That gnarly carburetor sound.

[mike walsh]

Hmm...maybe I'm 'overhearing' the obvious.

Do you mean that deep, throaty, tone that happens when you first punch the throttle?

That's what i figured, that "Whoooooop," as the secondaries tip in is what he's after. Bet he wants a cam that "hits."

[A Atwood]

Hmm...maybe I'm 'overhearing' the obvious.

Do you mean that deep, throaty, tone that happens when you first punch the throttle?

Okay, understand that this is not a sound that all V8's get. Only certain combinations got it. But when they really get it, the sound comes in when the 4 (or 8 ) barrels are opened up, and it doesn't go away as long as the carb is opened. It just sounds better and better with more and more rpm. The carb itself is not what makes the sound, it just lets the sound out. My buddy's would do it with or without the air cleaner. Incredibly loud. And his was a Holley 650 DP. I do think the larger the carb, the larger the sound (potentially). That is why the thermoquads were good at it(very large cfm). But there are plenty of cases where the quadrajet or thermoquad will not get the sound. It just depends on the engine.
When a person gets a ride in a car that has that ridiculous carb sound, they never forget it. It is so cool!

ARN

[A Atwood]

I understand about the sound and your post caused me to reflect upon a simpler time. Many stock or mildly modified engines of the 50's & 60's had the "sound" Maybe it was the small ports? small carbs? small cams? of that era?

I even specifically remember a friends car as you describe. The scream of the intake announced his coming. He had a 1956 Chevy with a warmed up 283, a pair of the original Chevy in-line two WCFB carbs and a four speed. The car actually sounded better coming at you than it did going from you.

The thoughts from those days make me smile.

This is interesting, my father in law (at the time) told me a story of a car he had that was a late 50's Chevy with a 283 and dual 4's. He said it was all carburetor. Said it had the loudest carb(s) sound he ever heard.

ARN

[strokersix]

Q-jet secondaries for sure! I love it.

[bottlefed]

Hemi with a crossram...the common term for those was "Honkin" The same with the Stage wedge engines "Honkin" I feel you were hearing the intake pulses, low stall converters, big intake ports and small exhausts as well as ineffecient cams all added to the sound. Some other sweet ones were the 3 twos anything from the early rochester 2gc's Tripower Ponchos

Cars me and my brother had back then that fit the description,

I had a 63 421 Superduty Catalina with a 421 4sd and 4.33? rear with 8 lug wheels. Nice sound but not all that deep I think because of the small intake on the Poncho did not have enough volume in the plenum for a deep sound.

68 Monaco with 383 and dual exhaust and single AFB slight honkin

426 Stage 3 with crossram intake "Honkin Mutha"

My brother had a 426 Hemi inline 2 4s "Honkin mutha"

I had a track car, 440 crossram with 2 600 holleys but it was way too modified to honk! this is why I am sure it was the induction pulses, on the same engine that would be a "honking mutha" stock with headers by the time you had a cam and head porting done and a converter that sound was history even with the big intake plenum.

[NoMoore]

I love this thread! Takes me back to high school pipes and turning the air cleaner lid upside down. I used to love that noise too. I still do.

[R.Olds]

I wish I could tell you...trying to hear anything from under the hood within the car over my loud exhaust would be a stretch at best.

Even when near the engine while tuning, the fans, valvetrain and ambient noise would mask pretty much everything else. I did hear
the sound of air flowing into the motor; almost a faint whistle with pitch increasing as the throttle opened (through the filter element I believe).

Is that what you mean?

Do you have a recording of this sound? I'm curious to hear what you're talking about.

The carburetor sound I am referring to is not something that is hard to hear. If you were inside my buddy's 71 Nova when he opened it up, the only thing you COULD hear was the carb. Totally obnoxious and harmonic at the same time. From outside the car, if he was headed in your direction and opened the throttle, same thing. All carburetor! You could hear his car(carburetor that is) coming in your direction before you would see him. He used to do it on purpose cause he knew we could hear it.
I have heard this sound the most on small Chevys, 383 and 440 BB Mopars, and Pontiac 400 & 455s. They also all have similar head designs. Not sure if that has anything to do with it though.

Hollywood used this sound in many movies with almost any car chase scene.

ARN

Any car I owned that had the Quadra bog on them, would make considerably more WOT roar then the average holley would, especially with a after market air cleaner.

Rick

[rfoll]

I had a setup that made sounds similar to those being described here. When the secondaries opened, it initially made the vacuum cleaner noise, but when rpms approached 5000, the noise was more like a siren, and very loud. Really disturbing to the guy in the other lane (street racing). The combo was a 327 with large popup pistons and a 300 hp cam. It had rams horn exhaust, Quadrajet manifold, and a Holley 650 dp spreadbore carb. The motor was incredibly torquey. Later on I put in a much larger cam and the noise was gone. My guess is the noise was the result of lots of vacuum at higher rpms as a result of the high compression/small cam combo. I used the intake/carb/cam combo on various other motors over the last 35 years and none produced anything like that sound. You would need race gas to run that much cr. these days... this was before the 1970's gas shortage.

[A Atwood]

I had a setup that made sounds similar to those being described here. When the secondaries opened, it initially made the vacuum cleaner noise, but when rpms approached 5000, the noise was more like a siren, and very loud. Really disturbing to the guy in the other lane (street racing). The combo was a 327 with large popup pistons and a 300 hp cam. It had rams horn exhaust, Quadrajet manifold, and a Holley 650 dp spreadbore carb. The motor was incredibly torquey. Later on I put in a much larger cam and the noise was gone. My guess is the noise was the result of lots of vacuum at higher rpms as a result of the high compression/small cam combo. I used the intake/carb/cam combo on various other motors over the last 35 years and none produced anything like that sound. You would need race gas to run that much cr. these days... this was before the 1970's gas shortage.

Yeah, it is when an engine like this gets the rpm up, like you described, that they really sound great!

Yours was a high compression deal. My buddy's Nova had a stock 71 350 shortblock. Weak compression. But his really roared. I mean it screamed.
And it had a 650 DP on a weind single plane (I believe the part # was 7546) with long tube headers. Stock heads. He said the cam was a 230 @ .050 Crane with .460 lift.

With these large quadra-jets, you would think the manifold vacuum at WOT would be very low. I still cannot figure out what exactly makes the sound. It can't be just air speed, cause a better design cylinder head will support higher air speed, yet no sound.

On the Compcams master lobe catalog, some of the lobes actually say they create more "throaty sound" than others. Could the cam's ramp rates have anything to do with it?

ARN

[rfoll]

Just to be clear, I had a spreadbore Holley on an iron Qj manifold. Theads were pocket ported 194 valve 462s. My understanding is higher compression ratios produce more vacuum, all else being equal. My suggestion about the vacuum at rpm is thinking about the narrow duration cam involved. Noises are all about harmonic frequencies and Obviously changing the cam altered them. There is also the possibility the huge dome on the piston had some effect. I ran an 800 cfp Holley spreadbore on this manifold, and it did not make near the noise, nor did the Qj carb that came on the manifold.

[A Atwood]

So the carb that made the most sound was the smallest of the three you tried.

Also, you say you have had this same combination on several other engines, but with no sound? Would seem that with the same cam heads & intake, the sound should be similar.

ARN

[Troy Patterson]

Any car I owned that had the Quadra bog on them, would make considerably more WOT roar then the average holley would, especially with a after market air cleaner.

Rick

That was because most guys didn't have a clue how big the Quadra Jet was and they would install little Holley double pumpers that weren't large enough to let the sound out.

Also, air / fuel ratio will affect the sound, increase it or decrease it or just change it.

Troy Patterson TMPCarbs.net TMP Carbs

[rfoll]

None of the other engines this setup was installed on had the high compression. Mfg claimed these to be 12:1 pistons, the dome was huge. As for the change from the Qj to the Holley, these were new designs when I bought it and it ran much better than the Qj I managed to screw up by tinkering with it. 38 years later I use the Qj on every street vehicle I own. They always get better MPG, and I have tried anything I could get my hands on that would function with my Equipment.

[Troy Patterson]

Quadra-puke, Quadra-flood, Quadra-bog, Quadra-bog - whatever people called them back in the day, they really were very good carburetors. I am a devoted big venturi / butterfly guy, but I've got to admit those little tiny primaries on the Quadra-Jet work really good and they give the feel of a much bigger cross sectional area. One of my first set-ups when I started messing with carburetors when I was 14-15 years old was going to be two Quadra-Jets on a Offy 360* intake I had for my '57 Ford with a 390. I built and ran the factory 3x2 intake with non-original carbs and unfortunately never got around to the dual Quadra-Jet set up. Wish I had.

But then, I sort of hijacking the thread aren't I

Troy Patterson TMPCarbs.net TMP Carbs

[quickd100]

I always got a kick out guys that disparaged one brand of carb or another. They are all just fuel delivery systems, they all have their individual quirks. I really like the Carter Thermoquad carb, easy to tune, dirt cheap, and lots of CFM potential. I've got a modified set on a tunnel ram on my Hemi. Dave