So we've bought an E30 BMW! For those of you who know nothing about these awesome little Germanic boxes of fun, here is a quick rundown on the car which BMW used for everything from basic transport to Group A race and rally success.
There were eight petrol engine options, with in-line four- and six-cylinder options, ranging from 66kW (89hp) in the early 318s up to 175kW (235hp) in the M3 Sport Evo, the ultimate incarnation of the E30 and a Group A homologation special. The most powerful six-cylinder was the 125kW (168hp) M20B25 2.5-litre unit, as found in our car.
All six-cylinder E30s were powered by a 12-valve single-overhead-camshaft in-line six-cylinder engine from the M20 family, and these were known for delivering spritely performance when they launched in the early 1980s. The first series of E30s, from 1983-1987, used Bosch L-Jetronic fuel-injection though this was replaced by the far more modern Bosch Motronic EFI system in 1987 for the second-generation E30, like what we bought.
For their time these engines were known for being smooth and free-revving, with appropriate torque for what is a fairly small (1000kg-1400kg) platform car. The platform is solid, with MacPherson strut front-end architecture and trailing arm independent layout in the back, though the size of the diff and driveshafts has proven to be a limitation when greatly increasing horsepower of the engine.
You could get a four-speed or five-speed manual transmission, or three-speed or four-speed automatic, though the automatic four-cylinder models are a new definition of the term "slow". Automatic E30s are generally regarded as being quite dull to drive compared to their manual counterparts.
While E30s are renowned for being rear-wheel-drive BMW also sold an all-wheel-drive variant called the 325iX, though none were ever sold new in Australia. Down Under also missed out on the Touring (wagon) and M3, due to the M car only being built in left-hand-drive format.
There was an economy version of the E30 known as the Eta, sold for a limited time due to its low-revving engine set-up. However, the 2.7-litre bottom-end could be used with the 320i, 323i, or 325i cylinder head for a cheap increase in capacity over the largest factory-available capacity from BMW, while M20 engines can be bored and stroked out to a theoretical limit of 3.1-litres.
In South Africa they had a special edition called a 333i which used the larger 3.2-litre M30-family six-cylinder from a 5/6/7 Series BMW, producing 145kW (194hp). Only 204 were built, possibly becausenbuyers had to choose between whether they got air conditioning or power steering thanks to the size of BMW's "big-six" engine in the fairly short engine bay.
The M20 engines can be built into quite serious performance engines, however the level of work involved pushes the costs far beyond the ease of simply swapping another, more powerful engine into the chassis. Partly due to their age M20s can suffer from broken timing belts and needing regular valve adjustments. For this reason many people simply bolt-in a twin-cam in-line six engine from a later series BMW (M50, M52, M54) or M car (S50, S52, S54).
More than 2.4 million E30s were built between 1982 and 1991, and they have had just about all sorts of engines swapped into them, including rotaries, twin-turbo V12s, and even electric motor conversions. If you want to watch the destruction of impure E30 PuRiTy then check out the channel HERE...