Weber Carbs..advantages? disadvantages? Cost?

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RandomInThe707

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I have some general questions about Weber Carburetors.

What are the advantages? Horsepower? Fuel economy?

What are the disadvantages? Do they increase wear on the engine? Cause smog issues? Cause anything to wear out faster?

I am assuming they can only replace an existing carb, not a fuel injector?

Are they difficult to install (for someone with limited mechanical experience)? If you have to pay someone is it an expensive job?

I am in California, but my vehicles are registered in an area that doesn't require smog (unless I go to sell them).

Thanks.
 
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Edelbrock carbs are actually Weber bssed. The REAL Weber carbs are VERY good and it takes a bit of tuning to get them right. An old Ford option was a 6 carb manifold with Webers. I believe they were only dealer installed and really looked wicked. Quite rare and Ford advertised 343 HP with a 289. I only saw one WAAAY back when. .John--Las Vegas.
 
Random ...just what are you trying to do?

A Weber is a good upgrade for some pre-injection emissions carb. It's a popular on Jeeps of that vintage. The Carter BBD was a pain.

Otherwise there's no way to trump injection with a carb.
 
I used to be the guru of Weber carbs back in their heyday with a chassis dyno and all the Weber carburetor parts in Santa Clara. The advantage of Weber carburetors was that Weber sold a large number of calibrated parts to tailor the air fuel ratio to the engine demand. You could not get that with many other carburetors. The thing that really sold Webers was their multiple carbureted one venturi per cylinder set up. This gave a 10-15% improvement in torque at low rpm, or a 10% improvement in peak power depending on how you tailored the tune. Every $$$euro$$$race car, or a super Shelby had a full set of these in the 60's.
Installing a single Weber carb is no big deal compared to installing any aftermarket carb.If you can tune it for a correct air/fuel ratio you are good to go.
Installing multiple Weber carburetors is very difficult. It involves setting up proper carb mounts, a throttle linkage,air cleaners, and buying a $$$load$$$ of jets. I don't recommend it to anyone any more.
You can use a Weber carb to replace fuel injection. It is especially useful if you are going to change the displacement or camshaft of a fuel injected engine and you cannot find a chip or tune to make the change. The other reason to convert to a single Weber carb is because you want absolute reliability in remote areas where fixing your truck with a rock is the only option.
 
I figured someone would be thinking this when they heard Weber

350_AssemblyIDA.jpg



Meanwhile, I'm thinking this:

WeberDGEV.jpg
 
There aren't any area's of California where you don't need a biennial inspection if the car is 1976 or newer. Where are these cars registered? It totally depends on the application whether it would be a good idea. What year/make/model is the vehicle? I work with carbureted vehicles every day.
 
They had their place on MGs, replacing the horribly complicated (SU?) factory setup.

If you don't know what you're doing you can make it run, but probably not well all of the time. Mounting it is a dream since we don't know what your car is. Nobody is born with a wrench in their hands though so if you're serious you'll figure it out.

You can potentially save money or aggravation if replacing a specific 80's emissions carb, but if your car is injected you're better off diagnosing what's bugging you and fixing it right.

Engine wear with a carb can go up a little due to fuel dilution from imprecise mix.
 
SU horribly complicated ?

There's not much more complexity in a traditional S.U. than an adjustable wrench.

An SU will run reasonably to pretty well, even if far from optimum, and even economically.

Webers, properly tuned are utterly awesome. Improperly tuned a pain, and 1bbl per cylinder improperly tuned, you'd think that there's a bypass been installed from the fuel tank to the exhaust system.

2BBL webers, and 2bbl strombergs stolen from larger displacement engines (e.g. Ford 4.1L (Weber ADG), and Holden 4.2L (stromberg)) are pretty good and vary forgiving on smaller 6 cyls, where Holleys you chase power valves, jetting, and AC pump cams.
 
"They had their place on MGs, replacing the horribly complicated (SU?) factory setup."

Grrrrrr, Americans!
Don't understand, but worse, Don't even TRY to understand.
Then worse still, expound there lack of knowledge!
 
I put a Weber (I think its a 32/36??) on my 78 Jeep CJ7 to replace the anemic 1bbl (258-6) and it woke it up. Better starting, more power, better sound and actually better mpg's. I ran that setup for years until the LT-1 swap came.
 
Originally Posted By: expat
"They had their place on MGs, replacing the horribly complicated (SU?) factory setup."

Grrrrrr, Americans!
Don't understand, but worse, Don't even TRY to understand.
Then worse still, expound there lack of knowledge!


Show me someone retrofitting SU carbs (plural-- because synching is a great use of a Saturday) on something that previously didn't have them.
cheers3.gif
Or putting a Jaguar engine in a Chevy.

34.gif
We got style. Blunt style.

(Lest anyone think I'm serious... I have no dog in the fight-- but the weber conversion is popular with MG owners who want a, uh, running car, and is an example the OP was looking for.)
 
So did we figure out what vehicle these might go on?
What the application might be?

In general, Weber is not a magic word.
A GM Quadrajet is a very good adjustable carb design.
 
Originally Posted By: eljefino

Show me someone retrofitting SU carbs (plural-- because synching is a great use of a Saturday) on something that previously didn't have them.
cheers3.gif
Or putting a Jaguar engine in a Chevy.

34.gif
We got style. Blunt style.


People everywhere (in the rest of the world, you know that bit) fitting SUs on all sorts of stuff.

The Oz aftermarket turbo industry of the 80s thrived on the simplicity of the SU carb, and it's suitability for draw through applications.

I fitted triples to my Holden 6. Balancing and tuning took about an hour. Adjusting for 3000 feet altitude difference (for economy, not absolute necessity) maybe 10 minutes.
 
"Show me someone retrofitting SU carbs (plural-- because synching is a great use of a Saturday) on something that previously didn't have them"

Really, today, Fuel injection (eg. Mega Squirt) is a far better way to go. However in the 70's twin SU conversions were VERY popular, and 100hp per Liter was very possible. Janspeed even offered SU's as a replacement for the asthmatic downdraft Weber that was used on some Ford Pinto engine applications. Burlen Fuel Systems still offer many such kits, but understand, Two Carbs and a special manifold can bee to expensive for many of us.
If a Carburetor that has one jet and three moving parts is considered complicated, What can I say?
If it takes you all Saturday to synchronize a pair of Carbs, again, What can I say? (I would expect 15-20 minutes if the engine is warm to be more than adequate unless there are other issues)
DGV Weber conversions ARE popular on North American MG's and Triumphs, They are also 'Horrible' if only because the required inlet manifolds are VERY poor! (poor A/F distribution and Hot spots)
It is NOT considered a performance upgrade! But perhaps North American mechanics, when seeing a Weber, will then leave the darn thing alone and pay attention to what proberbly 'does' require attention, like the ignition system.
 
Originally Posted By: mechtech2
So did we figure out what vehicle these might go on?
What the application might be?

In general, Weber is not a magic word.
A GM Quadrajet is a very good adjustable carb design.
I agree about the quadrajet, they are a very good design that can help make alot of power if set up right.
 
I work at a carburetor shop. Webers can make good power and have good driveability. The biggest problem I see is people installing carbs that are too large for their engine thinking it's going to make good power. They end up being undriveable because there is not enough velocity through them at low rpm and that kills torque.

SU's can be set up so they run well and make good power, however it is my opinion that there are better alternatives in most applications.

Quadrajets are very good carburetors and can make a lot of power and have excellent driveability. But again, installing the correct size is important. The formula for determining airflow requirements of an engine is as follows:

Max RPM x engine displacement is inches/ 3456 = Airflow in CFM

For example a 350 cubic inch engine spinning to a maximum of 6000 rpm would be:

6000 rpm x 350 cid / 3456 = 607 cfm (cubic feet per minute)

On a street car, I would round down to 600 cfm for the best driveability but you may be able to get better upper rpm power by going with a 650 cfm carburetor.

This formula is based on 100% volumetric efficiency which most 350's won't see so the carburetor does not have to be quite that large.
 
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Originally Posted By: Torino
Edelbrock carbs are actually Weber bssed.


That depends on which Edelbrock carb. If you're talking Thunder Series or AFB, then they are CARTER-based, even though the casting may say Weber. I forget the whole sordid history, but in the dying days of carburetors both Carter and Weber came under common ownership (Federal-Mogul maybe?) and eventually the rights to build Carter and Weber carburetors wound up with Edelbrock. Production was eventually consolidated down to one foundry, with the result that even the Carter carbs wound up with a "Weber" stamp on the casting. But the design is ALL Carter, no Weber at all. And I say that in a positive sense- Single-throat Webers in a multi-carb setup have incredible potential (if tuned properly). But a single multi-venturi Weber is nothing special at all- you can do as well or better with a garden-variety Holley, Carter, Stromberg, or Rochester 2V or 4V carburetor.

Then of course Edelbrock also sold their version of the Quadrajet (for a while, anyway) which had nothing in common with Carter OR Weber. Clear as mud?
 
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