440/6 V 440/4

[boss429kiwi]

Hi

What are the differences between a 440/6 and a 440/4 Superbird (besides carbs )
Are there any other internal and external engine differences?

Thanks
Gary

[odcics2]

Rods.  Crank maybe...

[BLK 68 R/T]

Rods, pistons, valve springs and harmonic balancer to my knowledge.

[chaaargerb]

Bottom end would be the same
Maybe a different cam.
Distributor would be a dual point on the six pack.
I also think the valve covers have different plug wire clips
No heat tube off the exhaust manifold

[6bblgt]

Rods.  Crank maybe...

Rods, pistons, valve springs and harmonic balancer to my knowledge.

NO, NO, NO

crankshaft had micro-finish and/or tuftrided/nitride hardened differences (but have the same dimensional spec. and are interchangeable)

long block differences are limited to:
PISTONS (10.5:1 440+6 VS. 9.7:1 440HP advertised compression ratio)
CAMSHAFT (3-bolt but same lift & duration - possible ramp design differences)
TIMING CHAIN SET/CAM SPROCKET (3-bolt)
VALVES
VALVE SPRINGS
LIFTERS

ALL 1970-'71 440HP & 440 Six Pack engines used the same HD rods (not "six pack rods") & offset balancer
just like the suspension & 18-spline transmission: these are XHD suspension & HD transmission (not "HEMI") components

compression is the big physical difference - everything else is quality/durability differences

[aerolith]

Good question K-Boss.

In my experince of Six-pack engines is as follows.
69-1/2 SP motors were fairly stock apart from special surface treatments to standard 440 components, with the awesome 906 heads and sexy Aluminum manifold!
They had a standard balancer and flexplate set-up with and non balanced converter.

In 70 it got a bit more complicated due te the heavy rod set-up.
Due to the extra weight of the HD rods/pistons, the crank was externally balanced with a special damper and a special weighted converter too, but an unfortunate iron manifold for some oddball reason?
The SP-piston is a heavy-wieght item, with the four opposing valve cut-outs for piston orientation at approx 10.5 to one compression' still running the 906 head.
(In 71, a special large flange crankshaft was introduced as per my 71 GTX with the HD rods/4 slot pistons and a new head casting with harder seats and low port design, still external balance)

I have owned all three set-ups in different SP cars and think the 70 one probably was the best of the two-half year run.
The 70/71 Damper is the biggest external clue to a real SP motor!

Areolite

[maxwellwedge]

Hi

What are the differences between a 440/6 and a 440/4 Superbird (besides carbs )
Are there any other internal and external engine differences?

Thanks
Gary

Other than what 6bblgt mentioned - a big premium in value 

[6bblgt]

.....

The 70/71 Damper is the biggest external clue to a real SP motor!

Areolite

the big damper & rods are ALL factory ORANGE painted '70-'71 440 engines 440HP (375hp) & 440 Six Pack (390hp)

roughly 40,000 US spec B & E-bodies with "U" & "V" code engines - additional 1,000s installed in C-bodies/cop cars/export & Canada spec'd cars

[Arnie Cunningham]

Some very obvious items such as the air cleaner assemby, different wiring for the carb solenoid, hit or miss on the heat stove, could get one if the engine didnt need it, AC.not available on 6 packs, was available 440HP with an automatic , different linkage setup,
The changes to the automatic transmission are notable as.well

[RealWing]

These are the 440-6 bbl differences that I'm aware of

•   High flow exhaust manifolds (RT 3418352, LT 2899968)
•   HD valve springs (3418491)
•   Intake/exhaust valves with flash-chromed stems and with 0.0005" smaller stem diameter (3418475/3418479)
•   The rocker arms were a special design with thicker steel than the standard 383/440 rockers.
•   Low-taper tappets 0.0005" undersized (3420039)
•   Camshaft with 3 bolt sprocket arrangement and lubrited low-taper lobes (3512033)
•   3 bolt camshaft/crank sprocket (2780572/2205568)
•   HP double roller timing chain (2205569)
•   Forged crankshaft that specially selected and shot peened (3512036)
•   Forged crankshaft vibration damper with external balance bob weight (3512017)
•   Forged connecting rods with increased beam thickness (p/n 2951906 and casting #2951908)
•   Piston with increased compression height and 4 valve notches (3420218)
•   Piston rings with moly filled top ring (3420228)
•   Hemi high pressure oil pump (2780639)
•   Larger capacity oil pan (2951314)

Jim

[6bblgt]

These are the 440-6 bbl differences that I'm aware of

•   High flow exhaust manifolds (RT 3418352, LT 2899968)
•   HD valve springs (3418491)
•   Intake/exhaust valves with flash-chromed stems and with 0.0005" smaller stem diameter (3418475/3418479)
•   The rocker arms were a special design with thicker steel than the standard 383/440 rockers.
•   Low-taper tappets 0.0005" undersized (3420039)
•   Camshaft with 3 bolt sprocket arrangement and lubrited low-taper lobes (3512033)
•   3 bolt camshaft/crank sprocket (2780572/2205568)
•   HP double roller timing chain (2205569)
•   Forged crankshaft that specially selected and shot peened (3512036)
•   Forged crankshaft vibration damper with external balance bob weight (3512017)
•   Forged connecting rods with increased beam thickness (p/n 2951906 and casting #2951908)
•   Piston with increased compression height and 4 valve notches (3420218)
•   Piston rings with moly filled top ring (3420228)
•   Hemi high pressure oil pump (2780639)
•   Larger capacity oil pan (2951314)

Jim

for 1970 the items I redlined are the same as 440HP - PLEASE correct me if I'm wrong

[RealWing]

I think you are correct about the exhaust manifolds and oil pan.
The 6bbl rods (2951906) are definitely different (heavier) than the std 4bbl engine rods (2406770). The heavier rods and much heavier pistons required a special vibration damper with a heavier bob weight. The 4bbl damper was p/n 2658457.

[6bblgt]

I think you are correct about the exhaust manifolds and oil pan.
The 6bbl rods (2951906) are definitely different (heavier) than the std 4bbl engine rods (2406770). The heavier rods and much heavier pistons required a special vibration damper with a heavier bob weight. The 4bbl damper was p/n 2658457.

that's the information YOU need to learn correctly, if you are going to repeat it!  

1970 Parts Catalog (May 1970 version)
9-31-4 ROD, Connecting 440
***** w/o H/Perf., Eng. Painted Blue - # 2406 770 ----- (350hp C-body engine)
***** w/H/Perf., Eng. Painted Orange - # 2951 906 ----- (375hp & 390hp B,C,E-body engine)

same deal with the balancer: heavy rods - offset balancer

[RealWing]

I'm just trying to learn here as well.
In looking back at the evolution of the connecting rods, I think I was confused (misinterpreted?) about the design changes made to the 440 rods.
I think that when the 6 bbl engine first appeared in 1969, it used the same rods as the 4bbl engine but were 100% magnafluxed (p/n 3462426, casting # 1851535)  Chrysler TSB 69-9-9 dated July 1, 1969 confirms this.

For 1970, it looks to me like the rods were redesigned with a heavier forging (p/n 2951906, Casting 2951908)and were then also phased into the regular production 440 HP and truck engines (with steel cranks) as you  pointed out.
Is this your understanding?

If so, my mistake.
Jim

[aerolith]

Hi Jim and others.

There has only ever been two 440 style rods.
LY's and Sixpack, (which are the engine builders terminology.)
413 and 426 rods are similar to LY's but never fitted to 440's.
The crossover year was 1970 for the rods and in 1971 a large 'centre-flange' steel-crank was introduced to stop centre thrust bearing failure.
I have not seen any large centre flange blocks for 1971, but deffo 1972 onwards.
This design was carried over onto the cast cranks too.

On a different note, my 1971 hipo GTX-440 engine was actually painted, late model 'BLUE' at the factory!
A mistake or correct for Canadian built 440 hipo engines?

Aerolith