By Dave Orange
I thought we would move away from the physical side of Automotive Engineering and talk about Liquid Engineering or in simple terms engine oils. For those of you who subscribe to one of the many monthly automotive magazines, I am sure you will have come across any number of extremely detailed and largely well written reports or articles singing the benefits of buying the very latest semi or fully synthetic engine oils with all their chemical additives for your modern.
It must be remembered motor manufactures combined with the leading oil companies spend millions if not billions every year on developing the next generation of engine lubricants. What must not be assumed is while these excellent lubricants have been developed for use in modern engines with their very tight machining tolerances, they should never be used in a classic or vintage vehicle like our Austin Sevens unless the oil company recommends it’s use (which I have to say is very unlikely).
Why I hear you ask, well it’s largely down to the oils viscosity or thickness, modern lubricants such as semi or fully synthetic oils are very thin (runny lubricants also act in part as a cooling agent, in addition to and much like the water in the cars radiator.
Our little old Austins whilst very modern and possibly well ahead of their time are no match when it comes to fine machining tolerances on a modern engine. In fact some of the bearing running clearances whilst well within Austin’s specification, if a modern lubricant were to be used it would run out of the bearing surface area long before it had chance to do its job, causing catastrophic engine failure. On the other hand the old named engine lubricants such as Castrol, Penrite and Morris etc, are still available today in SAE30 and SAE40 specification. These oils were developed for older engines with wider tolerances such as those found in our Austin engines, but most will have some form of modern chemical improvement such as added detergent.
So remember if you want to prolong your Austin’s engine life fill it with the correct engine lubricant SAE30 or SAE40. Just one further bit of useful information, if you’re planning to go touring in Europe take sufficient engine oil SAE30 or SAE40 etc with you for your needs, it’s not generally available in Europe.