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North Downs Engineering Co Ltd
Adrian Duncan and OTW

Part II

Performance and test, so how did they work in reality?? Let’s find out ………….

The tragedy of the Nordec (if it deserves that term!) is that it was in effect copied from a prototype which was in the process of being drastically upgraded at the very time when North Downs were first getting their engine onto the market. As a result, its performance was immediately overshadowed by the vastly improved Series 20 version of the McCoy 60 which was introduced in 1948. The same fate of course befell the competing Rowell 60 and Ten-Sixty-Six Conqueror.

As far as the British press was concerned, the Nordec got off to a very promising start. At the Northern Heights Gala at Langley Aerodrome in June 1948 John Wood with his RG10 powered speed model made a demonstration flight watched keenly by the then Queen Elizabeth and Princess Margaret. This also confirmed Wood's involvement with the development of the Nordec with 'Flight stating', " The Queen and Princess were given a demonstration of control line flying by J.B. Wood, whose company North Downs Engineering Co, are starting production of the only 10cc two stroke model power unit to be made in this country."

John and his plane were presented to Her Majesty so that he could explain speed flying and the style of model to her. According to 'Flight' 'The Queen was obviously amazed at the display and expressed pleasure in learning that the Nordec engine, with which the model was powered, is to be produced in quantity for export.' John and his 'Racer' design also went on to win the speed event at the West Essex event, setting the inaugural British Class D record at 95.3mph. A film clip of Wood’s flight can be viewed on the British Pathe site (link

John Wood is presented to HM Queen Elizabeth at the 1948 Northern Heights Gala at Langley Aerodrome

Col. Bowden made much of the engine in his previously-mentioned book on glow-plug engines, stating that the engine filled "a long-felt want in this country". He praised the quality of construction of his own example, and in this at least examination of surviving examples fully bears him out. He reported using his Nordec in a 44 inch long high-speed boat, an illustration of which appeared in the book. Finally, he noted that in 1948 the Nordec had established a British control-line speed record in its class at a 'shattering' 95.3 mph. Nothing there to make Dick McCoy, Ray Snow or Tom Dooling choke on their coffee, but there were few McCoys, Hornets or Doolings in Britain at the time for the Nordec to compete with. Just as well, perhaps …………….

Following the release of Col. Bowden’s book, the RG10 glow-plug version of the Nordec was tested by Lawrence Sparey, the test report being published in the March 1949 issue of 'Aeromodeller' magazine. This was in one respect a historic test - it was the first-ever test by Sparey of a glow-plug model engine. This illustrates the fact that interest in the glow-plug engine in diesel-minded Britain had lagged well behind that in the United States, where the glow-plug engine had been all the rage for well over a year prior to this date.

Right: John Wood starting his 'racer' with the 'Nordec Starter'

For a first test of a glow-plug engine, things went very well and Sparey was unstinting in his praise for the engine. He characterized starting as 'exceptionally easy' and running qualities as being 'free from all fussiness'. As a Nordec user myself, I would endorse both those comments. Sparey praised the engine’s response to adjustments of the needle, while commenting also on its prodigious thirst!! He referred most favourably to the quality of the engine’s construction and summarized its performance as 'excellent, if not remarkable'.

The latter statement must be read in the context of measured performances of other contemporary British models. It has to be said that performance standards for British glow-plug engines at the time generally lagged well behind those in America. The Nordec was entirely typical in this regard and hence was little if any worse than many other contemporary British glow-plug engines in terms of its specific output. The actual peak power measured by Sparey was only 0.48 BHP at 11,200 rpm using a straight 75-25 percent fuel mix of methanol and castor oil. No doubt things would have improved substantially if a proportion of nitro-methane had been added. Even so, this could scarcely be classified as a true 'racing' performance!

Regardless of the reason, there’s no question at all that the Nordec failed to approach the performance of the McCoy original. Even the 1946 version of the McCoy reportedly developed a measured power output in the order of 1.0 BHP at around 13,000 rpm (admittedly using nitro), and the Nordec certainly didn’t approach these figures.

And to make matters worse, the Series 20 McCoy 60 introduced in 1948 more or less concurrently with the original Nordec performed at a far higher level than its 1946/47 predecessor upon which the Nordec was based. In essence, the Nordec was out of date in design and performance terms as soon as it was released.

Nordec RG10 at left and McCoy Series 20 stripped for comparison

Not to be outdone, 'Aeromodeller’s' rival British magazine 'Model Aircraft' published a test of both the R10 and RG10 models which appeared in its June 1949 issue. Although the latter test was unattributed, it was almost certainly carried out by Peter Chinn. A slightly superior power figure to that obtained by Sparey was recorded, the published figures being just over 0.6 BHP at 12,000 rpm on glow-plug. But this more or less confirms the fact that the Nordec in its original form was a less than stellar performer by comparison with its competitors. That said, there’s no doubt that the original Nordec was (and is) a very nice engine to handle, especially for such a large unit.

Despite the use of a surface jet needle valve set-up, suction is actually quite reasonable, doubtless due to the relatively small venturi section used consequently, the Nordec was used in applications which stretched well beyond those normally expected from a racing motor.

Significantly smaller venturi and disc cut-out of the Nordec on right compared with the S20 McCoy on left. McCoy also uses die cast disc rotor.

Despite its rather excessive weight, it was actually used in large control line stunt models by a few deaf modellers with deep enough pockets to afford the fuel bills, and its running characteristics were surprisingly well suited to this application, particularly if a spraybar was fitted in place of the surface jet system.

But the Nordec had of course been intended all along for racing applications, and its natural métier was the control line speed model, although it was also tried out in the then-popular sports of tethered hydroplane and model car racing as well. North Downs offered a well-made flywheel and clutch set-up for use with the engine in a racing car application, and an aluminium spur drive mount from August 48, either as a finished unit or as castings. However, it seems that the Nordec was at best an indifferent performer in both of these applications and was largely ignored by the hydro and tether car competitors of the day. It certainly never achieved any real success in either of these fields.

Despite this, the Nordec continued to attract some interest from among the aeromodelling community, receiving some attention from the tuning experts who were an evolving breed at the time. Indeed, a Nordec was one of the first engines that the legendary tuner Fred Carter had a go at re-working, in order to get more out of the motor than its original configuration allowed. The results of his efforts were quite tangible. At a time when the stock engine was good for perhaps 100 mph under ideal conditions, Carter’s Nordec-powered 'Little Rocket' consistently turned in speeds of around 116 mph, a fine performance by then-current British standards. This success marked the beginning of Carter’s long run of pre-eminence as a racing engine tuner in Britain. Happily, the 'Carter Nordec' motor is still in existence, although not in the original 'Little Rocket'.

However, Carter’s performances paled beside those of the renowned Czech expert (and founding director of the MVVS organization) Zdeněk Husička. Having somehow, from behind the Iron Curtain, obtained an example of the Nordec 60, Husička achieved a speed of 129.56 mph at a contest in Brno in September 1952 using this engine. As far as I’m able to determine from the records currently at my disposal, this was the fastest speed ever officially recorded by a Nordec in competition. The engine was most likely one of the very rare Nordec Special Series II models to be described below - surely no-one ever got the original Nordec to go that fast!?!

Further development of the Nordec

With Wood being so actively involved in speed flying, he would have been well aware of  current design trends and development as well as the inadequacies of the original combustion chamber design. In late 1949 a revised head design was produced to address this issue. The new head was a casting instead of the machined unit formerly used, and this allowed the provision of a combustion chamber contour which more correctly matched that of the piston crown, thus eliminating the problem of 'gas pockets', promoting improved swirl and hence improving combustion efficiency.

New Nordec head Compared with McCoy on left Much larger ports in McCoy on right

The company released an updated version of the engine designated the 'Nordec Special' in December of 1949, still in both glow and spark ignition forms. This was more or less identical to the earlier models with the exception of the revised cylinder head. However, the somewhat restrictive porting and induction system remained unaltered, and in consequence the performance of this version still lagged far behind that of the now all-conquering Series 20 McCoy Red Head 60 and Dooling 61 designs. As a result, the original Nordec Special can hardly be termed a success in performance terms. The marketplace evidently agreed with this assessment, and sales were not brisk.

Right: RG10 MkI Special Series I. Often wrongly described as a MkII

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