A mechanical marvel
Eagle-eyed observers visiting the Honda museum in Motegi, Japan, will notice soon after paying their yen there is a racing motorcycle devoid of the familiar winged Honda vector. The emblem is distinctly Italian and proudly informs that you are ogling over an ‘FB MÒNDIAL’: made 1957, Milan, by the Counts Boselli (‘FB’ being Fratelli Boselli or Boselli Brothers) and their firm Mondial.
The machine in question is a gear driven double overhead cam (DOHC) 125cc single cylinder Grand Prix motorcycle, bought by one Soichiro Honda, direct from Count Boselli shortly after it won the 1957 world title. 1957 was the year the Italians (with the exception of MV Agusta) all pulled out of Grand Prix racing due to cost. Prior to this they had been leading exponents of high revs, high performance and high reliability – characteristics clearly endearing to Mr Honda and his fledgling motor company. In 1958 Soichiro Honda visited the Isle of Man TT for the first time, then returned in 1959 with five riders and his first bikes: 125cc gear driven DOHC twins. They won the team prize, with a best result of sixth, came back in 1960 for a best result of fourth, then scored a double victory in 1961 before proceeding to rewrite the history books as to which manufacturer should win the most motorcycle races (and seeing off the antiquated British bike industry in the process….). But back in 1953, way before 1957 and Mr Honda stripping his DOHC Mondial into its constituent components, a talented 32-yearold Velocette-enthused South Australian had long been aware that a series of gears driving two camshafts was the way to go – and he had just finished his first example of such. His name was Les Diener, and he gave his initials, LD, to his creation: the Eldee. Les Diener became hooked on bikes at the age of 13 when he and lifelong friend Keith Hamilton would pool their pocket money to ride (and fall off) an old single-geared, belt drive Levis two-stroke. A year later Les came by an old V-twin, side valve JAP engine which was the basis for his first bitsa and offered ample opportunity for the honing and development of his clear engineering talent. The next step forward was a 350cc OHV New Imperial Jap, then a trade-in for a 1936 Douglas, followed by the acquisition of a quite special overhead camshaft (OHC) 500cc CS1 Walter Moore Norton at the age of 17. When a 350cc OHC KCR Velocette, brought out from England by Rex Tilbrook, came up for grabs, the Walter Moore had to make way and a lifelong passion for the marque was born. Les began racing with the Atujara MCC in 1938, predominantly in scrambles and beach racing and showed a certain speed and deftness from the off. The KCR Velocette was sold in 1939 and replaced by a 1934 model 250cc MOV Velocette which became his main interest for the next 15 or so years as a racer and as a tuner. Despite many wins and South Australian championships, Les realised he could extract no more power from the MOV’S pushrod configuration and so gave some serious thought at the end of the 1952 racing season to convert his beloved MOV into a double overhead camshaft racer: thus Eldee 1 was born in 1953. Inspired no doubt by the Italians, fellow Australian Sid Willis grafted a DOHC factory Velocette head onto his 250cc Velocette racer and proved very difficult to beat in the late 1940s and early 50s, taking his bike to a fine fifth in the 1953 250cc Lightweight IOM TT. Following in these footsteps, Les and fellow competitor at the time Ted Carey both got busy on their own conversions, in Les’ words, “working and racing together on separate projects,” (incidentally Ted provided the piston and head for Eldee). Eldee 1 matured into ‘the bike to beat’ and was a testament to Les’ ingenuity and engineering capacity, clocking up a multitude of wins and placings and famously seeing off the works 250cc Moto Guzzi of Fergus Anderson when he came out for a visit. The engine retains the standard MOV bore and stroke of 68mm x 68.5mm and the double overhead cams (camshafts made from 60 ton steel, cams from oil hardened 12% chrome steel) are driven by a series of nine Velocette timing gears, with the inner timing case being welded to the crankcase. Oil reached the cam faces via a .030 inch jet and drained through the distinctive ‘Y’ pipe to the sump. Valve timing variation of three degrees is catered for by vernier adjustments on the final gear wheels (more on this later….), a two-piece crankpin dissects a Symco rod and is hugged by Les’ turned mild steel flywheels. Exhaust valve was sodium filled and the inlet chrome-moly, both running in bronze guides and brought back to seat by 140 pound springs. Valve to piston clearance was minimal at just six thou’, and tappets were set at eight thou’ inlet and fifteen thou’ exhaust with Les practising and racing without checking matters as he was confident that “with the double-knocker engine, they were guaranteed to stay put.” The piston (made by Ted Carey) is a slipper type running a “moderate hemisphere up top and a compression ratio of about 10 or 11:1,” (on methanol). Les had problems initially with the alloy cylinder he made to couple with a cast iron liner. He found he was losing compression under load as the motor got hot. He worked out that the iron liner had no flange to sit on top of the alloy cylinder and due to the cylinder head joint being partly on aluminium and partly on iron, as the variable expansions occurred, compression pressure was being lost down between the two metals until the engine cooled again. He related this back to Veloce Ltd in the UK who promptly sent him a patented Alfin barrel with a bonded-in liner – end of problem. The chassis was in Les’ words: “the best
of two worlds” being a home-made frame with a front end dimensionally similar to Mccandless’ Featherbed and the rear end similar to that of the 7R AJS. With a single top tube favoured instead of the Featherbed’s twin rails, Les hand beat a 4-gallon tank into what I consider a lovely, svelte and tapered shape allowing the jockey to get himself ‘tucked right away’. Forks were from a BSA C10 but shortened by four inches to keep the whole head assembly low and then fitted with Les’ own design of damping rods. The gearbox was four-speed with original Velocette ratios as standard, though Les had alternates that could be changed depending on the circuit. At Mildura, in 1956, Eldee 1 was resplendent in a full dustbin fairing. Although Moto Guzzi knew not at the time, Bill Lomas was ‘persuaded’ to loan the works Guzzi to Melbourne boys Bob Edmunds and Charlie Rice who plastered around the wind tunnel tested fabrication before making a glass fibre copy from the ensuing plug. In this guise, Les clocked a very admirable 116mph (186.6kph) at 9,000rpm down the mile-and-a-half long straight. He also records how “streamlining was all very new to me,” and how “when I put on the biggest front sprocket I could find (a 21T up from his usual 19T, overall gear ratio of 5.1:1), I didn’t realise at all how fast I was going,” until he left his braking far too late at the end of the straight and “up the escape road I went!” A clean break from racing was taken after a major crash in 1957 at Port Wakefield when a gearbox seized while lying second in the 500cc race on a 350cc Manx Norton. Disillusioned, Les loaned the Eldee to Ken Rumble who raced with some success until 1961 before it was sold to fulfil other ventures. It only took 26 years for the racing bug to
SECOND TIME AROUND
bore back into Les’ psyche and he picked up where he left off with the Atujara MCC in 1983 on an ex-tom Medlow 1939 Velocette MOV rigid racer, winning most races he entered in the postwar class. However, it was 1987 and an invite to be guest rider aboard a newly restored Eldee 1 at the New Zealand Classic Racing Register’s festival meeting that links most to this story and the subsequent construction of a replica: Eldee 2. Les admits to having “oft thought of building a replica of his beloved Eldee racer,” and it seems the stars aligned to foster requisite motivation as was required for such a project at Pukekohe, Auckland, 1987. Velocette enthusiast Peter Butterworth had acquired a Ted Carey head (as used on Eldee 1) from Australian Dennis Quinlan. Having no immediate use for it, Peter passed it on to David Rogers, who showed it to Les at the festival who immediately recognised it as being identical to the head in use on Eldee 1. Les, still perhaps a tad unsure about committing to the project, didn’t acquire the head there and then, leading David to ring Peter that night to enquire whether the proposed new destiny was a good direction. The next morning, when Les left his digs, there was the head, on the doorstep ready for hand luggage back to South Australia, and so the Eldee 2 project was born. Twenty-four years later, that head arrived back to New Zealand but this time full of life as a component part of Les’ fantastic replica of his original machine. I am proud to say that I am intimately familiar with Eldee 2 having being trusted as jockey on such a remarkable racing motorcycle by owner Phil Price. With Nick Thomson on the spanners and in the workshop, I feel we’ve done a good job of holding true to Les’ objective of getting to that chequered flag first. But more of that later… Original patterns for the cam box and timing cover castings were in the hands of Adelaide enthusiast Peter Westerman who proffered them for use for the replica, or Eldee 2, at the start of 1987. The timing side crankcase is standard MOV with obvious modifications to accept the train of gears, which were originally modified BSA items but now completely remade and hot from the Thomson workshop, all running on needle rollers. The drive side crankcase is a cast item recreated by Adelaide foundry Castech in CP601 aluminium alloy. Perhaps not as elegant as certain Italian items, though the webbed ribs on the outside do offer strength to accompany the heat treatment. Security of camshaft to gear is via a pin vernier, an item we have had fail, resulting in a bent exhaust valve (ultimately to be turned into my wedding ring…) and sheared the key locating the gear on to the camshaft . Nick has re-engineered the camshaft to accommodate an oversize key in addition to an increased diameter pin into the
final gear and initial runs show good. Valves are Superalloy now, replacing the Eso Speedway components Les fitted, the exhaust being 17⁄ 16” and the inlet 1½”. Les’ notebook detailing the early tests of Eldee 2 show a plague of oil from the coil valve springs (on the advice of Bill Lomas, valve spring seat pressure was set at 90lbs resulting in 160lbs pressure at full lift, showing horsepower increase and no loss of valve control) a problem which we suffered from too. Nick has been successful in curing this problem by making eccentrically turned caps to accommodate and enclose the valve gear, springs and exposed pushers, in addition to fitting an oil feed to drain pressure from the now capped area. The con rod is a hefty titanium number that wouldn’t look out of place in a 350; it is ‘I’ beamed and trimmed substantially and connects on the southern end to a big end needle roller pressed between high tensile steel flywheels balanced to a factor of 80%. We feel gains could be made upping the balance factor, finding a significant ‘roughening’ and increase of vibration at around 8,200rpm. The engine will rev to 9,000, but is discernibly smoother below 8,200 and seems to labour more obviously after this point. The little end connects to a piston recovered from some Les ‘made back in 1956’ and when he set up the engine for initial testing it was on petrol with a compression ratio of 8:1. It is now on methanol with a compression ratio in the region of 10:1. With a large dome and fairly long skirt, the piston shows extensive working inside to remove excess material, clearly the work of a dedicated tuner. The piston resonates in the same ‘square’ bore dimensions as Eldee 1, 68 x 68.25mm, the barrel being the favoured Alfin type, modified in this instance from a later 350cc MAC Velocette component. Hubs and brakes were cast to 1938 MK.VIII KTT Velocette specification after Les had a chance encounter with a retired pattern maker who offered to assist with the project ‘for a challenge’; the resulting aluminium items are laced to 18in Akront alloy rims shod in sticky Avon rubber. The twin leading shoe front brake is lined with high grade centrifugally cast iron and works very well indeed, the linings being green in colour and probably not worth inhaling near. The entire rear hub is made from the same material and it too works very effectively: soft and progressive and none too harsh. Such castings would perhaps have been better in magnesium as they are bulky affairs with great wall thickness and the choice of aluminium weighs heavy for a 250cc: the overall weight of the bike is around 270lbs (122kg). The chassis is sprung sufficiently on the rear by heavy Koni items and up front are Norton forks, with beautifully crafted
lightweight alloy yolks and taper roller bearing head races. The original fork springs have been discarded in favour of heavier weights, as Les must have been somewhat lighter than me and we have also added adjustable dampers supplied by Lansdowne Engineering in the UK, giving us effective control of both compression and rebound damping. The front end has always felt vague to me, with a tendency to patter exiting corners, despite many efforts to cure this. We made a fork brace which helped, but I think the weight of the lumpy front hub plus a not quite sorted spring rate is accentuating a bounce, but we’ll get there. The frame is a modified Norton International model, sporting Les’ own rear section, nickel-bronze welded to the front cradle and resulting in a lowered seating position, a factor that may also contribute to the unsettled front end with my heftier bulk aboard. At the back it sports a standard cased Velocette gearbox, hiding six speeds to keep the little gem on the bugle. A low level exhaust pipe stays clear of the track and protests by cracking when secured at the original three mounting points, so we leave mounted at the head and before the megaphone taper and it seems happy enough. Sparks are provided by a Les Diener wound magneto that now accepts an electronic triggering device from a Mitsubishi car and such sparks set fire to a mix brought in through a faithful Amal 15⁄ 32” carburettor, with a number five slide and jets to suit circuits. Needle is a Dave Kenah component with additional adjustment slots for height positioning. The fairing is a double bubble Morini item shrouding an aesthetically pleasing package, contributed to by the light blue 12-litre tank made by UK company Lyta, held down along the middle by Les’
Right: A front wheel landing for Bill and the Eldee at Ballaugh.
Above: Les Diener gets hands-on back in the day.
Below – Bill plying his trade Down Under on the KTT.
Above: Father and son Velo racing duo, Chris and Bill Swallow with the naked Eldee.
Bill Swallow tips into the Creg with one of the most iconic TT course backdrops behind him.
TT course veteran Bill Swallow presses on aboard the Eldee Velocette.