39
ENGINE
failure of the water pump. The most common serious
Finally, check the gear mating faces with Engineers
damage caused by a failure is metal particles from the
Blue to ensure good contact is made.
water pump travelling forward into the jackshaft
If you have a water pump which is known to have given
front bearing and causing it to seize. When this
good service, I believe at the moment it is certainly
happens, the engine block will have to be line bored
best to recondition the old pump with new seals and
and fitted with a bearing. If you are lucky, the
bearings rather than buy a whole new pump. Of
locating dowel for the jackshaft sprocket will shear; if
course this also gives the advantage of being cheap!
you're unlucky, the timing chain will break causing
Issue 196 (May 1997), pages 35,36
the valves to hit pistons. Either way, it's an expensive
operation.
Stuart Soutter of SOC Spares Ltd said that
Why parts suppliers, and Unipart, carry on selling these
he supplied this water pump and
pumps when there may be a problem with them, is
continued:
beyond me. If you have just fitted a new water
I WOULD ADVISE that due to the complexity of the
pump, I would strongly advise you remove it and
enquiry, we referred the matter to Unipart for their
check the skew gear for wear. If you do have a
advice. They have duly replied and we have forwarded
failure, get the pump checked by a metallurgist for
a copy to Ross.
correct hardness. Do not part with the pump until
I can only assume this has taken longer than he
this has been carried out.
expected but we felt that, as the supplier and not the
Issue 198 (July 1997) page 56
manufacturer of the item, we should try to find the
best advice possible, even if this takes a little longer.
Cam Covers. Dave Jell replied to a question
Issue 197 (June 1997), page 29
about the Triumph name being upside
down on some cam covers:
Tony Hart of Hart Racing Services wrote:
THE FOLLOWING explanation is what I was told
I SEE from the Club magazine that the subject of water
during my investigations about development of the
pumps has reared its head again. Back in 1984,
Stag.
British Leyland, as it then was, had a problem with
The first cam covers made would be made with low cost
water pumps, in that the skew gear had not been
tooling so they could be made cheaply. Once they
hardened properly and stripped the teeth, causing
were approved for production, then the more
overheating and, in some cases, engines to seize as
expensive tooling would be used as they would be of
they would with no water circulation. BL agreed, at
a high quality so as to press to production standards.
the time, there was a problem, in that the gears were
L/hand and R/hand tooling was made in prototype
not hardened to the correct specification and they
and production tools but, as production was not as
picked up the tab for repairing many Stags, TR7,
high as anticipated, when either tools was at the end
Dolomite and Sprint engines.
of its life, it was decided to use only one in the press
For the last four or five years, there appears to have been
at the time. The cam covers were interchangeable as
a problem with some new water pumps, some of
the oil filler and exterior bits were incorporated after
them stripping the gears on the water pump and the
pressing the blanks. This also cut production costs as
jackshaft. Attempts to claim any form of com-
only one press was required to make the covers. They
pensation from the supplier and Unipart, usually
still made the tooling in L/H and R/H so the nearest
fall on deaf ears, with excuses such as `Fitted
to hand was used at the time, therefore, some covers
incorrectly,' or `Worn water pump bearing in the
have Triumph stamped upside down.
engine block,' and `Jackshaft front bearing worn,'
The original covers were light blue with white plastic
being the reason for refusing any claims. The only
HT lead clips.
people having any success with compensation are
Issue 116 (February 1990), page 28
those having a metallurgist's report carried out to
ascertain that the hardness was not correct for the
use it is intended.
Engine Rebuilding. John Thorpe (0607)
I have not used a new pump for several years, preferring
wrote:
IF YOU ARE contemplating overhauling the Stag engine
to rebuild a known pump that has already covered
yourself, take a tip from me and devise some method
several thousand miles. At least I know the shaft and
of keeping all thecomponents associated with each
skew gear are hardened correctly. The suspect pumps
cylinder together. Figure 1 overleaf shows the
cover only a few hundred miles before failure, and a
dimensions of a box I made for the parts for each
rebuild kit is a lot cheaper than a new pump.
bank, and the photograph is of all the parts in their
When a water pump fails, it is necessary to remove and
respective places after dismantling. As I work on the
totally strip the engine to clean all the metal particles
engine, cleaning each part and checking them for
from the engine's sump and oil galleries. If you are
wear, I realise how easy it is to get in a muddle with
lucky, no other damage will have been caused; if you
the matching parts. It seemed a lot of extra work
are unlucky, extensive damage can be caused by the