On the subject of valve stem seals, a word of general warning if I may be so
bold..............
MG, in their wisdom, didn't fit them. Early cars had splash guards to
prevent excessive amounts of oil being splashed onto the valve stems, later
cars had just the rubber o-rings placed in the bottoms of the valve spring
retainers to prevent oil that puddled on the top of the retainer from
running down the crack between the two collets and then down the guide.
We recently had a B in the shop that smoked badly and used a lot of oil,
even though the engine had just been rebuilt (not by us, I should add!).
After we took the motor out and stripped it down, suspecting bad rings, we
found the only problem was that the shop that did the head had fitted the
type of valve stem seal that fits over the top of the guide.
Unfortunately, they were a bit too big in diameter and they caught on the
inside of the valve spring, which then simply lifted them up and down with
every movement of the valve. It made a very effective way of pumping oil
down the valve stem instead of keeping oil out!
So, if you elect to use stem seals, do make sure they are small enough to
(a) fit inside the inner spring without touching the spring, and (b) that
they are not so tall that the bottom of the spring retainer will crush them
when the valve is fully opened.
Lawrie
British Sportscar Center
-----Original Message-----
From: Dodd, Kelvin <doddk@mossmotors.com>
To: Neil Cotty <neilc@tradesrv.com.au>
Cc: mgs@autox.team.net <mgs@autox.team.net>
Date: Tuesday, February 16, 1999 12:07 PM
Subject: RE: Valve stem seals
>This is just a note covering an e-mail Neil sent me privately.
>
> The valve stem seals Neil received were evidently a mixed batch, for
>which I apologised. Our warehouse crew is not very good yet at matching
>parts that may have come from fill in vendors. It is something we are
>working at getting better at.
>
> I did suggest that for his performance application he may want to
>use seals only on the intake guides. Does anyone have any specifications
>for him regarding valve stem clearances for semi competition use?
>
>Kelvin.
>
>
>> -----Original Message-----
>> From: Neil Cotty [mailto:neilc@tradesrv.com.au]
>> Sent: Monday, February 15, 1999 7:40 PM
>> To: MG List
>> Subject: Valve stem seals
>>
>>
>> Hi all,
>>
>> I purchased some valve caps and some valve stem seals at the
>> same time -
>> both from Moss, both listed together in the Moss Comp.
>> Catalog MGB section.
>>
>> I received 6 seals that are reinforced with a metal clip and
>> two that are
>> more flexible, slightly larger. Can someone tell me why I
>> have two that are
>> different and if so which valves are these for? Is it for the
>> hotter #2, #3
>> Exhaust valves or have I just not received the correct seals? Durrr!?
>>
>> 'tanks, :)
>> Neil.
>> --
>> Neil Cotty - Sydney, Australia
>> 1970 MG B GT / 1961 MG A 1600 Mk1 / 1956 AH 100/4 BN2
>> GHD5UA200702G / YGHN2 100102-1399 / BN2L-232789
>>
>
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