If you have technical Rover V8 problems
aks Rene Winters
This part of site is an attempt to organize and add to the web resources for the Rover SD1
to form a cohesive and easily usable guide for those of us without easy access to
expert repair and/or advice. It is not offered in any way as a definitive source
and we take no responsibility for any errors that may exist.
Webmaster Rene Winters
the Rover V8 engine|
We will look at the 3.5 litre V8 engine which is fitted to our Rover SD1 3500 models.
Previously the engine has, of course, been fitted to other BL models.
A feature of the engine is its lightness brought about by the extensive use of aluminium.
Here you can see the V configuration of the aluminium block, 2 banks of 4 cylinders
forming a 90° angle.
It is designed for easy maintenance. The use of hydraulic tappets ensures automatic tappet
adjustment, and the use of electronic ignition eliminates distributor contacts reducing
ignition timing variation.
So regular servicing has been reduced to oil and filter changes, and carburetter adjustments.
We shall be examining these later on our website.
For photographic purposes we shall be describing the overhaul procedures on an engine
which has already been removed from a car.
However many maintenance operations can be carried out in the car.
The cylinder heads, cam, pistons and big end bearings can all be attended to without
removing the engine from the car.
The Dismantling Procedure |
Begin dismantling the engine by removing the manifold retaining bolts noting the positions of their
Following the reverse order to the tightening
Now lift off the manifold together with the carburetters.
You will notice that each carburetter supplies fuel air mixture to cylinders on both sides.
With the front of the engine at the top of this visual the left hand carburetter supplies cylinders
numbers 1, 4, 6, 7 and the right hand carburetter cylinders 2, 3, 5 and 8.
Next release the inlet manifold gasket clamps and discard the gasket and seals.
Remove the rocker covers, and the rocker shaft assemblies. Then withdraw the pushrods storing them in
their respective positions.
As the push rod ends are identical take care to store the pushrods the right way up so that the bottom of
the rod is returned to the tappet and the top to the rocker during reassembly.
Next withdraw the tappets, taking care to store them in removed order. In some cases, often on high
mileage cars, the tappet cannot be withdrawn through the top of its bore. In such cases remove the
tappets after removing the camshaft.
Hydraulic Tappet Operation|
We will look at the tappets in more detail, as a knowledge of their operation will be of considerable
use when diagnosing the cause of valve gear faults on an engine.
Each tappet consists of a body, in blue, a plunger, in yellow, and a push rod seat in red.
When the engine is running, engine oil, in green, flows around the annular groove into the plunger and
down through a ball and spring type check valve, A, into the lower chamber between the body and the
As the cam rotates, the lobe lifts the body. At the same time the force of the valve spring acting on the
push rod forces the plunger downwards. The pressure of the oil closes the check valve, trapping the oil
in the lower chamber.
The tappet becomes solid and begins to move the push rod opening the valve. During each operation of the
tappet, a slight leakage of oil occurs through clearances between the plunger and body.
The loss is made up when the tappet is on the back of the cam. Oil pressure in the lower chamber permits
the check valve to open and more oil to enter the tappet.
As engine speed reaches its maximum of 5500 to 6000 r.p.m., the speed of the tappet prevents complete
replacement of the oil in the lower chamber. This causes the oil in the chamber to froth allowing the
plunger and seat to move into the body, shortening the tappet. The valves are not lifted to their maximum
and so engine performance drops making sure that the engine does not over rev!!!
The dismantling sequence continues with the removal of the crankshaft pulley and then the timing
cover together with the distributor, oil pump, water pump and oil filter assembly.
Now release the chainwheel retaining bolt and withdraw the distributor drive gear and then the
chain wheels complete with the chain.
The camshaft is situated between the two banks of cylinders and runs in 5 bearings all of which are
of different diameters with the largest bearing at the front.
Carefully lift out the camshaft. You will notice that there is no positive method of locating the
cam in its bearings. If you were unable to lift out all the tappets, turn the engine upside down
before withdrawing the cam so that the tappets do not hinder cam removal.
Cam location is achieved by a slight taper on each of the cam lobes. As the cam rotates each
tappet exerts a force which pushes the cam to the back of the engine.
At the same time, the off centre contact between the cam and tappet causes the tappet to rotate in