification correctly
- 01
Verify a naturally aspirated BRZ/FR-S FA20D/4U-GSE by VIN, year, intake/exhaust/turbo hardware and engine markings. Stop if the assembly is FA20DIT, a later revision or a mixed replacement long block.
- 02
Secure timing-chain and cam positions by the model-year procedure. Index bank-one/bank-two cam carriers, rocker pivots and valve shims so every measured component returns to its original location.
- 03
Remove each head only after loosening its six bolts equally in the factory removal order. Protect the aluminum deck and keep debris out of oil-control passages and direct-injection hardware.
- 04
Measure the head at 20°C where practical. The cited data gives 0.035 mm maximum warpage, 98.5 mm standard height and 98.4 mm allowable minimum height; machining must preserve cam-carrier and combustion geometry.
- 05
Clean and degrease gasket surfaces, bolt holes and liquid-gasket interfaces. Follow the specified bead diameter, overlap and installation time; liquid sealant curing on the surface before assembly can create a leak path.
- 06
Install the correct new gasket and prepared head. Clean production bolt threads, apply sufficient clean engine oil to washers and threads, hand-start all six and map numbers from the correct LH or RH figure.
- 07
Tighten all six in order to 20 N·m, then repeat at 100 N·m. If a bolt produces stick-slip noise, stop, clean and fully dry holes/contact surfaces, and restart from the gasket-installation procedure as the manual directs.
- 08
Loosen all six by a full 360 degrees in the shown order. Retighten all six in sequence to 20 N·m and then 42 N·m.
- 09
Attach an angle gauge securely and add 100 degrees to all six in order. Then add another 100 degrees only to the factory-identified center pair, and add 50 degrees only to the four factory-identified outer bolts.
- 10
Audit paint marks and the stage log, assemble cam housings/timing chains with their independent sealant and torque procedures, hand-rotate through complete cycles and verify timing and oil-system cleanliness before startup.
Why the 100 N·m stage is not the final torque
The initial 20/100 N·m operation prestresses and seats the head/gasket joint. Subaru then deliberately removes that load with a 360-degree release before establishing the 20/42 N·m baseline for final bolt stretch.
Stopping at 100 N·m, skipping the release or torquing back to 100 N·m after the angle stages creates a different joint. Treat all eight operations as one inseparable procedure.
Center and outer bolts receive different final rotation
Every bolt first receives 100 degrees after the 42 N·m stage. The two center bolts then receive another 100 degrees, while the four outer bolts receive 50 degrees. The factory figures identify which positions belong to each group on each bank.
Do not infer groups from vehicle left/right or mirror a remembered diagram. Transfer the number map from the actual manual and record the center-pair and outer-group stages independently.
Stick-slip noise requires a restart
The manual treats creaking or stick-slip during the 100 N·m prestress as evidence that friction conditions are wrong. Its response is to clean bolt holes and contact surfaces, let them dry and repeat from gasket installation—not to keep pulling until the wrench clicks.
Uniform oil on the specified fastener interfaces and dry holes are both necessary. Pooled oil can hydraulically load a blind hole, while dry or contaminated bearing faces can consume torque in friction.
FA20D is not FA20DIT
The naturally aspirated coupe engine and turbo FA20DIT share family architecture but differ in heads, pistons, induction, calibration and application manuals. A secondary source showing similar numbers is not enough to merge safety-critical assembly instructions.
For a WRX or Forester XT, retrieve the VIN/year FA20DIT service procedure. This page remains indexable with an explicit limitation and excludes turbo use until that branch is supported by directly accessible factory data.
FA20D installation checklist
- BRZ/FR-S FA20D identity confirmed
- Turbo FA20DIT and unsupported revisions excluded
- Correct LH/RH factory figure visible
- Valve shims/rocker components kept by location
- Head bolts released equally in order
- Head warpage and height measured
- Bolt holes and passages clean and dry
- Liquid-gasket bead and timing observed
- New correct head gasket installed
- Threads and washers uniformly oiled
- 20 N·m prestress logged
- 100 N·m prestress logged
- 360° release logged
- 20/42 N·m reseat passes logged
- +100° all-six pass logged
- +100° center-pair pass logged
- +50° outer-four pass logged
- Cam carriers and chains independently verified
Subaru FA20D 2.0L naturally aspirated boxer-four specifications can change by model year, engine, platform, wheel, and installed component. Confirm the VIN or engine identity, part numbers, fastener condition, and the current manufacturer instructions before service.
Subaru BRZ FA20D Head Bolt Torque Sequence and Angles FAQs
What is the 2013 Subaru BRZ FA20 head-bolt sequence?+
In the factory physical order: all six at 20 N·m, all at 100 N·m, loosen all 360 degrees, all at 20 N·m, all at 42 N·m, +100 degrees all, +100 degrees the center two, then +50 degrees the outer four.
Should FA20D head-bolt threads be oiled?+
Yes. Clean the threads and apply sufficient clean engine oil to the production bolt threads and washers while keeping the holes clean and dry.
Why loosen FA20D head bolts after 100 N·m?+
That load is a prestress/seating cycle. The full 360-degree release resets the joint before the lower torque baseline and final measured angles.
What if an FA20 head bolt creaks while tightening?+
Stop. The manual directs cleaning and completely drying the bolt holes and contact surfaces, then restarting from the gasket-installation procedure.
Does this BRZ procedure cover a 2015 WRX FA20DIT?+
This page does not claim it does. Use the exact turbo WRX VIN/model-year service procedure even if a secondary chart appears similar.
Can an angle stage be replaced with a final torque?+
No. Subaru specifies measured rotation with an angle gauge; final observed torque changes with friction and is not a substitute.
Do aftermarket FA20 studs use these stages?+
No. Follow the exact stud manufacturer's lubricant-dependent torque sequence and the head-gasket/machine-shop requirements.
Technical sources
TorqueSheet favors engine- and component-specific manufacturer instructions over unsourced universal values.
12013 Subaru BRZ FA20 engine service-manual scanThe Subaru manual section publishes the six-bolt prestress, 360-degree release, 20/42 N·m reseat and staggered 100/100/50-degree finish for both banks.↗