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4th March 2003
It ain't what you got, reckons Dave Minton. It ain't even what you do with what you got; it's WHY you do, what you do, with what you got...
When Middle Englanders tell you in tones of undisguisable envy 'You must be mad,' you know you're on to a good thing. On their way along the lane out of the village where Mike has his stables and garage, they double-take at the girder forked Tiger standing with its dangling viscera and invariably comment along the 'Don't make 'em like that any more' lines before breaking into cherished memories of their own 1930s and 40s motorcycling.
It's when they query the engine-on-the-bench state of the bike to learn that it's being turned from a power-tweaked Tiger into a Teddy bear ready for its trans-Canada run this August that I'm convinced of the fine quality of our madness. What had been heartfelt memories of old-time motorcycling turns to heart-rending groans of envy as the visitors learn why I am attending to the old Trumpet's innards.
They protest their inability to manage such an adventure, applying much too much good sense to the whys and wherefores of inaction to make any real sense. And away the well shod, routine bound, good citizens walk with their tutting wives, heads shaking in mutual concord over our idiocy and their own safe stasis.
Don't worry, I'm not going to give you a nut-by-bolt recital of the entire workshop-routine. However, you have to understand that when a 1939 super sportster with a bronze cylinder head is to be used for a 4000 mile jaunt across mainly empty secondary roads on which low octane, lead-free and possibly stale petrol will be the only fuel, you don't go at it gung-ho. Or if you do, you pay the price. But I do feel sure you would be interested to learn what is involved.
A few years ago with expert guidance from Dan Force (01432 761425), the vintage and classic engineer and restorer who has a soft spot for Trumpets, I fitted my old T100 with E3134 cams. It also had 8.5:1 pistons, as well as a bronze head. Triumph offered the bronze head as a five quid optional competition extra because, as Edward Turner had quickly found out for himself (T110 owners later) his iron headed twins ran hot when pushed and bronze shed heat much better.
The trouble with bronze lies in its softness. You know what bronze is? Of course you do but, just as a reminder, it's a variable alloy made up primarily of copper and tin, somewhere around the proportions of 88% copper and 10% tin, plus a little zinc to ease casting and nickel for hardness. Thanks to its tin constituent, bronze is not susceptible to the valve seat incineration common to cast iron seats exposed to unrelieved combustion from unleaded petrol. But, to repeat myself, it is very soft, which augers ill for a 300 mile per day ride. Yes I know you've doubled that with ease. So have I. In fact I've covered a 1000 miles a day at times, but -- and this is the nub of the matter -- not on three-quarter century old bikes originally designed to run at a cruising speed of 50mph on leaded petrol.
So, firmly resolved not to find myself stranded in somewhere remote like Attawapiskat with valves chewing their way by inches into their ports, I've had the spare iron head reworked by a specialist engineering company to take unleaded petrol. Too many authentic tales of wrecked engines following loosened valve seats in lead-free converted heads determined that the engineers let loose on my head would be the very best.
Fortunately Quarry Engineering (tel 01568 780538, fax 780818) is in my own county. The name kept cropping up from sources as diverse as Bugatti and Brough owners. On visiting the place I found not as I had expected, an old boy in a shed, but two highly competent engineer / machinists working in a massive two storey works filled with a greater variety of machine tools than I have ever seen previously in private hands. They specialise in crankshaft, piston, cylinder liner, con-rod and bearing manufacturing, as well as the fabrication of just about any special part otherwise unobtainable, plus all the more familiar magical reworking of apparently irretrievably damaged and/or worn items.
From Dave Flake, Quarry's senior partner, I learned that mere insertion of new valve seats is not enough. Flake is an engineer, a professional title in Britain often misunderstood because of its adoption by such as dustmen preferring the prestige assumed though the wretchedly misguided claim of 'sanitary engineer'. Flake is also a skilled machinist as well as a highly competent mechanic, but primarily he is an engineer. This means he not only knows how to do things, he understands why; and if he does not understand why he has the intellect and knowledge to calculate what and how it should be done.
He explained that new valve seats would stop the seats corroding away, but that without lead oxide to lubricate them the cast iron valve guides would pick-up on the valves. He advised either bronze guides or the linering of the existing iron guides with bronze liners. As the latter cost much less than the former and would prove equally effective within the proposed parameters, I chose the linering.
The seats he used were the best available. I had always imagined them to be steel or nickel-iron alloy but Flake explained that he preferred sintered iron seats. Sintering is a kind of super-forging at immense pressure of metal powder into a part of such accuracy that it requires no further machining. As a point of interest, sintering was a patented BSA development sold on company collapse to Citroen among others, and you know the rest... The advantage of these seats is that they work harden in use and their expansion rate when hot is three times that of the iron they are embedded into, thus ensuring permanence.
Once bead blasted clean the head was returned at a cost of £80 inc VAT. As some better known companies are charging up to £30 per valve seat without guide bronze linering, I feel very satisfied indeed.
Rather than buy new 7:1 pistons, through good contacts I managed to buy a decompression plate from one of Britain's Trumpet gurus, but who requested not to be identified because he usually works on bikes and engines, preferring not to sell spares. True enough, by lifting the engine's top end I will be mildly encouraging the wrong rocker strike angle, but as the aim is above all else for reliability, what minuscule valve timing infraction results will cause no perceivable performance loss.
Then there were the E3134 cams. They were whipped out of their crankcase sockets and stored away for some future event. In their place went a pair of E3275 Speed Twin cams. In effect what I'll be riding across Canada will be a Speed Twin in all but the carburettor, which at 1-inch (25.4mm) is 1/16-inch (1.6mm) larger throat diameter than the tourer's instrument.
Is it truly worth it, all this argy-bargy, when either my Muzz Traveller (650 single Yam engine) or Laverda 3CL would have whistled me across Canada? Read the subtitle of this Bendswingin' again. '... It's why you do, with what you do, with what you got.' That's what counts. The technical tale of engine changes is not why at all. That's the how of it. The why is within me. It's personal.
As with anything, the satisfaction received from motorcycling is directly proportional to one's investment in it. Happiness is simply a reward. When the old Tiger was built so long ago who then would have believed that its life would stretch so many decades ahead? Let alone that it would carry the boy born in the same year of its fabrication across an entire continent on the eve of their officially registered old age. I take pride in my responsibility for its preservation.
We have been together since I became a journalist, years before half-old motorcycles were appreciated, but following persistent visits to an uncaring owner rescued it from a Dagenham gutter. Since then we have ridden together all over Britain, though good and bad weather, over good and bad roads. Not once has it failed me, apart from the time when the carburettor slide jammed immovably wide at its upper limit at an accelerating 80mph on the approach to a 60mph bend -- ah, the beast thrives even in old age. When first it was mine there was no classic bike trade, let alone restorers, so Comerfords of Thames Ditton thanks to the rough but kindly spirit of Bert Thorn did a great deal of the work.
Despite innumerable offers, some of them remarkably high thanks to the matching engine and frame numbers and the bronze head, it has remained securely in the family. It has by tenacity of ownership through occasionally hard times and a devotion far short of the current standards of impeccable spit-and-polish grown into me and I into it. We are becoming mile-worn together.
Now we are put to the test. The bike alone will neither succeed nor fail. I have done the best I can to invigorate the old Tiger. There's a lot of me invested in it. We fail or finish together and in the trying will be the satisfaction, the reward, the happiness.
That's the why of it.
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