V8 Newsletter
for April 2007 published in Safety Fast!, the monthly Club magazine


Oxford Blue 1589 was sold on the V8 website within a week. (Photo: David Bonniface)

What sort of person would buy an RV8 sight unseen from the other side of the world?
David Bonniface, an RV8 enthusiast and Club member in Tokyo, advertised his low mileage RV8 (Oxford Blue 1589) on the V8 website in early March this year and in less than 8 days reported it was sold! With a low mileage and a 5 litre engine upgrade it was certain to attract a great deal of interest but who was the mystery buyer who had snapped it up? Well later that day Al Barnett contacted the V8 webmaster to say he had bought this RV8! But why did he go for this RV8? Well Al Barnett explains:

What sort of person would buy from someone he does not know, sight unseen, a 12 year old car from the other side of the world, paying in a currency he is not familiar with and being subject to an import tax and VAT regime which seems pretty harsh. Well, the answer is me! A week ago I looked at the advert on the V8 website for Oxford Blue 1589 and thought, wow that looks a nice car. The more I read about the low mileage, less than 10,000 miles, the engine modifications - upgraded to 5 litres and heads gas flowed etc - the more I liked the prospect of owning the car.

My current RV8 (BRG 1839), bought new in 1995, has taken my wife and I all over Europe, crossing many of the great Alpine passes with the characteristic ease that typifies the powerful V8 engine. It has only ever let us down once, when the bottom hose frayed through, and so has been a much loved friend. It is running beautifully at the moment but the attraction of a low mileage replacement and the prospect of another 10 years of trouble free motoring were too strong to resist.

Distributor options for the MGBGTV8
Gordon Hesketh-Jones (Harvest Gold 1907) from Cornwall uses his car all the year round and with a total mileage now rapidly approaching 400,000 has a great deal of experience of maintaining the model from his regular servicing work and numerous rebuilds. One regular service difficulty was with worn distributors, so he set about some research into the options for the V8 which he reports on in this note.
An efficient distributor is clearly at the very heart of an engine and now that our cars are 30 or more years old, age will take its toll. A further problem is that whilst I personally have two excellent distributors both rebuilt by Holden (who purchased all of the rights, tools and stocks of spares for the Lucas distributor range when Lucas dropped out of that business), the quality of the contact sets and condensers now sold - even if they have a famous name on the box - is abysmally low. On my car over the past two years three different sets of contacts have lasted less than 1,500 miles before either developing "pips" or, in one case, the fixed contact stud "un-riveted" itself leading to a very variable spark effect! It seems that, whether I like the idea or not, I have to go for an electronic add-on to the distributor in some form just to get away from the points and condensers. So I set out to explore the market and look at the options.

Starting from basics, the distributor fitted to the MGBGTV8 is the Lucas 35D8 to specification 41394 which is similar to that used on the Range Rover, but with different (faster-acting) advance/retard and bob-weights. A unit to an almost identical specification was also used on the Rover 3500 and 3500S, but a very different specification applies to the SD1. If your distributor has covered more than 100K miles there will certainly be wear on the pinion, the shaft, or the bearings. If any one of these is badly worn or if all three are slightly worn, the result will be erratic firing of the plugs and this random output from the distributor shows up very clearly on a Crypton or similar engine analyser. Even on my current Holden distributor which has done less than 34K miles since the rebuild, the outline of the trace on the Crypton screen is fuzzy and slightly curved instead of being sharp and straight, indicating that one of the three wear points was probably not replaced - the pinion, bearing or shaft. Note that one of the most common problems with the 35D8 unit is that the advance/retard capsule diaphragm degrades (hardens) over time due to the ingress of petrol vapour so changing this is an easy and cheap action (costing around £25) which you

all of the benefits you had hoped for, so it is worth looking at the output of your distributor on an engine analyser screen before spending your money.
When fitting any form of electronic kit to your distributor (either opto-electronic or Hall effect-magnetic) which does away with the points, you need to be aware that this will change the character of the advance curve of your distributor. This is because the curve has been plotted with the points in place, so if you take them away then the mechanical load on the shaft and cam is no longer there, and the normal contact bounce no longer affects the movement of the bob-weights. The change might be minor within the generous torque curve of our V8 engines but will normally mean that there will be less advance at lower revs, although in the end the total amount of advance provided should be the same, but at higher revs.
Many suppliers of electronic-assisted distributor kits advocate the fitting of high-voltage coils, but if you do this you will need to change the wiring to your coil. Basically the standard coil is a 6volt device fed during normal running via the ballast resistor; the 12v supply to the coil only cuts in you're your starter motor is engaged, in order to give an extra kick to the coil. There is no doubt however that more than doubling the voltage to the plugs by using one of these high-voltage coils, added to the longer dwell (coil re-charging time) provided by the electronic kits will greatly improve both starting and running.
Comments on the various alternatives follow:

LUMENITION
On the face of it this London-based firm should be the obvious first choice for an add-on system as they have 30+ years of experience and half a dozen patents, however in the early 1980s I fitted one and it - plus two replacements - and they all failed, so I am biased against them. Their system comprises an infra-red generator (LED) with a photocell receiver and an eight-lobe signal chopper, these three items are located inside the distributor cap, then there is an additional black box containing the electronics to be mounted in the engine bay. The standard kit (which is not for high-performance or racing applications) for an MGBGTV8 costs £168 plus postage and VAT and can be bought from most MG accessory dealers. The high-performance kit (for high-revving), which includes a new coil, costs £258 plus postage and VAT. There is a 12-month warranty on Lumenition products. Incidentally the product name is derived from lumens. In the good old days before the metric stuff came in, "lumens" were the units for measuring the brightness of light so as the first ever product of the company was the opto-electronic ignition. The company name came from combining the unit of light measurement with "ignition". It is worth noting Lumenition now also manufacture Hall-effect distributor kits, but not for our 35D8 unit.

BOYER-BRANSDEN
This successful company started making electronic ignition kits for racing motor-cycles in 1969 and most of their business is still in motorcycles plus F3 and classic racing cars, however they make a cheap and simple kit for classic cars which retains the contacts. The unit uses the points to switch the electronics which is in a small box external to the distributor. As the points no longer switch any serious voltage or current their life becomes infinite, and the exact points