This article delves into the intricate design of a Volkswagen 2 litre 16V TFSI cylinder head (Part number – 06F 103 373) through a detailed cutaway analysis. Unlike previous visual guides that relied on color-coded paint, this exploration utilizes color-coded strips to clearly differentiate between intake and exhaust ports within the accompanying images.
YELLOW STRIP = Exhaust Ports. GREEN STRIP = Intake Ports.
Both color strips are precisely 5mm x 50mm, serving as a scale reference for viewers to accurately assess wall thicknesses as needed.
Special acknowledgment is due to ‘LUPOCHARGED’ for generously donating this TFSI cylinder head, making this analysis possible. Furthermore, sincere thanks are extended to the following individuals whose contributions covered the shipping expenses for this TFSI cylinder head, enabling its analysis:
Rubjonny, Club GTI Committee, Afbiker02, Sirguydo, EZ_Pete, G280PN, Richard Mk2, Nealey, Marty’s Dub, LUPOCHARGED, Gaz 37, Dragon Fly, Mushy 16v, Cerips, VW Singh-Gurds, Bootsie.
While initial plans included a plaque featuring all contributor names in the photographs, capturing both the names and the intricate details of the cylinder head cutaway proved technically challenging in a single shot without compromising focus. Consequently, a banner was incorporated into as many images as feasible. In some instances, these banners may obscure minor cutaway details, but these obscured areas are not critical to the overall analysis. In a few images where any obstruction was unacceptable, the banner was omitted.
While the banners are prominent, they are a preferred alternative to watermarks, which can appear less professional.
For enhanced searchability, relevant keywords will be incorporated throughout the image descriptions and concluding comments. Remember, the color-coding system clearly identifies each port type.
The cylinder head cutaway method employed here mirrors techniques used on previous heads, including Formula 1 components. This approach minimizes cuts while maximizing internal visibility.
For reference, a previous analysis of an older 16v cylinder head can be found here:
http://www.clubgti.com/showthread.php?193826-The-2-litre-16v-head-cutaway-and-maximum-porting-dimensions-thread
Let’s begin the visual exploration of the 2 Litre Tfsi cylinder head.
Valve Guides and Waterways in the 2 Litre TFSI Head
The extended valve guides, reaching significantly into the spring area, are clearly visible in this 2 litre TFSI cylinder head cutaway. This design characteristic is a notable feature of this head.
A very small waterway is present within the exhaust port divider of the 2 litre TFSI cylinder head.
Material Thickness and Core Shift Analysis
Material thickness is consistently robust, measuring well over 6mm in all wall areas. This substantial thickness suggests ample material for performance modifications and porting for those experienced in cylinder head work. Core shift appears minimal across most sections, indicating consistent wall thicknesses throughout the combustion chambers.
Intake Port Design and Waterways
Notably, no waterway is present in the intake port divider of this 2 litre TFSI cylinder head design.
Recessed Valve Guides and Flow Advantages
A key contributor to the improved flow characteristics of TFSI cylinder heads is the recessed valve guide design. This contrasts sharply with the older, larger valve guide bosses found in earlier KR/ABF engines. The trade-off with recessed guides is reduced support material, potentially leading to shorter guide lifespan. To compensate, these TFSI valve guides extend further above the spring perch, as previously shown.
Core Shift on Port Divider Waterway
Zero core shift is observed on the port divider waterway; it is precisely centered, demonstrating manufacturing precision in this area of the 2 litre TFSI cylinder head.
Intake Port Short Side Radius Analysis
This view highlights the intake port short side radius, directly at its apex. The transition here is arguably less refined than expected. While forced induction engines are generally less sensitive to minor airflow imperfections due to boost pressure, this short side radius presents a clear area for potential improvement through porting. Optimizing this area could yield further performance gains from the advantageous valve angles, recessed guides, and compact combustion chamber inherent in the 2 litre TFSI design.
Exhaust Port Short Side Radius Evaluation
In comparison, the exhaust port short side radius, with the valve seat removed, appears reasonably well-designed.
Further Examination of Intake Port Short Side Radius
Revisiting the intake TFSI short side radius, a key observation emerges. The top radius on the valve seat is not concentric with the port wall splay at the seat counter-bore. In fact, the seat top radius is partially obscured by the port splay in certain areas. This inconsistency was noted across all intake ports examined. The valve seat’s position relative to the counter-bore is clearly visible, being recessed at the ten o’clock position and extending outwards at the four o’clock position in this image.
Exhaust Port Dimple Feature
The exhaust TFSI short side radius reveals a dimple present in one exhaust port per bank. The purpose of this dimple is unclear; it may be related to a non-existent EGR (Exhaust Gas Recirculation) drilling.
Oil Galleries and Follower Detail
This image showcases the main oil galleries and follower detail within the 2 litre TFSI cylinder head, highlighting lubrication pathways and component design.
Direct Injector Location in TFSI Head
The location of the TFSI direct injector is clearly shown in this cutaway, illustrating its positioning within the combustion chamber for direct fuel delivery.
Dead Aluminum and Head Weight Considerations
A significant observation from this analysis is the substantial amount of “dead” aluminum present in the 2 litre TFSI cylinder head casting. Large volumes of unused alloy are situated beneath both the intake and exhaust ports. No waterways exist under the intake ports, and only a small waterway in the exhaust port divider branches into two at the head gasket surface. This extensive use of aluminum contributes to the head’s considerable weight, making it a notably heavy component.
This image illustrates the traditional oil feed passage around the head bolt. Note the ball bearing used to seal the drilling – a testament to intricate manufacturing processes.
Significant dead alloy is also evident at the yellow scale marker in this view.
Even more dead alloy is apparent in this perspective, further emphasizing the casting’s bulk.
Wall thicknesses around the intake ports measure a substantial 8-9mm, with solid alloy extending from the green scale tape down to the head face.
Abundant dead metal is also present beneath the exhaust ports.
A crucial design element is the clearance maintained between the spark plug boss casting and the port wall. This gap is vital for water circulation, preventing hotspot formation in this thermally sensitive area. Maintaining this thin section during casting can be challenging, often requiring ceramic sand inserts to preserve fine detail.
Significant wall material is present approaching the intake seats, as clearly seen in this 2 litre TFSI cylinder head cutaway.
Clearance is again visible where exhaust ports run close to the spark plug boss. The single 6mm waterway between the exhaust ports, which splits towards the head face, is also highlighted.
Ample metal is present in the roof area on the intake side of the 2 litre TFSI cylinder head.
F1 vs. TFSI Short Side Radius Comparison
Finally, a comparative view juxtaposes an intake short side radius from a Formula 1 cylinder head against the 2 litre TFSI cylinder head cutaway short side radius (on the left).
While acknowledging the performance disparity between Formula 1 and production passenger car engines, and considering the mass production volume of the TFSI engine (40 million units), the difference in short side radius design is still noteworthy.
Alloy Composition
The alloy composition/grade of this TFSI cylinder head, as indicated by markings on the head, is AL SI10 MG CU.
Valve sizes and port opening cross-section measurements at the faces will be added subsequently.
This analysis aims to be informative and visually engaging for both casual viewers and those involved in tuning or porting. Hopefully, tuners and engine builders will find valuable insights, particularly regarding wall thicknesses in areas of interest for modification.
Please feel free to share this article as a link on other forums or to use images (preferably those with banners!).
Brian.
