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The ED Story — Model Engines

by Ron Reeves (in collaboration with Ron Chernich)


Model Range

Probably because of their somewhat convoluted evolution, identification of engines within the ED range is more than a little confusing. The earlier engines were designated using a mark number (Mk) and, in most cases, a model name. Later engines simply had a name. For example the "Bee" was originally designated as the Mk I, the 2cc "Penny Slot" side-port was the Mk II, the 2.49cc front rotary valve was the Mk III, and the 3.46cc rear rotary valve "Hunter" was the Mk IV. While this all has an air of practicality, the mark number does not correspond to the chronological release order. To compound the confusion, some of the engines carry Mk numbers to indicate the variants, while most have individual design revisions designated by a series number.

Mk II and CS

Mk I "Bee" series 1

Mk IV "Hunter"




Miles Special


Super Fury

Super Fury Marine

Mk I "Bee" series 2




Racer Mk6

Mk V "Hunter"

Mk V "Hunter" R/C

"Hunter" Marine

Mk V Hunter marine

Mk V "Otter" Marine

Click on the images for individual engine profiles


Serial Numbers

From 1947 up to the end of 1959, ED used a simple code to identify the type, batch number, sequence number within the batch, and the year of manufacture. The location varies with the engine type although the edge of a mounting lug became the common position on later engines. In general, the serial numbers take to form:

    <type code><batch-month>  <sequence number>[/]<year>

The scheme allows the month and year of manufacture to be established reasonably well. However, to preserve confusion in an imperfect world, some engines place the batch-month code before the type code. In some cases, the slash between sequence number and year may be absent, but once you know what to look for, making adjustments for the occasional deviation is not hard.

The month is identified by a letter starting with A for January. The letter I was left out, most likely to prevent confusion with the number 1, so August is J. The sequence progresses up to M for December, finishing with an "N" group that we suspect was an extra batch scheduled to cater for the Christmas demand.

The sequence number is effectively a count of the type produced during the batch/month. So it is possible to have multiple occurrences of the same sequence number in the same batch for different engine types. Given a large enough sample of serial numbers, this value provides a measure of production figures for the engines and four digit numbers are not uncommon for the popular types.

Finally, the year is sort of like the good old "Y2K bug", only worse: even the decade digit is generally missing! It seems crazy that whoever devised this scheme did not expect the company to last ten years, but there you are: (mostly) a single digit only to denote the year. Some engines will have a "5" digit added so that, for example, a 1947 Comp Special could be distinguished from a 1957 one. In other cases, you need to intuit that the year must be 1957 because that type of engine did not excist in 1947! This only applies to the 50's though, no instances of an added "4" have ever been reported.

The codes allocated to the types were:

Bee (aka Mk I) series 11
Bee early series 2Q
Bee series 2, 3 transfer portsX
Bee series 2, 4 transfer portsV
Mk IINo code
Competition SpecialNo code, "/C" suffix after year
Mk IV (Hunter)4
Super FurySK

To take an example, ZC 208 6 is a Hornet (Z), made in March (C), of 1956 (6) that was the 208th engine completed in that batch. In this case, there is no slash between the sequence number and the year. This is not uncommon, especially in the later engines, but generally there is a wider space between sequence number and year allowing you to guess whether there are one or two digits for the year. A certain wry sense of humour is also evident in allocating Z to the Hornet. Think about it. What sound does the insect hornet make?

The serial numbering was not always consistent. Taking the Mk III for example, the type-code "3" has been observed both before and after the batch-month code letter. Marine versions generally have the letter "M" prefixed to the type code.

After 1959, ED changed to a letter to indicate the year, so A = 1960, B = 1961 and so on. After 1963 (the year of The Fire), it all went to pot until about 1966 when a new system came in.

Release History

In summary, the model designation, the major initial introduction dates and, where possible, the designer or consultant designer are as follows:

1946 Mk II 'Penny slot' 2ccrear sideport induction (likely an early Basil Miles design).
1948 Mk I Bee 1ccseries 1 - rear rotary induction (again probably a Basil Miles design)
1948 Competition Special 2ccrear sideport induction (Basil Miles)
1948 Mk lll, 2.49ccfront rotary induction (Basil Miles)
1949 Mk IV Hunter 3.46ccseries 1 - rear rotary induction (Basil Miles)
1950 Mk IV Hunter 3.46ccseries 2
1950 Racer 2.46cc series 1rear rotary induction (Basil Miles)
1951 Racer 2.46cc series 2webs added between bearings
1952 Baby 0.46cc series 1front rotary induction (designer currently unknown)
1952 Baby 0.46cc series 2front rotary induction (designer currently unknown)
1952 Hornet 1.46ccrear rotary induction (a derivative of the 'Bee')
1953 Miles Special 5.0cc.manufactured by Basil Miles at home and distributed by ED
1953 Racer 2.46cc series 3solid metal between bearings
1953 Mk4 Hunter 3.46cc series 3 
1954 Mk4 Hunter 3.46cc series 4 (shortened shaft design by Basil Miles)
1955 Racer 2.46cc series 4 
1955 Bee 1cc series 2 'Q'Completely revised
1956 Bee 1cc series 2 'X'revised case, 3 transfers
1958 Fury 1.46cc series 1reed valve induction (possibly a Basil Miles inspired design)
1959 Mk4 Hunter 3.46cc series 5RR (R/C introduction)
1960 Mk4 Hunter 3.46cc series 6RR (improved R/C variant)
1960 Super Fury 1.46cc series 2rear rotary induction (Gordon Cornell)
1960 Otter marine drum valve with throttle and silencer (Gordon Cornell)
1960 Pep 0.8ccfront rotary induction
1961 Bee 1cc series 2 'V'4 transfers
1962 Hawk 1.5ccfront rotary induction (Webra)
1962 Cadet 1ccrear side induction, and designed to carry a silencer (George Fletcher)
1963 Racer 2.46cc series 5 
1969 Racer 2.46cc series 6 
1970 Super Fury 1.49cc series 3rear rotary with RC carburettor available
1972 Condor 10ccfront rotary with silencer and R/C carburetor by George Fletcher.

Note - there were marine versions of many of the engines and by arrangement, some of the Taplin Twins were manufactured by ED.

While the previous list includes the majority of the popular engines for which ED were more readily recognized and which mostly carried the ED title, other manufacturers products were available under licence from ED or were distributed by ED as part of its product range. It would also appear that ED owed much of its success to the design prowess and determination of Basil Miles, who was one of the original founders.


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