Lewis-Precision motors - a first attempt

This is my first attempt at telling the Lewis-Precision story. With more information to hand, I've been able to answer some of the questions posed and write a clearer account. I'll leave this page as an example of how history written on the internet can evolve.


The engineering works of F.E. Baker Ltd. were established at Moorsom St., Newtown, Birmingham, in 1910 and at once began manufacturing a range of engines for use in motorcycles. By 1914, the success of the proprietary "Precision" engine had prompted a move to new premises: the Precision Works, Kings Norton, Birmingham. We can let them introduce themselves by quoting from their undated (but c1914) catalogue:

The "Precision" Engine has been adopted as the standard equipment by many of the largest and best reputed manufacturers of motor cycles both in England and the Colonies.

The Manufacturers of the engines do not themselves manufacture or in any way deal with complete bicycles, nor do they sell "Precision" Engines to members of the public, their products being supplied to manufacturers of the finished article only, and to dealers in cycles and motorcycles.

So F.E. Baker were wholesalers, and indisputably they were a major force in the Australian motorcycle industry before the first war. A.G. Healing in Melbourne were very large users of the Precision engine, and contemporary photographs show Precisions engines lined up on benches in considerable numbers: I count 29 of what look to be 3 1/2 h.p. units in one photo in A to Z of Australian-made Motorcycles. In the same book, Rob Saward reports that Healings were the sole agents for Precision engines sold in Australia.

From where, then, did Lewis source their 1911-on motors? Before we tackle that question, let's look at the similarities and differences between contemporary Precision and Lewis engines. Here we see the 1914 air-cooled offerings from Lewis (on the left) and Precision (on the right):

1914 Lewis air cooled motor cycle engine 1914 Prrecision air cooled motor cycle engine

If we start with the bottom end, we find that the motors are essentially identical except that the Precision timing cover is labelled "FEB" between the tappet bosses (absent on the Lewis version) and "PRECISION" across the bottom where the Lewis motor has "LEWIS" cast in. (Prior to the advent of the Precision engine, the LEWIS label was riveted on to the crank case of Lewis motors with aluminium rivets.)

The motors also differ in the magneto chain case, with "The Lewis" replacing "The Precision" on the Lewis version - but customisation of this sort was a common thing for Precision. Many Australian and British manufacturers - for example Bullock in Adelaide - had their brand names cast into the magneto chain case of their Precision engines.

Things get interesting when we look at the cylinder barrels. Looking across the range of British and Australian machines that used Precision motors in the 1911 - 1916 period, it's clear that most 3 1/2 h.p. (499 cc) Precision motors were supplied with a "square" fin pattern. The air-cooled Lewis motors have quite different cylinders: not only are the cylinder fins essentially "round" in plan, but also the bare, downward-angled exhaust port is quite different from the standard Precision offering.

Much of the above discussion also applies to the water-cooled motor of the day, although here the situation is complicated by the long history of water cooled engines at Vivian Lewis Limited. To be honest, the water-cooled cylinder offered by Precision in their 1914 catalogue bears little resemblance to the Lewis item:

1914 Lewis water cooled motor cycle engine 1914 Precision water cooled motor cycle engine

By contrast, the cylinder on the early-pattern water-cooled Lewis-Precision motor shows a close family resemblance to the earlier Lewis offerings, and from 1911 through to the final Precision engines of 1915-16 the changes in cylinder design were by evolution, rather than revolution.

Confused? So am I...

As I pondered the Lewis/Precision question, I could think of only one example of a Lewis machine was fitted with a square barrel. In the photo below of noted competition rider Edgar Ferguson, his c1914 machine sports what is obviously a square-finned motor:

Edgar Fergusson on his 1914 Precision motorcycle

At least the machine looks like a Lewis, and given that Edgar Ferguson is seen elsewhere in Lewis photographs it would make sense for his machine to be a Lewis. However consulting the registration records, we find that it is registered as a 3 1/2 h.p. "Precision"!

Another piece of information is a surviving machine, c1911, that has all the Lewis hallmarks but is fitted with a square-fin Precision motor with "The Precision" in script on the magneto chain case, and has "The Precision" sign-written on the tank. I'm chasing more information about this bike - does it have a Lewis frame number?

OK, back to the question: From where did Lewis source their 1911-on motors?

I suspect the answer is that they came directly from F.E. Baker, complete, by-passing the Australian agent. Certainly reports in the contemporary press describe the motors as being "British" and "imported", and the Precision parentage is undoubted. In support are a couple of other pieces of evidence: the engine numbers of Lewis engines fall into the general Precision sequence, and even though the timing chest is customised for Lewis, one engine at least proudly proclaims its UK origins:

Lewis, Made in England

The only doubts that remain are about the cylinders, both air and water cooled. Why did they differ from the catalogued Precision items? Why does the design of the water-cooled cylinder owe so much to earlier Lewis engines, and look so unlike the "standard" Precision item?

From this confused perspective, I can offer a couple of theories:

  1. F.E. Baker had a range of engines that they offered directly to selected large-scale customers, bypassing the local agents. To avoid conflicts with agents who had "exclusive" rights to the Precision engine in a particular territory, these engines used different cylinders, and did not carry the "Precision" brand. In the Australian case, A.G. Healing had exclusive rights to distribute "Precision" engines, but Bakers sold "Lewis" engines directly to Lewis. (To speculate further: if Lewis ran out of "Lewis" engines, did they built machines with "Precision" motors, and sell them branded "Precision"?)

  2. It is just possible (though I rate it unlikely) that Lewis bought only the bottom end of the motors from Baker, and manufactured their own cylinders. This would explain the family resemblance of the water-cooled cylinders to those on earlier Lewis motors, and would have some commercial advantage for Lewis: they could have a stockpile of Precision bottom ends, onto which they could selectively fit water- or air-cooled barrels as required by demand. One the other hand, what a lot of messing around!

While I'm speculating, let me throw in a wild one. As part of their commercial arrangement with F.E. Baker, could Lewis have supplied designs and patterns for their water-cooled cylinder? Lewis were, after all, a large customer, consuming perhaps 1000 Precision engines in the years 1911-1916.

A final thought: I have not seen the 3 h.p. (75 x 86 mm giving 380 cc) Precision motor on offer elsewhere. Was it exclusive to Lewis?

More questions than answers, I'm afraid. Any additional information would be most welcome. Watch this space.

(As metioned at the top of the page, there are now some answers and a new Lewis Precision page.)

Lewis air-cooled motors | Lewis motorcycle index | Lewis water-cooled motors

Copyright Leon Mitchell 2007

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