I thought it was high time I gave something back to this forum as I have been trawling it for info for years.
For the past few years I have been competing not very successfully in classic trials with a BIS. These are some of the things I have done to the car:
Cooling system. I am conviced that the overheating/head gasket problems of the BIS are due to the water pump being useless. Just try removing a top hose, crank it over and see how much water spurts out (none). I have removed the thermostat and fitted an electric water pump. (No, not in the space where the thermostat was). I will post pics at some stage to explain how I connected this up and which connections I had to blank off.
Other mods: SU carb from reliant robin (homemade manifold), External exhaust across the back of the car, coil spring spacers, nitrous oxide injection, facet electric fuel pump, oil catch tank, sumpguard, copper head gasket.
I've now given up on trialling the BIS, at least with the standard engine and gearbox. Just not enough power and the box is not strong enough.
I am open to offers on the engine and all ancilliaries (its still in the car at the moment) and for the gearbox (1st/reverse gears are broken).
Furthermore I have another BIS on my drive for spares which I will eventually get rid of. There are a few things I want from it first though so I won't be getting rid of the complete car just yet. There is no engine or box fitted to the car but inside it is crammed with many, many spares. Several complete engines, conditions unknown, gearbox parts and casings and many other parts. I have more or less all parts available and am open to offers for any specific part you might want.
Regards, James T