M178 CNC-Ported Heads — Flow-Matched Cylinder Heads for AMG GT Dry-Sump 4.0L V8
The AMG GT platform demands heads that can flow under sustained high-RPM, high-boost, high-heat conditions — lap after lap. Our M178 CNC-ported heads are flow-bench developed for the dry-sump 4.0L V8, assembled with upgraded valvetrain, and sold as a matched pair. Built at YPG Motorsport in Kuwait, shipped worldwide.
What Are CNC-Ported Heads?
CNC porting reshapes the intake and exhaust ports using computer-controlled machining to our flow-bench program. Every port is cut to identical runner volumes and matched flow rates across all eight cylinders. On a twin-turbo engine like the M178, ported heads reduce pumping losses, improve turbo spool, and allow more efficient combustion at elevated boost pressures.
M178 Ported Heads Specifications
| Parameter | Specification |
|---|---|
| Head type | M178 DOHC 4-valve per cylinder |
| Porting method | 5-axis CNC, flow-bench validated |
| Intake valves | Upgraded stainless steel, oversized |
| Exhaust valves | Upgraded Inconel, oversized |
| Valve springs | Uprated, matched spring pressure |
| Retainers | Titanium |
| Sold as | Pair (left + right head, assembled) |
| Application | Race / off-road use |
| Build time | 7–21 days |
| Shipping | FedEx / DHL worldwide to door |
Why Port the M178 Heads?
The stock M178 heads flow adequately at factory boost, but they become a restriction as you increase turbo size and boost pressure. CNC-ported heads remove that bottleneck — more air in at lower pressure drop, faster exhaust scavenging, and reduced heat soak. On the AMG GT platform, where sustained track duty is the norm, the thermal efficiency gains from ported heads translate directly to consistent lap times and reduced heat-related power fade.
Pair with an M178 forged short block for a complete forged long block, or bolt onto your existing healthy bottom end for a meaningful upgrade. Both are included in our M178 crate engine.
Upgraded Valvetrain
Our M178 ported heads come fully assembled with oversized stainless steel intake valves, Inconel exhaust valves, uprated springs with matched seat and open pressures, and titanium retainers. Every component is selected for durability under sustained high-RPM track conditions — the AMG GT's natural habitat.
Pairing with Your Build
- M178 Forged Short Block — add ported heads to complete the long block.
- Your existing M178 block — if your bottom end is healthy, ported heads alone unlock significant gains.
- M178 Crate Engine — ported heads included in our complete long block builds.
Read more: Short Block vs Long Block vs Crate Engine — What's the Difference?
How to Order
Contact us at sales@ypgmotorsport.com with your engine details. Ported heads are quoted per build. Shipped worldwide via FedEx or DHL.
Browse all AMG Engine Builds or explore the full M178 Engine Builds collection.
Frequently Asked Questions
What is included with the M178 ported heads?
A pair of fully assembled cylinder heads — CNC-ported, with upgraded valves, uprated springs, titanium retainers, and new valve seals.
Will ported heads fit my stock M178 engine?
Yes. OEM bolt pattern and gasket surfaces. Direct bolt-on replacement for factory M178 heads.
Are M178 heads the same as M177 heads?
No. The M178 and M177 use different head castings. Make sure you order the correct set for your engine.
Do ported heads require a tune?
We strongly recommend an ECU recalibration. YPG Motorsport offers ECU tuning for all M178-equipped vehicles.
What vehicles use the M178 engine?
The M178 is exclusive to the AMG GT, GTS, GTR, GT R Pro, and GT Black Series.