429
Tips
on fitting a new water pump
Bob Owen
has recently been refurbishing the engine in his MGBGTV8 and
has a couple of useful tips. (Apr 11)
Having
recently fitted a new water pump and timing chain from Clive
Wheatley mgv8parts as part of a refurbishment of my V8 engine,
I have a couple of points that could be helpful to others.
Water pump thread size
Firstly, although the pump is of Chinese origin, all appeared
to be fine except that I had problems with the fan belt pulley
fixing - the original bolts were binding but the bolt and pump
thread forms looked clean. I wondered if they had actually used
metric threads and in fact the "1/4" UNC" threads
were actually M6 - so M6 bolts went in by finger, as they should
( 1/4" UNC thread dia 6.3mm, pitch 1.27mm; M6 thread dia
6mm, pitch 1.0mm). This caution may apply to other aftermarket
components, especially if they are fitted to later metricated
models - that is not the case for this pump. More
Long timing cover bolts
Secondly, the dreaded long timing cover bolts tend to seize
and one of mine sheared off near the head. The fact that it
sheared off near the head showed that it was corroded into the
timing housing not (or as well as) into the block. I believe
the engine to be untouched since 1974 so it appears that BL
did not follow their own advice on thread sealants at their
engine assembly plant. The special sealant specified by BL/MG-Rover
is no longer available, but it wouldn't have been made by them
anyway. So I investigated the ubiquitous Loctite offerings.
A suitable thread sealant is Loctite 567- this seals and locks
but not to high torque (ie the lock is easily broken). So I
applied this to each bolt on the threaded section that enters
the block. More
I also wondered why the shanks of these bolts are such a close
fit in the timing housing when the housing is located in the
block by dowels, so the sole function of the bolts is to secure
the cover, not locate it. So I drilled out the timing cover
bolt holes 0.5mm oversize to both clean them out and enlarge
them. Then I used Loctite 8150 thread lubricant on the shanks.
In fact I had bought this for the exhaust manifold studs. So
hopefully
there will never again be a problem in |
Source:
V8 Workshop Manual Supplement AKD8468 page 26.50.01 Issue 1
Source:
V8 Workshop Manual Supplement AKD8468 page 12.65.05 Issue 2
dismantling my water pump and/or timing
cover.
The
Loctite products mentioned can be obtained, amongst others,
from BTLS-Hayley Lubricants of Andover in Hampshire. They can
be contacted on 01264 353111 or at www.lubricantsupplies.co.uk
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