I was there : Tickford’s K- and S-Series engine development

Although few people realise it today, there was quite some history of development work on Austin Rover engines at Tickford. As the Technical Manager – Engines at Tickford, it was my job to work on these and liaise with Longbridge to ensure we were delivering what the company required from us.

Interestingly, in the mid-1980s, Tickford had been carrying out development and testing on a four-valve per cylinder version of the 1600cc S-Series engine which was initially known as the S4v but later given the L16 designation. This engine never went into production and confusingly the L-Series name was later used for a completely different engine, a 2.0-litre diesel with ancestry going back to the O-Series.

One of the great things about the S4v programme was it was used to understand the features of the inlet system and other parts that were beneficial in improving volumetric efficiency and therefore power output. In general, the team at Rover had concepts, Tickford would rapidly build and test kits of hardware that could be assembled in a multitude of configurations while John Bingham at NEL in Scotland was using his engine simulation programme to create theoretical results so that the two approaches could be correlated and refined.

Moving to Tickford’s K-Series work

The S4v project was superseded by development work on the K-Series engine. At Tickford it expanded to use at least eight test cells, mainly testing the 8-valve K8 in its 1113cc and 1396cc forms. However, a small amount of work was carried out on the twin camshaft 16 valve engines. Around this time the majority of K-Series development was outsourced until the new test facilities in the ‘Flight Shed’ at Longbridge were available.

Durability testing was carried out at various places including BICERA at Slough and ERA at Dunstable but all performance and emissions development on the K-Series was being carried out at Tickford in Milton Keynes. There was close liaison between Austin Rover and Tickford with daily communication and weekly project meetings.

Typically, the Austin Rover Engineers would specify what they wanted and hoped to achieve. They would also supply any parts that were intended for production release. Tickford would design and quickly make any special experimental parts, perform the testing and analyse the results.

Great carburettor results: binned

One of the developments concerned the inlet manifold and fuelling system. As originally designed, the K8 1400 had a single point fuel injection (SPFI) system which had the theoretical advantage over a carburettor of being able to compensate better during transitions of load and speed. However, in real life, such a system was inferior in nearly every way and the fuel distribution between cylinders was appalling with some receiving far more fuel than the others.

A very brief experiment involved cobbling together an inlet manifold to fit a single SU carburettor from an 1100 engine to the 1400 K8. This was very successful, producing as much power as the SPFI with greatly improved fuel consumption and exhaust emissions. Tickford were told to bury the test results as Rover’s Marketing Department was insistent on being able to advertise the larger engine as having fuel injection.

There were already enough knowledgeable Engineers to realise that the only way forward was multi-point fuel injection (MPFI) to put the right amount of fuel in the right place at the right time. Tickford designed and made the first inlet manifolds to suit such a system by having a batch of inlet runners cast that had the necessary tight curvature then using these in a welded aluminium fabrication.

Trying out a turbocharger

The Rover Engineer in charge of the performance development was Graham Fairhead who rose to higher positions within the group and its successors. Working with him were Alan Warburton, who is very well known in the motor industry, and many others including Steve Wood who was a total enthusiast and built up a combination of K-Series parts to make an 1100cc 16v engine for his sprint car which he used mainly at Curborough, his local track.

It is not unusual for Engineers in charge of large projects to save a little of the money allocated to them in order to fund work on an interesting idea which merited investigation, but which would not be approved by higher authorities. It was through such a route that the skunk works Metro with a turbocharged K16 engine was created by Tickford.

Austin Rover was already experimenting with turbocharging the K16 engine and had some success on the dynamometer at Longbridge. This engine already had a Tickford prototype inlet manifold with MPFI. The young Engineer carrying out this work was Mike Trzinsky. He was only able to obtain power curves by manually adjusting the turbine wastegate to an appropriate opening at each engine speed.

Tickford K-Series engine
The one-off K-Series Metro Turbo. The headlights held in place by duct tape were a result of the car having been used to test various ideas for a facelift.

Blowing the Metro

Austin Rover found an old Metro car that had been used to try out various ideas for a facelifted model and delivered this and the K16 engine, with a turbocharger attached to Tickford.

The first job was to provide automatic control to the wastegate. The previous limitations had been because the turbocharger suppliers, Garrett, were unable to provide prototype wastegate actuators within a reasonable time and cost. It did not take much effort to discover that Helical Springs (now Helical Technology) of Lytham St Annes were making customised wastegate actuators and could produce one to the desired specification within a few days.

Having got the engine under some sort of control, the next issue was the maximum torque, which was far too much for the bought-in transmission as used in the Citroën AX – if the maximum boost was set to match the torque limit of 104Nm, the maximum power was well down on the potential for this engine.

Working with Superchips

Tickford came up with a solution with the help of a company in Buckingham, a few miles to the west of Milton Keynes. Here Detection Techniques (DT) had branched out into hacking into engine management systems and supplying modified control strategies that they sold under the Superchips name.

A new wastegate actuator was fitted to limit the boost naturally to prevent excess torque and a pulsing valve (borrowed from a Saab 99 Turbo, below) was interposed between the actuator and the boost sensing pipe at the compressor outlet. DT designed and made an electronic box that changed the duty cycle of the pulsing valve according to engine speed. The young Engineer at DT who did this was Julian Thomas – he later left to set up the very successful Racelogic company.

With a few dynamometer runs and some small modifications to the electronics the system, although not perfect, was good enough to build a car that could be tested without immediately breaking the transmission.

Saab 99 Turbo

Outgunning a Rover Vitesse in testing

Tickford carried out the engine installation but did no modifications to the chassis, steering or brakes. The top of the installed engine is shown in the under-bonnet image further up the page.

The air cleaner was used on many Rover products and nicknamed the corporate dustbin. The charge air cooler was adapted from a Renault and a special radiator made by Northampton Radiators. The standard K16 oil filter clashed with the front cross member of the subframe, so an adapter elbow was made with connections to an oil cooler. To prevent air locks in the cooling system a self-bleeding valve, as used on domestic heating systems, was connected to the highest point of the cylinder head water jacket.

The car was taken away to be tested at Gaydon and possibly on the surrounding roads. A then-current rumour said that there was a Rover Vitesse chase car which saw 145mph on the speedometer and the Metro was still disappearing into the distance. It was deemed that the vehicle was fundamentally dangerous in its current form, and it would never be possible to provide adequate brakes within the small wheels. It is believed that this car was dismantled and scrapped fairly quickly.

11 Comments

  1. Do any figures exist for the S4v / L16 project as rather mystified by how much of an improvement it was over the existing S-Series, would the likes of the 109-134 hp non-VVC 1.6-1.8-litre K-Series and 108-130 hp non-VTEC Honda D16 engine (in the 216/416) give a rough indication of what the S4v / L16 was capable of reaching?

    • Yes it would be interesting to know more about his engine, but I fear it is lost in time as was the still born Rootes V6 in 1970.

      I suspect as with the Rootes engine, it was “nothing special” and so why it was allowed to be forgotten once it was cancelled, as I imagine the long stroke nature of the S Series would not have lent itself well to a 16v head.

        • Similar potent undersquare 1.6 16v engines include the Daihatsu H-Series, Volkswagen EA111 and Nissan GA/QG though unlike the K-Series and Honda D-Series were putting out around 118-123 hp.

    • By chance I recently happened to meet an old colleague who still had a copy of a report I wrote about the many different inlet systems tested on the S4v and their effect on power and torque. With no air cleaner and no silencer the engine would typically produce about 88kw at 6000 rev/min and a maximum bmep of 12.4 bar at 4000 rev/min. These values are quite similar to the original Cosworth BDA. Incidentally the comment made elsewhere that suggests 4 v/cyl is not suited to an long stroke is not true. As Howard Barnes-Moss pointed out in his I.Mech.E paper back in 1973, there is a typical maximum piston speed for each valve layout at which the volumetric efficiency starts to drop off. A good 4v/cyl with modest inlet valve closing point can run to 20m/s so with a stroke of 87.5mm this equates to over 6800 rev/min.

      • Thanks for providing the information. So those values for the S4v work out as about 118 hp / 116.3 lb-ft (or 157.7 Nm) torque, which compares pretty favourably to the Honda D16 that put out less torque (with the 128 hp 216/416 GTi later being downrated to 121 hp) as well against the figures in the 1.6 Rover K-Series.

  2. Regarding the speed of the Metro Turbo, I recall the Brockbank cartoon where the old guy in the Rolls who had just been overtaken by a “supersonic” Mini said “If God meant cars that size to do 100 mph, he’d have given them bigger wheels”

  3. Great article Richard. Brought back some happy memories and a reminder of the people involved. I was working in Emissions at Gaydon at the time and I drove the Metro with the turbocharged engine on the track. I can confirm it was “lively” and the brakes were definitely not up to the job 😉
    It was an interesting time at the early days of fuel injection and it took quite a while (and a lot of software iterations) to match the capabilities of the SU carburettor.

  4. interesting part about the carburettor vs SPi, although I thought the 1.4 K-Series 8v was available with a carburettor in the metro (and possibly even the 214) in many markets.

  5. Very interesting piece.

    Internally the S4v was also referred to as ‘S16’. This engine for destined for the AR8, aka R8, the second-generation Rover 200 but was dropped, for investment cost reasons, in the summer of 1986 and was replaced by the Honda D16 engine, much to the delight of the Honda engineers.

    It may well have been destined for facelifts to Maestro (AR7) and Montego but it may have conflicted with the larger capacity O-series engine in both

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