Cobra weber intake

[deathsled]

My father holds the opinion (he's old school turning 90 in April) that I should get a Cobra Weber intake with the 48 IDA carburetor setup.  I, myself, have sufficient concerns that these carburetors are a nightmare to tune and to get running right.  They are pretty much a race only piece are they not?  I know they look amazing when the hood is opened to reveal them, but what good are they if the car will begin a new life of inactivity in the garage due to constant adjustments.  I'm hanging on doggedly to the one four barrel high rise set up and getting it refinished and repaired.  If I do go Weber, I need a backup plan if it fails.  Am I off base or is there a nugget of truth to the cursed Weber setup?  This question was asked by me many moons before but was lost with the crash.

Best regards,

Richard E.

[shelbydoug]

Webers are pretty much a slam dunk. There isn't much if anything that is unknown.

I would caution you if the car was an automatic transmission of if you need to drive the car as everyday transportation in a difficult climate.

Other then that, go for it.

You are not know if they are worth it to you unless you try them.

It seems that you can always get your money out of them if you choose to bail out?

The caution is that they are not going to make your 289 have the power of a 427. It's very difficult to explain the "Weber effect" to a newbie.

[SFM5S000]

Deathsled,

You're off base. There are serveral guys on this forum that run Webers. I am one of them as is Zray, Shelbydoug, Dan Case. They do not go out of tune. They are not difficult to adjust provided your linkage design is sound. There is a fairly steep learning curve in the beginning for a "street" driven Webered car.

In order to run on the street it does require a cam that has a minimum of 112 degrees lobe separation. You might be able to get by with 110 degrees as some claim to do.
Webers originally by design is a isolated runner that requires vacuum unlike a 4V carb that draws air/fuel from a central plenum. Cam profile design needs to be considered.

Webers have a characteristic uniqueness about them and how they "sound and drive"
I've driven my car in the San Francisco Bay Area stop and go commuter traffic. Or the stop and go traffic out of Monterey Car weekend in August (Laguna Seca etc.) with no issues.

Talk to people that actually run Webers not guys that "used to" or "I heard that they...."
Once you get a decent understanding of how it works, you won't want to look at another 14 inch chrome round air cleaner anymore. Just say'n.

Again talk to people that run them, not the BSer's. The only real drawback is that they are expensive (especially for the vintage 48IDA, 48IDA1's, and some early 48IDA4's). And by that i mean just about everything is done in sets of 8. They are infinitely adjustable. A set of 4 48IDA's can flow as much as 2400CFM if need be or less.

As far as looks, these are mine (see pic), vintage 48IDA circa 1964/65 there abouts. Dan Case has an on going data base and the ability to determine the approximate date and period of vintage Webers.

Cheers,
~Earl J

[kjspeed]

Richard - Although I've only had 2148 for less than 6 months, I'm going to chime in on the Weber question. I was bowled over by the look of the 4 48IDA Webers on top of the Boss 351 in my car the first time I saw it. I was a little concerned that they would be a nightmare to maintain, but I'm just stupid and bold enough to ignore any possible misgivings and went ahead with the purchase. The previous owner, John Barnes, has had them for 40 years on this engine and he assured me they were easier to tune and maintain than a Holley 4BBL. But of course he was going to say that, he was trying to sell me his car!


He included a Haynes manual on Webers, and more importantly, an 8-page guide written by Jim Inglese that he got when he purchased them back in the late 70's. I also spent the time to read everything on Jim's website (http://jiminglese.com/) and I'm pretty confident that I can at least maintain them and keep them in tune on my ride. I've already had to richen them up a bit to eliminate "popping" at cruising speeds. Super easy fix.


As Earl J mentioned, and as Inglese recommends, you have to run a cam with less overlap than with a plenum manifold and you have to choose the correct choke size for your application. Webers don't have chokes like traditional carburetors. Weber chokes are actually sleeves that are inserted in the carb throat to adjust the CFM flow. It's important to size them for your application. 48IDA's can be used on everything from a 289 to a 427 by choosing the correct choke. And by the way, I was concerned about cold starts with no choke but that's not an issue. Pump the gas once and it fires right up.


If you choose to go this route, make sure that you have a well-designed linkage and fuel pressure regulator as well. If I was starting from scratch I would rely on the expertise of someone who has experience setting them up and running them to guide me through the process (or just buy a turn-key setup) so you can maximize the pleasure you'll get out of them.


They are magnets at car shows. Pop the hood and watch the crowd gather! At local shows most people have no idea what they are. At serious shows many do and they love to look! Keep lots of towels handy to wipe the drool off your fenders 


Performance wise, I couldn't be happier! The mid-range torque and the howl they make when you open them up is nothing less than intoxicating. My B351 has 11.5:1 compression ratio so I run a blend of 110 purple race gas and 91 non-ethanol to make sure there's no detonation, but depending on your CR you can run lower octane levels if your engine is happy with it. Although I like to open it up frequently, I don't "need" to. Once the engine is warmed up you can drive it very conservatively for just cruising around if that's what you want to do. My car has a Richmond 5-speed stick and I live in Florida so I'm not dealing with cold weather driving. I am not sure how they work with an automatic.


One potential downside is the lack of a traditional air filter. I've run mine with nothing on them, but currently have wire mesh screens on them to keep out leaves and small animals. The hood clearance on my 68 GT350 doesn't allow for a large plenum air box or stack-type filters and I've been warned not to use the foam filters as they will eventually deteriorate and get sucked into the engine. Also, they can become fuel soaked and cause a fire (you do have a fire extinguisher on board, right?). So driving in dusty conditions can result in some amount of trash getting sucked into your engine. I try not to drive mine on windy days when the sand gets kicked up, but every once in a while I have to drive by a lawn maintenance guy using his 35HP leaf blower to blast debris into the road so someone's lawn looks prettier. Not good for my engine or paint.


I'm still very new to this and you can take my comments with a grain of salt. I would defer to the folks who have years of experience with these setups, but I wanted to give you my take as a newbie Weber user. Best of luck with whatever you decide!

[SFM5S000]

Here's a link to what I think is one of the better guides to understanding, setting up, and tuning Webers. (I hope this works). It's a long read but really good.  There are other books and Jim Inglese has a very good installation guide as well. Also don't confuse Inglese (by CompCams) and Jim Inglese. (Long story, but explained on Jim's website).

http://www.timsroadster.com/html/tuning_webers.html

Cheers,
~Earl J

[kjspeed]

I did forget to mention that my car has a 12 volt electric vacuum pump for the power brake booster. Weber setups don't create a lot of vacuum so that is a consideration as well.


Kevin

[terlingua11]

I have a weber set up on 6S1904. Jim C. put them on in 1990 and they have been on ever since. The car has been driven and they are a blast to have. In the entire time I have had them on, they have only had to be tuned once. I live in WI and the up and down weather does not effect them at all. I couldn't be happier and I have a set waiting to go on CSX2122 when I pull the motor. I couldn't see 1904 with anything but- A must have. I also second Dan Case if you have weber questions on originality etc. He has tons of documentation if you want to make sure you are period correct.
Jeff-

[KR Convertible]

Eye candy for sure!!   

[deathsled]

Gentlemen excellent information provided and thank you. 843 is a 4 speed Ford Toploader with richmond gears came out of Peter Klutt's racing Hertz. Naturally car was automatic originally and I'll put an automatic in when my knees go but that gives me a good 30 years more of rowing the gears. I presume a modified Monte Carlo bar is used. It's not rocket science. It's carburetor science!
Best regards,

Richard E.

[shelbydoug]

On the cam, you can run anything that you want to.

The appearance of the so called "Weber Cam" was something that Jim Inglese worked on with CompCams I believe?

All it does is reduce the amount of overlap in the cam timing in order to reduce the "blowback" out of the velocity stacks. It also cuts a good deal of power out of the engine. Around 30 hp I would say?

It came about because lots of people wanted to run air cleaners on the carbs, not open stacks or just screens.

If you do that with a camshaft with more than about 28 to 30 degrees of overlap, the blowback will soak the air filter elements with atomized fuel. That's the overlap a Weber cam has, about 28 degrees. That would be a stock Ford 351 Cleveland cam.

With the air filter elements wet with fuel when you go to restart the car, they WILL catch fire. If you are going to run without air cleaners and just stacks, you don't need the Weber cam.



When the carbs were raced on the Cobras there was no such thing as a "Weber cam". They ran what they would normally run in a competition car. No air filters.

Besides catching fire, the air filters will take about 80-100hp out of the engine which is about what they were adding to it in the first place.

Likewise the GT40's ran Webers with just open velocity stacks.



One of the issues with them on "Shelbys", not so much with the Cobras, is that you can't run the length of stack that overcomes much of the blowback, and tunes the torque more precisely.

If you notice KJspeeds stacks, they are all shortened as are the auxiliary venturies. The reason for that is on the 68 Shelby, there isn't enough hood clearance on the front two stacks so they need to be shortened.

I had that exact setup on my 68 GT350. Boss 351 and all. I think that's where John first saw it? Only my front two stacks were shortened. The rest were stock 3-1/2" height. That was 1978-79.



I have them on my Pantera now but that enables the carbs to run the full 5" tall stacks. If you look at vintage pictures of the Group 4 factory race Panteras, all of the stacks have been extended to about 5" tall.

In addition to changing the torque characteristics of the carbs, it also keeps the "vapor cloud" within the stack, or most of it anyway.



How I would paraphrase what everyone else has said here is that the carbs are very streetable, actually creating a true street/track car, and that they are just a bit of a learning curve because they are so different from what most have experienced.

I think they are worth it. I've taken them off twice under fits of rage, but have always come back to them.

It's kinda like being married to an Italian movie star. The rewards are great and you are going to be in for a few very, very interesting side journeys? Look out for the ones that throw things at you like frying pans and such. They take longer to recover from. Learn to duck. 

[SFM5S000]

shelbydoug,

There is some truth in what you're saying about running "any" cam on the race track BUT on the street where the engine sees real world slower speeds, lower RPM's, stop and go traffic. The "Any Cam" isn't going to cut it. Sorry to contradict you. That's why the cam from the Inglese/CompCams people offer and the need to be selective about cams. I think it's the same reason the people that "Used to" attempt to run them gave up.

Running Webers on the street there is a significant amount of reversion ('blowback" as you call it) of air/fuel mixture running with the wrong cam (intake valve opening before exhaust cycle is complete). A cam designed for Webers to run on the street NEEDS vacuum to run lower RPM's. You get that with more lobe separation.

There are other factors too i.e. timing, gear ratio, compression ratio etc. One of the most important details in the tuning process is the float settings need to be precise and your linkage needs to be of a good design. (I built my own).

Webers for the race track, do what you want or need. You're running the engine in the upper RPM range. As much as I would love to run a "LeMans Cam" with Webers on the street. It just won't work well, unlike with a 4V. Just my 2 cents.

Cheers,
~Earl J

[gjz30075]

I suppose to further the questioning Richard (OP) might ask:   I notice there are two types of intake manifolds for the sbf, for Webers.  One
has two water exits and the other looks like normal one (with thermostat housing).    Any advantage / disadvantage to either?

[shelbydoug]

shelbydoug,

There is some truth in what you're saying about running "any" cam on the race track BUT on the street where the engine sees real world slower speeds, lower RPM's, stop and go traffic. The "Any Cam" isn't going to cut it. Sorry to contradict you. That's why the cam from the Inglese/CompCams people offer and the need to be selective about cams. I think it's the same reason the people that "Used to" attempt to run them gave up.

Running Webers on the street there is a significant amount of reversion ('blowback" as you call it) of air/fuel mixture running with the wrong cam (intake valve opening before exhaust cycle is complete). A cam designed for Webers to run on the street NEEDS vacuum to run lower RPM's. You get that with more lobe separation.

There are other factors too i.e. timing, gear ratio, compression ratio etc. One of the most important details in the tuning process is the float settings need to be precise and your linkage needs to be of a good design. (I built my own).

Webers for the race track, do what you want or need. You're running the engine in the upper RPM range. As much as I would love to run a "LeMans Cam" with Webers on the street. It just won't work well, unlike with a 4V. Just my 2 cents.

Cheers,
~Earl J

I installed my first system in 1978. There was no such cam. I've been running them ever since in various vehicles.

The Weber 48 IDA  "eight stack" is not and was never intended to be a "street induction system".
It is a system that can be used on the street.

Lots of what makes them streetable or unstreetable is really taste or personal preference.

I don't disagree with you necessarily, but what I am saying is a special cam for them is in itself a compromise and to a great degree takes out of the system what you put it on the engine to gain.

This is part of the "indecisiveness" of what makes the setup questionable in the minds of the uninitiated.

Just running open stacks on carbs on the street is risky to say the least.

Until you get to around 80 degrees of overlap, you are going to get 12-14 inches of vacuum no matter what cam you use and no matter how you plumb them the system won't provide the VOLUME of vacuum that you need to operate power brakes (as per the vacuum pump in KJSpeed's '68).
I have a vacuum pump in my Pantera also.

Other then that, the issue is with blowback with air cleaners getting soaked with fuel, besides a very heavy idle.

I'm ok with someone using a Weber cam. I'm just saying it isn't necessary. Reasonable people can disagree. That's fine.

This is like disagreeing over Lasagna. I like it with some sausage mixed in and a crunchy top.

Some like Merlot with it. I like Pinot Grigio, better yet Bud Light (tastes great - less filling). Call me crazy?

[Bigfoot]

Lasagna
Now that's a topic

[Bigfoot]

Red lasagna better than white.