|
Part 4 The Battery
There have been many suggestions as to why the battery was moved to the boot on the TR8. The most obvious being to offset the extra weight of the V8 engine. This I would entirely agree
with, but I can think of other equally practical reasons. After owning an 8 for a number of years it soon became very obvious that it gets very hot under the bonnet -much more so than with the 7 engine -this
obviously is not a good environment for the battery. Similarly the V8 really needs a larger battery and there is insufficient room on the existing battery tray. So, with the minimum disruption to the existing
electrical system, how do we put the battery in the boot?
Genuine 8s run a cable from the boot directly to the starter motor then and the ancillaries emanate from that point. This is fine on a production car but when it comes to a conversion
there are simpler, and somewhat safer, ways.
The solution that I have found to be the simplest is to fit a battery cut out switch in the circuit This has the dual role of a good anti-theft device and a point from which additional
ancillaries can be fed.
So, what do we need? First, the battery tray in the boot. Needless to say the original TR8 trays are no longer available, but Rimmers have re-manufactured the early Coupe ones as part
of a kit so it is simply a nut and bolt job with the holes already drilled in the floor from the original design. As an aside, one of the reasons why the tray is in the right hand comer of the boot rather than the
left is because the boot stay is on the left and if it became detached it could short straight across the battery. I understand that S&S have had the early TR8 fibre battery boxes' re-made so this is a second
alternative. The third way is to construct your own box. but don't forget that an insecure battery is an MoT failure and could cause a fire. As a matter of interest, my first V8 conversion incorporated a plastic
marine battery box, round which I fabricated a steel easing securely bolted to the boot floor -the advantage with this idea is that you
have a solid box with all the correct air vents and battery cable exits. Whatever your decision make sure it is secure.
To establish the short earth or negative lead at the back of the car, use the earth lead from the battery in the engine bay and connect it to the floor via the threaded hole already
available in the chassis rail. Make sure that the threads and surrounding floor area are clean to ensure a good contact and grease the bolt. A dummy run can be carried out with this cable but replace it in the
engine bay until the conversion is complete.
Next the live or positive battery lead to the engine bay is required Again this can be purchased as part of the Rimmer kit, but for those who wish to remain independent, a 13 ft or
approx 4 metres of 15 sqmm length of battery cable will be required together with the correct end termninations (for those with deep pockets, 25 sqmm cable can be used to reduce the volt drop). This will be
sufficient to reach the cut off switch then continue on to the V8 starter motor. A third cable approx 4ft long will be required to connect the switch to the existing TR 7 battery cable when the engine part of the
conversion is being carried out The main cable can either be routed to the front of the car by being attached to the underside of the car with insulated 'P clips after exiting through the inner rear quarter panel or
by following a passage over the inner rear wing, along the inside edge of the inner sill and through into the engine bay via a hole in the bulkhead to the right of the throttle pedal. In both cases correctly sized
holes fitted with the appropriate grommet
must ~ used to avoid chaffing. I prefer the latter method as it keeps the cable inside the car but on the downside it requires a lot more work to feed it through the interior trim.
Having reached the engine bay, it is now time to find a suitable place for the battery switch. The most convenient place I have found is to the left of the servo below the clutch master
cylinder. It is a bit tight and the position of the air scoop must be taken into account but it can be bolted through the bulkhead and does not obstruct other components. Again the final positioning may have to be
left until the engine is out as it is difficult to drill the locating holes with the TR7 engine in-situ.
An additional braided earth strap some 15 inches long will be required when the V8 is in place to directly earth the engine to the chassis. This is fitted on the right hand side of the
engine between the engine AV mount (engine side!) to the threaded hole in the chassis rail.
Again don't forget to clean the contact surfaces well before fitting.
I will leave the writing at this point as more work will be required when the engine is out.
I have found that a good source for the electrical components mentioned above, is a company called Europa in Burton-on- Trent on 01283 815609. A quick call should produce a nice
brochure on specialist automotive spares.
Finally, returning to the boot, if the standard steel frame is used for the battery box, a cover will be required to protect the battery to avoid dropping tools or luggage across the
terminals. On the genuine TR8s, boot carpet material was used which was clipped in place with a press-stud. A good trimmer could make one quite easily but I understand that Rimmers are in the process of
re-manufacturing the original article.
|
