I just bought one of these...
Have any of you guys heard of or used this before?
It's got a VERY interesting operation.
http://en.wikipedia.org/wiki/Reece_Fish_Carburettor
No needles, nor jets
Operation relies on the swinging arm, which is attached to the hollow throttle spindle. The arm runs up and down a tapered groove and this is basically how the mixture is varied. As the fuel is drawn up the arm and fed into the choke area to spray out of crossholes in the spindle. Altering the main running mixture is controlled by a taper screw, just where the fuel goes into the throttle spindle. Moving the throttle on the spindle controlles the part throttle mixture.
There is no choke tube and there are no jets. The restriction caused by the throttle and spindle sucks fuel into the air stream. Fuel trapped in front of the swinging arm gives an accelerator pump effect.
Therefore you tune a Reece Fish carb on your own motor. You need to be skilled at making gradual adjustments. Maybe take your car to a rolling road - tuning these does not take long.
Tuning
Setting the full power mixture:
Undo the grub screw in the float chamber case, so as to allow access to the main jet adjusting screw (Vizard says he has no better word for it). This screw can only be got at and adjusted when the throttle is fully open - which suits the need. Run the engine flat out on the dyno. The Reece-Fish comes with a special adjusting tool. Adjust the mixture screw, until it shows the maximum reading on the dyno.
Setting the part throttle mixture:
Situation: The fuel comes out of the throttle spindle through holes which start off live when the throttle is in the closed position (pointing forwards and backwards - this is in line with the airflow through the carb). When the butterfly is fully open, these holes are at 90 ° to the airflow.
Alter the position of the butterfly on the throttle spindle arm: either let more air or less air in. This will change the mixture as it changes the amount of fuel which happens to be sucked in with the throttle spindle at that particular position.
The pump action is achieved by the swinging arm in the float chamber.
In 1976 it was said:
The Reece Fish is a very novel carb with a flow potential much greater than a conventional carb of the same size. They do not come cheap.
Mr. Leonard Reece did not favour horizontal fittings, because in the event of spillage, fuel would run out of the intake. He would prefer it to run the other way: into the manifold. Therefore these carbs are available in downdraught pattern of various degrees of semi-downdraughting. Mounting the carb horizontally would not be a good idea.
From the brochure:
The level of the fuel in the float chamber, which is so critical in most carburetters, is relatively unimportant.
It is perhaps not too economical, as perhaps you need to run it rich on part throttle, to mask any flat spots?
Martin Bristow has a Reece Fish carburetor for an Imp, but 15 Dec 99 he hadn't fitted it yet.
Appartently when it's well set up, it should give performance similar to the 28/36 Weber.
It's a very strange thing to look at and its simplicity is legendary! It has no jets as such and is completely adjustable by screws
Whether this means that you can get the settings more accurate, or whether it means that you fiddle with it every week to try to get that little bit more has not been decided yet.
It has no cold-start device. Pump the pedal to inject fuel.
A heater device is needed on some cars, to keep it from icing up.
Special Reece Fish manifolds also exist. They're not cheap either. How much benifit is derived from these, is not clear. Vizard says that compared to the SU manifold it is a lot better and does away with the hot spot.
