Something Fishy. . .

[Anonymous]

Anyone know anything about Fish Carburetors?

I hear they are pretty amazing where fuel economy, tuning and performance are concerned. . . Like - there's only one gasket to change, no venturi and no float bowl system.

Any thoughts or knowledge? I'm considering buying one (two, actually) and I am trying to do some online research but I'm not coming up with "enough" info for my own satisfaction.

-J

 

[wallaka]

I've heard that they are mostly a hoax. Apparently they do OK at full throttle, but anything less they are just a semi-controlled gas leak.

Never knew anybody with first-hand experience, though. This is all hearsay from the Internet.

 

[Lazy JW]

I spoke with Mike Brown on the phone several years ago about the Fish carbs, he was building a few and selling them.Said it took too many years to sell off even a small production run so he gave it up. He did say that if you wanted to they could be leaned out quite readily and do a pretty good job of frying your engine An interesting fellow, he made no outrageous claims about the Fish carb, just that they could work well if you were careful.

He is into bulding little steam engines and other such alternative energy gizmos. I bought a set of plans for a small steamer, haven't done anything with it yet. He has a website, do a search.
Joe

 

[Thad]

Scattered among the archive are some posts about the "Fish", "Fisch" and so on.
The design was basically a constant velocity carb off idle metering was by cam opening a sliding jet, mid range -hi speed metering by a swing arm and ramp. The swing arm being attached to a spray bar in the center of the carb. As the throttle opens the arm swing up and the gap between the swing arm opening and the ramp increases.
The Predator carb of the 70-80's was on the same design, if you will, the Fish design on steroids. So if you want good pics and details of ops do search on Predator
The Fish, in it's day, was an improvement, but was soon surpassed by others carb design that were more adjustable at more point of operations.
The latest Re-pop are small one bbl units.

 

[fb71]

sounds like a model airplane engine carb. The carbs on OS Tigers, KB's, etc, are similar.

 

[xctasy]

It, the Fish carb, is a turkey. And was when they tried putting it into the Monica in the late 70's, and its been a full'o'shyte internet talk point for the last 10 years.

On the positive, it is a technically brilliant item, with immense intelligence in every feature, and adjustability which is very impressive. Fitting one correctly sized to a oval track race car (a single 1.5" item on a Mini 1000 or two on a 1275 Sprite, f'instance) gives great dollops of high end power. On the down side, it has very specific requirements which would probably work well as a feedback carb, but that make it way too hypertensive to use in a car. For example, atomisation is quite poor across thae range of air and fuel flows, and consquently, the emissions or way off, and general air flow near the slinger arm is poor. Any time someone changes a minute part, the air fuel ratio can go haywire, and require retrimming on a CO meter.

Jim, you'd aggree that Ford tried a halfway house of the variable venturi carb used on 302's and CVHH Escort and European Pinto 1600 carbs from 1979 to about 1982. They worked well, but soon got replaced by other carbs because they were like SU or Stromberg CD carbs...very sensitive to bong heads with screw drivers messing with them. That was after sinking a few hundred million into making them. So I'm ultra weary of any new carb, because theres a billion bucks in todays money to valiadate that there is even a future for it on an OS model air plane engine, let alone a lawnmower or, dang it, a blQQdy motor car. It's quite suited to a nitro benzyne and cast oil burning air plane engine, where the fuel air ratios can have a wide variance, and it'll still perform good, epecially if you can trim it on the fly.

Making the Fish carb a commerical automotive sucess is a step more difficult. To get good results you'd still be behind any port EFI system. As I said, its a turkey.

 

[fb71]

I never said I thought it was a good idea for a car. For a model airplane, it works just fine. But like you said, castor-laden 15% nitro being fed to engine operating at a steady state is very different than a passenger car application. As for the VV carb, you're correct that a monkey with a screwdriver can foul them right quick. However, a well-trained and skilled technician with the proper tools can make a VV perform like a 600cfm Carter while getting the fuel economy of a tiny 0.98 venturi 2100 on a 5.0L (at part throttle, of course). There's a reason they were banned from circle track racing at Budd's Creek.... (305 cubic inch, 2 barrel carb class)

 

[xctasy]

Cool.


I used one in 1993 on my mates 1980 1.6 Cortina, and my wifes father had a 1984 1.6 Cortina with it too. It was the European VV, like a 1-bbl Motorcraft that actually worked. It was also just like a tiny Predator, with an SU style apperture growth under vacum, a sort of anodized green 'epiglotis'. Everything was potimised, casting was really good, there was no horriable Stromberg Zenith CD perishing parts, no SU alloy galling or wear. I have no idea way it was replaced by the Solex-Pierburg carb. Maybee the supplier gave them a better rate than the inhouse supplier?

The fuel consumption was insanley good! Old 1.6's, 1-bbl or 2-bbl, were hard pressed to get 30 mpg imperial, but the 1.6 gave 40 mpg easily. There was a large loss of power on the 2-bbl 1.6, but compared to the awfull 1973 to 1979 1-bbl 1.6, it was fine.

Ford must have loved the abilty to ensure there was no messing about with the carb, becasue there were no service parts for it. As long as it wasn't messed with...

I'd love to grab three 302 VV'S, and spend time reprofiling the damping and needles. I love variable venturi carbs, they are so good for torque.


As a footnote. I've looked very carefully at the Fish carb, but if it can't sustain a stable fuel air ratio due to its design. If you could design a cumputerised system like a modern air fighter, which caters for the super crtical flow, then it might be able to atomise better, but unless the droplets are as good as the better carbs, then its basically hamstrung before it gets off the drafting board.

A component that has gone through the auspices of engineering room development and been tooled up for production is a better bet. The Fish can't create a stable flow due to the sheer bluntness of the distrubution mechanism. Even the first EEC CFI would be better, an anular Autolite 2-bb would be betterstill, perhaps the VV better again.

That is why a bird in the hand is better than, um, two in the bush. Cold Turkey, anyone?

 

[Anonymous]

Wow. Thanks guys. I got more from these few posts than I have found anywhere that one would think you could find some good info. It's nice to be a member of a site with some cats that have some seasoned and hard knowledge. Thanks for the scoop. This was the impression I was getting from my own research.

Now check my post about my proposed setup and tell me what you think!

 

[xctasy]

Anyone know anything about Fish Carburetors?

I hear they are pretty amazing where fuel economy, tuning and performance are concerned. . . Like - there's only one gasket to change, no venturi and no float bowl system.

Any thoughts or knowledge? I'm considering buying one (two, actually) and I am trying to do some online research but I'm not coming up with "enough" info for my own satisfaction.

-J

The only source of good information I have read is the first and second versions of the David Vizard books on the A series Mini engine. In it, he commented on his inability to make the 1.5" Fish work as well as an 1.5" SU. He commented that the Fish did produce admirable power at certain points, but that the air fuel trim was hard to tailor throughout the rev range. The pluses were the adjustability, so he affirms the fact that the carb has ability to reach power and economy and adjustability, just that it was a unstable and not repeatable. That's why I say as a fuzzy logic feedback carb, it could be really good.

Standard, the Fish carb is only good for two factors, , performance and adjustability, or economy and adjustability. Performance and Economy and adjustability are not able to be reached at any point.

The real clincher was when Mechanical Engineer Vizard decided to let loose with a few modifications to improve the air flow and fuel atomisation. The results ruined what air fuel adjustability there was. Hence the very disturbed flow and blunt edges of the Fish carbs swing arm are all there for a reason, and a lot of science has gone into it.

Again, I repeat, it is like a fighter plane...its easier to control the swing arm and its fuel dispensory with its seamingly dumb a$$ blunt edges and big swiss cheese holes with its unstable and seamingly preverse blunt flow. Fighter plans use computer control in a super crtical state to ensure a sub crtical air flow never causes yaw instability. And so it is with the Fish carb.

Do a web search, and buy a copy of the Vizard A-series book, or rent one form a library. That is a pivotal discussion on the carb.

If you've got some two carbs lined up, I'd create a servo for triming the fuel air ratio, and link it to two wide band oxygen sensors, and go have some fun. Don't try to re-invent 20 years of development, but be dumb enough to figure out how to tune it, for it is really easy to tune.


As for details, Vizard book, Vizard book, Vizard book....

 

[Anonymous]

Sweet. Thanks for the info. I'm a big fan of Vizard (what gearhead isn't?). I've finally come to a decision and I think I'm going with holley/webers. . .

 

[Anonymous]

What gearhead isn't? Well, there's a group of Chevy builders that think Vizard is full of it. Just shows you can't please everybody, shouldn't try, shouldn't care.

In this country, for as long as I was aware of it (from the late '50s), there has been a minor conspiracy theory about a super-efficient "100 mpg" carburetor developed by a little guy and killed off by Detroit due to oil company pressure. I always supposed that the original take-off point for this flight of ever-wilder fantasy was the Fish carburetor. True?

Interestingly, the Predator is one of Vizard's favorite carbs, and others who have tested it have been impressed, particularly with the ease of tuning. With a little hunting (it might be on Predators own site), you can find the complete factory manual and tuning guide. It's not as simple as just changing the cam, but quite straightforward, nonetheless. The Predator seems not to have ever quite caught on outside of the dragboat crowd, which is too bad.

 

[Lazy JW]

...

In this country, for as long as I was aware of it (from the late '50s), there has been a minor conspiracy theory about a super-efficient "100 mpg" carburetor developed by a little guy and killed off by Detroit due to oil company pressure. I always supposed that the original take-off point for this flight of ever-wilder fantasy was the Fish carburetor. True?....

I believe the Pogue Carburetor was one of the earlier miracle carbs. Supposedly someone recently re-discovered his drawings and are trying to build one.

Most of the miracle carbs try to "vaporize" the gasoline with heat, etc. Seems as though the modern gasoline has been re-formulated to defy proper vaporization. This re-formulation is allegedly part of the conspiracy as well.

The main problem I have trying to grasp this "vaporization" concept is the fact that propane is pretty much vaporized already when used as engine fuel, so why don't we get fantastic results from using propane? I dunno
Joe

 

[wallaka]

Probably because the vaporization claims are just speculation, with no hard evidence. Like most miracle cures.

 

[Thad]

Seems to be several carbs call Fish, Fisch, Fisk. Strange Pogue is a type of fish. In the late '40 early '50 the original(?) Fish was an improvement of then existant but then soon other carbs surpassed it. There was some being built up 'til the early '60s in Florida for dirt track and attempts to run on stock cars. Don't know if it was the original. Sure some were rip off on the name rumours had made legendary.

There is always been rumours of the great "auto cartel conspiracies". 50 mpg carb, 100 mpg carb, 50,000 mile ties etc.
As for as claims for this wonder carb suppressed by the conspiracy, simple physic and math show that a gallon does not contain enough energy to propell a 4,000# car at 50 mphwhile getting 50 mpg. But that was the claim.

Propane is a good fuel for many reasons but the main draw back is fuel density. Same for diesel vs gasoline. Density and energy are directly proportial.

Second no OEM vehicle is designed to fully use the available energy of propane, and very few aftermarket user modify their vehicle to get full benefits. The octane rating (IIRC) is around 110 or better. And everybody waste that benefit by burning in 9.5 - 10.0 compression ratio engines.

 

[lyonsy]

i wish we still got the good stuff out here but they have this lpg mix of propane/butane and even with 9.5 comp you get troble pinging but run the propane turbo 10psi on 10.1:0 comp = damn quick