Leyland P76 Owners 2004

Valve stem seals

VALVE STEM SEALS

Articles supplied by Jilden

  • Many owners know the frustration of having the local engine shop not getting the valve stem seals right on the V8 heads. In my experience, there are only two reliable ways to do the job properly. Not only that, but seals should only be fitted to the inlet valves, unless hardened exhaust valves are fitted. No V8 motor left the factory with exhaust stem seals, allowing engine oil to get to the point where it is most needed.
  • If the heads have the early plain topped guides, they need to be machined down to take full rubber seals, such as Datsun L series ones. The guides need to be shortened as the Datsun seals are too tall otherwise. The Rover type of seal introduced for this style of guide is useless, as they have no spring loaded lips at the top.
  • For later heads with stepped guides, the seals to use are those specified for the late Rover V8’s, such as the Landrover Discovery. They are quite a lot shorter than the Datsun seals. Under no conditions are the Datsun seals to be fitted to the stepped guide as they are too tall, and will get their tops battered by the spring retainers, unless your cam is well worn.
  • When done this way, you should have a reliable engine which uses a little oil to keep the valves happy, instead of having to resort to upper cylinder lube or hardened valves or seats.
  • Once the heads are done properly, valve stem seals can be replaced with the heads in place in the car. Bend up a 450mm piece of 10mm rod into a sharp vee, 50mm from one end. Then bend the rod at right angles next to the vee to form a handle. The rod can be used to depress the valve spring by hooking the point of the vee over a rocker stud with a nut on it. To hold up the valve, turn an old spark plug into an air connector and use a compressor, or feed about one metre of small rope into the cylinder and jam it up with the piston.
  • Jilden.
    • Last updated
    Dec, 2005
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