Match Race 1972 ~ 'Duster 340 vs 'GTO 400'
1972 Duster 340....... 14.45 @ 95 MPH.........3.55 w/Automatic
High Performance Cars Magazine {May 1972}
'Still a Potent Performance Car Despite the Low-Compression'
'The 'new' 1972 'Duster 340' still has the Mini-Hercules Engine plant, but Horsepower is now down to 240 HP,
due to Lower-Compression as a result of restrictions in emissions from the EPA. The 1972 340 now has an
advertised 8.5 to 1 Compression-Ratio, down from 10.3 to 1 in 1971.'
'The 240 HP rating is calculated at 4800 RPM's, which is down from the previous years 1971 340 which had
an output of 275 HP @ 5000 RPM's. Despite those advertised Horsepower numbers, most 'performance-minded'
drivers know that the 340 Horsepower numbers were purposely under-rated from Mopar.'
'The 'new' Low-Compression Cast Pistons are now found further down in the Cylinder, as the Piston-Pin locations
have been re-positioned .100" higher in the Piston boss, lowering the Compression height. The Pistons are still
Flat-Top slugs with Valve-Reliefs {notches} to allow for cylinder/valve burn-off.'
The 340 still has 'Forged Steel' Connecting-Rods and with the less friction Full-Floating pins. The late-year 1972 340
will now have a Cast Crankshaft, which is lighter than the previously utilized Forged Unit, but is not as strong.'
'The Mini-Hercules is still equipped with the responsive Hydraulic-Lift Camshaft, which has a 268*/276* Duration
and 44* Overlap. And the 'stiff' Valve-Springs balance out the Valve-Train with the durable and reliable stamped-steel
non-adjustable Rocker-Arms permit the Engine to easily crank out over 5000 RPM's.'
'The 1972 340 Cylinder Heads {#3418915} are now equipped with smaller {1.88"} Intake Valves, but the Heads still
retain the same #915 'J-Head' Cylinder and Port configuration and size, as well as 1.60" Exhaust Valves. The 'J-Heads'
have good Port Volume which provides for excellent Port Flow across the full RPM chart.'
'The factory rates the Cylinder Head combustion-chamber at 71 CC's, and this provides for an EPA accepted lower
emission discharge at lower RPM's. But, these Heads can be milled down to 64.7 CC's by removing {.032"} which will
gain an additional {.83} in Compression, and the 340 will still idle fine with the higher Compression.'
'The Cast Iron Intake Manifold {#3614025} is a bit bulky at #50 lbs., and the casting is very rough. The Plenum-opening
is rough-surfaced and poorly cast, and the Port-Runners are unequal with high-spots. But the Spread-Bore throttle
bore openings and 360* Dual-Plane design do provide for an adequate Flow thru the Runners.'
'The now proven Carter Thermoquad Carburetor with the 'thermoplastic' center housing provides for 28% cooler temperature
in the Fuel Bowl. The reduced temperature of the Fuel translates into higher engine efficiency, which allows for increased performance. The 800 CFM Thermoquad runs with a 1.375" Primary and 2.250" Secondary. The 'big' Thermoquad more than makes up the difference in the Low-Compression, and once the 'Monster-Sized' secondary throttles open up, the light #3165 lb. 'Duster 340' quickly takes off with a 'thunderous' air-grabbing vacuum sound coming from under-the-hood.'
'The Air-Cleaner is an Unsilenced Unit which is a wide-diameter low-profile style, which utilizes an under base-pan trap-door, and a single snorkel air-vent tunnel.'
'Ignition is new for 1972, as Mopar has switched over to Electronic Ignition. Now, the Distributor will utilize a 'Magnetic'
pick-up, and a firewall-mounted ECU {Electronic Control Unit} which will provide for an 'amplified spark'. This will provide
for more spark at higher RPM's and 35% higher voltage to the Spark Plugs.'
1972 Duster 340....... 14.45 @ 95 MPH.........3.55 w/Automatic
High Performance Cars Magazine {May 1972}
'Still a Potent Performance Car Despite the Low-Compression'
'The 'new' 1972 'Duster 340' still has the Mini-Hercules Engine plant, but Horsepower is now down to 240 HP,
due to Lower-Compression as a result of restrictions in emissions from the EPA. The 1972 340 now has an
advertised 8.5 to 1 Compression-Ratio, down from 10.3 to 1 in 1971.'
'The 240 HP rating is calculated at 4800 RPM's, which is down from the previous years 1971 340 which had
an output of 275 HP @ 5000 RPM's. Despite those advertised Horsepower numbers, most 'performance-minded'
drivers know that the 340 Horsepower numbers were purposely under-rated from Mopar.'
'The 'new' Low-Compression Cast Pistons are now found further down in the Cylinder, as the Piston-Pin locations
have been re-positioned .100" higher in the Piston boss, lowering the Compression height. The Pistons are still
Flat-Top slugs with Valve-Reliefs {notches} to allow for cylinder/valve burn-off.'
The 340 still has 'Forged Steel' Connecting-Rods and with the less friction Full-Floating pins. The late-year 1972 340
will now have a Cast Crankshaft, which is lighter than the previously utilized Forged Unit, but is not as strong.'
'The Mini-Hercules is still equipped with the responsive Hydraulic-Lift Camshaft, which has a 268*/276* Duration
and 44* Overlap. And the 'stiff' Valve-Springs balance out the Valve-Train with the durable and reliable stamped-steel
non-adjustable Rocker-Arms permit the Engine to easily crank out over 5000 RPM's.'
'The 1972 340 Cylinder Heads {#3418915} are now equipped with smaller {1.88"} Intake Valves, but the Heads still
retain the same #915 'J-Head' Cylinder and Port configuration and size, as well as 1.60" Exhaust Valves. The 'J-Heads'
have good Port Volume which provides for excellent Port Flow across the full RPM chart.'
'The factory rates the Cylinder Head combustion-chamber at 71 CC's, and this provides for an EPA accepted lower
emission discharge at lower RPM's. But, these Heads can be milled down to 64.7 CC's by removing {.032"} which will
gain an additional {.83} in Compression, and the 340 will still idle fine with the higher Compression.'
'The Cast Iron Intake Manifold {#3614025} is a bit bulky at #50 lbs., and the casting is very rough. The Plenum-opening
is rough-surfaced and poorly cast, and the Port-Runners are unequal with high-spots. But the Spread-Bore throttle
bore openings and 360* Dual-Plane design do provide for an adequate Flow thru the Runners.'
'The now proven Carter Thermoquad Carburetor with the 'thermoplastic' center housing provides for 28% cooler temperature
in the Fuel Bowl. The reduced temperature of the Fuel translates into higher engine efficiency, which allows for increased performance. The 800 CFM Thermoquad runs with a 1.375" Primary and 2.250" Secondary. The 'big' Thermoquad more than makes up the difference in the Low-Compression, and once the 'Monster-Sized' secondary throttles open up, the light #3165 lb. 'Duster 340' quickly takes off with a 'thunderous' air-grabbing vacuum sound coming from under-the-hood.'
'The Air-Cleaner is an Unsilenced Unit which is a wide-diameter low-profile style, which utilizes an under base-pan trap-door, and a single snorkel air-vent tunnel.'
'Ignition is new for 1972, as Mopar has switched over to Electronic Ignition. Now, the Distributor will utilize a 'Magnetic'
pick-up, and a firewall-mounted ECU {Electronic Control Unit} which will provide for an 'amplified spark'. This will provide
for more spark at higher RPM's and 35% higher voltage to the Spark Plugs.'
