Hi All,
I have a 12g940 head ex Marina which has valves and springs - just dropped a valve out to have a look at the seats etc and have noticed there are no valve stem seals...is this right, or do I need to order some?!!
Cheers
Russ
940 valve stem seals
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IslipMinor
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Russ,
The 12G940 valve stem seals should be the later, lip seal type, and were only fitted on the inlet valves as 'standard'. There is not normally any partial vacuum while the exhaust valve is open, so no reason why oil should be drawn down the stem.
There is also an argument that any oil that is available would benefit the exhaust stem lubrication. From personal experience, I had bronze guides fitted that caused all sorts of problems, partly due to the manufacturing tolerances and partly to removing the by-pass hose, but even after they were replaced, and seals then fitted to all the valves, I still had a bit of problem, so the seals were removed from the exhausts as a precuation. That was 4/5 years ago, and no problems since.
The more the engine is modified, the less tolerance there is in its basic design for changes that could cause either lubrication or cooling issues.
I would definitely fit the later lip seals, but to the inlets only.
The 12G940 valve stem seals should be the later, lip seal type, and were only fitted on the inlet valves as 'standard'. There is not normally any partial vacuum while the exhaust valve is open, so no reason why oil should be drawn down the stem.
There is also an argument that any oil that is available would benefit the exhaust stem lubrication. From personal experience, I had bronze guides fitted that caused all sorts of problems, partly due to the manufacturing tolerances and partly to removing the by-pass hose, but even after they were replaced, and seals then fitted to all the valves, I still had a bit of problem, so the seals were removed from the exhausts as a precuation. That was 4/5 years ago, and no problems since.
The more the engine is modified, the less tolerance there is in its basic design for changes that could cause either lubrication or cooling issues.
I would definitely fit the later lip seals, but to the inlets only.
Richard
I have just reground the valves on the A+ 1275 goldseal engine I am going to fit in my series II on the valve guide front all guides had seals fitted the head can be seen on my website http://www.morris-1000.co.uk/Engine%20U ... engine.htm So I don't know if the later A+ engines used to have seals fitted to all valves. When I purchased this Ital engine I was told no work had been done on the engine since it had been fitted into the ital in 1987 the engine has now done about 20000 miles, since reconditioning by leyland cars acording to the old owner, and this seems correct looking at the condition of the engine.
