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| Mains (Main Bearing) Stud Kit |
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It has become
apparent with the launch of the new Rover 4.0 and 4.6 litre
engines that there are some serious weaknesses in the design
of the V8 engine produced up until 1994. Many publications,
manuals and expert opinions, have suggested that the post-1982
(stiff block) is essential for ultimate reliability, especially
for higher performance engine rebuilds.
However, further reading will show that the actual strength
of the block has never been a problem as the main cause of
serious V8 engine failure, but is due to the lack of main
bearing cap stability. We therefore supply a mains stud kit
to ensure ultimate reliability in the strength of your block,
whatever the age. |
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| The
pre-1982 block is identified by webbing across the valley
of the V8 engine, on pre-1982 blocks there are three webbings
and their cross-sectional diameter is not constant over the
entire length of this bracing - the centre is reduced in diameter
from 15mm to 6mm.
The post-'82 block (stiff block) bracings are constant
in cross-sectional diameter (15mm) along its entire length
offering a far stronger bracing to the engine Block. However,
further reading will show that the actual strength of the
block has never been a major problem as the main cause of
serious V8 engine failure is due to the lack of main bearing
cap stability. On pre-1982 engines the amount of bearing
cap contact with the sides of the engine block is minimal
(see diagram above) only 12mm. |
| On post-1982
blocks (stiff block) the main bearing cap engine contact is
slightly increased to 16mm, but still offers very little strength
improvement where most needed. The other serious flaw in the
original design of the main bearing assembly is with the main
bearing bolts. The standard Rover bolts are considerably thinner
than the actual diameter of the main bearing cap they are
securing (see diagram) this results in a very unstable support
for the mains, and leads all too often to the failure and
total engine demise (the last thing you want after an expensive
engine rebuild). The strength of these bolts does not allow
adequate torque settings - when using a 'stud kit' this will
allow an increase in overall torque settings.
Another important aspect of the Main bearing stud kit is
that when an engine is being re-assembled, most engineers
would not bother to check the trueness of the crank itself,
and this has led to many engines being assembled with 'Bent'
crankshafts, although very minor and unnoticeable, this
will certainly lead to premature demise of the engine and
detract from the expected smoothness of you rebuild. |
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Because the Mains stud kit aligns your bearing caps perfectly
and does not allow them to 'Walk' or move to accommodate an
inaccurate crank, you will find when assembling, that a less
than perfect crankshaft will not be able to rotate when you
have three or more mains caps fitted, enabling you to reject
your faulty crank and ensure total professionalism in your
rebuild. |
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links to other component pages
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Prices do not include local EU.Tax.(VAT).
Prices & stock are subject to change without notice. Information and advice, as always, is free.
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