BB - Weber to 4 bbl Carb: Switch

[priobe]

I have been a member here for a long time and figured I would post something to see the response to a question I have always had.

I was wanted to hear from those that might have switched from 48 IDA to a 4 bbl carb. I know there have been a lot of people that may not have been able to successfully tune their Webers which ultimately made the switch to a 4 bbl. I really did not want to discuss this or have a debate over what is better.

I have had my webers for a long time and have tuned them pretty well. I guess I am looking for a change and to see the difference. It looks like intakes and carbs have come down in price over the years so now maybe a good time to purchase a package and try it out. But is is worth doing?

The motor is a 427 SO, with 10.5:1 compression.

I guess if the question is what am I looking to get out of it, well I would say a change and to see what others can provide to me.

I have heard people say 4 bbl is the way to go, and others say webers have that cool factor and low end torque. Wanted to see if anyone has made the change and what was the outcome.

[Grubby]

Single carbs can run really well across the RPM band. They can make a ton of power.

Weber’s look cool.

John

[blykins]

The camshaft is the biggest contributing factor in either setup.

I only use Webers on situations where a rules class dictates it. Otherwise, the 4 bbl intake and the appropriate camshaft will do just as well.

[Timinator]

A nice Holley 4647 is about as good as it gets. Probably need a 50cc pump.

[priobe]

Blykins

Just possibly looking for a change. I owned / built this car since 2000, always have been webers. I have this motor running very good with webers.

What rules are you referring to? Are you speaking of not using split duration for the webers?

I’m looking to entertain a 4bbl. Not looking to discuss torque number and HP. I drive the car on the street.

[tomshep]

I'll just throw out if I was looking for a new induction "adventure" it would be fuel injection.

Tom

[Jim Vander Wal]

Priobe,
I'm not trying to be difficult but...
Change for the sake of change can be fun but is usually expensive and often a step backwards. This is a "ask me how I know" question.
If you're not looking for enhanced performance why bother? You already have, by your own admission, a system that works well for you. You have what most would consider a seriously cool set-up, why change?
I often start a new endeavor with "I'm thinking...". My friends would be doing me a great favor if they'd just smack me up-side-the-head to straighten me out and ask "WTF".
And for Timinator, hoo-chee-momma, have you priced a Holley 4647?. Those must be the holy grail of carbs. Most likely though, they are 60 years old and surpassed in performance by a new $600-800 carb.
Jim

[blykins]

Originally Posted by priobe

Blykins

Just possibly looking for a change. I owned / built this car since 2000, always have been webers. I have this motor running very good with webers.

What rules are you referring to? Are you speaking of not using split duration for the webers?

I’m looking to entertain a 4bbl. Not looking to discuss torque number and HP. I drive the car on the street.

The rules would be a class that has to use the Webers because the class dictates it.

[Snake2998]

Weber type manifolds loose a lot of power because of poor and restrictive air cleaners such as socks and wire screens and poor trumpet dimension. This is where a 4 barrel gains. If one used decent plenums with decent air cleaners feeding the plenum I think you would win the power battle over 4 barrel, otherwise you will gain power with the change.

And of course Webers are terminally cool.

[Nola Cobra]

This may be a little off topic. I switch from a traditional 4-barrel setup on my ole Roush 392AL after about 6 years and approximately 20k miles of driving. As related to the cam, it’s an off-the-shelf XE-274HR-12 which is probably not the ideal/custom cam of choice but works for a street engine… hi-in-sight maybe I could have opted for a custom grind (discussion for a different day).

My car is mainly street driven with several track days and one drag strip trip (off idle passes for the experience) many many years ago. The thing I did notice with the carb setup is I could stop aggressively enough to stall the engine and on the track cornering hard the engine would stumble slightly on the exit…. Yes, some carb tuning and mods would likely have solved this symptom but again the car is mainly street driven, cruising the back roads.

Fast forwarding to mid 2013 I installed a set of weber’s with an initial setup by Jim Inglese. After some fiddling and methodically dialing them in the only issue was fine tuning the linkage/bellcrank. Ultimately, I whittled a bellcrank from aluminum which made the tip-in smooth as butter. The weber setup has been trouble free for years now and I have logged another 20k miles on the car. Most of my driving these days is a combination of some around town idling, not on purpose, with the majority of time spent cruising on the back roads. We usually log a couple hundred miles at a time.

Again, this isn’t answering your question, I do have the original intake/carb/classic Cobra air cleaner but it’s wall art now and I have no plans to remove my weber setup. The beauty of our love of good friends and sharing our Cobras is we can run whatever engine, transmission, fuel delivery, bling, etc. that tickles our fancy with the only limitation being our wallets.

Best of luck.

[Timinator]

Originally Posted by Jim Vander Wal

Priobe,
I'm not trying to be difficult but...
Change for the sake of change can be fun but is usually expensive and often a step backwards. This is a "ask me how I know" question.
If you're not looking for enhanced performance why bother? You already have, by your own admission, a system that works well for you. You have what most would consider a seriously cool set-up, why change?
I often start a new endeavor with "I'm thinking...". My friends would be doing me a great favor if they'd just smack me up-side-the-head to straighten me out and ask "WTF".
And for Timinator, hoo-chee-momma, have you priced a Holley 4647?. Those must be the holy grail of carbs. Most likely though, they are 60 years old and surpassed in performance by a new $600-800 carb.
Jim

No, I honestly haven't priced one since I bought the one for my Pantera 30 years ago. It was definitely worth the $400 I paid for new back then! I think is was a Boss 429 original carb? But, back then, there wasn't any Holley or Carter or even Weber's that ran as well as one of those.