Rover V8 Cylinder Head Numbers
Posted: Thu Nov 23, 2006 11:34 pm
Hope this helps you find out what your heads are guys, the identification marks are in the rocker area in the centre of the head,
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1976-87 SD1 production for twin SUs (carbs in general), all V8s from the introduction of the SD1 took on the new specification cylinder heads. They incorporated larger inlet & exhaust valves as well as revised combustion chambers (36cc), taking a 19mm reach spark plug. Anything with a V8 between these dates should have this spec. The SD1 also introduced inlet valve umbrella oil seals, simply a nitryl washer which is pushed over the valve stem before fitting the spring and retainer. These seals often breakdown under the severe environment inside the engine and disappear altogether!
Casting Numbers: ERC 0216
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Efi. On introducing fuel injection a small cutout was ground in each inlet port to clear the injectors, as Efi was introduced with the vitesse, the heads also incorporated flowed valves; with a 30° back cut and wasted stems on the inlet valves, very different from the standard SD1 type. As the SD1 was phased out of production, the Range Rover was just going over to Efi, thus all V8s after this date feature virtual vitesse spec Efi cylinder heads, including the first 3.9s.
Casting Numbers: ERC 0216 (note: As SD1 type, but machining process differs from traditional SD1).
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Early 90's. Here comes the confusing time period. It seems sure that all V8s now had vitesse valves, as after 1993 Efi became standard. In 93 or just before, the valve guides changed to the modern cap type (blue), one for each valve, all V8s took on this feature yet the casting remained as per vitesse. 4.2 Litre motors however also had factory standard vitesse heads, but during production Rover switched to composite gaskets, whilst retaining vitesse heads. The heads were machined to bring back the required compression, the same thing happened to the then current 3.9; you may also see some 4.2s with only 10 head bolts, the outer 4 holes through the head being plugged, these are the composite gasket units.
Casting Numbers: HRC 2210
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Tempest and Thor. With the introduction of the new Range Rover in 1994 a new head was brought into being, with a revised casting (No 2479) the head had larger ports than the vitesse heads but retained the same valves and guides which were present from ~1993 onwards. The combustion chamber volume (29cc) was also reduced (by simply machining off more material on the face) to compensate for the increased thickness of the composite head gaskets and probably most noticeable, the 14 head bolts were reduced to 10, the 4 outermost being removed. Incase you're told otherwise, 4.0 and 4.6 litre heads are identical.
Casting Numbers: HRC 2479
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1976-87 SD1 production for twin SUs (carbs in general), all V8s from the introduction of the SD1 took on the new specification cylinder heads. They incorporated larger inlet & exhaust valves as well as revised combustion chambers (36cc), taking a 19mm reach spark plug. Anything with a V8 between these dates should have this spec. The SD1 also introduced inlet valve umbrella oil seals, simply a nitryl washer which is pushed over the valve stem before fitting the spring and retainer. These seals often breakdown under the severe environment inside the engine and disappear altogether!
Casting Numbers: ERC 0216
-----------------------------------------------------------------------------------------------
Efi. On introducing fuel injection a small cutout was ground in each inlet port to clear the injectors, as Efi was introduced with the vitesse, the heads also incorporated flowed valves; with a 30° back cut and wasted stems on the inlet valves, very different from the standard SD1 type. As the SD1 was phased out of production, the Range Rover was just going over to Efi, thus all V8s after this date feature virtual vitesse spec Efi cylinder heads, including the first 3.9s.
Casting Numbers: ERC 0216 (note: As SD1 type, but machining process differs from traditional SD1).
-----------------------------------------------------------------------------------------------
Early 90's. Here comes the confusing time period. It seems sure that all V8s now had vitesse valves, as after 1993 Efi became standard. In 93 or just before, the valve guides changed to the modern cap type (blue), one for each valve, all V8s took on this feature yet the casting remained as per vitesse. 4.2 Litre motors however also had factory standard vitesse heads, but during production Rover switched to composite gaskets, whilst retaining vitesse heads. The heads were machined to bring back the required compression, the same thing happened to the then current 3.9; you may also see some 4.2s with only 10 head bolts, the outer 4 holes through the head being plugged, these are the composite gasket units.
Casting Numbers: HRC 2210
-----------------------------------------------------------------------------------------------
Tempest and Thor. With the introduction of the new Range Rover in 1994 a new head was brought into being, with a revised casting (No 2479) the head had larger ports than the vitesse heads but retained the same valves and guides which were present from ~1993 onwards. The combustion chamber volume (29cc) was also reduced (by simply machining off more material on the face) to compensate for the increased thickness of the composite head gaskets and probably most noticeable, the 14 head bolts were reduced to 10, the 4 outermost being removed. Incase you're told otherwise, 4.0 and 4.6 litre heads are identical.
Casting Numbers: HRC 2479