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Using large quantities of oil? It is not unusual for our engines to use as much as 85 miles to the pint and yet be in perfectly serviceable condition. The cause is not as might be supposed, Pistons Rings, but oil going past the valve stem seals. R-R engines used a seal made of asbestos string impregnated with Russian Tallow and it is squashed against the valve stem at the top of the guide by the cover it fits under. Pressure from the centre spring holds it in place until it eventually wears away. If they are in perfect condition the engine will do several hundred miles to a pint but as they deteriorate oil consumption increases. Picture shows Payen Seal HR336 GM Europe (4 in pack) Cut off the bit below the spring Large quantities of oil going down valve guides is not a good thing and it is a nuisance to have to keep topping the engine up when you are on holiday or whatever. There is a relatively simple solution and that is to fit more modern valve stem seals from a “Cam in Head” Vauxhall engine of the early eighties. These fit at the top of the valve stem just under the collets and require no modifications to the car at all. They do not clip to the top of the valve guide they just remain at the top of the stem and deflect the main flow of oil from the rocker arm away from the guide. According to those that have used them for a few years, oil consumption can drop to 2000 miles per pint! It is possible to remove the valve springs with the cylinder head on the car, there is even an R-R tool to hold the valve closed if you can find one, but most people make their own. All you need to do is hold the inlet valve closed, take out the pushrods and lift the rockers out of the way and then, using a couple of suitable levers (I used two screwdrivers), press down on the spring cap and remove the collets and then lift off both valve springs and fit the new seal over the valve stem. The new seal will need its spring removed and the bottom cutting off with a scalpel so the overall height is not greater than 0.424”. Re-assemble with care and you will be back on the road in a few hours.
Pictures of tool for holding inlet valve shut. It screws into plug-hole and pulls up against inlet valve. Moles grips hold shaft while springs are removed and seal fitted.
There is a tool that will make the job easier and it is available from www.sears.com, its part number is 00947704000 but they only ship within the USA so you may need help to get one if you in another country Drawing showing required dimensions of suitable seal |
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