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Swing n Sting Dart Engine

The Dart was running again, but we found we needed a little help in the system

John and Geoff Stunkard - May 30, 2013 10:00 AM

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After getting the specs from us, QFT recommended this great street carb, the SS-750-AN. It uses their latest annular booster technology, mechanical secondary operation, and an electric choke. Also shown is the 30-803 QFT regulator.

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The Edelbrock RPM Air-Gap intake had come from Mancini. It is a square-bore design that allows the carb to be raised off of the hot intake valley; QFT had included a fresh gasket for the throttle body-to-intake connection.

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Meanwhile, James and the Nickels Speed Shop crew had gotten us our lines and fittings; all of this can be purchased online as well. We needed a fitting with a port for the pressure gauge from our old line; they had it.

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We took our feed line built by Hensley from the pump to the carb and refit it easily to run from the fuel line to the new regulator.

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The braided lines are cut apart using a cut-off wheel; tape around the braiding keeps it from fraying. Using a bench-mounted vise will allow you to get the ends properly tightened.

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 A very important step is making sure the lines you built are completely cleaned out. Spray some brake cleaner down into them and then blow them out with compressed air.

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We found the Engine Works fittings were very nicely made and finished.

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The line from the pump to the engine compartment was flared on the car; this requires a bit of effort due to the tight confines here.

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 This is the regulator and mount sent by QFT, which we mounted to the inner fender. Here is how the primary feed line is mounted.

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Next, we added the gauge from our old line onto the primary leg of the regulator; pressure is adjusted using the nut and the extension coming from the top.

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Now we focused on the throttle side, fitting the return spring and accelerator cable. The special bracket and transmission kickdown cable came from Mancini’s deep “small parts” product line.

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 Tracy used a vacuum gauge to set the idle speed and mix. The QFT carb is very tuneable but required a little adjustment from what we received right out of the box.

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Here is how our new carb and lines looked. The use of gentle bends and quality fittings has left us with a safe and satisfying installation.

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The fall leaves were changing and the Swing ’N Sting Dart was again back on the road after a year.

Our project, which had received so much assistance from Mancini Racing, Hughes Engines, Hensley Performance, Mr. Gasket, PRW, Cometic, and so many others, was a lot of fun to drive, but we were running into a few issues that we had not planned on. The first was fuel demand; the carb we had selected when using the 318 was really working hard now.

We had made a mistake of not cleaning out the new bowl feed lines, and had gotten a lot of garbage into the internal passages and delicate metering parts of our Quick Fuel Technology’s HR-680-VS model. With 74 more inches thanks to Mancini Racing and Hughes’ super-hot hydraulic Whiplash cam opening the valves in our Magnum-style AAEQ heads, we decided we would check with QFT on our options before going forward with a simple carb rebuild.

Our friend Tracy Hicks of Wizeguy Rod & Custom in Jonesborough, Tennessee, helped us find this car, and had been part of our earlier forays into building it. We called him and he recommended we get into touch with Nickels Performance in Piney Flats, Tennessee. Nickels runs a full-tilt mail-order business that ships worldwide, but they also have a speed shop on the premises. So he called counterman James Edens and got us what we needed in parts to go from the feed line to the regulator and over to the new carb.

New carb? Yep. After checking with QFT, they asked for some info to make a right selection. This information is needed to select the best possible compromise. Our point person there was Bill Wetzel, but you can contact QFT’s other customer service guys to have somebody help you sort out exactly what you need. What Bill and the engineers came up with for us was surprising – the SS-750-AN.

This was because it went against my conventional ideas about both size and vacuum secondary selection. With a 750cfm rating, this is a street carb with mechanical operation, and was selected due in part to the car’s light weight and converter stall. Since we did not have a lot of gear in the back, we would be using the primary section of the carb for street driving; as a square-bore layout, the primary circuit would provide enough fuel for almost 400 cubes under the 3,000 rpm range. However, when that Dynamic-built converter came in hard, all the fuel needed to meet the demand was on tap.

Moreover, the development of annular discharge technology is a terrific benefit over all the things we used to think about carb selection. The annular design places multiple outlets at the lower stepped area of the venturi, creating very precise metering based on actual fuel demand, as well as throttle position. This means more horsepower in most cases and more exact fuel burning due to a better air/fuel mixture as the intake charge enters the intake runner and combustion chamber. With the specs on our Hughes Whiplash cam (which had impressed every single person who has heard it at both idle and at speed), this technology was perfect.

We would be remiss to not add that the SS-750-AN also looks very nice. With red anodized billet metering blocks, booster inserts, and throttle body, plus sight glasses in the float bowls, polished aluminum construction, and the electronic choke, it was a crowning touch to the engine in the car.

But we still needed to install it. That effort was again helped as QFT had a very nice off-the-shelf pressure regulator (p/n 30-803) available as well. For lines and fittings, we went with Engine Works, which is a private label brand that Nickels Performance markets. This included the braided line, plus AN-6 fittings and couplings; everything was on the shelf and, having talked to James ahead of time, the order was ready to be picked up and paid for when we arrived.

The Nickels Speed Shop is very cool, as it is one of the few places still having retail space for performance products; the only similar design with such a large variety we had seen recently had been Mancini’s Clinton Township location, which is the last speed shop still open in the greater Detroit area. At any rate, we were ready to go, and we headed the 30 miles to Jonesborough where Tracy would help us out.

The result? Let’s just say that we might need some tires soon! Tracy, whose 540-inch Rodeck Chevelle is scary fast, came back from the first test run with a big smile and the rubber streaked down onto the country pavement was through most of second gear.

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