The issue was exacerbated by other elements in the K-Series’ cooling system.‘ It tends to not have the best thermostat in the world.’
How to fix the fault?
Metal dowels are, quite simply, the most significant way of fixing the K-Series’ head gasket issue.‘ Rover themselves later updated it. And this is not just aftermarket,’ says Steffen.‘ Whenever you order a head gasket kit now, it will come in metal dowels.’
Rover’ s entire solution wasn’ t ideal, though.‘ They came up with this MLS, the multi-layer steel gasket, to see if that helped it. I was never a big fan of that, it seems to just cause another problem and they tended to leak externally
Later K-Series engines had improved head gaskets and components, but it’ s only the aftermarket and greater advances in technology that have fully solved the issues
when they leaked.’ For the Elises he builds, very high-end, high-quality and very fast versions, Steffen goes beyond Rover’ s head gasket fix.‘ The head gasket I use, it’ s a modern one. It’ s a multi-layer, but not like the old multi-layer ones, it’ s all peened through with elastomers and stuff.’ It also goes onto a later, more rigid block with extra webbing in its casting, called an N-Series block.
‘ The dowels we use are not rolled metal, they’ re proper machined steel ones, they fit in there really nice and snugly.’
Winter 2025 The Engine Rebuilder 55