Super Six install on 1974 Dart
This thread will document my project to install the "Super Six" 2-barrel setup on my 1974 Dart, originally equipped with a Holley 1945 one-barrel carburetor.
Why I'm doing this:
1. The Super Six and Carter BBD carburetor should improve the general performance of the engine. I had already wanted to do this at some point.
2. I'm doing it a bit sooner than planned because the engine is running very lean with the 1945 even though I've installed a bigger jet (64). Hopefully the Super Six will solve the mixture problem, but if not at least I'll have a better setup to work with. The 1945 is recently rebuilt and was NOS 5 years/10k miles ago, so I don't think there's much hope of improving its function. I don't want to replace it with another one, so why not make an upgrade?
3. The engine is newly rebuilt and has always had (and still has) lots of ping under load. I've done a lot of troubleshooting and I think I've narrowed the list of causes down to lean mixture. How I know the engine is running lean: several reasons but ultimately I installed an AFR sensor. It reads 15-16 under power.
The engine:
- Original to the car, 90k miles, never rebuilt until this year
- Ignition: stock electronic ignition, new plugs, nearly new wires, coil is original
- Timing: stock (0 degrees initial, about 30 degrees mechanical, all in by 3000 RPM; vacuum advance is 0 up to 6 inches, then increases to 17.5 degrees by 16 inches)
- Exhaust: stock (2" all the way back, no catalytic converter)
- Drive train: 904 transmission, 8.25" sure-grip differential with 2.71:1 gear ratio
Rebuild:
- Bored cylinders 0.030" oversize, removed about 0.100" total from block and head
- Compression ratio is now 8.9:1 static (8.0:1 "dynamic" depending how you calculate)
- Reground original camshaft to RV-10 Reverse Dual Pattern, degreed during installation
- Replaced all exhaust valves (worn stems) and one intake valve (pitted stem), replaced valve springs
- Smoothed combustion chamber valve pocket areas, smoothed and evened manifold areas (no major porting, just light cleanup)
- Rebuilt harmonic balancer
- Original crankshaft didn't need any work done
- Replaced all main and rod bearing sleeves
- Rebuilt oil pump (checked within specs in factory shop manual)
- Replaced water pump
- Kept same fuel pump, which was pretty new
- Painted everything Chrysler blue, black, or Slip Plate (exhaust manifold, pulleys, etc.)
- Adjusted valves to 0.015" intake, 0.015" exhaust per cam spec sheet
- Filled cooling system with Evans waterless coolant
Here's what the engine looked like after the rebuild. I also touched up the engine compartment with some red paint while it was empty.
The Super Six setup came complete from a junkyard 1979 Lebaron 4-door. Here it is ready to come home. Someone on slantsix.org described it as looking like it came from the bottom of a lake, and I can't disagree. The main parts I'm using are the intake manifold, linkages, brackets, and air cleaner. All of those should clean up just fine. If the carburetor is trash, so be it.
I had to go back for the piece I didn't know to get: a 3" bracket that connects the kickdown linkage to the transmission. It swings fore and aft and has a D-shaped hole in it that is different between A-bodies and F-bodies. Thanks to matv91 on slantsix.org for pointing that out. Here's that piece.
This thread will document my project to install the "Super Six" 2-barrel setup on my 1974 Dart, originally equipped with a Holley 1945 one-barrel carburetor.
Why I'm doing this:
1. The Super Six and Carter BBD carburetor should improve the general performance of the engine. I had already wanted to do this at some point.
2. I'm doing it a bit sooner than planned because the engine is running very lean with the 1945 even though I've installed a bigger jet (64). Hopefully the Super Six will solve the mixture problem, but if not at least I'll have a better setup to work with. The 1945 is recently rebuilt and was NOS 5 years/10k miles ago, so I don't think there's much hope of improving its function. I don't want to replace it with another one, so why not make an upgrade?
3. The engine is newly rebuilt and has always had (and still has) lots of ping under load. I've done a lot of troubleshooting and I think I've narrowed the list of causes down to lean mixture. How I know the engine is running lean: several reasons but ultimately I installed an AFR sensor. It reads 15-16 under power.
The engine:
- Original to the car, 90k miles, never rebuilt until this year
- Ignition: stock electronic ignition, new plugs, nearly new wires, coil is original
- Timing: stock (0 degrees initial, about 30 degrees mechanical, all in by 3000 RPM; vacuum advance is 0 up to 6 inches, then increases to 17.5 degrees by 16 inches)
- Exhaust: stock (2" all the way back, no catalytic converter)
- Drive train: 904 transmission, 8.25" sure-grip differential with 2.71:1 gear ratio
Rebuild:
- Bored cylinders 0.030" oversize, removed about 0.100" total from block and head
- Compression ratio is now 8.9:1 static (8.0:1 "dynamic" depending how you calculate)
- Reground original camshaft to RV-10 Reverse Dual Pattern, degreed during installation
- Replaced all exhaust valves (worn stems) and one intake valve (pitted stem), replaced valve springs
- Smoothed combustion chamber valve pocket areas, smoothed and evened manifold areas (no major porting, just light cleanup)
- Rebuilt harmonic balancer
- Original crankshaft didn't need any work done
- Replaced all main and rod bearing sleeves
- Rebuilt oil pump (checked within specs in factory shop manual)
- Replaced water pump
- Kept same fuel pump, which was pretty new
- Painted everything Chrysler blue, black, or Slip Plate (exhaust manifold, pulleys, etc.)
- Adjusted valves to 0.015" intake, 0.015" exhaust per cam spec sheet
- Filled cooling system with Evans waterless coolant
Here's what the engine looked like after the rebuild. I also touched up the engine compartment with some red paint while it was empty.
The Super Six setup came complete from a junkyard 1979 Lebaron 4-door. Here it is ready to come home. Someone on slantsix.org described it as looking like it came from the bottom of a lake, and I can't disagree. The main parts I'm using are the intake manifold, linkages, brackets, and air cleaner. All of those should clean up just fine. If the carburetor is trash, so be it.
I had to go back for the piece I didn't know to get: a 3" bracket that connects the kickdown linkage to the transmission. It swings fore and aft and has a D-shaped hole in it that is different between A-bodies and F-bodies. Thanks to matv91 on slantsix.org for pointing that out. Here's that piece.
