Essay : K-series – myths and facts

THE K-Series engine could have been the best thing since sliced bread – and in many ways it still is.

But a lot of half truths and downright lies are spouted about this engine – and our ex-ARG man-in-the-trade and Mike Humble thinks it’s time to put the record straight.


FAQ PDQ QED…

Q Was the K-Series entirely a British engine?

A – Yes it was, Austin Rover was given the go-ahead and funding from the Conservative government in the mid 1980s to design and produce the K-Series as we know it today. The revolutionary through bolt for the cylinder head was also developed in the UK but supplied by a German fastening specialist.

Q If I remove all the head bolts will the sump fall off?

A – No, This is an urban myth, the cylinder head bolts hold together the head, block and main bearing assembly only. The sump is held on by traditional bolts like any other car.

Q I have been told the bottom end of the engine will seize if I remove the bolts incorrectly, is this true?

A – Well yes and no. A clever design & fail safe feature of the crank bearing design locks the crankshaft once the head bolts are removed. Winding the engine over with a spanner is virtually impossible but should never be attempted. The reason being is that the engine has no cylinder bores but instead has liners fitted into the block. Winding over the engine would cause the liners to lift and destroy the o ring seal at the bottom of the liner.

Q Is it true that the engine only holds a few pints of water?

A – No, allthough the total amount of coolant used including the heater is small compared to other makers engine`s, hence the rapid warm up from cold.

Q Is the single cam version any good

A – Very much so, in fact in terms of refinement and sheer driveability, the 8-valve 1.1- and 1.4-litre K-Series is amazingly smooth and quiet, even by todays standards, spinning round to over 6000 rpm with no fuss.

Q Why did Rover fit plastic inlet manifolds in later years

A – Quite simply to save money, the original water heated manifold was made from virgin 365-grade aluminium which is to aircraft quality and very expensive. The move to the plastic type was said to speed up engine warming and reduce emissions. In reality it made no difference but caused terrible reliability in terms of the silicone gasket failing causing coolant to leak into the cylinder bores, causing head gasket like symptoms, engines could and often did hydraulically lock up or at worst, snap connecting rods & cam belts!

Q Why does my engine sound like its knocking for a few minutes after a cold start?

A – Its whats known in the trade as piston slap, nothing really to worry about. It’s the downside to having an all-alloy engine with mixed metal internal parts. Because different metals expand and contract at different rates some untoward noise is common. Honda petrol engines do a similar thing; listen to an old Accord 2.0 on a frosty morning, it sounds like its going to explode. Later engines had a new design of lightweight piston which claimed to reduce this noise, but the jury is still out as to whether these later pistons are any good.

Q Why do these engines eat cylinder head gaskets?

A – In most cases, the problem revolves around four common threads as follows…

1: The reality is not as bad as the myth. Fiat have a similar case with the 1.1- and 1.2-litre FIRE engine fitted to the Punto, in fact even worse.
2: In many case its down to a different fault with the car ie: a leaking radiator causing coolant loss and or air locks or corrosion in the engine owing a weak or non existant anti-freeze mixture.
3: Thermostats over time, can weaken, causing a rush of cool water into the engine when the stat opens causing Thermal Shock – a major problem on 1.8-litre Rovers and Land Rover Freelanders.
4: Many later (post 1993) engines were incorrectly torqued at the factory causing the head to lift slightly and shuffle on the engine block, wiping away the critical silicone sealing areas of the head gasket. As a cost cutting measure the original steel locating dowels on the engine block were changed for cheaper plastic ones that would crack and break up with head, causing the head to shuffle even worse!

Q Will these engines really go the distance between timing belt changes?

A – Very much so. The wide belt and pulleys, a relatively short length of belt and the smooth free reving nature of the engine all contribute to the long life of the cam belt. Early cars were listed as needing a change at 96,000 miles! But this time was reduced as a fail safe measure, even so, its extremely rare for a belt to break before its time providing it was fitted correctly. Always change the water pump at the same time as the belt.

Posted in: Engines, Essays
Keith Adams

About the Author:

AROnlineholic between 2001 and 2014 - editor of Classic Car Weekly, and all round car nut...

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