“The exhaust note rising to a crescendo”. “Taking on a deeper, more purposeful note in the upper rev ranges”. This is the staple vocabulary of the motoring journalist driving the latest supercar in the 1960’s, 70’s and 80’s and beyond, spellbound by the recent assault on his senses for the benefit of his readers. The amount of references made by writers to drives propelled by great engines (whether notably loud or quiet) is endless, as are the appreciations of those lucky enough to experience them first-hand. The same could be said of the comparisons for the music lovers amongst us between a fine engine and an orchestra. So how deep does this parallel go? Very, if the number of musicians who have chosen (funds permitting) to indulge their passion in classic cars is to be believed.
More than a matter of timing
Both the orchestra and the complex engine’s well-being and potential are in the hands of two people; the conductor and master tuner respectively. In both cases the assumption is that they are simply there to ensure all is well, and make sure that the “timing” is correct. For example, surely conducting is so easy, almost anyone could do it- all they do is stand at the front and wave a stick to a beat. How very wrong this is!
Let me explain by delving more deeply into both. First-of-all, there have been in some cases hundreds of recordings of the same piece of orchestral music, but each one is different, and in some cases very much so. The main contributing factor to this is the conductor, who can either be barely adequate, or extract greatness. The art, indeed the requirement, is that there is a deep understanding of what is going on and why. They may choose to focus on bringing the percussion out rather more than usual, or make particularly slow a section simply marked “Legato” by the composer. They may choose to make the string players caress their bows instead of mechanically oscillating back and to. Multiply this by the number of different instruments, time signatures and mood changes and the possibilities and permutations are almost infinite.
Genuine character
So it is with the black art of engine tuning. Modern cars more or less take care of themselves because almost everything is managed by electronics and virtually silent hydraulic tappets. What is perhaps less appreciated is the lengths that the makers of better cars nowadays go to make them sound “right”. Look at a contemporary engine and it will almost certainly be dominated by plastic, but have you noticed a little strange-looking dead-end tube here, a small vacuum-controlled valve there? These are the tools the modern engine designer uses to contrive an engine which could be very quiet on light throttle for comfort (and drive-by noise regulations), but still sounds “purposeful” when, and only when they want it to, and by exactly how much too. Sometimes they are frankly trying to make a wonderful and captivating sounding silk purse out of a sow’s ear, but in all cases they are emulating something that great engines had in spades decades before them……. Character!
Character is an interesting expression; it can allude to both good and bad traits. How many used car dealers have trotted-out that famous line, “they all do that, sir!”? The question is, do they? This is further confused by the fact that people want character in their cars, which is why the makers go to the aforementioned lengths today, and why the classic car is still such an object of desire now.
The voice of experience
For me, as a musician and a mechanic, there is something wonderful about “conducting” a complex engine, born of immense passion and technical ability, down a road when it is just right and all is well with it, and its characteristics shine. As it is with a “complex” musical ensemble and its leader, so it is with the person who has its optimal running within their charge; the engine tuner. It is not enough to look at a set of specifications and parameters and meet them. Every engine is different, even two ostensibly identical ones, and it is an intimate knowledge of the heartbeat of the engine that differentiates excellence from someone meeting basic requirements.
An internal combustion engine is at the very least a wind instrument. It has ducts, more often than not with several interconnected and attuned branches, that have an acoustic property that is controlled by a valving system. If that isn’t a wind instrument, what is? Add the mechanical element, and sounds get more multi- dimensional as tappets with a pre-set clearance do their work many times a second as just one example. No wonder engines have been likened to a “living thing”! But it’s the meat, the savoir-faire and knowledge of the individual involved, that opens the way for things to be just right, the perfect harmony (oops) of the machine….and even to prevent expensive mishaps. For example, piston slap (the piston rocking in the bore more than it should) is a sign of excessive wear in some engines such as an Aston DB4/5/6 or a classic stock small-block Chevy V8, but is entirely acceptable and even necessary in a fast road or race Chevy V8 with certain pistons until warmed-up. Similarly, a Ferrari Daytona should be clattery when idling; if not, the tappets are too tight, whereas a 365GT/4 or 400’s engine’s top-end should be much quieter- although their distributors can rattle at idle due to referred noise from the timing chain….and so it goes on! At least one tip to those who have a concern about a noise in a four-stroke engine is a simple one. Look at a mark on the front pulley of the crankshaft and listen to the noise; if the sound is at half engine speed, it’s almost certainly valvegear- related.
A trained ear
The “wind instrument” aspect assumes, and can only be refined when, the mechanical side is all as it should be. One will never get an engine acoustically balanced if for instance a valve isn’t seating perfectly. This and so much else is revealed by the musical ear listening intently to a carburettor inlet through a pipe (don’t try this at home!): If there is an intermittent faint spitting, the valve is not seating and/or the mixture’s lean and combustion is incomplete. If the hissing’s louder as the mixture screw is turned, you’re going too rich! If there is a lovely regular “pop” from each inlet on a multi-choke setup, you’re on your way to victory.
Some engines considered the height of refinement and luxury will never idle perfectly smoothly- a strange anomaly caused by a carburettor being in the middle of a lengthy inlet, causing some cylinders to be more starved of the ideal fuel/air mixture than others. The Rolls-Royce Phantom 111 engine, for all its venerable V12 complexity, is a perfect example of this. And so the list goes on, almost ad-infinitum. It’s this very cocktail of noises and sensations that should or shouldn’t be there that has captivated even the most brusque and prosaic of grown men, lady-folk and children for the last hundred plus years…
Start your engines!
Telephone: +44 (0) 1244 53 5000
Iain Tyrrell Consulting: Heritage Building, Aviation Park, Flint Road, Chester CH4 0GZ, United Kingdom
FOLLOW IAIN:
Iain Tyrrell 