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.

SU Carbs - HIF, a more finely honed instrument

Modern technology continually sweeps its ever-growing arm across all manufactured products and the SU was no exception. From closer scrutiny, and more demanding emissions control the HIF variant was born. So what have they done to improve it over its predecessor - the HS - and is it worth hanging out for? PROS. Integral float - the 'IF' in the new type number HIF. The previous H and HS type carbs with their side-mounted remote float bowls worked fine until used in racing where serious cornering speeds generated enough G-forces to lean-out the fuel mixture. The remedy was to fit a spacer between the float lid and float bowl to raise the fuel level held in it. OK when running, but at idle and rest, fuel would bubble out of the jet - causing bore washing, poor pick-up, and horrendously rich CO mixtures at idle! Fitting the float integral with the carb, directly below the jet hole (port/orifice), eliminated this problem. Jet temperature compensation - This was first aired on HS types

SU CARBURETTORS - HOW THEY WORK

Basic knowledge Even though the SU carburetter (carb) is a very basic yet precise instrument, some fundamental understanding on just how it works is needed to be able to deal with common problems and tuning. Following is as basic a description of what's going on that I can manage! First you need to be comfortable with the main aim of any carb - to supply the engine with a finely atomized fuel/air mixture in the right strength for all operating conditions. This means from idle to flat out and everything in-between. All carbs achieve this using the same method - a venturi or choke (restriction) is used to speed up the velocity of the in-coming air to create a reduction in pressure. This is used to draw fuel from the float chamber via a suitably sized jet hole into the air stream, and hence into the engine. The perfect carb will supply the engine with optimum mixture for both maximum power throughout the full throttle-angle range (variable restriction - as in butterfly and spindle) a

SU Carbs - The history

Practically every Mini owner can name the brilliant engineer responsible for our obsession. Many can name the man responsible for the rubber suspension spring.

A goodly number know a fair bit about the engine's heritage and the man who came up with the extremely efficient cylinder head design.They account for the biggest chunks of the Mini's anatomy. But what about that other extremely simple yet hugely effective instrument that features so prominently when engine tuning occurs - the SU carburetter? A limited few can tell you what 'SU' stands for, extremely few have any idea of its concept and evolution. So let's put that right… In the beginning Strangely enough, it all started way back with William Banks Skinner; one of the owners/directors of the well-known Lilly and Skinner footwear distributors.