Engine Tin Gasket 911 1974-1983: Porsche Part Numbers and Replacement Guide

If you own a Porsche 911 from 1974 to 1983, you know that even small components play a big role in the car’s performance and longevity. One such component is the engine tin gasket – a seemingly simple part that seals the sheet metal shrouds (often called "tin") around the engine. These shrouds direct cooling air over the cylinders and oil cooler, and without a proper gasket, air leaks can cause overheating, uneven cylinder temperatures, and reduced engine life.

Finding the right gasket isn't always straightforward because Porsche used different engine configurations during this period. From the 2.7-liter to the 3.0-liter SC and even early 3.2-liter Carrera engines, the tin gasket design varied. This guide covers the correct part numbers for each application, what to look for when buying, and how to install them correctly.

Why Engine Tin Gaskets Matter

The engine tin on an air-cooled 911 is more than just a cover – it’s a critical part of the cooling system. The metal shrouds channel air from the fan over the cylinders, heads, and oil cooler. If the tin gaskets are missing, torn, or incorrectly installed, air will escape, reducing cooling efficiency. This can lead to hot spots, cylinder scoring, and eventual engine failure. For a car that’s now decades old, replacing these gaskets is a common restoration task.

Identifying the Correct Part Number for Your 911

Porsche used multiple engine tin gasket part numbers depending on the engine variant and year. The most common are for the 2.7L, 3.0L SC, and early 3.2L. Here's a breakdown:

1974-1977 911 2.7L Engines

For the 2.7-liter engines (1974-1977, including the Carrera 2.7), the engine tin gasket kit includes several pieces. The main lower tin gasket part number is Porsche 911.104.121.00. This gasket seals the large lower tin piece to the crankcase. There are also smaller gaskets for the upper tins, such as 911.104.122.00 for the left side and 911.104.123.00 for the right side. A full gasket set for the 2.7 is often sold as 911.104.120.00 (kit). Note that some early 1974 models (with the 2.7L with thermal reactors) may have slightly different tin arrangements – always check your specific engine number.

1978-1983 911SC 3.0L Engines

The 911SC (1978-1983) used a 3.0-liter engine with a different tin configuration. The main lower tin gasket is Porsche 930.104.121.00 (note the 930 prefix, which is the Turbo part number, but it also applies to SC models). The upper tin gaskets are 930.104.122.00 and 930.104.123.00. A complete gasket set for the SC engine is 930.104.120.00. Be aware that the SC engine has additional tin pieces around the oil cooler and distributor drive – make sure your set includes those.

1983 911 Carrera 3.2L (Early)

The 1983 model year saw the introduction of the 3.2-liter Carrera engine, but production started late in the model year. Some 1983 Carreras (with engine numbers beginning with 64D) use the same tin as the SC, while later ones use the updated 3.2 design. For early 3.2 engines (through 1984), the lower tin gasket is 911.104.121.02 and upper tins 911.104.122.02 and 911.104.123.02. A full kit is 911.104.120.02. If you have a 1983, confirm your engine type before ordering.

Aftermarket Options

Several brands manufacture high-quality replacements. Elring and Victor Reinz are well-known for offering gaskets that match OEM specs. They often list their part numbers alongside Porsche numbers. For example, Elring's kit for the 911SC is 514.720 (lower) and 514.710 (upper set). These are generally more affordable than genuine Porsche parts and work just as well if installed correctly. Just ensure the material is coated on both sides for a good seal.

Where to Buy Engine Tin Gaskets

Genuine Porsche parts are available from Porsche Classic dealers or online specialty retailers. For aftermarket, suppliers like Pelican Parts, Stoddard, and EBS Racing carry the common kits. Always cross-reference your year and engine code (found on the engine case near the distributor) before purchasing. If you're unsure, measure your old gasket thickness – it should be about 1.0 to 1.5 mm with a paper or composite material.

Installation Tips for a Leak-Free Seal

Replacing engine tin gaskets requires patience and attention to detail. The tin pieces are easily bent, so handle them carefully. Here are key steps:

1. Clean the sealing surfaces thoroughly. Old gasket residue, oil, and dirt must be removed. Use a scraper and solvent, but avoid damaging the aluminum.
2. Check the tin for warping. Lay the tin on a flat surface – if it rocks, gently flatten it with a rubber mallet. Warped tin will not seal even with a new gasket.
3. Apply a thin layer of gasket sealer on both sides of the gasket. Use a high-temp silicone (like Permatex) that’s oil-resistant. Do not overdo it – excess sealer can squeeze out and block oil passages.
4. Tighten fasteners in a pattern. Start with the bolts closest to the center of the tin and work outward. Torque to about 5-7 ft-lbs; these are small bolts that strip easily.
5. Let the sealer cure for at least an hour before starting the engine. Then, re-torque after a heat cycle.

Common mistake: installing the gasket upside-down or missing a piece. Lay out all tin pieces against the engine before final assembly to ensure everything fits.

Final Recommendation

For most 1974-1983 911 owners, buying a complete gasket kit (either OEM or from a reputable aftermarket brand) is the best approach. It ensures you have all the small gaskets for the various tin pieces. If you only need one specific gasket, use the part numbers above to order individually.

Before purchasing, always verify your engine type: 2.7L (1974-1977), 3.0L SC (1978-1983), or early 3.2L (1983). A quick look at your engine number (stamped on the left side of the crankcase, near the oil filler) will tell you. With the correct gasket and careful installation, your 911’s cooling system will perform as intended, keeping that air-cooled flat-six running strong for many more miles.