Corbeau Seats Rally 2019

Historical Article - Nov 1992 - A Guiding Hand - Do not adjust your seat too muc...

A question frequently asked by customers buying new valve guides is what size the guide should be reamed to once fitted. The answer initially is easy, 9/32” (.812”). However, nothing in life is simple.

Correct sizing of the guide is very important. Not only does the guide support the valve, but also helps dissipate heat from the valve – especially important for the exhaust valve. This particular point is even more critical now that hi-grade fuels are no longer available, worsened by many people converting to lead-free fuel.

Historical Article - Nov 1992 - A Guiding Hand - Do not adjust your seat too muc...

A question frequently asked by customers buying new valve guides is what size the guide should be reamed to once fitted. The answer initially is easy, 9/32” (.812”). However, nothing in life is simple.

Correct sizing of the guide is very important. Not only does the guide support the valve, but also helps dissipate heat from the valve – especially important for the exhaust valve. This particular point is even more critical now that hi-grade fuels are no longer available, worsened by many people converting to lead-free fuel.

Corbeau Seats Rally

MiniSpares crew wows the crowds at Clacton

The first ever closed public road tarmac special stage rally in England, the “Corbeau Seats Rally” took place on Sunday 22nd April

Camshaft Design

Elgin Cams is a company that is a direct descendent of such famous California specialists as Isky, Delong, Winfield, etc. etc. Elgin has taken the art of cams into the science of the '90's. Computer designed and handcrafted workmanship guarantee a first class camshaft. Custom designed cams are a specialty. Part No Applications: CAM001, CAM002, CAM003, CAM004, CAM005, CAM006, CAM007 Elgin has made cams or sold his design to General Motors, Ford Motor Co., Nissan Corp., Zakespped International, Porsche Motor Sports, Winston Cup "Engine Builders. Elgin has the largest percentage of cams used at the SCCA Runoffs from GT-1 to Formula-V. He also has provided original or new technology for antique and vintage racers. Much information has been recorded about the four stroke internal combustion engine and yet only a small percentage of people really understand how it works and fewer people know how to modify an engine to suit their needs.

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

Brakes - Pipe End Flares

One day I'm going to have to try and assess just how it is that every now and again I get a 'run' on folks asking me about a specific problem. These problems exist all year round, year in, year out. And said problems crop up throughout the year. But - every now and then there's a blood-rush on a certain issue. Just recently that issue has been brake pipe ends. The bit that seals the pipe off against it's relevant fitting. There are two types of end - male and female. The male end is convex in shape, the female concave. The male end is used where a male pipe union (nut) is used on the brake pipe - that's a nut with an external thread - that will be screwed into a female fitting such as found in a wheel cylinder or master cylinder. The female end is used where a female pipe union (nut) is used on the brake pipe - a nut with an internal thread - and will be mated to a male fitting such as found on rear flexible brake pipes. Under no circumstances should you mix the too up as the brake p

Brakes - Rear brake bias adjustment

When altering the front brake set-up away from the standard installation, it invariably alters the amount of rear brake bias needed to re-balance the cars brake balance.

The problems start occurring when folk graft alternative brake set-ups onto the front of their Minis. Be this 7.5" discs onto a previously drum-braked model, or going from current standard disc set-ups to one of the 4-pot varieties. The question then is 'what bore size rear wheel-cylinders do I need?' Unfortunately this isn't straightforward. Actually, that's not strictly true - more on this later. The pressure developed in the lines determines brake effectiveness - aside from disc size, pad type, co-efficient of friction, etc. that is. Understanding this may assist in choosing which way you should go for your particular set-up.

The basic facts you need to remember when dealing with brake pressures is how they are affected by the components you use.

Cylinder head - What can easily be achieved

During a discourse with the editorial staff at Mini Mag, it was decided the build feature presented an ideal opportunity to demonstrate just exactly what such an engine build is capable of in days where it's generally believed you have to have an all-singing, all-dancing 1380cc engine to have an enjoyable road burner - leaving those with very limited budgets a little depressed. During a discourse with the editorial staff at Mini Mag, it was decided the build feature presented an ideal opportunity to demonstrate just exactly what such an engine build is capable of in days where it's generally believed you have to have an all-singing, all-dancing 1380cc engine to have an enjoyable road burner - leaving those with very limited budgets a little depressed. So the idea was to finish the engine off using a relatively 'mild' specification to maximise drivability. The camshaft used was the fantastically versatile Swiftune Racing SW5 profile that provides drive from nowhere up to 7,000rpm - d

Cylinder heads - About Min Tec Heads

'Modified to give maximum performance gain for cost. Combustion chambers, inlet and exhaust ports extensively re-worked. Stone-ground finish in ports promotes ultimate fuel atomisation. Terminology - VFM - Value For Money CR - Compression Ratio VE - Volumetric Efficiency Three-angle valve seats in head. Cooper S size valves with current maximum flow profiles and Tuftrided for durability/longevity when used with unleaded fuel (hence 'black' finish). Combustion chamber volume used to give slight static compression ratio increase over standard. Head mods employed greatly increase volumetric efficiency, boosting actual running (dynamic) compression ratio. Where much sportier cam profiles are used, a higher compression ratio is advised to achieve maximum power potential. Seek advice on what is required'. That is the opening paragraph from the fitting instructions sheet as supplied with the heads I do for Mini Spares.

Cylinder Head - Unleaded Fuel Use

The specter of 'unleaded fuel only' - instigated in UK on January 1st 1999 and seemingly from decades ago across the rest of the world - seems to be forcing more and more folk into frightened, panic orientated action. And Mini owners are featuring heavily in this. See bottom for useful part numbers. The situation not at all being helped by all sorts of conflicting information from 'leaned' sources, such as lead levels in humans has declined greatly since 1935 - despite the rapidly expanding ownership of petrol-burning vehicles. And benzene and toluene used in unleaded fuels are cancerous. Still, the powers that be are relentlessly forcing through the 'no heavy metals in fuel' bills, not being at all put off by such trivia. Not surprising bearing in mind the complete debacle on the catalytic converter front - the type decided on for world wide and universal use was developed and tested in California!

Cylinder Head - Unleaded Fuel Use

The specter of 'unleaded fuel only' - instigated in UK on January 1st 1999 and seemingly from decades ago across the rest of the world - seems to be forcing more and more folk into frightened, panic orientated action. And Mini owners are featuring heavily in this. See bottom for useful part numbers. The situation not at all being helped by all sorts of conflicting information from 'leaned' sources, such as lead levels in humans has declined greatly since 1935 - despite the rapidly expanding ownership of petrol-burning vehicles. And benzene and toluene used in unleaded fuels are cancerous. Still, the powers that be are relentlessly forcing through the 'no heavy metals in fuel' bills, not being at all put off by such trivia. Not surprising bearing in mind the complete debacle on the catalytic converter front - the type decided on for world wide and universal use was developed and tested in California!

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.

C-AEA527 Dual Valve Springs Fittting Instructions

This valve spring set has been developed to fit standard sized top caps, and cope with racing rpm, savage cam lobe opening rates and high valve lifts up to 0.520”. Most cylinder heads when modified for racing culminate in a fitted valve spring height of around 1.420” to 1.440”.

C-AEA527 DUAL VALVE SPRINGS FITTING INSTRUCTIONS

See bottom for useful part numbers.

However where possible, it is always advantageous to correct and match the valve spring heights (measured from the spring seat in the head to the underside of the spring retainer cap), as these will vary particularly where new valve seats are cut and the standard valve spring seats are left – some by as much as 0.050”!

MSE6 - POST 1992 Unleaded Stag

Modified to give maximum performance gain for cost. Combustion chambers, inlet and exhaust ports extensively re-worked. Stone-ground finish in ports promotes ultimate fuel atomisation. Three-angle valve seats in head. Super-quality MG Metro valves modified to increase airflow. MSE6 - POST 1992 unleaded stage 2 (Road Rocket) large-bore head Part No Applications: MSE6, TAM1059, TAM1061, TAM2069, 12G1963, 12G1015, ADU4905 Inlet Valves: 35.6mm(1.401") dia. Original equipment type P/No. TAM1059 Exhaust Valves: 29.2mm(1.150") dia. Original equipment type P/No. TAM1061 Exhaust seats: Latest type Beryllium-based for lead-free fuel P/No. TAM2069 Valve Guides: AE Hepolite cast iron P/No. 12G1963 Valve Springs: Nominal 140lb. Max actual valve lift 0.400" P/No. 12G1015 Stem Seals : Latest 'top-hat' design with tensioner springs (inlets) P/No. ADU4905 Chamber Volume: Nominal 20cc Combustion chamber volume used to give slight static compression ratio increase over

MSE6 - POST 1992 Unleaded Stag

Modified to give maximum performance gain for cost. Combustion chambers, inlet and exhaust ports extensively re-worked. Stone-ground finish in ports promotes ultimate fuel atomisation. Three-angle valve seats in head. Super-quality MG Metro valves modified to increase airflow. MSE6 - POST 1992 unleaded stage 2 (Road Rocket) large-bore head Part No Applications: MSE6, TAM1059, TAM1061, TAM2069, 12G1963, 12G1015, ADU4905 Inlet Valves: 35.6mm(1.401") dia. Original equipment type P/No. TAM1059 Exhaust Valves: 29.2mm(1.150") dia. Original equipment type P/No. TAM1061 Exhaust seats: Latest type Beryllium-based for lead-free fuel P/No. TAM2069 Valve Guides: AE Hepolite cast iron P/No. 12G1963 Valve Springs: Nominal 140lb. Max actual valve lift 0.400" P/No. 12G1015 Stem Seals : Latest 'top-hat' design with tensioner springs (inlets) P/No. ADU4905 Chamber Volume: Nominal 20cc Combustion chamber volume used to give slight static compression ratio increase over

MSE4 - Post 1992

Modified to give maximum performance gain for cost. Combustion chambers, inlet and exhaust ports extensively re-worked. Stone-ground finish in ports promotes ultimate fuel atomisation. MSE4 - POST 1992 unleaded stage 2 (Road Rocket) large-bore head Part No Applications: MSE4, C-AEG544, C-AEG106, TAM2069, C-AJJ4037, C-AEA526, ADU4905 Inlet Valves: 35.6mm(1.401") dia. Tuftrided EN214N s/steel P/No. C-AEG544 Exhaust Valves: 29.5mm(1.161") dia. Tuftrided EN214N s/steel P/No. C-AEG106 Exhaust seats: Latest type Beryllium-based for lead-free fuel P/No. TAM2069 Valve Guides: Magnesium bronze P/No. C-AEA526 Valve Springs: Nominal 180lb. Max actually valve lift 0.500" P/No. C-AJJ4037 Stem Seals: Latest 'top-hat' design with tensioner springs (inlets) P/No. ADU4905 Chamber Volume: Nominal 20cc Three-angle valve seats in head. Cooper S size valves with current maximum flow profiles and Tuftrided for durability/longevity when used with unleaded fuel (hence 'black' finish).

MSE4 - Post 1992

Modified to give maximum performance gain for cost. Combustion chambers, inlet and exhaust ports extensively re-worked. Stone-ground finish in ports promotes ultimate fuel atomisation. MSE4 - POST 1992 unleaded stage 2 (Road Rocket) large-bore head Part No Applications: MSE4, C-AEG544, C-AEG106, TAM2069, C-AJJ4037, C-AEA526, ADU4905 Inlet Valves: 35.6mm(1.401") dia. Tuftrided EN214N s/steel P/No. C-AEG544 Exhaust Valves: 29.5mm(1.161") dia. Tuftrided EN214N s/steel P/No. C-AEG106 Exhaust seats: Latest type Beryllium-based for lead-free fuel P/No. TAM2069 Valve Guides: Magnesium bronze P/No. C-AEA526 Valve Springs: Nominal 180lb. Max actually valve lift 0.500" P/No. C-AJJ4037 Stem Seals: Latest 'top-hat' design with tensioner springs (inlets) P/No. ADU4905 Chamber Volume: Nominal 20cc Three-angle valve seats in head. Cooper S size valves with current maximum flow profiles and Tuftrided for durability/longevity when used with unleaded fuel (hence 'black' finish).

MSE3 -Pre 1992

Modified to give maximum performance gain for cost. Combustion chambers, inlet and exhaust ports extensively re-worked. Stone-ground finish in ports promotes ultimate fuel atomisation. MSE3 - PRE 1992 unleaded Stage 2 (Road Rocket) large-bore head Part No Applications: MSE3, C-AEG544, C-AEG106, TAM2069, C-AJJ4037, C-AEA526, ADU4905 Inlet Valves 35.6mm(1.401") dia. Tuftrided EN214N s/steel P/No. C-AEG544 Exhaust Valves 29.5mm(1.161") dia. Tuftrided EN214N s/steel P/No. C-AEG106 Exhaust seats Latest type Beryllium-based for lead-free fuel P/No. TAM2069 Valve Guides Magnesium bronze P/No. C-AJJ4037 Valve Springs Nominal 180lb. Max actually valve lift 0.500" P/No. C-AEA526 Stem Seals Latest 'top-hat' design with tensioner springs (inlets) P/No. ADU4905 Chamber Volume Nominal 20cc

Cylinder Heads - Valves, Shape, Material and Finish

For the very good and simple reason it minimised airflow obstruction by having the least amount of material in the way. Very plausible, and a design that many have stayed with to this day - surprising considering the magnitude of expertise housed in the more recognised A-series tuners. Probably something along the lines of 'if it ain't broke, don't fix it', or perhaps (and more likely?) 'Can't teach an old dog new tricks'.

However, as time and technology progressed, man's ever-inquisitive nature started to determine more exactly what and why - and airflow activity was not passed over. Not only 'how much' was being measured, but 'where and how' to further determine where improvements could be made. After all - it has long since been realised that the engine is essentially an air pump. The more you get in, the more you get out, so improving the air's tortuous route to the cylinder has to help.