Forums Forums Enthusiast Forums A - Z Autowirral Twin Weber Carburettors info

One of the major advantages in using the carburetors is in it's throttle response. This is more apparent in the racing field where no filters or collectors are used in the intake. Also, compared to the single throttle injection, the Mikuni and Weber style side-draft uses dual, 2 barrel throttles for a total of 4 individual throttle mechanisms to mix the fuel and air with more control and immediacy, resulting in a positive production of gasoline/air mixture, and in turn making potentially more torque than single throttle. As you may know, there are 4 throttle, fuel injection mechanism too. And the resulting principle is similar. The two systems do have very similar, and distinct advantage over the single throttle setup

So, what's so hot about using carburetors?
Well, here are some characteristics you may find attractive:

First of all, carburetors need no intervention of ECU's which can be both expensive and in most cases limited in adjustability, unless expensive alternatives like those programmable variety is in your budget. Although it takes some practice, setting a carburetor can be as simple as changing the jets and monitoring air/ fuel ratios. The goal is to match the jets within the carburetors to the required spray pattern and volume to desired mixture at a given rpm and vacuum. There are usually main jets and sub jets for various compensation, both of which have to be manually setup.

Second, the carburetors can be adjusted for much wider variety of engine setups using the same unit for the most part. Since the carburetor's adjustment is in the jets alone, it can accommodate almost anything you can imagine...as long as it's normally aspirated. (Well, some forced induction setups exited in the past but all of them are running fuel injection now)

Third and best reason for the carburetors is the esthetics... The setup simply looks really nice!!!! and it sounds mean! Once an addict, you'll never go back.

Carbs

Basically there is a choice of makes here, commonly used are Weber and Dellorto. The problem you will have with other makes is finding a manifold to fit the carbs to your engine. Both these makes have readily available manifolds. The carb works by using jets to supply the fuel. The fuel flow delivered through these jets is basically determined by suction from the vacuum in the cylinders (Venturi effect). Different size jets will allow different amount of fuel supply. The Weber DCOE40/45 kits can be supplied with the correct jetting for a standard or modified engine for your car and the linkages to connect them up. Webcon (Weber) have released a series of kits for carb conversions on various cars. The cost is around £1000 including all you need which is both carbs, manifold, gaskets, fasteners, sensors, linkages and the alpha 3d programmable 3d ignition system.

Throttle bodies

A lot of people get confused and say throttle bodies when they mean carbs and vice versa and often think that they are the same thing. Essentially they are the same thing and do the same job but the main difference with throttle bodies is that they use injectors instead of jets to control the fuel delivery. This means that you can electronically control and program the fuel delivery from an ECU and therefore have more control. They are more expensive though and ultimately don't deliver a great deal more power than carbs but they do offer refinements An injected car and cold starting can be a bit spluttery with carbs whereas even a cammed up engine will start perfectly from cold on throttle bodies and idle smoothly as low down as 600 rpm in many cases. The throttle bodies do provide more torque lower down generally and ultimately a better spread of power.

I am a huuuuuge fan of carbs ever since I used to Race MotoX. I would like to get myself an old Ford XR3 engine and get some Real nice carbs on it, maybe when I have some time and space I will get it going,