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409 "W" engine in 65 Impala

Nashville Cat

Veteran Member
Senior Member

Anyone else love 409's ?

Grand Slam W-Series 1965 Chevrolet “409” Impala​

By DAVE CRUIKSHANK NOVEMBER 24, 2023

Way back in the mid-1950s, Chevrolet was riding high with the debut of its small-block V8 engine. The new mouse motor was compact and powerful and could be easily modified for more grunt.
But GM knew it had heavier cars and trucks on the drawing board and needed a bigger V8 to power this future portfolio. In 1958, Chevy’s W-Series big-block V8 was unleashed in the Impala,
and “Rat Motor” took its place in the lexicon of automotive slang.


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The W-Series Chevy big-block was named after its W-shaped valve covers, which were a result of its offset overhead valve design. The valves were not aligned with the center of the cylinder bore,
but rather angled towards the center of the engine. This created a wedge-shaped combustion chamber between the piston crown and the cylinder head deck, instead of the conventional chamber
in the head. The spark plugs were inserted vertically into the quench area of the chamber, which improved the flame propagation and reduced the risk of detonation.


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The W-Series engine had a cast iron block with 4.84-inch bore centers, two-bolt main bearing caps, and a side-oiling lubrication system. The cylinder heads were also made of cast iron
and had two valves per cylinder, operated by tubular steel pushrods and stud-mounted rocker arms. The intake and exhaust manifolds were attached to the heads by four bolts each,

and the exhaust ports were siamesed between adjacent cylinders.

The W-Series engine was used in Chevrolet passenger cars and light trucks from 1958 to 1965. Some of the models that featured this engine were the Impala, Bel Air, Biscayne, Corvette,
El Camino, and Suburban. The engine was also used in some racing applications, such as the Z11 Impala and the Mystery Motor, which were modified versions of the 409 and 427 engines,
respectively. The W-Series engine was known for its high torque and low-end power, which made it suitable for drag racing and street cruising.

The W-Series engine was superseded by the Mark IV engine in 1965, which had a more conventional wedge-shaped combustion chamber and valve arrangement. The Mark IV engine
was the basis for the later generations of the Chevy big-block engine. However, the W-Series engine still has a loyal fan base and is considered a classic and collectible engine by many
enthusiasts. There are also some aftermarket parts and blocks available for the W-Series engine, which allow for more performance and customization.

This brings us to our feature car, Mark Smith’s 1965 Impala SS, which was the last year for a factory-installed 409 mill. This is a factory black-on-black car that has been lovingly restored.

Smith, hailing from Montoursville, Pennsylvania, owned the car for 13 years and it took him three years to restore it back to the glory you see here. Mike’s brother spotted it in a garage and
thought it was complete and all there, it had rust in the floors, windshield header, and floors. The rust was exorcised from the exoskeleton and then was treated to a full repaint by Ed Strobel and Matt Lance.


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The old Chevrolet Impala is running a dual-quad 409 engine, good for over 400 horsepower. All that juice is sent to the rear via a four-speed manual, Hurst-shifted transmission. We love how
Mike retained the stock look with the spinner caps, whitewalls, and factory stance. The bucket seat interior is stone-stock and that’s okay, as it will remain cool forever.


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The Bill Mitchell fastback styling is timeless here and although it’s a huge car, the black seems to shrink it a size or two. From a design standpoint, 1965’s full-size cars represented the full transition
to GM Design leader Bill Mitchell’s vision of car styling, and from the Impala all the way up to Cadillac, each division was tailored to a fresh new look.

Complete with that forward-thinking styling blended with iconic W-Series power, Mike’s 1965 Impala bridges both generations beautifully. Perhaps that is why this generation of the Chevy Impala
is such a fan favorite. No matter what it is exactly that draws the affection of Bowtie enthusiasts to these cars, we think you’ll agree that Mike’s ride has it in spades. And that is exactly why we like it so much.



 
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I had a 65 Impala coupe with a 327 PG, 65 SS 327 parts car and a 65 SS vert that was orig a 327 PG but I put a 73 truck 350 & T-350 in, had orig 12 bolt rear, 65’s my favorite year Impala 👍👍🙂
 
That air cleaner on the '65 was a work of art. As a youngun I hated any factory air cleaner, had to have something aftermarket. Now I so appreciate the hemi, 409, L79 and especially the dual 4 nailhead caps. So cool. After buying my '36 I started looking for either a big Cad motor or a 401 or 425 dual quad nailhead. My buddy gave me a good running 425 that was originally a dual quad, but that had been replaced with a single 4. After plenty of searching, finally got all the correct stuff minus the kickdown plunger and fuel lines.

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Well, I know that '65 is not original as there were no 2X4 409's made after '64. 400hp was the top dog 409 for '65 and the W-engine production was stopped after Feb. when the 396 made it's debut in March of '65. Yes I am a 409 coinsure. I own a 425/409 dual quad '63 2dr post Biscayne and have an extra 409 waiting to be used in something. Just need to find it.
 
Well, I like to think my "impulse buy" circa 1970 was a '58 Impala with a 348, but it might have been a 6-cylinder! About to get drafted or join the Army Reserves during Vietnam was not a good time for me after selling my beloved '67 Chevelle SS (L78). What a ridiculous direction for me to go! I bought this thing off a guy at work in the GM Foundry where I worked for $50! I didn't even get it all the way home across town before it broke down on me! LOL! But, even the 348 was a cool engine...a poor man's 409 for sure!

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Well, I like to think my "impulse buy" circa 1970 was a '58 Impala with a 348, but it might have been a 6-cylinder! About to get drafted or join the Army Reserves during Vietnam was not a good time for me after selling my beloved '67 Chevelle SS (L78). What a ridiculous direction for me to go! I bought this thing off a guy at work in the GM Foundry where I worked for $50! I didn't even get it all the way home across town before it broke down on me! LOL! But, even the 348 was a cool engine...a poor man's 409 for sure!

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I remember the days you could buy a "Running" car that would get you around?? for $50, I bought a Caddy from a friend that stopped by one Saturday asking for a ride back from the JY, said he was tired of messing with and was going to get $50, I gave him $50, a ride home, had another friend follow me to the JY, I pulled the almost new battery out, and IIRC got more than $50, car ran fine I should've kept it lol
 
Well, I know that '65 is not original as there were no 2X4 409's made after '64. 400hp was the top dog 409 for '65 and the W-engine production was stopped after Feb. when the 396 made it's debut in March of '65. Yes I am a 409 coinsure. I own a 425/409 dual quad '63 2dr post Biscayne and have an extra 409 waiting to be used in something. Just need to find it.
You can stroke it 1/4" with a stock 454 crank !
 
There is some guy on the 348-409 site that run a factory block 409 in the 9's in a 62 bubble top car. Impressive.
 
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