Engine - 1098, Initial Tuning

The 1098 (1100) engine has had a lot of bad press over the years - largely because of early experiences when trying to tune the motor brought about problems with the then standard components available - they simply were not up to taking any real punishment as experienced in racing.

See bottom for useful part numbers.

This fallacy was handed down generation to generation like some scary bedtime story. Those that have used the unit in more recent years, employing more capable componentry know what a demon motor this can be. Following is an initial look at what it will do with a little modification - the results compared directly with it's smaller brother the 998 for illustration of the potential.

Abridged History
When the Mini was first conceived it ustilised a de-stroked version of the then quite remarkable 948cc A-series engine.

Engine transplants - Ancillary parts

Engine mountings are a whizz to fit as the Mini ones fit straight onto any of the other units. Just remove the Metro/AA/1300GT ones and swop the mounts over from the Mini unit. If they’re split, fit new ones, they’re cheap.

Terminology -
BBU - Big Bore Unit
SBU - Small Bore Unit

NOTE: This information covers transplanting large-bore engine units into small-bore engined Minis. For further information for exact differences between pre-A+ and A+ units, see relevant separate article.

Engine mountings and steady bars.
Engine mountings are a whizz to fit as the Mini ones fit straight onto any of the other units. Just remove the Metro/AA/1300GT ones and swop the mounts over from the Mini unit. If they’re split, fit new ones, they’re cheap. If using the AA/1300GT unit - it's advisable to cut off the 'wings' on the front plate that carried the engine mounts on the radiator end.

SU Carbs - Poor idle quality

Something that crops up when any modifications are made to an engine - mainly in the form of improving induction and exhaust capability - is that of idle quality.

After applying aforementioned freer-breathing products to enhance power output, many complain that no matter what - including post rolling-road tuning - they can not get a satisfactory, steady idle setting. And this after checking for manifold/gasket air leaks and spindle to carb body play (usual suspect as the spindle wears quite dramatically over several thousand miles). There is one thing that is often over-looked - the air valve found on many later model cars. This sprung-loaded air valve is built into the butterfly, sometimes called a 'poppet' valve or anti-dive valve. It is primarily there to reduce emissions when the engine is on the over-run - closed throttle at speed, i.e. anything other than at idle and gearbox in neutral.

C-STN17 - MINI SPARES STAGE ONE KIT (998cc only)

Beware: Instructions must be read carefully.

Although the 998/1300 stage one kits are bolt on parts easily fitted by any person with mechanical knowledge, the following must be understood.

MSG12 GEAR LEVER BIAS BARREL - FITTING INSTRUCTIONS.

The bias barrel was originally developed as part of our five speed gearbox package, necessary to facilitate accurate gear selection and gear lever position.

It soon became apparent that this device would vastly improve the gear change on the standard four speed rod change gearbox, endowing Minis and Metros with the ‘modern car’ feel, and taking the quessology out of gear selection.

Cadwell Park Mighty Mini Season Opener

The 2009 Super Minis Championship kicked-off at the most technical and demanding of circuits; Cadwell Park.

Set in the idyllic hills of Lincolnshire, Cadwell is an aggressive rollercoaster of a track that demands total respect and commitment; get it right, and it’s one of the most rewarding experiences, get it wrong and it can bite with terminal ...

A SERIES 5 SPEED GEARBOX - CUSTOMER SELFBUILD KIT FITMENT OF ANCILLIARY PARTS

With the engine and new 5 speed transmission re-installed in the vehicle, the new gear selector parts must be fitted before re-connecting the gear selector extension shaft. The new selector parts can be assembled without removing the gearchange remote from the vehicle. It is recommended that the gear lever be removed....

27.06.10 Thruxton Race report by Keith Calver

Following the Brands Hatch race, all was well with the car. Just as well – I was playing catch-up with grinding heads after my nice new grinder tool holder fell apart, and it took the makers 4 weeks to get it back to me. That and magazine work and an emergency engine build for a customer. I made enough time to give me a full morning on the car before having to load it up. Nothing bad came to light. As the race was the last day of a 4 day 'jolly'....

Historical Article-August 1994-Lilly the Pink

Lilly the Pink Progressing swiftly from Norfolk cruisers to International 14 racing boats - the aquatic equivalent of Group B rally cars - James Hoseason steadied his sea legs...

Historical Article-August 1994-Lilly the Pink

Lilly the Pink Progressing swiftly from Norfolk cruisers to International 14 racing boats - the aquatic equivalent of Group B rally cars - James Hoseason steadied his sea legs...

Historical Article-August 1994-Steady Eddy

Steady Eddy My first visit to Mini Spares must have been over 12 years ago and while buying the usual go faster bits, I enquired about a Saturday job. A very lean and handsome Keith Calver could only offer me full time employment. I declined and subsequently have spent a small fortune over the years and drunk far too many pints of beer with K.C.

Historical Article-August 1994-Steady Eddy

Steady Eddy My first visit to Mini Spares must have been over 12 years ago and while buying the usual go faster bits, I enquired about a Saturday job. A very lean and handsome Keith Calver could only offer me full time employment. I declined and subsequently have spent a small fortune over the years and drunk far too many pints of beer with K.C.

Historical Article-August 1994-My 35 Years

After taking '0' Levels in 1963, I embarked on what I thought at the time would be a short stay job packing parcels for an Austin Morris dealership. I had always been fascinated by the Mini since my friend's father had bought a surf blue standard model in 1960....

Historical Article-August 1994-My 35 Years

After taking '0' Levels in 1963, I embarked on what I thought at the time would be a short stay job packing parcels for an Austin Morris dealership. I had always been fascinated by the Mini since my friend's father had bought a surf blue standard model in 1960....

Historical Article-November 1995-Engineering Success

Engineering Success
A little bit about us, and what we are about! Mini Spares Centre Ltd is the holding company for the following companies:- Competition Silencers International Ltd Minilife Ltd Special Tuning Ltd Leyland Special Tuning Ltd Special Tuning Abingdon Ltd Mini Spares Ltd Network Hardware Ltd Mini Spares Ltd, the engineering division, holds BS5750 approval IS09002, but most of our turned machined products are subcontracted out to specialists. ie. Gears....

Historical Article-November 1995-Engineering Success

Engineering Success
A little bit about us, and what we are about! Mini Spares Centre Ltd is the holding company for the following companies:- Competition Silencers International Ltd Minilife Ltd Special Tuning Ltd Leyland Special Tuning Ltd Special Tuning Abingdon Ltd Mini Spares Ltd Network Hardware Ltd Mini Spares Ltd, the engineering division, holds BS5750 approval IS09002, but most of our turned machined products are subcontracted out to specialists. ie. Gears....