SHOCK ABSORBERS

Technical lowdown on shock absorbers,what to look for and what to buy Having introduced the fairly unknown Kayaba (KYB) range to the mini market in 1997 I am still amazed how gullible people are when buying cheap dampers. I have tried every type popular type available in the last 35 years, Armstrong including their adjustables, Girling, lockheed, Koni, Spax., Avo, Bilstein,Monroe,Boge,Gabriel and GMax The best to date were probably the very expensive special design Koni adjustables that we had built for the Monte Carlo rally. I also used the spare set on my 8 port car. You get what you pay for? For a non adjustable, Bilsteins rate highly although like the Koni specials are expensive, but you get what you pay for. The essence of a quality damper is to upgrade performance by using more sophisticated higher quality component build in the valving, piston, rod and seals etc along with a performance upgrade to improve the cars road holding.

Primary Gear - Bush Replacement

With the cost of new primary gears spiralling ever upwards, and the availability of good, serviceable used ones, fitting new bushes to existing gears is becoming a more common solution. For some reasons for bush failures and rectification to stop it re-occurring, see article Primary gear - Bush problems. Since there is no useful information given in any of the workshop or DIY manuals on this subject, following is my approach to dealing with the issue. The first thing to get to grips with is which bush is which. This has added an element of confusion to many conversations I have had with folks on this subject, so - the FRONT bush is the one nearest the engine block, the REAR bush is the top-hat one nearest the flywheel. This is because the front of the engine is actually the radiator end - quoted in 'in-line' engine-speak. The REAR bush is the same on all primary gears - be they for small or large bore engines. The FRONT bush is different for each though; the small-bore one is smaller

GEARBOX - Up-Rating Drop Gears

The standard drop gears are fine for practically all road use - almost irrespective of power output. part numbers: DAM9373, C-STR123, C-STR124, C-STR30, C-STR30A, C-STR30T, C-STR30TA, C-STR230, C-STR240, C-STR250 Terminology - Drop Gears - Transfer gears (primary, idler and input gears) Large-bore - Refers to anything based on a 1275-type unit Small-bore - Refers to anything based on 850/998/1098 units Despite what many folk believe - they are more than strong enough, and will perform perfectly well if correctly set up. That means getting the idler and primary gear end floats right, and using new bearings for the idler gear at each re-build. Simply following the methods outlined in the relevant workshop manuals will achieve these simple goals. There are two problems with standard drop gears - the main one is the helical cut of the teeth, the other a very limited selection of ratios. The helical-cut teeth are essentially power absorbing - both from increased metal-to-metal c

Gearbox - Up-rating diffs and FDs

There’s a good selection of straight-cut final FDs available. Examine the FD table, and using information from

'Gearbox - Final dives, standard' and 'Gearbox - Formulae for car speed, etc.'

you can assess which would best suit your usage. Bear in mind that they’re noisy, make sure you select one that’ll fit your diff unit, and also consider that using drop gears will allow fine-tuning of the ratio where necessary. See

'Gearbox - Up-rating drop gears'

Gearbox - Up-rating diffs, FDs and ancillaries.

part numbers: C-BTA166, C-BTA167, DAM6624, BTA101, 2A7062, DAM5071, DAM6027, RPS1418, C-AJJ3385, C-22A1731, ...Read more

Primary Gear – Bush Problems

Although not of immediate interest to many road-runners/street-burners, mainly accorded to the racing scene, it seems to be a perplexing problem to a very large number of folk around the world, and has burned up plenty of telephone time.

part numbers: 13H2934, LUF10005, CE12, 22G109, DAM8889, DAM8887

With the cost of new primary gears spiralling ever upwards, and the availability of good, serviceable used ones, fitting new bushes to existing gears is becoming a more common solution. For some reasons for bush failures and rectification to stop it re-occurring, see article 'Primary gear - Bush problems'. Since there is no useful information given in any of the workshop or DIY manuals on this subject, following is my approach to dealing with the issue.

The first thing to get to grips with is which bush ...

Brakes - Silicone brake Fluid

To use or not to use - that is the question! BRAKES - Silicone brake fluid, to use or not to use - that is the question! Over more recent years I've had affair number of discussions on the use of silicone brake fluid as opposed to the more common type. I have to say some folk are vehemence in their belief that this stuff is 'the answer' to all kinds of brake maladies. Some time ago I contacted the two major brake specialists in this country (UK) to see what they had to say. Their reactions was as vehemence as those believers above. For what it's worth, I thought I'd spread the word according to the manufacturers - which happens to be similar to my limited experience with this 'liquid savior'. Some has heralded silicone-based brake fluid as being the last word in brake fluid, yet also brings a look of horror onto the faces of some. The classic car folk swear by it, particularly for vehicles that are not used much where brake seal failure can be experienced, and because it does not

Valve Guides - Materials and Useage

Material choices for guides are down to two distinct types - cast iron and bronze. Yes, cast iron. NOT steel as described in many adverts and by vendors. Never have been, never will be. These are as fitted to the various A-series cylinder heads as standard in all applications. Cast iron is used because it is a very dissimilar metal from any used in valve manufacture - important to eliminate galling that causes seizure of the valves in the guides - is softer, yet resilient enough to wear well. Bronze, on the other hand, is a very general description as there are a variety of 'bronzes' used by various folk. In days gone by, the bronze base type used was 'PB1' (also known as 'Navy Bronze') - a phosphor-bronze alloy that was very orange in colour, and very soft, used primarily in race engines. Unfortunately they wore out very quickly. Silicone-brass content bronze is probably the most popular now - often with a high aluminium or manganese content - is very yellow/gold in colour.

Engine - Identification Data Updated

If you have the engine tag still attached to the engine - just in front/below the thermostat housing - or perhaps the original engine number in the log book then the following should help you determine which engine you have. For Metro units, see 'Engine - Metro identification data'. Original engine identification numbers 850cc 8A Austin up to 25000 8MB Morris up to 25000 8AM Austin & Morris 25000 onwards 8AH Austin & Morris Automatic 8AJ Austin & Morris closed circuit breathing 8AK Austin & Morris automatic with closed circuit breathing 8WR Wolseley Hornet & Riley Elf 8AC Moke 85H/101 All variants 1969 onwards Note: third suffix letter denotes compression type, L = Low, H = High, e.g. 8AM/U/H101 denotes high compression. 998cc 9WR Wolseley Hornet & Riley Elf Mk2, pre closed circuit breathing 9AD Austin, Wolseley Hornet & Riley Elf Mk2 with remote type gearbox and closed

Engine - Running in Procedure

This is another of those subjects that crops up on the message board frequently. I am constantly surprised by the number of engine builders - or people who charge other folk for building engines at any rate - that never hand out such an information sheet. It seems pretty daft to me that having taken a wad of money off of a customer for an engine you've lovingly put together, you'd want to help that person get the very best out of the engine. And the running/breaking in procedure is absolutely crucial. It at least ensures no damage is incurred when the engine first bursts into life. A collection of the usual suspects have explained their own methods on the board, along with various others - many of which probably work just as well for them, a few which are down-right dubious. Following is a sheet I administer with every customer engine I build.

Air filtration - K&N Air cleaner test.

In the forefront of Mini tuning, improving the over-all breathing capability of the very asthmatic A-series the air filter set-up is one that sees priority attention. All the widely available (and widely varying) stage one tuning kits include at the very least a replacement - and hopefully - high-flow air filter element to fit into the standard plastic case,

In the past few years (well, must be nearly 6 years by now!) since I got involved with writing for the specialist Mini Magazines I have been continually fighting with the problem of limited space. This has limited what I have been able to cover, both in subjects and in details. Up until recently (say the past year or so) I have been covering fairly broad topics in a fairly broad terms and detail. Basically trying to cover perhaps the most popular areas dabbled in by the Mini owning masses.

Cooling - Controlling water temperature

The introduction of the Cooper S proved to be a testing time for the Mini’s systems, but conveniently provide a guideline as to what the standard cooling system was capable of - that used on the ‘S’ was marginal to say the least!

It wasn’t uncommon for many S’s to spew water from their overflow pipes when ever it was doing anything other than a steady 70 miles an hour, over-heating eventually caused through water loss. Perhaps some deductions can be made from the following…

There are a number of elements involved in controlling water temperature. Some confusion over what to sort first when over-heating occurs leads to wasted time and money, and possibly terminal engine damage. Maximum power is usually generated from A-series engines at 70 – 75 degrees C (160 to 170 degrees F). The main problem with this on a road car is the oil’s unlikely to get hot enough for maximum performance – the results outlined previously.

Cylinder head - Suitability basics

Whatever else owners do to their Minis by way of interior/exterior modifications or none at all, a very large proportion desire and search for an increase in engine performance.

See bottom for useful part numbers.

Now this may not be super-sonic speed-inducing power, it could just as well be for maximum economy. In either case, it's the engines volumetric efficiency (VE) under scrutiny - it's ability to breath in as much correctly proportioned air/fuel mix as possible in any given situation. Although the induction/exhaust system plays an important part, there are effectively two major factors that dictate performance increases - the camshaft and cylinder head. The induction and exhaust elements (stage one kits, exhaust systems, etc.) and camshafts are covered in various other articles in my 'Corner'. So here we'll have a look at cylinder heads and dispel some of the myths and legends surrounding them.

Cylinder head - Torque-down and head gasket problems

This is to help those floundering in an unknown sea of techno-babble and 'magical' cures… Part No Applications: C-AHT288, CAM150, CAM151, TAM1617, CAM4545, 51K1193, TAM1521, GEG300, C-AHT188, C-STR1057, A regular visitor to the message board, and something I am asked frequently about in my other incarnations for other technical media. Generally when something has gone badly wrong! Many folks have just as many ways of dealing with the following subjects - all can and will claim their way has worked for them for the proverbial millennia - so a few words as a basic reference and guide as I see them; we all know there are always exceptions to the rules. This is to help those floundering in an unknown sea of techno-babble and 'magical' cures…

Engine - 998 tuning, further options

Following on from the easily bolted on performance enhancing components out-lined in the stage one section, we need to consider where to go to get more power output.

Terminology:
MSC/MM - Mini Spares Centre/Mini Mania
BBU - Big Bore Unit (refers to all 1275cc-based units)
SBU - Small Bore Unit (refers to all sub-1275cc units, here the 998)
BHP - Brake Horse Power
CR - Compression Ratio

To improve engine out-put, you need to increase the engine's 'breathing' ability. The stage one kit deals with all the easily bolted-on external parts, and represents the best increase for investment. From here on in the power increases will cost commensurately more money. Power production of any engine, once the 'breathing apparatus' (induction/exhaust system) has been dealt with to cause no restriction ...

Engine - Identification data

If you have the engine tag still attached to the engine - just in front/below the thermostat housing - or perhaps the original engine number in the log book then the following should help you determine which engine you have. For Metro units, see 'Engine - Metro identification data'. Original engine identification numbers 850cc 8A Austin up to 25000 8MB Morris up to 25000 8AM Austin & Morris 25000 onwards 8AH Austin & Morris Automatic 8AJ Austin & Morris closed circuit breathing 8AK Austin & Morris automatic with closed circuit breathing 8WR Wolseley Hornet & Riley Elf 8AC Moke 85H/101 All variants 1969 onwards Note: third suffix letter denotes compression type, L = Low, H = High, e.g. 8AM/U/H101 denotes high compression.

RUNNING IN NEW ENGINES

Install engine. It is absolutely imperative that the cooling system is more than sufficient to deal with any temperatures likely to be produced by the engine. More power means more heat to be dissipated. A standard radiator is very unlikely to be able to cope with a reasonable power increase over standard.

Do not fill cooling system yet. Set clutch throw-out and free-play take up. Double-check all connections electrical, oil, fuel and cooling system. Put in engine oil – use a cheap multi-grade mineral oil. DO NOT use either semi or full synthetic oils. They will stop the rings from bedding in. Remove spark plugs, and spin engine over in bursts of a few seconds to pick up oil pressure and prevent starter motor damage. DO NOT start engine until oil pressure picks up.

Once oil pressure is showing, check ignition timing statically. Set to figure advised by distributor maker, or if no figures available, set at around 6-8 degrees BTDC. Re-fit spark plugs a

Engine transplants - Engine to gearbox fitment

Contrary to popular mis-guidance, all BBUs will fit all four-syncro gearboxes. It was only the three-syncro boxes that varied in casting dimensions causing hassles where 1275s were applied to 850/998 gearbox casings.

Terminology -
BBU - Big Bore Unit (1275cc based engines)
SBU - Small Bore Unit (850/998/1098cc based units)
FD - Final Drive

NOTE: This information is largely for transplanting large-bore engine units into small-bore engined Minis. For further information on up-grading transfer (drop) gears, refer to relevant separate article.

Contrary to popular mis-guidance, all BBUs will fit all four-syncro gearboxes. It was only the three-syncro boxes that varied in casting dimensions causing hassles where 1275s were applied to 850/998 gearbox casings.

Engine transplants - Engine to gearbox fitment

Contrary to popular mis-guidance, all BBUs will fit all four-syncro gearboxes. It was only the three-syncro boxes that varied in casting dimensions causing hassles where 1275s were applied to 850/998 gearbox casings.

Terminology -
BBU - Big Bore Unit (1275cc based engines)
SBU - Small Bore Unit (850/998/1098cc based units)
FD - Final Drive

NOTE: This information is largely for transplanting large-bore engine units into small-bore engined Minis. For further information on up-grading transfer (drop) gears, refer to relevant separate article.

Contrary to popular mis-guidance, all BBUs will fit all four-syncro gearboxes. It was only the three-syncro boxes that varied in casting dimensions causing hassles where 1275s were applied to 850/998 gearbox casings.

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.

Fuel - Leaded/unleaded fuel and the alternatives

The fuel situation seems to be worsening at a great pace these days. And as is exhibited by the questions that appear on the message board many folk are confused by what they can and can't do, and what is best to do as far as race engines go.

Many have posted (particularly from the States) that nothing need be done - just run on unleaded. They've been doing this for years and never had any problems. I have trouble believing that in the face of what I know and have investigated - so here's what the score really is.

Years ago this stuff called Tetraethyl lead was originally conceived as an octane enhancer. It was soon discovered, however, that the metallic oxides produced by the combustion process formed a protective coating on the valves and seats. This coating prevented micro welding of the valve seat to the corresponding seat in the head under high temperature operation.