CAM TIMING - Basic Notes

To avoid lots of swearing and unnecessary damage, check the timing gears slide neatly onto their respective bosses. If tight, first check for any high spots in the gear bores and key-way slots. Clean out using with fine emery cloth, medium Wet 'n' Dry paper, or some such. Remove the Woodruff keys then dress the bosses using abrasive material as mentioned previously. Re-check fitment before re-fitting keys. Check the key-ways and keys too before re-fitting. Get rid of unwanted sticky-out bits on the keys that would inhibit a slide fit. Clean out the key-way and de-burr top edges. I always file a slight 'flat' across them to give plenty of clearance to the gear key slot. If the pulley is a slack fit on the key, turn it anticlockwise before nipping the bolt up. ALWAYS fit it like this. It's imperative to fit cam (and followers in the case of solid wall blocks) following manufacturers instructions precisely using a good quality cam lube.

DIAPHRAGM SPRING - Verto types including injection

The Verto/Valeo type diaphragm included the pressure plate in its assembly, much like a 'normal' car set-up. The spring being of the 'finger' type as opposed to the disc spring used on earlier, three-piece assemblies. There were originally three diaphragm specifications using progressively stronger springs - small-bore, big-bore, and Metro Turbo. Later joined by the type used on the injection cars, though most definitely not interchangeable. Initially, the biggest problem was the Turbo ones were never really available on their own. If you wanted one you had to buy a whole clutch/flywheel assembly - the cost exorbitant. Rover originally believed that if the clutch plate was worn out, then the flywheel and pressure plate would be too. It has only been recent times that the diaphragm/pressure plate has been available on it’s own - but not until after the Turbo unit became unavailable. Even that has changed recently with the cessation of the Turbo diaphragm as a service part.

DIAPHRAGM SPRING - Verto types including injection

The Verto/Valeo type diaphragm included the pressure plate in its assembly, much like a 'normal' car set-up. The spring being of the 'finger' type as opposed to the disc spring used on earlier, three-piece assemblies. There were originally three diaphragm specifications using progressively stronger springs - small-bore, big-bore, and Metro Turbo. Later joined by the type used on the injection cars, though most definitely not interchangeable. Initially, the biggest problem was the Turbo ones were never really available on their own. If you wanted one you had to buy a whole clutch/flywheel assembly - the cost exorbitant. Rover originally believed that if the clutch plate was worn out, then the flywheel and pressure plate would be too. It has only been recent times that the diaphragm/pressure plate has been available on it’s own - but not until after the Turbo unit became unavailable. Even that has changed recently with the cessation of the Turbo diaphragm as a service part.

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.

Flywheel - Pre-Verto Types

The early spring-type clutch flywheels are of no use except where total originality is required on a concours car. The taper is too small and diaphragm pressure ring non-existent. No use to man nor beast. Part No Applications: C-AEG421, C-AEG420, C-AEG619, C-AEG620, 2A3657, 2A3658, 2A3659, 2A3512 With the exception of the fact the two-piece flywheel is two pieces bolted together - this and the later one-piece cast item can be treated as the same thing. They will universally fit all transverse engine cranks from 1964 onwards, so that should be easy enough. If all you can get is the hulking great 1300 type, then this too is as universal to fit, but I highly recommend you get that extra cast lump machined off of the outer edge as a bare minimum. Further lightening of these cast flywheels is possible by having metal machined off of the diaphragm side, from the outer edge of the diaphragm pressure ring outwards.

Thread Locking Compounds - Application

This is the frequently abused and mis-used stuff dolloped on to bolts/nuts to stop them coming undone. Having seen and heard of many horror stories concerning this stuff, I thought a few words of caution and common sense wouldn't go amiss.

There is a plethora of types on the market with no easy reference as to which to use for what application except in certain cases. Loctite have a very useful guide, their dealers generally able to help with choosing which is best for any given application. The trouble comes when folk buy stuff unwittingly from their local 'do it all' motorist/car spares place. Good stuff is expensive, and it doesn't go all that far. But at least it does its job when used in the correct applications. Unfortunately many buy a cheaper variety with not quite the same application strength, and then apply twice as much hoping it will do the job. It doesn't.

Thread Locking Compounds - Application

This is the frequently abused and mis-used stuff dolloped on to bolts/nuts to stop them coming undone. Having seen and heard of many horror stories concerning this stuff, I thought a few words of caution and common sense wouldn't go amiss.

There is a plethora of types on the market with no easy reference as to which to use for what application except in certain cases. Loctite have a very useful guide, their dealers generally able to help with choosing which is best for any given application. The trouble comes when folk buy stuff unwittingly from their local 'do it all' motorist/car spares place. Good stuff is expensive, and it doesn't go all that far. But at least it does its job when used in the correct applications. Unfortunately many buy a cheaper variety with not quite the same application strength, and then apply twice as much hoping it will do the job. It doesn't.

Clutch - Adjustment of operating linkage

This is one of those areas where there is more than one way to skin the cat - depending on who you speak to. This is the method I have used for eternity, which has been totally reliable and never had a problem with.

This only applies to non-Verto type clutches, as the Verto types are not adjustable. You just have to make sure all the operating linkage components are in good order.

First off, ensure your operating linkage is up to scratch. For details on this, see 'Engine transplants - Clutch and flywheel'.

Satisfied all is OK, you can proceed with setting the linkage up.

1 - Remove/disconnect clutch return spring.

2 - Undo throw-out nuts (15/16"AF nuts on outer end of plunger) lock nut and back nuts off away from clutch cover.

Engine transplants - Changing FDs and speedo drive ratios.

What they don’t tell you in the manual! Terminology - FD - Final Drive (diff ratio) What they don’t tell you in the manual! If you’ve decided the FD fitted isn’t what you want, changing the FD is possible without separating the engine from the gearbox. Removing the diff case will allow you access to the diff assembly to change the crown-wheel, and access to the gear-change linkage. Use a manual for crown-wheel replacement. While you’re in there it would be just as well to replace the thrust washers and diff-pin as these are the source of many a gearbox problem. Particularly for up-rated engines where fitment for the competition diff-pin is highly recommended. Once again, follow the manual here. Now the bit they don’t tell you how to do... Rod-change types - Removal of the speedo drive housing gives access to the pinion retaining nut (1.5”AF socket needed and a long bar). To be able to undo the pinion nut (torqued up to 150lb ft !!) you need to engage two gears - 2nd and 4th - t

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.

Engine transplants - Clutch and flywheel assemblies

To go in to all the possible permutations would take a few chapters on it’s own. Suffice to say that the Metro had a few weirdo fitments such as cable operation, an in-line ‘damper’ (some got fitted to Minis too - eek),

Terminology -
BBU - Big Bore Units
SBU - Small Bore Units

NOTE: This information is largely concerned with transplanting a large-bore engine into a small-bore engined Mini. For further information on clutch and flywheel assemblies in particular, refer to relevant separate article.

To go in to all the possible permutations would take a few chapters on it’s own. Suffice to say that the Metro had a few weirdo fitments such as cable operation, an in-line ‘damper’ (some got fitted to Minis too - eek), and ‘top-hat’ plunger and rod bearing operation.

Engine transplants - Clutch and flywheel assemblies

To go in to all the possible permutations would take a few chapters on it’s own. Suffice to say that the Metro had a few weirdo fitments such as cable operation, an in-line ‘damper’ (some got fitted to Minis too - eek),

Terminology -
BBU - Big Bore Units
SBU - Small Bore Units

NOTE: This information is largely concerned with transplanting a large-bore engine into a small-bore engined Mini. For further information on clutch and flywheel assemblies in particular, refer to relevant separate article.

To go in to all the possible permutations would take a few chapters on it’s own. Suffice to say that the Metro had a few weirdo fitments such as cable operation, an in-line ‘damper’ (some got fitted to Minis too - eek), and ‘top-hat’ plunger and rod bearing operation.

Engine transplants - initial information and engine choices

Is this familiar? - You take the small one out; you put the big one in. In, out, in, out, shake your fist about, you do the hokey-cokey and you turn around, that’s what it’s all about...

Terminology -
BBU - Big Bore Unit
SBU - Small Bore Unit
Bodge - English term for 'make do' engineering- assured to fail at an in opportune
Moment.
Dizzy - Distributor

NOTE; this information is largely for transplanting large-bore units into small-bore engined cars.

Is this familiar? - You take the small one out; you put the big one in. In, out, in, out, shake your fist about, you do the hokey-cokey and you turn around, that’s what it’s all about...kinda sums up the situation many folk find themselves in when attempting to endow their beloved Min with a more impressive turn of speed.

Flywheel - Verto types (not injection)

There is only one version of this flywheel as standard, and fits all A+, Verto or Valeo (same type, different manufacturer) installations. And it's heavy. Very heavy.

Those up-rating power outputs in later Minis bearing this set-up were stuck with it. It is possible to shave a few ounces off this chunk of iron, but is difficult - especially for the DIY-er - and not cost effective when paying to have it done. Mini Spares recognised this shortfall early on. Sympathising with the plight of their customers, they produced a replacement outer section for the Verto kit from the same high-grade steel as used in the other light-weight versions.

	LB	KG
Standard Verto flywheel outer section only - unmodified	12.83	5.82
Steel Verto flywheel outer section only	8.84	4.01

Flywheel & Clutch - General information

If there's one subject that gets washed over when transplants or modifications are discussed its the flywheel and clutch assembly. There also seems to be a widely held belief that up-rating an engine from anything other than standard automatically requires a 'competition clutch'.

This, as with many other subjects concerning the Mini, is a myth. May be it's because the prospective transplantee needs not only a bigger/more powerful engine to amaze folk with in the bar stool bullsh*t stakes, but also anything that can be dubbed with the word 'competition'. 'Up-rated', after all, is a fairly tame word.

Although many have written much about how to modify engines, some suspension, and even on bodywork, very little has been written about the flywheel and clutch. Bit strange as it's an essential part of transferring engine power to the wheels! So let us delve into the myths and legends concerning this enigma of power transfer.

Primary Gear - Setting end float

A fairly crucial part of how the primary gear operates is its tolerances and running clearances. End float is a continual problem as folk either ignore it through ignorance or lack of accessible information on how to do it, or belief special tools are needed.

Terminology: DTI - Dial Test Indicator Also, later factory assembled engine units (from about 1992 onwards) were built up using whatever thrust washers were available, since Rover were not making regular orders for all shim/washer sizes due to the forthcoming end of production. Consequently, many units left Rover with incorrect (usually too big) clearances. The primary gear was no exception. Too much end float and clutch disengagement is adversely affected, the gear floating up and down the crankshaft in unison with the clutch plate. The result is a graunching gear change since the plate isn't clearing the flywheel and pressure plate surfaces fully. Too little end float and the gear is likely to be pinched tight as it

Wheels & tyres - Bigger wheel fitment consideration

Predominantly 13-inchers, but 12s as well, the main thrust of the questions being 'what do I need to do?'

This subject is a regular visitor to the message board and 'Knowledge' section of Mini Magazine for whom I write - fitting bigger wheels. Predominantly 13-inchers, but 12s as well, the main thrust of the questions being 'what do I need to do?' along with 'which wheel arch extensions will I need?' The answer has always been somewhat 'clipped' purely because of the space availability issues both in the magazine and on the message board, so something a little more detailed was required. Although the Mini suspension was designed around the use of 10-inch wheels with cross-ply tyres, a quick dash through history reveals that fitment of these bigger wheel sizes isn't a recent, 'modern' application.

MINI ENGINE STABILISER MSSK1000

1. This is an auxiliary steady bar kit and should not be used to replace any other standard fitment parts that have broken.

2. Remove the radiator support bracket from the radiator and the thermostat housing.

3. Slacken the nut retaining the exhaust manifold at the radiator end of the engine.

4. Remove the three bolts securing the bulkhead blanking plate as shown in the diagram. If the car has a heater pipe as indicated on the diagram then this should be disconnected at the engine.

MINI ENGINE STABILISER MSSK1300

1. This is an auxiliary steady bar kit and should not be used to replace any other standard fitment parts that have broken.

2. Remove the radiator support bracket from the radiator and the thermostat housing.

3. Slacken the nut retaining the exhaust manifold at the radiator end of the engine. Remove the exhaust manifold stud by tighterning another nut against the original manifold nut and then screwing the nut out of the cylinder head.

4. Remove the three bolts securing the bulkhead blanking plate as shown in the diagram. If the car has a heater pipe as indicated on the diagram then this should be disconnected at the engine.

Verto Clutches - Alternatives and differences.

This article has been written owing to the increasing amount of people who ring Mini Spares stating that their 1275cc Injection type Mini will not start after fitting a new clutch...