The Mk3 Golf VR6 has become a legend; the later R32s owe their existence to this six-cylinder VW hot hatch
The overall distance that air has to travel through a VR6 head is the same for all cylinders, but some have longer inlets and others longer exhaust ports.
oriented across an engine bay rather than down it. The VR6 has just one head and one head gasket, with the intake on one side and exhaust on the other. From the outside, the block looks like a chunky in-line four, but inside are six closely-packed cylinders, each bored at skewed angle into the cast iron block.
It’ s difficult to know which is most fascinating, the VR6’ s bottom end or its head. Let’ s start with the core, the block and crank. Unlike conventional engines, the pistons don’ t run perpendicular to the top face of the block, so their slight angle leaves a wedge-shaped combustion chamber. Later VR6s use pistons with slanted tops, and therefore more uniform combustion chambers.
The VR6’ s cylinders are only separated by 15 ° V-angle, and even more strangely, the centre path of the cylinders does not converge at the centre line of the crank; in essence, the crank is‘ too high’. This has two benefits. One, with such a narrow V angle, it allows space at the bottom of the block so the bores aren’ t too close together. And two, it means the engine doesn’ t need to be so tall, therefore keeping it easy to package into an engine bay, the whole point of the VR6’ s existence.
It seems ludicrous to mention an inline engine when referring to the VR6, just as its name does, when its pistons are so clearly in a V. Until you look at the crank and firing order. Just like a straight six, the VR6 has a firing order of 1-5-3-6-2-4. What’ s more, the cylinders move in pairs, 1 and 6, 2 and 5, 3 and 4 move up and down together like a straight-six.
To match all of that bottom-end weirdness, the head has to be just as unusual. The first VR6s are 12-valve engines, two per cylinder. Within the combustion chamber, they’ re all oriented front to back down the engine – not with the intake valves on one side and exhaust on the other like in a normal cross-flow head. This is because, while it’ s a twin cam engine, it uses a single cam for each bank. Each chain-driven cam operates both intake and exhaust valves. Counter to the other technical advances in the engine, the valves, in a rather old-school style, are all straight up and perpendicular to the face of the head.
Summer 2026 The Engine Rebuilder 21