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”!
Valves, guides and springs.
Concerned about fitting up-rating parts to injection engines?
A short while ago I had several conversations via e-mail with folk abroad who were a little concerned about fitting up-rating parts to their injection engines - like one of the many 'GSi' tuning kits available. A rumour had been put about that fitting this kit caused engine damage. Closer questioning culminated in the rumour saying that the high lift (1.5 ratio) rockers were causing camshaft and valve/guide damage. You know me - I can't let things like this alone until I find out the root cause. After some more digging and goading, I believe I've found the problem.
Cam damage is usually caused by something amiss in the valve train - obviously. Since the engines concerned were as they came from Rover and had done many thousands of miles without issue, it had to be something to do with these kits.
Valves, guides and springs.
Concerned about fitting up-rating parts to injection engines?
A short while ago I had several conversations via e-mail with folk abroad who were a little concerned about fitting up-rating parts to their injection engines - like one of the many 'GSi' tuning kits available. A rumour had been put about that fitting this kit caused engine damage. Closer questioning culminated in the rumour saying that the high lift (1.5 ratio) rockers were causing camshaft and valve/guide damage. You know me - I can't let things like this alone until I find out the root cause. After some more digging and goading, I believe I've found the problem.
Cam damage is usually caused by something amiss in the valve train - obviously. Since the engines concerned were as they came from Rover and had done many thousands of miles without issue, it had to be something to do with these kits.
C-AEA526 DUAL VALVE SPRING FITTING INSTRUCTIONS.
This valve spring set has been developed to fit standard sized top caps, and cope with fast road/rally rpm and high valve lifts, without crushing, of up to 0.49
C-AEA525 DUAL VALVE SPRING FITTING INSTRUCTIONS.
This valve spring set has been developed to fit standard sized top caps, and cope with mild/fast road rpm and high valve lifts, without crushing, of up to 0.475” without modifications when fitted to a cylinder head that has standard or near standard valve spring heights.
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...
Brakes - Fundamental Considerations
When looking to increase their cars performance, most folks immediately turn to
considering higher engine power outputs. Because of this pre-occupation brakes
tend to slide down the improvements priority list. However, they are far more
important - being able to accelerate at warp speed to hyper-space in the
twinkling of an eye is all very well, but disastrous if you can’t stop. You
will make a very big hole in the scenery, and possibly end up wearing an wooden
over-coat.
Getting the braking system sorted out can help to make the car quicker, as you will be able to more confidently, therefore maximising speed in any given situation. Being one of those ‘sciences’ used in the automotive industry I hope to shed some light on the subject as it's another of those where many questions from confused and mislead folks that clog up my e-mail board.
The advent of the Metro, and the brakes used on it has spawned a lot of activity in this direction. It was soon discovered that they could b
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
Rocker gear - General compendium
Whether you’re building a solid road performer or fire-breathing monster, the main goal is to improve air/fuel flow into the engine.
The more you can get in, the more power you can get out. Cheapest chunk of power improvement comes from sorting the asthmatic manifolding and exhaust by applying a stage one kit. Then what?
Considering the ‘get more in to get more out’ theme, the main restriction - all else being equal - is the valves and their behavior. How big they are, how efficient they are and how long they’re open for determines how much gets in with each gulp each bore/piston makes. Modified cylinder heads are popularly next, although it has to be said that although a well modified cylinder head will improve performance, the gain against cost is nowhere near that given by the ‘stage one’ kit application. A good stage one kit’s improvement verses cost is around £12.50 per 1 hp, a decent modified head typically £30 per 1hp - dependent on application. Hmm.
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.
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 head - Min Tec head range
I'm often asked about the range of cylinder heads I do for Mini Spares/Mini Mania, so here's the low-down…
Although the following range of heads accommodate specific fitments - like pre-1992 where by-pass hoses and heater take-offs on the clutch end of the head are used and post-1992 where neither of these exist, and on SPi (single point injection) heads where they don't usually have a threaded hole for the temperature sender - in reality it is easy to convert almost any of them to fit any other engine since holes are easily blocked off - or by-pass hoses not used, water pumps blanked off and drilled thermostats fitted (see articles on cooling/engine transplants). A list of which is what and what to do to each to convert is at the end of this article.
For more in-depth descriptions of the head specs, see article 'Cylinder head - About Min Tec Heads' - basically the valve sizes used have been decided on after extensive and in-depth flow test...
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…
Distributors - working basics
To maximise power and economy potential from any engine, burning the compressed fuel/air mixture at precisely the right point throughout the engines entire rpm range is essential.
Terminology - TDC - Top Dead Centre BTDC - Before Top Dead Centre Dizzy - distributor CR - compression ratio
To maximise power and economy potential from any engine, burning the compressed fuel/air mixture at precisely the right point throughout the engines entire rpm range is essential. This ‘point’ is generally somewhere before the piston reaches TDC on its power stroke described in degrees - i.e. 10 degrees BTDC. This point isn’t constant throughout the rpm range. Low rpm values are normally less than high ones.
Ultimately the dizzy provides this spark at exactly the right point to effect this burn.
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 ...
Lubrication - Oil pumps
Essential to the well being of every engine is its oil pump and oil. Much in the same way as the heart and blood is deemed relatively important to us humans! It's also another of those greatly misunderstood and, unfortunately, misrepresented subjects connected to engines.
An alarming number of so-called A-series engine specialists would have you believe that once parting with a veritable bundle of your hard earned readies on that mega motor, what you really need to keep it in good health is a high-pressure/high-flow oil pump. Seems a sensible consideration - except in the A-series world it's impossible. Oh, there are pumps that will give better flow rates than others, but high pressure? Absolutely not.
Oil pressure is regulated by the relief valve in the block of an A-series, not in the oil pump as with say a Ford. Yeah, you know - the one that gets jammed, causing heart failure as you believe your crank bearings have dissolved, and is a pig to get out.
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