The M178 is the most exotic engine in the AMG lineup — flat-plane crankshaft, dry-sump lubrication, exclusive to the AMG GT family. The factory heads flow well at stock power, but they become the bottleneck once you push past Stage 2 with upgraded turbos. YPG Motorsport M178 Ported Heads are 5-axis CNC ported to race specification, delivering measurably higher intake and exhaust flow across the entire lift range.
No core exchange required — these ship as a complete pair ready to bolt on. Free worldwide shipping included.
What's Included
- 5-Axis CNC Ported Intake Ports — precision-machined for maximum airflow volume and velocity. Not hand-ported — repeatable, consistent results across both heads.
- 5-Axis CNC Ported Exhaust Ports — optimized for scavenging efficiency and reduced backpressure at high RPM, critical for the M178's higher-revving flat-plane crank character.
- Five-Angle Valve Job — competition valve seat geometry for improved flow at low lift and better sealing under high cylinder pressure.
- New OEM Valve Seals — factory-spec seals replaced throughout to eliminate oil consumption issues.
- Combustion Chamber Unshrouding — subtle chamber work to improve flame travel and reduce hot spots under boost.
Performance Gains
- 15-25% increase in intake port flow — measured on a SuperFlow SF-600 flow bench at 28" H₂O test pressure across 0.100"–0.500" lift range.
- Improved exhaust scavenging — reduced reversion and backpressure, critical for the M178's flat-plane firing order and twin-turbo hot-vee layout.
- Better spool characteristics — improved exhaust flow feeds the turbos faster, reducing lag on Stage 3 and Stage 4 turbo builds.
- Extended RPM range — the M178's flat-plane crank already revs higher than the M177. Ported heads remove the airflow ceiling past 7,200 RPM, letting the engine pull harder through the top of the rev range.
When Do You Need Ported Heads?
| Build Stage | Power Level | Ported Heads Required? | Notes |
|---|---|---|---|
| Stage 1 (ECU Only) | 560–630 HP | No | Stock heads flow enough for Stage 1 calibration |
| Stage 2 (ECU + Downpipes) | 630–720 HP | No | Still within factory head capability |
| Stage 3 (Hybrid Turbos) | 776–900 HP | Recommended | Ported heads unlock the full potential of hybrid turbos |
| Stage 4 (Full-Billet Turbos) | 900–1,500+ HP | Mandatory | Stock heads are the airflow bottleneck at this power level |
Compatible Vehicles
- Mercedes-AMG GT — C190 (2015+)
- Mercedes-AMG GT S — C190 (2015+)
- Mercedes-AMG GT C — C190 (2017+)
- Mercedes-AMG GT R — C190 (2017+)
- Mercedes-AMG GT R Pro — C190 (2019+)
- Mercedes-AMG GT Black Series — C190 (2020+)
Fits all M178 flat-plane crank applications exclusively. For M177 cross-plane crank vehicles (C63, E63, GLC63, G63, GT63), see M177 Ported Heads.
M178 vs M177 Heads — Key Differences
Both are AMG 4.0L twin-turbo V8 cylinder heads, but the M178 has different port geometry and combustion chamber design optimized for the flat-plane crankshaft's firing order and higher rev ceiling. The M178 also uses a dry-sump oiling system with different oil drain provisions in the heads. M177 and M178 heads are not interchangeable. For a full engine comparison, see our M177 vs M178 comparison guide.
Why YPG?
YPG Motorsport's AMG GT S build — the YPG9XX — produced 850 WHP on the M178 platform using Stage 3 hybrid turbos and CNC-ported heads. Our GT R track car — the YPG750 — runs the same head specification at Kuwait Motor Town. We don't outsource head work — every set is ported to our exact flow targets, measured and verified before shipping. 15+ years of AMG engine expertise.
Pair With
- M178 Crate Engine — 1,500HP+ Forged Build — complete long block with forged internals + ported heads included
- M177/M178 Forged Internals — Rods & Pistons Kit — world record spec CP-Carrillo assembly
- Stage 4 Turbo Upgrade — M177/M178 — 1,500HP+ billet turbos
- Stage 3 Turbo Upgrade — M178 — ball-bearing hybrid turbos
- AMG GT/GTS/GTR Catless Downpipes
- Eventuri M178 Cold Air Intake
Build Process & Delivery
- Build time: 1–2 weeks from order
- Shipping: Free worldwide — USA, UK, Europe, Australia, Middle East
- Core exchange: Not required
- Support: WhatsApp direct for GCC customers. Email support worldwide.
Price: $6,500 — Free worldwide shipping. Contact YPG Motorsport via WhatsApp for build consultation.
Frequently Asked Questions
How much do M178 ported heads cost?
YPG Motorsport M178 Ported Heads are $6,500 per pair with free worldwide shipping. No core exchange required.
What is the difference between M177 and M178 ported heads?
The M178 is the flat-plane crankshaft, dry-sump variant found exclusively in the AMG GT family. The M177 is the cross-plane crankshaft, wet-sump variant used in the C63, E63, GLC63, G63, and GT63. The cylinder heads have different port geometry and combustion chamber design — they are not interchangeable.
What vehicles use the M178 engine?
The M178 is exclusive to the Mercedes-AMG GT family: AMG GT, GT S, GT C, GT R, GT R Pro, and GT Black Series. All other AMG 4.0L twin-turbo V8 models use the M177.
Do I need ported heads for a Stage 2 tune?
No. Stage 1 and Stage 2 builds run well on factory heads. Ported heads become recommended at Stage 3 (hybrid turbo) power levels and are mandatory for Stage 4 (full-billet turbo) builds above 900 HP where the stock heads become the airflow bottleneck.
Are these hand-ported or CNC-ported?
5-axis CNC ported. Unlike hand porting, CNC porting ensures perfectly repeatable results — both heads flow identically, which is critical for cylinder-to-cylinder consistency on turbocharged engines running high boost.
Can I install ported heads on a stock bottom end?
Yes. Ported heads bolt directly onto the factory M178 block with no modifications. However, if you're porting the heads to support Stage 3 or Stage 4 power levels, forged internals are strongly recommended to match the increased airflow and cylinder pressure capability.
