The cylinder head will now sit on the block, but the next obstacle involves the pistons. When the A-series pistons reach the top of their travel, they will touch the valves, so you have to pocket the pistons to make sure that they clear. This is a little bit more complicated, but luckily even taking into account all of the chamber combinations you get with aftermarket Mini pistons and stock ones, you can get a compression ratio to work because the BMW K’s chamber volumes are roughly the same as the A-series.

    “Next, you have to drive the double overhead camshafts, so we’ve developed a belt-drive system which is based on the most heavy-profile toothed belt you can get. We’ve got a pulley on the end of the crank, we use the old camshaft to drive the oil pump (which we now call the idler gear) and then we’ve got the two pulleys on the BMW head. Using one of our conversion plates and some cam adaptors, you then have a drive system set up for the cams giving a nice triangular belt-run on the front of the engine and for a belt tensioner, we use a Ford Pinto component because it just happens to fit a Mini backplate in the right place.

    The interesting thing is that the A-series is one of the few engines to still go clockwise in rotation. The BMW runs anti-clockwise, so the tricky thing would be if the cam profiles were asymmetric because the valve timing events would be completely wrong – but luckily the BMW cams are completely symmetric so you can run them in both directions.

    Thinking I’ve spotted a flaw in the plan, I ask John about what exhaust manifold they use because the bike one is useless... SC offers a stainless steel 4:2:1 manifold which follows the same route as an LCB allowing pretty much any aftermarket Mini exhaust to be hooked up to it. It’s even been designed to suite both 8-valve and 16-valve engines and to provide a good compromise.

    If you think you might be interested, SC offers a £20 manual which follows the A-series transformation from OHV old favourite to Bavarian-crowned howler and you wouldn’t be surprised to hear that these are selling like hot baked goods.

    Unfortunately, this does mean that BMW K engines are no longer found languishing on Ebay, popularity now means that these engines are being rabidly picked – particularly the 16-valve variants for around £350.
“The manual is a step-by-step guide and it includes lots of technical info on the different heads – the flow figures, cam types, injection and all the rest of it,” says John.

    Okay so what next? If you’ve bought a manual and you want to go for it – what are the options? “We sell conversion kits which consist of all of the parts to get the K head onto the block and get the drive system sorted – and these retail for £535 plus VAT.