do not press the back button…
Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
Fits:
Porsche 911/911S Carrera 2.7L 1974-77
Click 'Zoom in' for large parts diagram.
Diagram ref no 24
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91110419206
The product you are viewing cross references to these numbers
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 914 (1970-1976)
Cylinder head copper base gasket 0.25mm
Copper 0.25mm cylinder base gasket by Porsche for selected Porsche 911 models from 1965–73 and the 914-6 from 1970–76. This gasket fits between the cylinder barrel and engine crankcase during flat-six engine assembly.
Sold each
Fits:
Porsche 911 1965 - 1973
Porsche 914-6 1970 - 1976
Diagram ref no 26
What This Product Does
The gasket seals the joint at the base of the cylinder while maintaining the specified spacing between the cylinder and crankcase. Its thickness contributes to cylinder positioning and must be considered when measuring deck height and rebuilding the engine.
Functions
- Seals the cylinder-to-crankcase joint
- Provides a controlled 0.25mm base thickness
- Supports correct cylinder positioning during assembly
- Helps prevent oil seepage around the cylinder base
- Forms part of the sealing system for each cylinder
Technical Details
- Porsche reference: 90110419100
- Material: copper
- Thickness: 0.25mm
- Inner diameter: approximately 92.2mm
- Outer diameter: approximately 103mm
- Required quantity for a complete flat-six engine: 6
Internal application data also identifies use with 911 T-E/E, 911 T-V and 911 T-K engine or model variants. Confirm the required gasket thickness through the appropriate engine measurements before assembly.
Symptoms of Fault
- Oil seepage visible around the cylinder-to-crankcase joint
- A flattened, distorted or damaged gasket found during dismantling
- Previous use of unsuitable sealant around the cylinder base
- Incorrect cylinder height or deck measurements during an engine rebuild
Why Replacement Matters
A cylinder base gasket can become compressed or damaged after installation and should be inspected whenever the cylinders are removed. Installing the specified gasket helps restore the intended cylinder spacing and sealing arrangement. During a full rebuild, all cylinders should be measured and assembled consistently, with related seals, hardware and wear components checked while access is available.
OE Reference
- 90110419100
- 901.104.191.00
FAQs
- How many gaskets are required?
Diagram data specifies six for a complete flat-six engine. Confirm the quantity needed for the work being undertaken. - Can an old cylinder base gasket be reused?
Replacement is advisable once the cylinder has been removed because the installed gasket may be compressed or distorted. - Does gasket thickness matter?
Yes. Base-gasket thickness affects cylinder positioning and should match the engine measurements and rebuild specification. - What should be checked during installation?
Inspect the cylinder and crankcase mating surfaces, verify deck measurements and check the associated seals and hardware.
Check fitment for your specific vehicle, model year and engine before ordering.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90110419100
The product you are viewing cross references to these numbers
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
This 0.50 mm copper cylinder-head base gasket by Porsche is intended for selected early Porsche 911 engine applications from 1965 to 1973, including specified 2.0L, 2.2L, 2.4L and 2.7L RS variants. It is used within the cylinder and cylinder-head assembly during engine rebuilding or sealing work.
Fits:
Porsche 911 1965-73
Diagram ref no: 26
What This Product Does
The gasket provides a precisely sized sealing layer at the cylinder base. Its specified thickness helps maintain the intended cylinder installation dimensions while sealing the joint against oil leakage. Correct gasket selection is important whenever cylinders are removed, inspected or refitted during an engine overhaul.
Functions
- Seals the joint at the base of the engine cylinder
- Supports the specified cylinder installation height
- Helps prevent oil seepage from the cylinder-base area
- Provides a replaceable sealing surface during engine assembly
- Supports accurate reassembly of the cylinder and piston installation
Technical Details
- Manufacturer: Porsche
- Reference number: 90110419102
- Material: copper
- Specified thickness: 0.50 mm
Symptoms of Fault
- Oil seepage visible around the cylinder-base joint
- A flattened, marked or damaged gasket found during dismantling
- Persistent engine oil leakage after accessible external seals have been checked
- Incorrect cylinder installation measurements during an engine build
- Evidence of fretting, corrosion or an uneven sealing surface when the engine is stripped
Why Replacement Matters
A compressed or damaged base gasket may no longer seal consistently after the cylinder has been removed. Renewing the gasket during rebuilding helps reduce the risk of repeat oil leaks and avoids another engine strip-down to correct a compromised joint. The 0.50 mm specification should only be used where it matches the engine configuration and measured build requirements. Related sealing surfaces, cylinders, pistons, rings and engine hardware should also be inspected while access is available.
OE Reference
- 90110419102
- 901 104 191 02
- 901.104.191.02
FAQs
- When should this gasket be renewed?
It is normally replaced when the relevant cylinder is removed during an overhaul, or when damage or leakage is found at the base joint. - Can a different gasket thickness be substituted?
The selected thickness affects engine assembly dimensions. Use the specification required by the engine configuration and measured rebuild clearances. - What should be checked at the same time?
Inspect the sealing faces, cylinders, pistons, rings, oiling system and associated hardware before reassembly. - Does every oil leak indicate a failed base gasket?
No. Oil can travel from other seals or joints, so the source should be confirmed before dismantling the engine.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90110419102
The product you are viewing cross references to these numbers