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Olds With 4 Quadrajet Carbs: Madness or Hot Rodding At Its Finest?
By Mike Magda posted on Oct 27, 2014 in Carburetors, Engine, Event Coverage
(8) Comments
Just about every passion essential to the spirit of hot rodding is embodied in the Quadrajet Madness project – a two-year tech odyssey that resulted in a wicked-looking 16-barrel, 3,000 cfm induction system for a 425ci Olds Rocket engine powering a ’66 Cutlass street/strip car.
The QuadQuad project makes its debut at the Olds Nationals.
Neill Gathings and Tom Cox, both engineers and inventive DIY’ers who found a second calling at the dragstrip, are the mad men behind the Madness project and fabricated the tall, individual-runner intake manifold that supports four Quadrajets on top.
“This was an all-out, gonna-do-it-no-matter-what effort,” says Gathings, “and it changed us forever. The journey and knowledge gained by the trials were worth more than the final destination, for sure.”
Even though this carb-manifold arrangement hasn’t been seen much since its debut at the 2006 Olds Nationals, and no one else has tried a similar concept, it’s a little premature to assume it didn’t work at all. As seen in the accompanying videos, the engine idled rather aggressively and responded to whips at the throttle in neutral. But it just wouldn’t drive and accelerate under load. The team narrowed down possible solutions, however, time and money became a factor and the project has been dormant.
Tom Cox, left, and Neill Gathings conceived the QuadQuad idea and handled all the fabrication.
Gathings’ introduction to the Quadrajet carburetor came many years ago when the high-dollar 390ci FE build in his ’73 F-100 rejected six different carbs. Cox suggested a Qjet.
“Tom had much more experience with cars,” remembers Gathings, noting that Cox had a head and intake porting business at the time. “So, you’d think I would have listened, right? Wrong. Another year passed before I took a trip to the wrecking yard to find what was the best carburetor I’ve ever had, a Quadrajet off a ‘72 Delta 88 455. That little 750 cfm carburetor got my mind flowing on what carburetors were all about.”
Starting over with Qjets
Gathings and Cox raced a ’66 Olds that ran in the low 12s and wanted more “crispness” on the street, so the 830 cfm Holley double-pumper was swapped out for a Qjet. Working from popular how-to books and growing experience with the carb, the car soon inspired a wild vision.
The team used Photoshop in the early stages of planning to envision what four carbs would look like on a cross-ram and tunnel-ram.
The team settled on a sectional design for versatility.
“We decided that it was time to jump off into the deep end and build something big, as if the Rochester division created an exhibition car using Qjets,” says Gathings, adding that he and Cox always believed the Quadrajet was unfairly saddled with a poor reputation due to poor tuning by the owners and lack of a strong racing promotion from GM. “We had a vision of what it would have been like to make a car that could bring attention to the carburetor like never before.”
That vision was a ’66 Cutlass named “Quadrajet Madness” that would be similar in concept to the famous Hurst car. Instead of a massive supercharged engine, this Olds would be built with a massive tunnel-ram “Quad-Quad” manifold showcasing a quartet of Qjet carbs on top.
“Thus, the system would complete a mechanical sculpture that both Archimedes and Bernoulli would have been impressed with,” beams Cox.
The team started by evaluating what was available, notably an early cross-ram intake, but then settled on a tunnel-ram.
“We mocked up the tunnel ram with four Qjets we had laying around to check height and overall fit,” says Gathings. “It was really starting to come together.”
CAD drawings also helped finalize the concept.
“The theory behind the QuadQuad is pretty simple actually. It began with the idea that dual-plane intake manifolds split a four-barrel carb in half, so each cylinder sees half of the carburetor at any one time,” explains Cox. “This being said, we began looking at what happens if we try to make the intake an independent runner and how it would affect the cfm per cylinder. While looking at the alignment we noticed that the runner spacing and thus the carburetor division would be identical to any dual plane intake. We determined it was clear that the pulse or signal would be incredibly strong with zero interference between cylinders. The engine would have all the flow needed to support 600-plus horsepower without being over carbureted.”
Quartet of restored beauties
Sparky's Qjet Restoration
Sparky’s Carburetor Service in Wisconsin handled the restoration, modifications and fuel-curve setup on the four Quadrajet carbs. Operated by Greg Kalkoff, Sparky’s specializes in Qjet carbs from the musclecar era and emphatically asserts that no Holleys or Edelbrocks will be accepted.
“Our success was dependent on getting the carbs matched exactly,” says Gathings. “We were moving into new territory for all involved. The technical details were discussed as to how the engine will have enough signal to keep the circuit active and what did that mean to the pulse generation on each carb.”
Sparky’s developed a rebuild strategy was that baselined the carbs similar to an Olds W30 model and completed the restoration process before returning the units.
For more information on Qjet restoration and modifications, visit sparkyscarbs.com.
The team found six Qjet castings that featured straight fuel inlets off salvaged Olds engines, and the four best units were sent sent off for restoration and calibration. Problem was, very little info was available on multi-Qjet arrangements. Will the engines provide enough signal to keep the circuits active? What parts of the carb will be affected by low and instantaneous vacuum created by the pulse? The team investigated other performance Quadrajets from the musclecar era.
“Those carbs omitted the power piston and rod on the primary side due to vacuum signal loss and the inability to control the circuit properly,” says Cox. “The factory used jets only for the primary side of the carbs and plugged the power piston completely, thus negating the issue of vacuum signal abnormality.
<p>Your browser does not support iframes.</p>
Olds With 4 Quadrajet Carbs: Madness or Hot Rodding At Its Finest?
By Mike Magda posted on Oct 27, 2014 in Carburetors, Engine, Event Coverage
(8) Comments
Just about every passion essential to the spirit of hot rodding is embodied in the Quadrajet Madness project – a two-year tech odyssey that resulted in a wicked-looking 16-barrel, 3,000 cfm induction system for a 425ci Olds Rocket engine powering a ’66 Cutlass street/strip car.
The QuadQuad project makes its debut at the Olds Nationals.
Neill Gathings and Tom Cox, both engineers and inventive DIY’ers who found a second calling at the dragstrip, are the mad men behind the Madness project and fabricated the tall, individual-runner intake manifold that supports four Quadrajets on top.
“This was an all-out, gonna-do-it-no-matter-what effort,” says Gathings, “and it changed us forever. The journey and knowledge gained by the trials were worth more than the final destination, for sure.”
Even though this carb-manifold arrangement hasn’t been seen much since its debut at the 2006 Olds Nationals, and no one else has tried a similar concept, it’s a little premature to assume it didn’t work at all. As seen in the accompanying videos, the engine idled rather aggressively and responded to whips at the throttle in neutral. But it just wouldn’t drive and accelerate under load. The team narrowed down possible solutions, however, time and money became a factor and the project has been dormant.
Tom Cox, left, and Neill Gathings conceived the QuadQuad idea and handled all the fabrication.
Gathings’ introduction to the Quadrajet carburetor came many years ago when the high-dollar 390ci FE build in his ’73 F-100 rejected six different carbs. Cox suggested a Qjet.
“Tom had much more experience with cars,” remembers Gathings, noting that Cox had a head and intake porting business at the time. “So, you’d think I would have listened, right? Wrong. Another year passed before I took a trip to the wrecking yard to find what was the best carburetor I’ve ever had, a Quadrajet off a ‘72 Delta 88 455. That little 750 cfm carburetor got my mind flowing on what carburetors were all about.”
Starting over with Qjets
Gathings and Cox raced a ’66 Olds that ran in the low 12s and wanted more “crispness” on the street, so the 830 cfm Holley double-pumper was swapped out for a Qjet. Working from popular how-to books and growing experience with the carb, the car soon inspired a wild vision.
The team used Photoshop in the early stages of planning to envision what four carbs would look like on a cross-ram and tunnel-ram.
The team settled on a sectional design for versatility.
“We decided that it was time to jump off into the deep end and build something big, as if the Rochester division created an exhibition car using Qjets,” says Gathings, adding that he and Cox always believed the Quadrajet was unfairly saddled with a poor reputation due to poor tuning by the owners and lack of a strong racing promotion from GM. “We had a vision of what it would have been like to make a car that could bring attention to the carburetor like never before.”
That vision was a ’66 Cutlass named “Quadrajet Madness” that would be similar in concept to the famous Hurst car. Instead of a massive supercharged engine, this Olds would be built with a massive tunnel-ram “Quad-Quad” manifold showcasing a quartet of Qjet carbs on top.
“Thus, the system would complete a mechanical sculpture that both Archimedes and Bernoulli would have been impressed with,” beams Cox.
The team started by evaluating what was available, notably an early cross-ram intake, but then settled on a tunnel-ram.
“We mocked up the tunnel ram with four Qjets we had laying around to check height and overall fit,” says Gathings. “It was really starting to come together.”
CAD drawings also helped finalize the concept.
“The theory behind the QuadQuad is pretty simple actually. It began with the idea that dual-plane intake manifolds split a four-barrel carb in half, so each cylinder sees half of the carburetor at any one time,” explains Cox. “This being said, we began looking at what happens if we try to make the intake an independent runner and how it would affect the cfm per cylinder. While looking at the alignment we noticed that the runner spacing and thus the carburetor division would be identical to any dual plane intake. We determined it was clear that the pulse or signal would be incredibly strong with zero interference between cylinders. The engine would have all the flow needed to support 600-plus horsepower without being over carbureted.”
Quartet of restored beauties
Sparky's Qjet Restoration
Sparky’s Carburetor Service in Wisconsin handled the restoration, modifications and fuel-curve setup on the four Quadrajet carbs. Operated by Greg Kalkoff, Sparky’s specializes in Qjet carbs from the musclecar era and emphatically asserts that no Holleys or Edelbrocks will be accepted.“Our success was dependent on getting the carbs matched exactly,” says Gathings. “We were moving into new territory for all involved. The technical details were discussed as to how the engine will have enough signal to keep the circuit active and what did that mean to the pulse generation on each carb.”
Sparky’s developed a rebuild strategy was that baselined the carbs similar to an Olds W30 model and completed the restoration process before returning the units.
For more information on Qjet restoration and modifications, visit sparkyscarbs.com.
The team found six Qjet castings that featured straight fuel inlets off salvaged Olds engines, and the four best units were sent sent off for restoration and calibration. Problem was, very little info was available on multi-Qjet arrangements. Will the engines provide enough signal to keep the circuits active? What parts of the carb will be affected by low and instantaneous vacuum created by the pulse? The team investigated other performance Quadrajets from the musclecar era.
“Those carbs omitted the power piston and rod on the primary side due to vacuum signal loss and the inability to control the circuit properly,” says Cox. “The factory used jets only for the primary side of the carbs and plugged the power piston completely, thus negating the issue of vacuum signal abnormality.
