NASkeet
Samba Member
Joined: April 29, 2006
Posts: 2958
Location: South Benfleet, Essex, UK
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 Posted: Tue Mar 19, 2024 12:09 pm Post subject: Re: Rebirth of the Minnow Fish carburettor |
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Whilst attending a voluntary, end of first academic-year, physics summer-school in June 1976, at the Pulton Place annexe (domain of the Departments of Physics and Electronics, plus the college’s computer centre) of Chelsea College, University of London, in Fulham (close to Fulham Broadway, District Line tube station, on the Wimbledon branch), Richard Ashdown, one of the research-laboratory technicians there, gave me several past issues of a motoring magazine named Safer Motoring (later renamed VW Motoring), devoted to vehicles from VW-Audi.
https://en.wikipedia.org/wiki/Chelsea_College_of_Science_and_Technology
http://www.kingscollections.org/exhibitions/archives/studentdays/chelsea-college/history
http://www.kingscollections.org/exhibitions/archiv...-1972-1985
The first academic-year physics, chemistry & mathematics studies were undertaken at Chelsea College’s main college buildings, close to the fire station in Manresa Road, adjoining the King’s Road in Chelsea (almost equidistant from South Kensington & Sloane Square, District Line tube stations), so I had previously had no reason to visit Pulton Place in Fulham (1¾ hours commuting time by public transport from Canvey Island, Essex), where my second & third academic-year physics studies during 1976~78 would be undertaken, and had no previous acquaintance with Richard Ashdown.
https://www.streetcheck.co.uk/postcode/sw61ef#google_vignette
Walking times between London Underground railway stations
I had seen Richard Ashdown’s green & white, 1973 VW 1600 Type 2 Westfalia Continental motor-caravan in the Pulton Place annexe’s car park, so I had placed a note under the front windscreen-wiper blade, which introduced myself and mentioned my own family’s ownership of an identical orange & white example, that my father had bought second-hand in January 1975; for which I was making a custom, supplementary crankcase breather amongst other things, during my machine-workshop summer-school week. I have so far recounted the early years of my family’s ownership, from January 1975 up to the late-1980s or early-1990s, as follows:
Forum Index > Bay Window Bus > 41+ Years with a VW Kombi: There's Never Been a Dull Moment!
https://www.thesamba.com/vw/forum/viewtopic.php?t=651954
From those magazines, I became aware of several VW related things, including the Minnow Fish carburettor as a bolt-on performance upgrade for air-cooled VWs, commonly used singly on various competition cars; including that of Peter Noad (23rd October 1936 to 11th February 2019), who was also recognised then and later as a prolific automotive journalist and book author, re vehicles from the VW-Audi Group. The Minnow Fish carburettors were similar to the Reece-Fish carburettors, which were typically used in pairs.
https://cartunevw.co.uk/peter-noad
Rather than purchase a Minnow Fish carburettor by mail order and attempt to fit and tune it ourselves, we decided to make the pilgrimage to Lochgilphead, during our forthcoming August 1976 holiday in Scotland (home for the first nine years of my childhood), where we would have one fitted and tuned on the rolling road dynamometer, by the celebrated Robert ‘Bob’ Henderson; much vaunted guru of air-cooled VW tuning, during the 1970s and originator of the Minnow Fish.
http://www.autoinsider.co.uk/local/garage-services/ai_24800.php
http://www.hotfrog.co.uk/business/argyll/lochgilphead/minnow-fish-carburettors
http://www.historicvws.co.uk/technical/minnow_fish_carb/minnow_fish.htm
http://www.fireballroberts.com/fish_story.htm
‘Bob’ Henderson created the Minnow Fish carburettor, as a development of the Fish carburettor, but for the smaller-engined British & European cars, such as the Austin-Morris, BMC & BLMC Mini and the VW Type 1 Beetle. There is even a section about retro-fitting & tuning a Minnow Fish carburettor, in David Vizards book, “How to Modify your Mini”.
https://www.amazon.co.uk/Modify-Your-Mini-David-Vizard/dp/0912656476
https://www.amazon.co.uk/Modify-Your-Mini-David-Vizard/dp/0863430414
My father later described ‘Bob’ Henderson's road test of our van; expressing his amazement at how well it handled (the advantage of fully independent suspension and associated low unsprung weight!), when skilfully driven at high speed, around the twisting lanes of Western Scotland.
In the ensuing years, this installation was to prove both a blessing and a curse; an opinion which has been echoed by others who have had personal experience of the Minnow Fish and/or Reece Fish carburettors. These included the late Arthur Barraclough, whose 1970 VW "1600" Type 2, 'Rosie' (VW Type 2 Owners' Club, 1995 'Van of the Year'), was once equipped with the former, plus Ivan McCutcheon (editor of Volksworld magazine) and Tony Royston (proprietor of Microgiant, in Rawreth, Essex).
Forum Index > Bay Window Bus > Arthur Barraclough's, much vaunted, modified, 1970 VW Type 2
http://www.thesamba.com/vw/forum/viewtopic.php?t=196043[/quote]
When relatively new and unworn, the carburettor gave lively performance (by the standards of an early-1970s vintage, 1584cm³ flat-four engine, with a restrictive inlet manifold and a mere 7•5:1 compression ratio!) and a consistently indicated fuel consumption of 25 ± ½ MPG (i.e miles per Imperial gallon), between fuel tank fill-ups, almost irrespective of the type of motoring undertaken; including motorways, country lanes and mountain passes.
As the van was used, during only mild or warm weather, our Minnow Fish carburettor had yet to exhibit any icing problems. However, as a precaution, I decided during the late-1970s to fit the matching, 90W electric de-icing element, activated via a relay in the engine compartment, using a dashboard switch with integral warning light. This was a heated rear window switch, salvaged from a VW Type 4 (i.e. VW 411 & 412).
I disliked the non-matching switch knobs, so I replaced the remaining VW Type 2 knobs (shaped like a dimpled, truncated cone), with those of the VW Type 1, 3 & 4 pattern (shaped like a stepped, truncated cone), which were then more readily available in car breakers' yards. Few if any British specification 1968~79 VW Type 2 were equipped with a heated rear window and 1968~79 VW Type 2s were seldom if ever found in my local car breakers’ yards! Ironically, the lock-knob of my more recently acquired, second-hand VW Type 2 glove-box cover sourced from the USA, is also of the VW Type 1, 3 & 4 pattern, so everything matches quite nicely!
At one stage, during the early-1980s, the pancake air-filter element, atop our Minnow Fish carburettor, was subject to severe fouling, owing to oil mist and oil/water emulsion (commonly referred to as mayonnaise!), from the crankcase breather system. I renewed the air-filter element and disconnected the breather tube, allowing it to vent directly into the engine compartment; which had previously been recommended to me by Robert Henderson, when he fitted our Minnow Fish carburettor, back in 1976.
It was not long before the engine compartment was a dirty, oily mess, which took me ages to clean. Not realising the importance of the crankcase breather at that time, I unwisely blocked it off, in a bid to prevent the oil fouling! We next used the van for a weekend outing with our Dutch friends, during which we lost 2 of the 2½ litres of oil from the sump (some of it, deposited on the windscreen of our friends' car), until we were alerted by a flickering oil-pressure warning light, after a distance of about 80 miles. Identifying the blocked breather as the probable cause, I uncorked it and topped up the oil, from the 2 litre can, we always carried when touring.
Having a blocked breather (which can occur without human intervention!), led to crankcase pressurisation, possibly exacerbated by piston ring blow-by and/or worn valve guides, resulting in oil being forced out the dipstick hole and past seals and gaskets; which necessitated a further cleaning job. I later rigged up an oil-breather baffle chamber, from a VW 1100 Golf Mk 1, which reduced oil-fouling of the air filter. Only proper reconditioning of the engine, at a later date, would cure the problem.
Our 1982 summer touring holiday, was in Denmark, Norway & Sweden. In Sweden, two hours after our departure from Västervik, heading south towards Kalmar, the engine suddenly died less than 200 metres from a petrol station. The engine turned over easily, but would not fire. Seeing that the fuel gauge needle was close to 'reserve', I suspected that we might have run out of petrol, as had happened on at least one previous occasion, so we pushed it into the petrol station and filled up the tank. After filling up, our renewed attempts to restart the engine, were equally fruitless, but this time I noticed the smell of petrol.
Suspecting that the Minnow Fish carburettor might be flooding (something that was mentioned in the troubleshooting sheet, supplied with the carburettor), I removed the fuel-level check-plug from the float chamber, which confirmed my suspicions. After removing the float chamber, I discovered that the brass float had partially filled with petrol, which I could hear sloshing around inside. This necessitated a telephone call to the Bärgnings Kåren, for which the petrol station, kindly didn't charge us.
A Chevrolet tow truck (not found in Great Britain! | featured as part of my ink-jet printed, full-colour, 1968~79 VW Type 2, 30th anniversary, iron-on, T-shirt transfer!) was dispatched, to tow us "four miles" (note that in Sweden, the word "mile", is used as a reference to 10 km!) further south, to Kalmar, in Southern Sweden, where at about 7.00 PM in the evening, in a small back-street workshop, our brass float was drained and then repaired using solder. Had our float been moulded from plastic, we probably would not have been so fortunate. As a souvenir of our tow, we scrounged a self-adhesive badge of the Bärgnings Kåren, which is now attached to the elevating roof, along with various others.
The combined towing & repair charges were quite expensive, so we didn't have sufficient AIT vouchers (provided as part of our AA 5-star Continental travel insurance), to cover the cost, so the difference was paid in cash. Several weeks after we returned to Britain, we received a letter from the AA, saying that the Bärgnings Kåren, was still owed the sum of money, corresponding to what we had paid in cash; suggesting either dishonesty on the part of the patrolman or some confusion about the paperwork. Either we are now black-listed by the Bärgnings Kåren, or the AA managed to resolve the issue, but we never heard any more about it.
https://assistancekaren.se/other-languages/
Preparation at the petrol filling station, for our expensive, 40 km tow to Kalmar.
Note also, the North American specification, front side-marker reflectors & rear side-marker lights, plus the home-made, black butyl-rubber, stretchy roof-rack cover.
Setting off for our Hungarian touring holiday, during the wet June of 1985, we were obliged to turn back, when the engine virtually lost all power, less than four miles from home. The gentle incline (gradient significantly less than 1-in-50 or 2%) which we normally climbed in 4th gear, could not be ascended, even in 1st gear. Slipping the clutch, to get over even minor humps, we limped home at a snail's pace, with hazard warning lights flashing. What caused our power loss, I never discovered, but I suspect it was one of those elusive gremlins, which occasionally liked to play games, with our Minnow Fish carburettor!
After stripping down the entire fuel and ignition systems, which were cleaned, reassembled, refitted, adjusted and tested, we could still find no reason why the engine refused to run properly. After turning the engine over on the starter and rechecking systems for the umpteenth time, it suddenly burst into life, exhibiting such a lively responsiveness to the throttle, which hitherto, had never been experienced. Being shy of trusting this unexpected good fortune, I took the fully laden van for a test drive, including all the hilliest parts (including a few hills, steeper than 1-in-10 or 10%) of neighbouring Benfleet; performing better than I can recall it ever had! The following morning, we again set off for Hungary; experiencing no further problems with the van, for the remainder of our holiday.
During the outward journey to Czechoslovakia in 1987, through West Germany, our Minnow Fish carburettor flooded, which it had done a few times before in the past; this time in the pouring rain, following a short break, late one afternoon, in the small town of Schwandorf, about 25 miles north of Regensburg, on Route No. 85. The weather was too wet to work on the van, so we found over-night accommodation, not far from our parking place in the town square.
The following morning, when it had stopped raining, I removed the carburettor float chamber, but found no sign of dirt or debris, which might have caused it to flood on this occasion. The brass float was intact; the soldered repair, made five years earlier, having worked well. The float chamber was replaced and the engine turned over on the starter, until it fired. Thereafter there were no more flooding problems that I can recall and it remains a mystery as to why it flooded at all. Thankfully, the VW behaved itself whilst in Czechoslovakia, which was fortunate, because it might have been very difficult to obtain any necessary spare parts behind the 'Iron Curtain'.
During the 1987/88 and 1990/91 winter seasons, when I used the VW Type 2, instead of my Triumph Toledo, which was off the road, I encountered severe icing problems with the Minnow Fish carburettor and inlet manifold. Knowing that the Minnow Fish was more prone to icing than the standard Solex carburettor (owing to more efficient fuel vaporisation from the three jets in the throttle butterfly), I had fitted the recommended 12V, 90W electric de-icing element, a few years after the original carburettor installation in July 1976.
https://en.wikipedia.org/wiki/Carburetor_icing
https://classics.honestjohn.co.uk/askhj/answer/106130/how-do-i-prevent-carb-icing-
The inlet-manifold, exhaust pre-heat connections (during summer use, when petrol usually vaporises easily, it is better to block these off, to maximise air density; increasing both torque and power), for the Scat 'Monza' style exhaust silencer, had also been drilled through, to provide whatever exhaust heat was available. Normally, the VW was laid-up during the late autumn, winter and early spring, so I had never previously experienced this problem. Despite the electric heating element, which got exceedingly hot, it seemed to have little effect on ice formation.
At one stage, icing became so severe (a noticeably thick layer of ice on the outside of the inlet-manifold down-pipe, immediately below the carburettor), that the engine stalled whenever I eased my foot off the accelerator, to slow down or change gear, consumed fuel at an alarming rate (something like 10 MPG or worse!) and sounded more like an asthmatic, 2 cylinder, 2 stroke engine, than a VW flat-four. Fuel dilution of the engine oil was so bad, that on one particularly cold, damp day, the dipstick reading increased by about 1 litre; indicating that there was 2½ litres of oil and 1 litre of petrol and/or condensed water vapour in the sump.
In the end, the only way I could overcome the icing, was to blank off most of the pancake, paper element air filter, on top of the carburettor; directing pre-heated air, from around cylinder No. 2, towards the unobstructed portion. Despite these measures, it was often necessary to drive the first mile or so, until icing became noticeable, stop the engine and allow the now warm engine compartment environment, to thaw the ice, then finally restart the engine and resume my journey.
The poor fuel-economy and having a constantly stalling engine each time I changed gear weren’t the only sources of annoyance. The chronic lack of power was particularly noticeable on the steep upward gradient section of the M40 motorway, between Oxford (the World’s best-known university-city) and the junction of the M25 London-orbital motorway.
In that case, I had the indignity of climbing the gradient at 30 mph in 2nd gear, in the ultra-slow lane of the two crawler-lanes used by HGVs – heavy-goods’ vehicles, being overtaken by heavy articulated lorries (i.e. truck tractor-units with semi-trailers in USA parlance!?!). Perhaps I should have found an alternative route which didn’t involve using this steep section of the M40 motorway!
Whilst I had the 1973 VW 1600 Type 2’s VW 1600 Type 1 style engine removed during the 1988/89 winter season, to add a brake-servo vacuum connection to the inlet manifold, for the twin remote-acting vacuum brake-servos I was retro-fitting, using a home-made, custom tubular-steel cradle, suspended beneath the longitudinal chassis-rails (n.b. British specification 1971~79 VW 1600 Type 2 brakes were NOT factory-equipped with vacuum servo assistance, despite having front disc brakes), I also took the opportunity to make a few more upgrades.
Having initially upgraded the headlamps in mid-1976 (in time for our August 1976 touring holiday in western Scotland) from the original P45t flanged, 45/40W glass-envelope bulbs to P45t flanged, Lucas 60/55W H4 quartz-halogen bulbs, I had decided to undertake a further upgrade in 1988/89 to P45t flanged Ring 100/80W H4 quartz-halogen bulbs, which by then had become readily available at my local car accessory shop. This was prompted by the increased amount of night-driving on twisty, windy, narrow, unlit, rural roads, commonly encountered in the British Isles and various parts of Europe.
This increase in lighting power plus anticipated future increases in required electrical power for a variety of accessories, and the fact that we had coincidently acquired a freebie, genuine VW Type 1 engine, alternator support-pedestal cum oil-filler, when we had the engine-starting crank-handle facility retro-fitted, prompted me to upgrade from the original factory-standard 38A dynamo to a 55A alternator.
In addition to overlooking the different specification of the alternator’s associated fuel-pump and fan-housing plate, I was also unaware of the Minnow Fish carburettor’s, standard throttle linkage configuration, being incompatible with the alternator housing; all of which, I was fortunately able to modify, without any major effort.
I had long bemoaned the parlous lack of instrumentation to monitor the engine and electrical system, which comprised only an oil-pressure warning-light and an ignition warning-light, but by late-1988 I had finally managed to convince my father that in the first instance, a set of three VDO Cockpit gauges to monitor oil-pressure, oil-temperature & cylinder-head temperature would be invaluable; enabling us to guard against the common causes of sudden & catastrophic engine failure, about which I had read in the VW Motoring magazine . A few years later, I also retro-fitted a matching VDO Cockpit 8~16V voltmeter to monitor the electrical system, which I managed to source for the modest sum of about £2 or £3, from a VW Golf at the local car breaker’s yard.
The VDO Cockpit 50~150 ºC oil-temperature gauge, also highlighted that the temperature of the oil in the engine’s crankcase-sump, barely exceed 50 ºC at any time during my 128 mile journey on the various meandering, single-carriageway rural roads, dual-carriageways & motorways, between Canvey Island, Essex and the RMCS – Royal Military College of Science, Schrivenham, Oxfordshire, when the Minnow Fish carburettor was suffering from chronic icing problems, during the winter of 1990/91. Being aware of this ultra-low oil-temperature, prompted me to refrain from revving the engine hard or allowing it to labour.
https://en.wikipedia.org/wiki/Royal_Military_College_of_Science
https://en.wikipedia.org/wiki/Royal_Military_College_of_Science#Shrivenham
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Regards.
Nigel A. Skeet
Independent tutor (semi-retired) of mathematics, physics, technology & engineering for secondary, tertiary, further & higher education.
Much modified, RHD 1973 VW "1600" Type 2 Westfalia Continental campervan, with the World's only decent, cross-over-arm, SWF pantograph rear-window wiper
Onetime member, plus former Technical Editor & Editor of Transporter Talk magazine
Volkswagen Type 2 Owners' Club (Great Britain)
http://www.vwt2oc.net
Last edited by NASkeet on Tue Mar 26, 2024 2:10 pm; edited 3 times in total |
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