The RB Engines: 383-413-426-440
Mopar Big Engine Evolution: 350 to 426 Hemi
The B series engines were the first to be designed by the new corporate engineering department. The RB (“raised B”) arrived just one year after the launch of the B series engines, with the 413; just as all the B-engines had a 3.38-inch stroke, all the RB engines had a 3.75 inch stroke. For 1960, a “ram induction” system shot the 413’s torque up to 495 lb-ft on the Chrysler 300F, trumping the old 392 Hemi by a good margin.
|Original Block||4.06||3.375||350||Raised Block||4.18"||3.75"||413|
The two 383 engines
In 1963, Dodge buyers had a choice of the 383 with a two-barrel carb (305 hp) or a Power Pack version, with a high performance cam, dual-breaker ignition, dual exhausts, and four-barrel carb (330 hp). The 426 cubic inch V8 was marketed to racers; the 415 hp version had twin four-barrel carburetors and a manual choke (470 lb-ft), while the 425 hp version (480 lb-ft) upped the compression ratio from 11 to 13.5:1.
The 383 cubic inch RB engine was only available in 1959-1960 on the US built Chrysler Windsor and Saratoga (thanks, Ian Smale and Bill Watson); one of Trenton Engine’s lines had been converted to the new RB engine (to make the 413), and demand for the 383 was too high for the remaining line. The solution was to create an RB 383 to fill the gap, until the plant figured out how to quickly switch from one block to the other. American-made Chrysler and Imperial cars used the RB blocks, with the 413 going into Imperial, New Yorker, 300E, and 300F. U.S. Chrysler/Imperial usage for those years was:
|Chrysler Windsor / Saratoga||RB - 383||47,219||52,349||99,568|
|Chrysler New Yorker / 300||RB - 413||17,025||20,602||37,627|
|Imperial||RB - 413||17,262||17,719||34,981|
In 1966, thanks to development of precision thin wall casting techniques used to make the 1964 small 273 ci V-8, the RB block could be pushed out to 4.32 inches, providing the 440, the largest V8 ever made by Chrysler. (Ironically, the largest engine overall — the Viper V10 — was based on the little 273’s engine family).
Curtis Redgap wrote:
The 413 cubic inch (6.8 liter) RB engine was used from 1959 to 1965 in cars; it powered almost all Chrysler New Yorkers, all Imperials, as well as being an option on the lesser Chryslers, Dodge Polara, Dodge Monaco, and Plymouth Fury. It was also fitted to some European cars such as the later Facel Vega Facel II.
In the 1959 Chrysler 300E, the 413 was fitted with inline dual 4-barrel carburetors; it was factory-rated at 380 brake horsepower at 5000 rpm and 450 lb-ft at 3600 rpm. The next year, on the Chrysler 300, it gained a long-tube ram induction system which continued on the 1961 300-G, and remained on the option sheets for Chrysler 300s through 1964.
The 413 was not developed to be a racing engine, but a high torque, medium horsepower powerplant to haul the Chrysler luxury barges. Still, because it was Chrysler’s biggest engine in displacement for some years, the Petty racing clan did their own development work on the 413 starting in 1960. Then, in 1962, a special version of the 413 known as the “Max Wedge” was sold for drag racing and street use, with an official 420 bhp at 5,000 rpm.
The 413 was used in medium- and heavy-duty trucks until 1979.
The RB-engine performance story
The 'RB' engine performance story begins with the introduction of the long ram, 2-4 barrel setup in 1960; this 413 cubic inch engine, with ram induction manifolds and 400 bhp (gross), first appeared on the 1960 Chrysler 300F, and was put to good use in racing and at the Daytona speed trials.
|Valve Arrangement||Overhead, in-line, hydraulic|
|Bore, Stroke, Compression||4.18 x 3.75: 10.1 to 1|
|Max. BHP @ Engine RPM||375 @ 5,000 (std) or 400 @ 5,200|
|Max. Torque @ Engine RPM||495 @ 2,800 (std) or 465 @ 3,600|
|Firing Order||1, 8, 4, 3, 6, 5, 7, 2|
|Valves||Intake: 2.08” Exhaust: 1.60”|
|Valve Lift||Intake and Exhaust: 0.430”|
|Valve Open Duration||Intake and Exhaust: 268°|
|Valve Overlap||48°: Intake opens 20° B.T.D.C., Exhaust closes 28° A.T.D.C.|
|Piston & Piston Rings||Aluminum alloy pistol with three rings|
|Crankshaft||Drop forged steel|
1962 saw a new and highly unusual setup: the 413 Max Wedge, with two 4 barrel carburetors and two ram-air intake tubes crossing each other to gain an optimism length to produce an incredible (for 1962) 420 hp. Though it produced tremendous power, the artistic setup proved to be less than perfect at the track, where the tradeoff of power at one rpm for another was judged to be not worthwhile, and in 1963 the 413 Max Wedge was dropped. Both 413 and (starting in 1963) the 426 were available with either the high-performing 300J heads or the less desirable 516 head. (The heads had a wedge design, hence the name "Max Wedge.")
The Max Wedge was continued in 1963 and 1964 as a 426 in the Stage II and Stage III versions. These Max Wedge engines were unique, with special blocks, rods, crankshafts, pistons, heads, valves, valve gear, intake manifolds, carburetors and exhaust manifolds. A street-tuned 426 Wedge was also launched, but it was based on the Chrysler New Yorker’s luxury 413 four-barrel, and performance was not far above the similarly outfitted 383.
Ads for the 1963 Dodge “Ramcharger” V8 pointed to records set by NHRA campaigners in 1962 (with the 413), with Jim Nelson setting a quarter mile time of 8.59 seconds (AA/D), Dick Ladeen hitting 12.71 seconds (SS/S), and Bill “Maverick” Golden getting to 12.50 seconds (SS/SA). An A/FX record of 12.26 in the Golden Lancer was also noted.
The 1963 Ramcharger V8s (413 and 426) had numerous performance and reliability features, according to Dodge:
- New short-ram intake manifold to increase power output over at speeds over 4,000 rpm; tappets could be adjusted with the manifold in place
- Extra large valves (2.08 inches intake)
- Port areas of each cylinder head around 25% larger than with the standard 413 engines, with stainless steel head gaskets and a special deck structure for better sealing
- Oversized long-branch exhaust with three inch outlets and cutouts; two-inch diameter twin tailpipes
- Three-valve fuel pump with high spring load; electric fuel pumps available as an option
- Forged aluminum pistons with a chrome-plated iron top compression ring; connecting rods were individually magnaflux-inspected.
- Larger oil galleries, a larger oil intake tube, larger main and rod bearing oil grooves, and a fore-aft swinging oil intake in the sump to assure circulation when the oil moves to the rear of the pan (on hard acceleration).
- Mechanical lifters for high engine speeds with high strength valvespring retainers and springs. Rocker arms included lock nuts on the lash adjusting screw.
- Hardened journals and alloy bearings for extra crankshaft capacity; specially balanced drive shaft
- Special distributor and dual breaker points
- Heavy duty manual gearbox or optional automatic, set to upshift at 5,600 rpm, with highest maximum overall breakaway ratio (5.39:1) and overall efficiency of any stock automatic.
- Sure-Grip rear axle and heavy duty rear springs standard with the Ramcharger engine.
The 426 was rated by Dodge at 415-425 gross horsepower and 470-480 lb-ft of torque; the 413, at 410-420 hp and 460-470 lb-ft. These engines were meant for racing only.
The engine was a success, with numerous victories and speed records in NHRA races. Ronnie Cox won Top Stock Eliminator, tying Al Eckstrand’s record of the 112 mph quarter-mile trap speed (in 12.4 seconds for Eckstrand, 12.92 for Cox).
The A-864 hemi was introduced in 1964 in the "light weight" Plymouth and Dodge models as a race only package, to be replaced by the A-990 hemi in 1965 (also as a race only engine). Meanwhile, the Dodge Ramcharger drivers continued to pile up records with the 426 Wedge, upgraded with larger Carter AFB-3705S carburetors (with .25-inch larger primary bores), larger air horn diameters, new larger primary riser openers in the intake manifold, a higher lift and longer exhaust duration cam, modified combustion chambers and intake valve ports, more durable head gaskets, new fan and drive unit, and optional aluminum front-end package that cut the Ramcharger package weight by nearly 150 pounds.
The 440 engine was introduced in 1966, the same year the 426 engine was replaced by the same-displacement, legendary 426 Hemi "elephant engine." A large-bore version of the 413, it was used not only for performance, but also for luxury yachts such as the Imperial. Horsepower was slightly higher than in the 413, but torque leaped up, at 480 lb-ft.
The high performance 440 was introduced in the 1967 GTX and R/T models (see Super Commando photo below); the company slotted in brand new, better-flowing heads and a more aggressive, hydraulic camshaft. The Magnum and Super Commando (A134) engines produced 375 horsepower, yet were reliable and relatively easy to tune.
In 1968, the 383 Road Runner and Super Bee models were introduced, starting the biggest performance surge since the early 1960s; they were essentially created by taking the new head and camshaft designs and putting them into the 383.
In 1969, the first 440-6 barrel engine package was produced with special rods, crankshaft, timing chain, camshaft, valve springs and intake system; it enjoyed a three year run. The three two-barrel carburetors were dubbed a “Six Pack.” Midyear, the company added a high-rise Edelbrock manifold (this was cut early in 1970).
It is worth noting that early 1969 440s had the same connecting rods and crankshaft as in 1968, but heavier connecting rods were introduced around three months into 1969 model-year production; to offset the added weight, a new crankshaft and rebalanced vibration damper and flywheel were used. Mixing and matching these parts results in nasty vibration problems.
For 1970, strong “Six Pack” connecting rods were added to all 440 high-performance engines. They were used until 1975.
In 1971, the 440-6 barrel and the Hemi were the last truly high performance cars produced in the era; the year also saw the use of a cast iron 383 crankshaft as a cost saving measure, on automatic-transmission cars.
On July 4, 1971, four cars with 426 cubic inch versions of the 440 with ported 440 heads were entered in the Daytona Grand National race, and they finished 1-2-3-4.
|1970 383||1971 383||1970-71 426 Hemi||1971 440||1971 440+6||1977 440|
|Horsepower (gross)||335 @ 5200||300 @ 4,800||425 @ 5,000||370 @ 4,600||385 @ 4,700|
|Horsepower (net)||250 @ 4,800||350 @ 5,000*||305 @ 4,600||330 @ 4,700||195 @ 3,600|
|Torque (gross)||425 @ 3400||410 @ 3,400||490 @ 4,000||480 @ 3,200||490 @ 3,200|
|Torque (net)||325 @ 3,400||390 @ 4,000||400 @ 3,200||410 @ 3,200||320 @ 2,000|
|3 x 2bbl
|Intake/exhaust duration||268° / 284°||268° / 284°||284° / 284°||268° / 284°||268° / 284°|
|Base transmission||3-spd stick||3-spd stick||3-spd auto||3-spd auto||4-spd manual||3-spd auto|
|Gears||2.55, 1.49, 1:1||2.45, 1.45, 1:1|
|Standard axle ratio||3.23:1||3.23:1||3.35:1||3.23:1|
|1972||Type||Net Power||Torque (lb-ft)|
|440||Base||225 @ 4,800||345 @ 3200|
|440||Dual snorkel||230 @ 4,400||355 @ 2,800|
|440||Dual exhaust||245 @ 4,400||360 @ 3,200|
|440||High Perf.||280 @ 4,800||375 @ 3,200|
|440||Cold Air Pak||290 @ 4,800||380 @ 3,200|
|440||3-two barrel||330 @ 4,800||410 @ 3,600|
The performance aspects of the 'B' and 'RB' engines faded from 1972 on, though not as suddenly as casual observers may expect, because net horsepower ratings were adopted in 1972 as well. This resulted in a substantial drop in rated horsepower as the effects of using an air cleaner, water pump, alternator, muffler, and other “accessories” were included. The company did provide both gross and net numbers for some engines in 1971, providing some perspective. The measurement difference was responsible for a “drop” of 50-65 horsepower.
There were some drops in power in 1972 as compression was dropped to reduce emissions, a cheap way to meet new pollution standards. In 1974, every RB engine had a cast crankshaft, replacing the old forged ones.
By 1977, when Lean Burn system made its appearance on the 440 “for better driveability and overall performance” (until, many would say, the system stopped working), the engine was used for big luxury cars: it was standard on Chrysler New Yorker Brougham and Town & Country, and optional on Chrysler Newport, Plymouth Gran Fury, and Dodge Monaco. Performance was now to be found in the 360 four-barrel equipped F-bodies, not the B bodies.
The last 'B-RB' engine was produced in August 1978, ending the history of Chrysler Corporation big-block engines — though it took over a year to clear the already-made engines out of stock. The 440 high-performance engine had a slight power boost to 255 hp, but it was only available as an option for B-body patrol cars.
Mopar B and RB engine parts
Over 750,000 440 engines have been produced, so parts tend to be available. The RB engine size was stamped on a pad at the left front of the engine adjacent to the front tappet rail. Distributors are at the right front of the engine. Parts replacement information (such as undersize crankshaft) is next to the engine size.
1961 was the first year for the now-universal closed crankcase ventilation system, then used on all cars sold in California; it used a flexible tube to connect a valve to a carburetor fitting just below the throttle blades. The carburetor would draw the crankcase vapors in, burning them to painlessly eliminate a source of pollution.
Chrysler wrote this about the 440, in 1978: “The combination of its large displacement, large intake and exhaust valve ports and manifold passages, 4-barrel carburetor and low-restriction exhaust system give the 440 extra power for quick acceleration at all speeds-low, middle, or highway cruising-or for towing large travel trailers. The 440 V-8 features a deep-skirt engine block, rugged cast ductile iron crankshaft and aluminum-on-steel main and connecting-rod bearings for exceptional durability and smooth operation.”
RB-engine articles by Rick Ehrenberg
- A head for our time: A look at the latest and greatest in cylinder heads for your Mopar.
- High-performance oil pumps for classic cars
- 440 Six Pack - Chrysler's Ultimate Street Motor
- High-tech carb tuning with a wide-range oxygen sensor
- TTI X-style exhausts: pick up an extra 24 horsepower
- Restoring and tweaking 4-piston disc brakes (1965-1970s)
- The men behind the RB-engines: Willem Weertman | Pete Hagenbuch
- 383 and 440 specifications for squad car use, 1967-1976
- The 426 Hemi
- B engines: 350, 361, 383, 400
- Max Wedge engines
- How to Rebuild Big-Block Mopar Engines - 20% off - covers all years Chrysler, Plymouth, and Dodge big-block (B and RB) engines
- Big-Block Mopar Performance : Modifications for B/RB Series of Chrysler, Dodge and Plymouth Engines for Street and Racing Use - Chuck Senatore / Paperback / Published 1999 - Our Price: $14.36 ~
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- Also see: Low-Buck Bolt-On Upgrades by Rick Ehrenberg