An Abridged Genuine Fish Carburettor General and Legal History.  By Bob Henderson

Therefore straight from the Minnow FISH’s mouth….

As the only ever legitimate and authorised Fish carburettor “Concessionaire”outside North America I decided to write this as a result of so much recently ill informed and inaccurate information being bandied about generally and on the Internet plus the recent attempted resurrection of an imitation and fake Fish carburettor. For instance I, at no time either granted, sold or authorised any of my exclusive Fish carburettor “rights” to Leonard Reece or anyone else. His version was never anything but an inefficient and illegal fraudulent fake copy., In addition to this fact and coupled with the strong personal and grateful moral obligation that I have always felt about such a great man and his “crowning” invention. To such an extent that I have often been accused of being a Fish carburettor “missionary”, probably because it has always been more of a crusade, to me, than merely a business.  World Champion Graham Hill often greeted me as, “The Fishmonger”. For over sixty years the Fish carburettor has been and still is the centre of my life and business but I still await the “T” shirt!

Here exposed is also some of the false technical advice / information that I will deal with after this history bit. ALONG WITH EXPLODING SOME OF THE “MYTHS” AS WELL. Plus our standard (unchanged in fifty seven  years!) Fitting, Tuning and Snag Sheet information for downloading.


The original inventor of the product was, of course, John Robert Fish and it dates back to the 1930s. His sole aim originally was to find a way of curing carburettor fuel float chamber wastage due to “slop” , or surge of the then inaccurately metered fuel. This, particularly, while a vehicle was cornering, or to a lesser extent when braking or accelerating very hard.. This wastes petrol and is constantly overriding any inherent relative accuracy of the  normal jetted  fuel metering control, in the case of the conventional manometer (“U” tube) principled versions .

During the Second World War “Bob” Fish worked for Bosch North America and invented, amongst other things, a very special and efficient gun barrel reamer. Bob was an inventor at large, not essentially or originally a car man at all. For instance, it is believed that his earlier inventions to help his wife’s leg circulation was what led to the invention of the life saving so called, Iron Lung.  As a brilliant all-round inventor he obviously already well understood things like pressure differentials  and thermal efficiency and on  which his carburettor also became based and those points that I will deal with in due course. when more in context. His many “inventive” ideas led him, on one occasion, to send comprehensive and very detailed long cables to the U.S. President, with very specific details as to how best to rescue some unfortunates that were trapped in a submarine on the sea bed at the time..

Post war he attempted to re- establish his fledgling carburettor business, having frequently proved that one of his relatively small single choke / bore “M” model carburettors would out perform even the large Four Barrel carburettors of the industrial giants and monopolists like  Rochester and Carter, as fitted to the mass produced G.M. Chrysler and Ford vehicles . The Fish unit still being substantially more economical as well! His only mistake was to, perhaps naively, take on these “original equipment” leaders head on. That effort was doomed to failure from the start because apart from being a small “upstart”, the Fish carburettor only had three moving parts as against the dozens involved in the complex and  unnecessarily expensive conventional carburettors. This would have enabled the costs to be drastically reduced  and more importantly, the large profits of these industrial giants. Plus of course the significant drop overall in national   petrol / gasoline consumption and again loss of excessive profits to the oil giants. And that, of course then, would never be tolerated or allowed to happen!

Big business names ganged up on Bob Fish. He found, apart from being subjected to publicity lies, deliveries of materials not arriving and some companies having  been “got at” and even refusing to supply materials at all!  He fought on regardless for a while until the “powers that be” then faked up a criminal charge against him for supposedly “Fraudulent use of the Mails”, This led to the  blocking of his postal communications, which, in turn, cut him off financially from his customers, existing and future. The pretext being, for this commercially and criminally motivated “dirty trick”,  was that as some of his customers had happily and knowingly paid for their promised carburettor well in advance but  had not as yet received them. As far as I know not one single genuine customer had ever complained about the situation, but the vested interested “authorities” used it as a false excuse and reason to start the legal action with an “Injunction” and once started, they then delayed and delayed it from actually going to court, thus depriving Bob of the ability to establish his honesty and  innocence of the  completely baseless charge . And in truth  the case never came to court at all, which speaks for itself and  to Bob’s innocence confirming that it was always nothing more than a deliberate delaying tactic to financially ruin him and prevent the new “revolutionary”carburettor invention’s promising future. Clearly the dirty tricks department was at work. An historic version of the modern C.I.A’s commercial department perhaps?

The Massachusetts Fish carburettor factory, after its mail had been cut off, had then, out of survival necessity, to be moved out of that state’s legal jurisdiction to Daytona Beach, Florida, where Bob Fish could all but start again, helped initially by good sales to the big game-fishing boats. Local motor racing then entered the picture in the form of a young Stock Car driver by the name of “Fireball” Roberts., who with his out of date car fitted with the famous M1 Fish carburettor proceeded to repeatedly beat all the latest factory entered cars on the Daytona Beach track. This was in the days when the now famous Daytona 500 race was partly run on the beach as well as the road.

Long before the now full “manufactured” track was instigated and developed by the legendary  Bill France. Even here the big factory companies conspired to stop all the splendid publicity being generated by Fireball Roberts in his Fish carburettor powered  car. They certainly did not like to see their latest factory backed vehicles being clearly and continuously beaten by some local lad in an “old banger”fitted with a relatively small Fish carburettor that was outperforming even the larger engined and latest multi four barrel conventional carburetors.

So the dirty tricks started again. Fireball would almost always gain the “Pole” position trophy in qualifying only then too often suffer from tyre failure and other“mysteries”during the race when leading the “big boys” by an embarrassing  amount. This too often denying him the final victory. Among these  blatant problems was that he was being deliberately supplied with defective tyres. You cannot cut a tyre open before a race to check its faulty construction, can you? On other occasions they would strip his engine down to desperately try and find something to protest about rather than accept that the result was almost entirely due his driving and superior Fish carburation. Other times he was sabotaged by fuel contamination and so it went on..

On one occasion they eliminated his victory by claiming that his engine had slightly shortened push-rods. This was quite true because the rules allowed for cylinder heads to be machined to correct them and balance any changes in compression ratio, which in turn very slightly changes the operating angle of the valve train rockers. This was corrected  by their legendary racing mechanic Jerome “Red” Voigt…..and all the other competitors by simply grinding about a 1/16” of the push-rods, so correcting the geometry. Fireball was disqualified for an “unlisted” modification despite the fact  that all the other cars did exactly the same very minor and generally accepted “blueprint” correction. That was the sort of opposition and conspiratorial pressure that Bob Fish had to contend with from the vested interests repeatedly in their almost frantic efforts to “kill” the Fish carburettor.


During all this commercial turmoil his greatest friend and leading financial benefactor was Eric Liebman, who ran Fish Canadian Carburetors.   Gratefully and in return, Bob Fish granted him sole “Rights” to his carburetor for the northern States, Canada and the Rest of the World. And to quote from Eric’s later letter to me along with my own “rights”, documents  and contract. ….   “Partly out of friendship, but mostly for all the money I had sunk into the project in the early days when no one wanted to know him”. That was the situation when I first met Eric in Ottawa during 1956 and became one of his local Canadian   area dealers and going on to built up a wide and varied experience with the product.


On an unplanned visit back to the U.K. in 1959 I brought some Fish carburettor                 “samples”  for my enthusiastic motoring friends for them to try, test and who after the initial scepticism were flabbergasted (there is no other word for it).  I phoned Eric to tell him he had a potential Fish carburettor market available on this side of the Atlantic. To which he “told” me to stay in the U.K. and do the job myself, “since you are the only one on that side of the pond that knows or understands how the carburettor even works.. AND if you do, I will grant you full World Rights out side North America to sell, develop and manufacture  your own uprated version to suit the smaller European engines”.. That legal confirmation letter and contract was dated in 1960 and superseded  our previous contract from 1956. Eric continued; “When as you know  President, Eric Lubke (after Bob Fish’s death) of the Fish Carburetor Corporation, Daytona Beach, gave me written authority to have you produce your much improved versions for sale on this side of the water as well” and included the phrase; “These Rights are now yours as of this date”.

We did indeed sell our smaller more accurately metered (for the smaller engined imports) Minnow Fish carburettors back to Canada and North America and to quote from their then latest sales leaflets at the time; “The unbeatable Minnow Fish Carb.  It was always hard to beat a Fish carburettor equipped car, foreign or domestic. Now it is impossible even with conversions 2-3 times the price of a Minnow Carb. You cannot beat it price-wise, performance-wise or economy-wise.”  I think that alone confirms the legal and moral correctness of the fact that Minnow Fish Carburettors are the only genuine “inheritors” and legal British and European  users of the Fish name. The majority of the (our) North American “imports” concerned were for the VW Beetle, Renault Dauphine, B.M.C. Sprites, Minis, M.G.s and the odd XK engined Jaguar

My then urgent quest was to set up a U.K. / European manufacturing company and sales organisation. I investigated some possible local sub-contractors and which in the process included Wrythe Foundry in Carshalton, Surrey, who were making up the patterns and to provide us with aluminium and bronze castings for the project. They happened to mention what was going on to a local engineering and camshaft grinding business called Leonard .Reece & C o., of Carshalton Beeches,.Leonard himself then rushed down to visit us at Soho Mills, Hackbridge and literally begged (and I do not mean this unkindly) to be given the chance to carry out most of the machine shop work for us on the castings and brass parts that we would supply to him from the foundry. He went as far as to confide in me that he had missed out or failed to hold down previous contracts and he wanted this belated “final chance” to set up a proper production system instead of just undertaking odd “jobbing” work. His only regular work at that time was the grinding of camshafts for the new company called Cosworth Engineering run by Keith Duckworth and  Mike Costin who had both recently left the infamous Colin Chapman of Lotus Cars.  Leonard was grinding the A2 profile onto the recently introduced  Ford, very over square, 105E engine’s camshafts.  These for use in the then new International Formula Junior Championships.


Unfortunately my initial faith in Leonard Reece as being an honourable and reliable man. started to take a bit of a knocking as he had originally contracted to have the tooling-up and be in production of a given number of the  carburettor parts within THREE months. A year later and he had not yet met his obligations and also, more importantly, was the fact that over 80% of his production was regularly failing our engine dyno testing. It became obvious that my original insistence that  every carburettor be dyno tested first before despatch was more than an essential  “quality control” and condition of our business deal..The entire international Fish carburettor’s reputation was at stake, particularly when I was  still battling to build up the Fish carburettor’s efficiency reputation in a new and very sceptical tuning market. This was hard enough work in itself due to the then current and generally very hidebound  market with its almost religious, conservative mania for the acceptance of the principle and culture of “twin or multi carbs” as being absolutely essential in any form of enhanced performance tuning..

Unfortunately it became clear that at Len’s  rate of progress we were going nowhere fast, This mainly because he was too easily diverted and always wanted to “play” at something else and so neglected the basic business’ Perhaps being too helpful (and I mean that as a personal compliment) for his own business’s good? This also led  to him having the odd problem of even meeting his regular weekly wages bill. I had to help him out on more than one occasion and all too often, for my(Fish) own good. He was excellent at his “one off challenges” such as the restoration of historic camshafts which were usually individual items and when there was no rush or a regular production schedule to be kept.


Eventually I had to find an alternative / additional sub-contractor, which I did in the form of Alec Wright, who was also an existing, appreciative and genuinely interested carburettor client. His company was called Precision Engineering (Whyteleafe) Ltd.  ( a Company I was to buy out “Lock Stock & Barrel” a  year or so later). Alec was as good as his word and within a month was producing a high percentage of usable parts. Leonard was egotistically furious at the new and relatively more efficient competition, claiming it was “not possible” for it to be done in that time?! I tried to be more than fair to Len and promised to continue to take any “passable” production from him indefinitely. This  so he would not loose out on even his lethargic efforts to date. But his apparent ego was such that he would not agree to this, despite my pointing out that this way he would not loose out on his own financial front and that if it just continued as it was we would ALL be out of business at his present rate of usable and acceptable production. Plus of course I was also already letting down Eric Liebman, my Canadian mentor to say nothing about my fellow U.K. Directors, agents  and supporters. Len, however, would not be reasoned with and insisted, where he was concerned, it had to be “all or nothing”. When I obviously could not agree he flounced off to America and Canada to try and secure some separate deal for himself behind my “exclusive”.back.


He got short shrift for his deceitful efforts, this from both Eric Liebman in Canada and the then new President of Fish Carburetors  Cpn., in Daytona Beach, Both pointing out that, through me, he had been, in effect, letting them  all down badly as well. Plus, regardless of that his general  quality was  clearly not “acceptable”. to them unless ,“checked and tested to Bob Henderson’ s standards first” Len was very frustrated and certainly not a happy man on his return from North America. Despite his, now proven treachery, I left my offer open to him to take anything serviceable from him indefinitely on into the future. But he would still not be reasoned with and then promptly refused to allow us to even remove our engine / carburettor dyno test equipment and all our un-machined carburettor castings and other parts from his premises Needless to say, that situation had to be dealt with firmly and promptly, which it was, much to Len’s chagrin and even fury. In that state of unreasoning  mind he rushed off to the local Wallington Police and wanted to charge us with theft! Poor Len was to finish up with a disproportionate amount of metaphorical egg on his face when it finally got through to him that we could not be charged with “stealing” our own property!


After all this unfortunate and entirely unnecessary turmoil Len announced his intention to produce his own “copy” of the Fish carburettor and to set up in competition to us. It was legally pointed out to him that he would be in breach of patents and other contractual matters but he insisted on going ahead anyway. For instance John Robert Fish, shown as the “Inventor”, had a fully valid and applicable British Patent filed back in 1957 and finally published early in 1961. Both dated long before Len Reece had even heard the name Fish!  Eric Liebam and I, after consideration, decided not to start very expensive litigation as Len Reece had no money to pay any “infringement damages”, let alone any legal fees / costs. and we could be doing without any more time-wasting diversions while trying to catch up on our (Reece inflicted) growing backlog of orders. Perhaps in retrospect a wrong decision?.Apart from the fact that I knew that Len never actually fully understood how the Fish system worked in all its combined entirety. So we were confident that any effort on his part would be somewhat short of being entirely satisfactory! And so it turned out. Our only worry was for any long term damage that might be done to the “FISH” name.


However, much to Len’s and any other odd potential copyist’s frustration, even the published patent specifications do not divulge the required overall working combination knowledge in full.,  And again to emphasise this matter and to quote Eric Liebman in a letter to me dated 18th October 1972 shortly before his death he wrote, “ You will soon be the ONLY (underlined)  man alive who understands the FISH carburetor!” What more needs to be said?

Well Len Reece went ahead with his rather abortive and inadequate version and had the absolute gall to add his own name to it as well, which of course only confirms his underlying conceit and ego .What particularly annoyed Eric Liebman was that after my own improvement patent application was registered and despite Eric’s encouragement I never added by own name to any Fish related product. I was always content to leave all the overall credit to the original inventor but I did register the name Minnow (a small fish, which I thought appropriate) and the Fish outline symbol. But there was never a “Henderson Fish” carburettor despite the Fish  carburettor “Improvement” Patents showing  me as the “Inventor” and being genuinely granted in my company’s name.


Len Reece went ahead with “his version” which neglected several vital aspects and resulted in a carburettor that at full throttle, amongst other fundamental problems, was only metering correctly at one specific point and if this was then adjusted to another range the original was lost again.  All a bit of a “hit and a miss” by original Fish metering standards. He had also “borrowed” one of my own developed metering grooves but then used it on the wrong sized models !   So the  economically vital part throttle metering lost most of its essential differential efficiency advantages and suffered “flat spots”. He also claimed  that the rotating metering / float chamber was his idea but it is  quite clearly shown on my own earlier granted Patent specification and drawings. He failed, in addition to understand that the intake flow shape is “designed” and essential to enable the inherent density increase to be fully utilised. In other words he got less dense mixture through the same size bore. Len seemed to get a bit frustrated about his lack of sales and spent a lot of money, that he could ill afford, on regular adverts in the motor magazines mostly of the Boy Racer type.

Unlike Len the only magazine advert exception we ever used, for a while, was a very small one in the VW Beetle  owners magazine called Safer Motoring and that was only to placate one of our dealers. It simply stated; MINNOW FISH CARBURETTORS, More Power than Twins. More Economical than Singles, More Efficient than Injection.


In a general Fish carburettor article that appeared in a 1965 issue of  Cars & Car Conversions Len Reece had the absolute gall, again, to give them a picture of our Minnow Fish twin choke prototype carburettor as clearly shown in our already referred to Patent drawings and specifications. The inventor is clearly stated as being; Robert McLaren Henderson. This photo had been had taken for us by the Beeches Studio located near Len’s workshop. I still have the paper work today that shows that I paid the £5.4s. on the 30th July 1963 for the commercial photo . Len was then guilty of giving the magazine the false impression it was his design. I expect to be including the drawings of this granted Patent for any reader to see the details of this prototype and thereby backing up my contentions and also confirming that the rotatable metering chamber, already mentioned, that was included, was also “ours” not Len’s at all, just another bit of his poor quality and audacious “copying”..  These are available as a PDF file here

Len used the idea to enable him  to produce alternative  semi down and side draft models. Again lacking the understanding that under most normal conditions  a straight down-draft carburettor is always inherently more efficient than some wet dribbling and badly atomised side draft model particularly at lower speeds and throttle openings. All our own racing successes were with a down draft versions regardless of the extra bends or curves that may have to be negotiated. We only used the “swivel chamber” idea very rarely ourselves for some special competition and for most aircraft installations also. This then only because of some installation priority. Our own reasoning for rotation the metering chamber even if not the carburettor as a whole, was rather different as we were just seeking to lower the rich end of the metering groove deeper, compared to the original American versions, into the fuel to compensate for any extreme angular changes that would not normally occur in every day road use, but could during some aerobatics or some forms of car racing etc.

Perhaps also worth mentioning is the fact that, as far as I know, our “twin choke” model is unique,  because unlike all the other twin choke side draft models, such as Weber’s D.C.O.E and Solex’s PHH and which are in fact two separate jetted carburettors, but sharing a singe centrally included float chamber. Whereas, as can be seen in the accompanying drawings, there is only ONE main (adjustable jet if you like) metered feed system that then splits either way on into the two entirely separate discharge points in their respective “chokes”..


All the reputable motor car magazines, well knowing the honest legal situation, largely ignored Len and as far as I recall none afforded him even a proper comparative Road Test, which is where a lot of our own sales had originated from and until  the reliable “Word of Mouth” syndrome took over..I do however remember one published “boy racer” picture where the driver of a Reece Fish Mini was purported to be leading the race. But in truth the  reality, it turned out, was that he was about to be lapped by them all! Any reader will appreciate the hilarity and derision that produced! In actual practice I know of no race, let alone championships, that were ever won using Len’s fake carburettor. He also tried to sell the odd ones in Toronto which were immediately jumped on by Eric Liebman’s Fish Canadian Carburetor’s lawyers.


Meantime the REAL Fish carburettor, the Minnow Fish, won championships in almost all classes of car competition here and abroad with the exception of single seater racing cars. In the case of 1,000 cc Mini racing and after Minis had been largely vanquished and superseded by the remarkable Fraser Imps.   David Morgan in one of our Single SM6 model carburettor Minis took back three lap records from the Imps  much to the annoyance of Alan Fraser himself at the time. David went on to win the Mini / 7 club championship on more than one occasion. On another occasion  at Brands Hatch the Minnow team filled the first five places, which was commented on in Autosport, the leading weekly racing magazine in its next issue, as “remarkable”.. I think that was the same year that a Minnow won the K.M. Trophy again for the third time outright, which entitled us to keep it permanently but we declined the honour and gave it back to be handed onto the next generation, as it were. In addition to which, Our Autocross VW Beetles literally, on a regular basis, thrashed not only all the Minis but the Cortina Lotus and Porsche opposition in the hands of Minnow Fish carburettor drivers like Jack Frost and Laurie Manifold, who was features Editor for the Sunday People newspaper at the time. Another client, Wally Pratt, reigned supreme for several years, in his ”road going”  850cc Fiat in his Hill Climbing Class. He regularly beat the famous and much more expensive Arbath tuned examples, the much vaunted Italian tuning company. This with a car that we had modified for him and was independently tested and found to have had its top speed raised from 66.2 to 83.3 MPH (Practical Motorist December 1963). Wally regularly won almost all his Hill Climb 850cc Class events and was only eventually beaten by a cheating oversize 1000,cc engined Mini van fitted with full race Janspeed engine that was so temperamental and inflexible that it had to be taken to meetings on a trailer! Wally, on the other hand, just turned up with his every day car plus wife, dumped her, took off his bumpers and chucked out some of the seating etc., competed and then replaced everything and went home again. And off to work in the same car the next day. That’s genuine versatility and flexibility for you!

On the  International front one of the cars that we were involved in tuning was a class winner at both the Nurburgring  1000, km and Le Mans 24 hour in the same year. The extra torque from the single Minnow Fish SM6 carburettor with a right angle adaptor.(all the other competitors using  pairs of twin choke DCOE Webers) enabled the drivers to stay in top gear with the Coventry Climax engines on one of the long German climbs up from Adenau to the violent, on suspension, concrete banked Karussell, whereas the multi twin choked carburettor equipped “works” cars being much less flexible  had to thrash away in third gear at high revs., which added to their fuel consumption problems and meant more pit / fuel stops as well. Not an advantage in long distance endurance racing!


On the Road Test front, again I am not aware of any worthwhile reputable motoring Magazine conducting comparative Road Tests with the so called Reece Fish. Whereas the Minnow Fish carburettor and WITHOUT any (Reece-like) accompanying (bribery?) adverts,  had frequent coverage, which included the following samples;

B.M.C Mini 850cc               Top speed raised by 10 MPH

Ford 105E Anglia 1,000cc   Top speed raised by  8 MPH

Vauxhall Viva      1,159cc    Top Speed raised by 10 / 12 MPH

VW “Beetle” 1200cc            Top Speed raised by 13 MPH

And in fact became faster than the factory 1500cc model!

The first full Road Test of a Fish carburettor in the U.K was carried our by the weekly magazine “Motor” and was published in their June 22nd 1960 issue. The car they provided was  a clapped out 1958 Ford Mk2 Consul and due to the shortage of time available the carburettor was very hastily, all but, “ thrown” onto the car with no time to do any proper tuning. I was not happy with the situation and was frankly amazed when they came back a couple of weeks later full of praise and enthusiasm,  having compared it with an earlier test of a similar car that was newer and in good condition. It prompted them to say; “The Fish not only improved the performance of the car as it stood, but actually showed worth while  improvements ALL round on the performance of the (original) machine”, Which was of course in “as new” sound condition! And instead of the usual fuel increase the fuel consumption improves usefully”.(at a steady 30 MPH better by about 18%) From our point of view we considered it a very poor result even though entirely positive.  In practice we only improved the top speed by a bout 2 MPH (with its well worn engine) but did reduce the top gear 50 – 70MPH time by about FIVE seconds. They also went on to say;” The experience on the road shows the car to be more than a match for most similar machines and when using the car for towing the extra torque was extremely useful”. Not a brilliant write-up but it established the Fish carburettor as a genuine and “respectable” tuning product,  A quality one too as they then said, “Finish (pre Reece at that point) of all the parts is of an exceptionally high  order”.


In addition to all this our own normal road-going everyday single carburettor Minnow Mini G.T.  in 850cc form reached 93 MPH ( Practical Motorist July 1963) more than matching the later much bigger engined, twin carburettor, Cooper Mini “S” models. We had only ever claimed  90 MPH.   Practical Motorist’s final comment was; “Overall, the Minnow proved a tractable town vehicle with an almost embarrassing performance on the open road – embarrassing for the owners of certain other high-powered cars, that is… ”.  At the end of their test we removed the cylinder head for them to check and measure the bore stroke dimensions, which were of course genuine  standard 850cc. Not bad for a basically standard engined bread and butter small  engined car. In addition to which and never remarked on, was the fact that our Minnow Mini G.T. , with its “ugly duckling”  shape matched the later and much bigger engined Cooper “S” production models with 12 BHP less at the wheels! I may, later, enlarge on this aspect.

Then and when in 1275cc form, the police timed a fully laden (plus two children) Minnow Mini  G.T. at  112 MPH on the motorway, probably making it by far the fasted, genuine road going Mini ever! On another occasion, the Carlisle police in their calibrated 3 litre Ford Zephyr, complained that when they were doing 104 MPH (pre motorway) we were pulling away from them! This, as we crossed the Border into Scotland.  On the every day front and in the case of the standard works supplied 1275cc Cooper Mini “S”, when we then replaced the two large standard S.U. carburettors with just one of our SM6 model Minnow Fish carburettors, we saw a gain of 17% in power at the wheels!



The very respectable and authoritative weekly magazine Autocar  in their 30th September 1966 issue and again  when carrying out a full and exhaustive road test on our  new 1966 1700cc V4 Ford Corsair, that had nothing done to it except the fitting of a single Minnow Fish carburettor, went on to record a FOUR MPH higher top speed than they had obtained when testing Ford’s own and tuned G.T. version!  This despite the G.T. version having a bigger engine, a sportier camshaft, a Twin /Dual Weber carburettor and a closer ratio gearbox. The article was accompanied by such comments as; “ ..the change in acceleration was so phenomenal that it seemed too good to be true” The Editor told me at the time that he could not remember them ever having used the word “phenomenal”, in a comparative road test before!

Then later in the same article they wrote about the  larger Ford 2 litre V4 engined G.T. version that they had tested earlier. “That the engine had sounded “hard working” by 4,000 RPM. whereas, with the Minnow-converted (smaller engined and smaller carburettor) car the rev-counter shot round to 6,000  RPM without the slightest hesitation”   Ford were reputedly not amused! But it does also make the valid point that it is not always what a conversion does but HOW it does it!


At our Soho Mills Hackbridge works, we had installed probably the very first commercially / client available U.K. Roller Dyno as well as our engine / carburettor testing  dynomometers. (this confirmed recently by a Europe-wide manufacturer’s historic Roller / Chassis  Dyno survey). This had helped to build up a reputation for tuning in general. Since we were the only company offering this sort of accurate tuning service to the public anywhere in the country or Europe at the time. We had clients coming literally from hundreds of miles away.  Partly encouraged by our “guarantee” that if we did not gain at least 5% more power at the wheels on their presented and often standard vehicles, then there would be no charge at all! A free tune-up in effect. Obviously too good to miss! This service brought in various competition cars as well as the regular road going vehicles.  It was a useful and  lucrative, almost sideline, that also helped financially until we caught up on the Reece inflicted delays.


In 1969 / 70 we finally moved everything to Scotland as I had always intended. This to Lochgilphead in ARGYLL. and despite having been lied to and cheated by The Highland and Islands Development Board, who never paid us a single penny of the “thousands” due and agreed / promised to  us by their then Deputy Chairman, a Mr. Rollo, during his several “enticement” business visits to us in Hackbridge, Surrey (Moving costs, training grants and working capital etc. ).


The move  finished our minor competition escapades as it was now far too far to the various tracks / circuits and of course all our competing clients had all remained in the south of England!   That was over forty seven years ago and we are still here with still no advertising and not even a business sign outside our works and tuning facilities on Manse Brae, Lochgilphead, Argyll.. Historically all this experience had then led to us being by far the first and original U.K. /  European pioneers of the turbocharging of road going petrol engined cars.. I was also the first to write an authoritative book on the subject either in the U.K. or Europe.  We had our road going and competition Turbo systems working and well proven on numerous models long before either Saab, Porsche or B.M.W. And, more importantly, without their throttle / turbo lag problems! In one case we had a championship winning Saab running in Norway long before Saab, themselves got the “message”!

In addition to which we led the way and  pioneered road-going rear boot spoilers.  We managed to generate nearly a 100 lbs of down trust at 90MPH.  This being in 1969 on our single Minnow Fish carburetted un-blown “Highlander” version of the Hillman Avenger that was faster than Root’s own highly tuned 18 mpg! “Tiger” . This “Tiger” being fitted with a tuned engine using  two twin choke DCOE Weber carburettors. A much later Press caption on the “Highlander” added, “Certain Aerodynamic modifications  were made including the rear spoiler which has(now) become COIMMON PLACE SINCE.(B.M.W.,Porsche and Saab)    Later the same year we produced an even faster Turbo version of the HIGHLANDER” Avenger, as well to mark and celebrate our Minnow Fish carburettor production move to Scotland..A published caption at the time read;  Picture; Left: The Minnow Fish Avenger “Highlander”. This car personified the FIRST successful  road-going Turbo systems in Europe and was produced to celebrate Minnow Fish’s move north in 1970 A further caption read; The LAG FREE Minnow Turbo system produced in excess of double the standard power output giving 120 MPH cruising speed and acceleration of 0- 60 in an average of 7 seconds. (0-100 MPH in under 20 seconds.) This car set standards of performance increase and efficiency yet to be matched by ANY other turbo systems since.(B.M.W.,Porsche & Saab.again). The Highlander rear “spoiler” really came into its own during our consistent and regular 100 MPH motorway cruising up and down between London and Scotland at the time particularly on the wet and windy days / nights!


The essential relationship of our special “Aircraft / altitude” pressure and density sensitive Turbo version of the Minnow Fish carburettor led to our, as yet, never equalled “lag free” Turbo system. And one that in the forty seven  years since has never been equalled on a “percentage gain to boost used ratio”.  That had then, in turn, led to and enabled us, while still using a basic normal everyday car engine to design and produce  Scotland’s Super Car. The “Argyll Turbo G.T”.A mid engined, up to, 188 MPH vehicle that was the “star” of the last Scottish Motor Show to be held at the Kelvin Halls in Glasgow in 1983. The car had been launched a month or so earlier by the Duke of Argyll at Inverarary Castle. Again that saga, in due course, may also be added to this growing tome.


Finally, for the moment, and historically where the fraudulent, egotistic and inappropriately named Reece Fish carburettor was concerned and despite the rather sad, pathetic and vindictive efforts by Len, I would rather try and remember him as originally imagined, as a friend and even one of natures gentlemen, that for some reason of perhaps a repeatedly frustrated ego or as my own father used to say, “Commerce can make devils of us all”. I don’t really know for sure. But regardless of the reasons my prime and  serious resentment, all along, was never just personal but that he usurped and sullied the Fish name and for a while and temporarily caused the part denigration of the Fish carburettor image.

Rather confirming this, is my attitude and policy even today and along with our ongoing limited production of Minnow Fish carburettors themselves we occasionally receive the odd Reece “copy” to overhaul and sort out as best we can. The new owners are not usually aware of the original or personal patent infringement and should therefore not be penalised in any way. In some instances we have been able to re-machine  and re-meter the offending instrument, to try to improve their  functions a bit! At least a little bit closer to that of the  original Minnow Fish standards of accuracy. It is also heartening that some of our own 50 odd year old models, from that period and having been used on several cars of often different engine sizes, are found, when dyno tested again, regardless of appearance, to be still metering and functioning “as new”.


Now to explode some of those “myths” and inaccurate ideas about how and why the Fish carburettor worked in several superior ways, particularly when compared with the then current conventional units of all makes. The basic principles, working methods and systems have been falsely espoused on Wikipedia and other sources. Usually when referring to the fraudulent copy. of our carburettor. In part it states;”The float chamber was sealed and pressurised by ram air effect from the air inlet.” (NO IT DOES NOT AND NO CARBURETTOR COULD POSSIBLY WORK IF THIS WAS SO). The on; “..which then caused fuel to flow through the jet”. (AGAIN NO IT DOES NOT). Then “This flow rate was entirely independent of fuel level and pressure”. They got .that little bit right at least!. But then; “but did remain approximately proportional to the mass airflow”.(THERE IS NOTHING APPROXIMATE ABOUT IT. IF THE CARBURETTOR IS SET FOR THE INDIVIDUAL ENGINE SIZE AND CONDITION THE RESULT IS A “CORRECT AIR / FUEL RATIO ACCORDING TO THE ENGINES EXACT DEMAND AND LOAD,  THERE IS NOTHING “APPROXIMATE” ABOUT IT. (almost regardless of fuel level ).  Although this IS one of the several aspects that the Reece copy failed or fell down on badly, it was possibly due to his failure to ever actually fully understand all the complex working principles involved as in the case of some now published “misunderstandings” that we are now looking at.

The Fish carburettor is / was originally designed, first and foremost, as and to be primarily, a very efficient “part throttle” and an instantly reacting  “economy“ carburettor, to respond to weight of air differentials rather than gas speed of an indeterminate density.. The 20% average, largely thermal, power gain over any other single choke carburettor was an almost accidental bonus!

The reference to a “jet”, as in main metering, is also technically wrong. In a conventional carburettor, a main metered jet is “sized” or used for any specific engine cylinder size, remember that the carburettor(s) are only ever “feeding” one cylinder at a time!  and that has to supply the right amount of fuel at full throttle and as demanded by the depression / gas speed generated by the, again, sized venturi. This since gas and fluid rates of acceleration flow are never directly proportionately equal. So the result is that it can only ever be even near correct at one specific point in its operation. If it’s rich enough at low gas speeds then it gets disproportionally richer at the higher speeds so requiring an “air corrector” bleed-in jet to help reduce the then growing over richness “main Jet” inaccuracy. The Fish merely has a maximum flow screw. Not a jet. This being merely to cut back any over richness of the metering groove at full throttle to suit any particular engine size or rev range. Then resulting in consistent and accurate (so requiring no correction) metering all through the rev range and NO separate air corrector required.  Therefore it is not a main jet in the normal or conventional sense.

In truth the Fish principle is very sensitive to mass air flow or more importantly air density or weight (therefore oxygen (energy) content) either due to changes in altitude or temperature. It is therefore entirely self compensating, unlike conventional carburettors that need to be re-jetted for any such changes in environment, ambient or altitude conditions..Examples of this being places like Mexico City or the North American Rocky Mountains.

In reality, as we have now seen, during static running the Fish  fuel level has virtually no relationship to the metering at all! Just as long as the fuel level is above the metering groove and lower than the discharge spindle. height. Because the Fish carburettor works entirely on pressure differentials and not a restrictive venturi to increase the gas speed over an unreliable metering jet. Some have likened the Fish system to a syphon, Plus its  vastly superior atomisation ratios that enables the correct, well atomised mixture to feed the engine with a cooler and therefore denser mixture. This well worthwhile “thermal” gain, in effect, allows better (denser) filling of the engine’s cylinders adding considerably and thermally to the normal volumetric efficiency of any engine and therefore a useful addition of torque. This happy situation often even allows slightly more advance from the ignition for the then slower burning (combustion) better atomised and cooler mixture. This resultant slower burning combustion rate  also of course is further insurance against potentially destructive “pinking” and detonation from a given compression ratio and the then required fuel octane rating..In effect, with a Fish, you can run a lower octane fuel on the same compression ratio!

One rather non technical journalist described the “phenomenon” as getting more power though the same size hole. Another went too far by suggesting that the Fish was a self-supercharging carburettor. To most  it might be better understood as being related to the effect, we see today, of using an inter-cooler on many turbocharged engines. They are used to cool the over warmed compressed  intake air charge back down to nearer ambient. So then restoring some of its otherwise lost density and therefore its total combustion power. This Fish carburettor’s vastly superior thermal efficiency does have a potential drawback though. With this much greater temperature drop through the Fish carburettor unit and particularly on cold and very damp days, the tendency to icing is naturally much greater. In Canada for instance it was not much of a problem because it is so cold and so much drier that there is much less moisture content in the air to freeze. Whereas, in contrast, here in the west of Scotland with its very wet and barely freezing winter conditions, carburettor icing can be potentially horrendous. Hence the need and  use of electrical de-icer units to overcome the dramatically increased “guaranteed” icing tendency on some models..(hot air can be used as do most manufacturers but of course it reduces the air density at the same time so runs the risk of being self defeating in certain circumstances!).

It is the design of the different metering grooves and their relationship to the ratio of the discharge spindle holes that will always ensure consistent and very accurate mixture strength at all times and conditions. This, regardless of temperature, weather or altitude (no re-jetting required if you happen to live in the Rocky Mountains or Mexico city). The discharge spindle and its differential holes act almost as a bonus and as a very efficient emulsion  tube as well..The Fish carburettor is exceptional and unique in that it is the only “self-compensating” carburettor that has ever existed.( traditionally on aircraft they have had to resort to aneroid controls to change and control the fuel flow at different air density and temperature at varying altitudes). It was the almost  total lack of all this understanding and how to put it to work that led to the Reece copy failing so often to come up to genuine “Fish” expectations. Apart from the inherent fuel metering inaccuracies, Len Reece’s total lack of understanding of the thermal efficiency element of the Fish principle was shown again in his complete  neglect of the  carburettor’s intake shape, so automatically losing a worthwhile percentage of that inherent thermal efficiency gain! Ignorance is not always bliss and certainly was not for Len Reece’s  unfortunate customers..

Bob Fish himself, always claimed that intake  “plumbing”, both entry and manifolding, should be designed as a “whole”(where possible) along with the unit itself. This was more than proved, in later years, with his One Man, backpack, Fish carburettor powered helicopter installation. Which did manage to lift a soldier off the ground but could not them carry his gun or equipment as well.! One of those things that seemed a good idea at the time  But at least it was only the Fish system that could even lift the soldier in question! Thus convincingly proving the power to weight efficiency advantages of the Fish carburettor.

With a genuine Fish carburettor the only exception to this automatic pressure differential metering function of the carburettor is when the an “acceleration” shot is required. This is taken care of by a very simple and basic one way  feather (flap) valve, which  just adds the extra fuel temporarily required to the normal flow from the same place and at the same time! Totally unlike conventional carburettors that need a separate accelerator pump and jetting / metering system.

The other, shall we say Urban Myth, that is apparently being propagated by some American alleged petro-chemical “expert”is that the Fish carburettor can run a normal petrol (gasoline) engine “happily” on diesel and even heavy fuel oils. I am afraid that that is a “miracle carburettor too far”.What it can do is utilise a slightly lower octane fuel on a given compression ratio and / or accept a slightly more advanced ignition timing. Or reduce the “pinking” level for a given combination of settings. Plus for instance when using a T.V.O. system on a low compression ratio tractor with a Fish carburettor it is possible to switch from the petrol to kerosene much sooner and requires much less pre-heating and in a warm climate may require no preheating at all!  WHAT IT WILL NOT DO, as I have seen recently espoused,  is to enable the use of heavy heating oils on normal petrol engine without drastic changes to the compression ratio  and ignition systems. And frankly I am not aware of any such available combination of specifications that would even start to make such  unrealistic pontification even half feasible. On the other hand in some instances, even on a competition engine the cooler denser mixture can utilise a slightly “hotter” spark plug. Which means that even in turbocharged circumstances an extremely “cold” spark plug is not always required an so avoids the  “off boost” or town running tendency to “wet” or to foul a colder plug in the then low compression no boost mode. But there is a limit to “miracles”, even  Fish ones!


With any genuine Fish carburettor an entirely different working principle is involved. It is so simple and basic that I have often found that many so called “experts” cannot adjust their minds to even accept it! This became manifestly clear in the early days, in the U.K., when a well respected Technical Editor, (M. I. Mech. E and all that), who had reputedly worked for both Coventry Climax Engines and Jaguar Cars, claimed that after careful inspection and judgement that the Fish principle could not possible work and was prepared to put his reputation on it! Ironic then that his successor on the same magazine should, only six  years later, used the word “phenomenal” in describing the results of a single Minnow Fish carburettor conversion on a V4 Ford engine..

Conventional  carburettors rely on the UN-reliable and even variable  manometer (“U” tube) control of the fuel level at the discharge metering  point. Added to which they have to contend with a restrictive venturi to hopefully accelerate the air flow over the jet to even enable the, often poorly, metered fuel to be drawn along and up (and having to overcome gravity to some extent) into the air stream from that,  usually a single central  rather un-atomised wet dribbling flow that is slow to dissipate and / or mix fully or accurately. The Minnow Fish carburettor on the other hand has always a minimum of THREE discharge points, often five and at full throttle TEN. A conventional carburettor cannot, even within its own limitations, start to work efficiently at both high and slow engine speeds with its same compromised basic jet and venturi combination settings. One part of the system is always in opposition to the other! So a rather inefficient compromise has ALWAYS to be made. Some have tried to overcome this inherent problem by producing a “Dual” or progressive system, Sometimes mechanical and sometimes vacuum operated with mixed results.

It is impossible to have  it both ways, (hence the modern arguments for fuel injection). Some years ago one carburettor manufacturer even tried  multi stages of venturi but the idea seemed to die along with the unfortunate car it was attached to at the time! Sometimes, incongruously, a rough surfaced inlet manifold helps! Which is, of course, not the best way to produce a homogeneous and efficiently combustible ignition situation and often wastes  some un-burnt fuel as well. (usually shown up by black sooty spark plugs). Contrary to popular belief, wet petrol in itself, does not burn! Then at best any selected (and always a compromise) venturi size, will strangle the top end performance plus suffering from progressively poorer fuel breakup down at very low gas speeds. The final compromise is always  therefore a choice, metaphorically speaking,  between  the  “devil and the deep blue sea” or  just more and more compromised compromises. .

All of which just emphasises the universality and uniqueness of the Fish carburettor, in that one model“will fit all”, as it were, within certain very wide limits of engine size (cylinder number and displacement) and with not even having to change any venturi and main jets.  We have only ever produced two nominal bore sizes, namely 1.25, the  SB and LV series the 1.55” SM group. The SB has covered from 650cc right up to 1,600cc and the SM versions from G.T. spec / competition from 1,300cc (Mini Cooper “S”) right up to over 3,000cc and even, on occasion, to over 5 litres on low revving American V8s . To emphasise the matter even further is the fact that we did once use TWO SM (turbo) series on a (single) turbocharged 3.2 litre racing Porsche using over 7,500 RPM and exceeding 170 MPH ! One long term client even used the same unit, over fifteen years, on five different cars ranging from a 850cc Renault Dauphine up to a 2,600cc Ford Zephyr.


What is the future of the Fish name? That remains slightly unsure at the moment because I am now in my mid 80s and with a medical condition that may preclude me still doing any dyno testing when I am a 100 years old! None of my family are interested in carrying on the engine / car tuning and carburettor business so perhaps some like-minded enthusiastic tuning engineer or business man might by chance turn up enabling me to pass it all on to a “good home”, as was  the original case of Eric Liebman to myself in the 1950s. We shall see then if such a unusual and trusting bit of personal and mutual missionary history can repeat itself?.

R.M.H. Minnow House, Lochgilphead, Argyll. Scotland   PA31  8RB       tel; 01546 60 2418