Plymouth, Dodge, Chrysler Poly A Block Engine Family 277 301 303 313 318 326 History and Myths

Sdílet
Vložit
  • čas přidán 2. 07. 2024
  • The ultimate history and myths summary about Plymouth, Dodge, and Chrysler's Poly A-block engine/motor family produced from 1956 - 1967 including automotive, industrial, and marine applications. Displacements include the 277, 301, 303, 313, 318, and 326. See the website www.poly318.com for many more details and photos including a tour of the engine plant.
    Corrections of mice and men: At 8:50, I meant to say the engine was advertised at 395 foot-pounds torque but said "horsepower." For what it's worth, the Golden Commando 395 had 305 HP.
    0:00 A New Engine Era
    01:10 What is a Hemi, Poly, and Wedge Engine?
    02:30 1956 - Introduction of the 277 and 303
    04:42 1957 - Introduction of the 301, 313, and 318
    07:53 1958
    08:25 1959 - Introduction of the 326 and Industrial and Marine 318
    11:00 1960
    11:26 1961 - Introduction of the Dodge Frank Motorhome 318
    12:20 1962 - Engine Redesign
    14:43 1963
    15:11 1964 - Release of the Light A (LA) 273 Rival
    15:53 1965
    16:11 1966 - End of Domestic Car and Truck Production
    16:42 1967 - End of Export, Motorhome, Industrial, and Marine Production
    17:05 Myth Busting the A-block
    17:18 Myth 1: Semi-Hemi Is Not Semi-true
    18:04 Myth 2: A-blocks Are Cheaply Built
    19:35 Myth 3: A-blocks Are Incapable of Performance
    21:37 Myth 4: Industrial and Truck A-blocks Are Thicker Castings
    22:33 Myth 5: A-blocks Are "Wide-blocks" Larger than a 440
    24:12 Myth 6: A-blocks Are Boat Anchors Heavier than a 440
    25:33 Conclusion and Impact
    Copyrighted Content Use:
    All spoken/textual content and the photographs, images, and diagrams marked with copyright have been researched, written, photographed, and/or designed by Justin Lotspeich of poly318.com over many, many hours of work and are copyrighted. I have no issue with people using the copyrighted text, images, photographs, and drawings for non-commercial not-for-profit purposes, such as posting on free online forums; I only ask that they attribute the content to poly318.com and not modify images. I do not give consent to monetized content creators or other for-profit creators to use the copyrighted content including audio and text.
  • Auta a dopravní prostředky

Komentáře • 82

  • @IndridCool54
    @IndridCool54 Před 4 měsíci +9

    I’m an old dude and former automotive machinist who loves engines and this was a really well done video. 👍🏼👍🏼

    • @Poly318
      @Poly318  Před 4 měsíci

      @IndridCool54, I appreciate your feedback. Thanks.

  • @MrGlenferd
    @MrGlenferd Před 4 měsíci +12

    I put a 66 or 67 poly 318 into my 70 fargo. Got a big older 4 speed truck transmission and. Bell housing. It bolted together except for one main bell housing bolt that didnt line up. Ran it for a decade like that. Was a great combination.

  • @NipkowDisk
    @NipkowDisk Před 4 měsíci +5

    Thanks a million for covering this series!

  • @heathmcinerney4995
    @heathmcinerney4995 Před 2 měsíci +2

    The Poly 318 is an awesome engine. Thankyou for your factual and sensible video.

  • @davef.2329
    @davef.2329 Před 3 měsíci +2

    Great video and trip down memory lane. I had a poly-318 Coronet in high school and it was very reliable, economical, and took a helluva beating, but kept on ticking (literally).

  • @UncleTonysGarage
    @UncleTonysGarage Před 4 měsíci +17

    Nice video, but two things...
    The term "Semi Hemi" didn't come around until the middle 60's and it was applied to Big Block Chevy engines who were then competing against the 426 Hemi.
    Chrysler only referred to the Poly's as "single rocker shaft engines" when they were in production.
    As for them being cheaper, yes the quality of the components was top notch, but they had fewer parts and less metal overall, Chrysler was able to save on the second set of shafts, the rocker shaft stands and their machining, the pushrod tubes etc.
    They were by no means "cheap" engines, just cheaper than the Hemi.

    • @eugenepolan1750
      @eugenepolan1750 Před 4 měsíci +3

      If you say "Less Expensive" rather than "Cheaper", it doesn't have a negative connotation.

    • @Poly318
      @Poly318  Před 4 měsíci +4

      Thanks for the comments. While Chrysler Corporation never referred to the Hemi-block poly as a "semi-Hemi," the earliest evidence of the term I have found is long before the Chevy reference. I located a microfiche 1958 Los Angeles Herald Examiner classifieds ad from an auto wrecker advertising "running Dodge and Chrysler semi hemispherical motors." The period hot rodders I have spoken with who were building Hemis in the late 50s and early 60s also confirm that they were using the moniker when buying Hemi-block poly engines for parts. When someone would say they picked up a 354 it was assumed to be a Hemi, so they would say, "I picked up a 354 semi-Hemi" to clarify it was a poly head. This newspaper and personal sources are from Southern California, so the term may very well have been regional to where other regions were not calling them sem-Hemis until the 1960s. There was no similar need to differentiate the A-block since it was unique. They and all period sources I've found referred to it as either a Plymouth [displacement] or a poly [displacement], such as a Plymouth 318 or poly 318.
      From the internal Plymouth documents written by the Qualimatic Mound Road plant engineers and by Plymouth's Finance Department, almost all of the savings in the A-block came from the plant and production process design versus hard parts. While there was minimal savings in a lighter engine block and the single rocker-arm assembly design, the automation coupled with the extremely precise machining tolerances they were able to produce ended up allowing them to build far more engines per hour than the Hemi and Hemi-block poly and with less errors that created factory waste and less warranty issues from dealerships. Two prime examples the A-block design, factory, and finance team give in 1955 documents are the automation of torqueing the head bolts by machine and the cylinder head line. The A-block's head bolts were torqued by machine and had an excellent record of not having leak issues, whereas the Hemi and Hemi-block poly engines were done by hand and would result in human error and head gasket leaks. The other example is how the A-block design team and equipment suppliers invented a single machine to process the cylinder heads that only clamped the head once the entire process, whereas Chrysler Corporation 6 and 8 cylinder heads prior to the A-block including the Hemi and Hemi-block poly required 3 to 4 separate machines and multiple clamping/unclamping actions of the head to process it that introduced stacked tolerances and resulted in junk heads the factory had to either take off the line to repair or scrap. The A-block factory and design applies these similar concepts to every aspect of the engine plant, which resulted in both superior machining and savings.

    • @488ci
      @488ci Před 4 měsíci +1

      I like that you did the proper research and how you explained everything. Seems like they were building very good and efficient engines in the late 50s. Then by the mid 70s the grand fury was getting horrible fuel mileage and had less power. My dad bought one brand new in 1977.

    • @Wiencourager
      @Wiencourager Před 4 měsíci

      All of the poly heads were called semi hemi. Had nothing to do if the block was the same as a hemi engine or not. Chrysler usually referred to them as dual or single rocker shaft. Hot rodders called them semi hemi or poly engines, later on mostly to differentiate them from the later wedge engines.

    • @moparnut6286
      @moparnut6286 Před 4 měsíci +1

      ​@@Poly318... Pay no mind to uncle caveman he's just a hack pretending to be knowledgeable. Any one can search and be a keyboard expert.

  • @donaldperrotta8514
    @donaldperrotta8514 Před 4 měsíci +3

    My dad bought a new 59 Plymouth Savoy with a poly 318 & automatic push button transmission … motor & transmission were bullet proof reliable !!!!

  • @Troy440Dodge
    @Troy440Dodge Před 4 měsíci +8

    There's enough quality information in the video. Makes an old Mopar man like me appreciate my automotive choice even more. Subbed instantly!

  • @petergrey7125
    @petergrey7125 Před 3 měsíci +1

    Great video with great content. I have a 66 Plymouth fury convertible that has the 318 A block. Could change it out but I like the idea of keeping it original to the car. Part of the fun is finding parts for it and making it run well enough to keep up with the big blocks.
    Please keep up the great and informative videos . 👍

  • @paulpaul8953
    @paulpaul8953 Před 2 měsíci

    I bought a nice original '58 Plymouth Plaza sedan a few years ago. Not being a MOPAR guy, I knew nothing about 50s Plymouth engines. I have been nothing but impressed with the 318 two barrel engine. It is reliable and powerful, a lot of fun to drive!

  • @alanpearce9071
    @alanpearce9071 Před 4 měsíci +2

    Our family had a slew of 318's.
    '59 Suburban with a Torqueflite and a gas heater, a '60 Dart Pioneer w/ Powerflite, a '64 Savoy w/ Torqueflite, a '64 330 w/ Torqueflite, and a '63 440 w/ Torqueflite that I did change the intake to a 4bbl.

  • @donaldlong9259
    @donaldlong9259 Před 4 měsíci +2

    I have one of these rebuilt sitting on a stand in my conex box. Even picked up a dual carb intake for it. garage art!

    • @mickangio16
      @mickangio16 Před 4 měsíci +1

      Need something cool to put it in👍

    • @petergrey7125
      @petergrey7125 Před 3 měsíci +1

      Lol! I just picked up and dual quad intake for mine. Hard to find.

  • @chuckwhitson654
    @chuckwhitson654 Před 4 měsíci +2

    I put an old 318poly into my buddy's ram charger. It has a ton of wear and tear on it but smoking a little, a quart or quart and a half a week of oil and he kept it awhile

  • @watsisbuttndo829
    @watsisbuttndo829 Před 4 měsíci +4

    Would like to see some flow bench data on the poly vs LA.

  • @felonysounds
    @felonysounds Před 4 měsíci +2

    My dad bought a 55 4 door savoy 6 cylinder, bought a 56 4 door for parts that had a V8, it's a poly with dual points and I believe a 2 barrel or single barrel 🤷 has spark but could never get the poly V8 to fire. My dad passed in 2016, we still have the 55 savoy and the poly V8 and transmission is still bolted to it. Always had plans of putting the V8 into the good car, only thing savable from the parts car was motor, trans and glass, hood and trunk and doors

  • @michaelwallbrown3726
    @michaelwallbrown3726 Před 4 měsíci +1

    i have a polyhead 318 in my 1965 Coronet 440 ragtop i love it for it's uniqueness and dependability would get it rebuilt if anything would happen to her

  • @race8427
    @race8427 Před 4 měsíci +4

    It would have been nice to see further development done on the poly heads.

    • @hoost3056
      @hoost3056 Před 4 měsíci

      They could have made the Poly a beast if they wanted to but it's a marketing thing. It wasn't meant to overshadow the B and the Hemi .

    • @adotintheshark4848
      @adotintheshark4848 Před 4 měsíci

      develop a 4-valve setup

    • @mrdanforth3744
      @mrdanforth3744 Před 4 měsíci

      The 318 was overshadowed by the bigger B engine for performance. The 318 had a lot of potential that was never developed.

  • @soilwork1981ify
    @soilwork1981ify Před 4 měsíci +3

    My 66 Dodge Cornette 500 2 door had the 318 poly.

    • @adotintheshark4848
      @adotintheshark4848 Před 4 měsíci

      65-66 Belvederes and Coronets were beautiful, under-appreciated cars, especially the hardtops.

  • @chasefell4234
    @chasefell4234 Před 4 měsíci

    I have a 66 Travco with original Poly 318-3. This engine pulls the coach quite well. I have the hydraulic lifters and the 4V carburetor.
    . I can make the case that the A engine cools better because of the mass of the heads. Long live the Poly. Great video BTW.

  • @user-fl3ey6pe6k
    @user-fl3ey6pe6k Před 4 měsíci +2

    great content, I worked at mound rd engine and other big 3 plants as an outside contractor doing concrete form work. I look foward to more of your videos, thank you

    • @Poly318
      @Poly318  Před 4 měsíci +1

      Thanks for your support. After researching the Mound Road plant, I would love to have toured it before its demolition. I guess I could see if Stellantis will let me stand it the parking lot that now covers the old plant to see if an aura exists 😆

    • @user-fl3ey6pe6k
      @user-fl3ey6pe6k Před 4 měsíci +1

      @@Poly318 you didn't miss much. mound rd engine was a dump, low ceiling, i could never have punched into that plant for 30 yrs, i worked at warren truck and stamping and i had to drag up for outside work cuz i needed fresh air. i look forward to more of your videos. My dad was a district manager for Dodge from 67-73 and he had excess to any ride he wanted back then, he had a 70 RT/SE convertible with a 383 mag and he let me sit on his lap while he did whole shots in the under construction neighborhood and mom had a 340 4 speed , those were the days, i never have seen a 318 poly but it sounds like TCC should have run with it, just imagine a 340 poly

  • @ImNotHereToArgueFacts
    @ImNotHereToArgueFacts Před 4 měsíci +1

    Had a '66 Belvedere 318 in '82
    The interior was trashed and someone primered it brown looked like with a paint brush.
    It was hideous
    I tried to blow it up and burnt up 2 tires.
    I filled it hose water trying to freeze crack it.
    Grandad replaced the tires and freeze plug 6 months before died.
    I inherited his '77 Ford F150 351M and gave the car to my cousin.
    Wish I still had both today

  • @michaelgautreaux3168
    @michaelgautreaux3168 Před 4 měsíci +1

    👍👍
    Many thanx.

  • @jeffalan6339
    @jeffalan6339 Před 4 měsíci +1

    Who says the Internet cant be informative?
    I onow 340 wnd 340 6 bbl and 440 also 5440 6 bbl a hemi owner addition ally 413 ramcharger.
    Thid video provided more info than all thoe mopar guys.
    Todays engines are all about technology and fuel efficiency
    Back then romp and stop gastest car wins.
    My old nova SS installed 406 SB lunati racing cam it would turn completely sideways from dead stop get 13 on the highway ,17 in town.
    I long fit yhe day of hemi charger
    440 6pk sioer bee
    440 corner RT
    Even 340 duster

  • @rossawood5075
    @rossawood5075 Před 4 měsíci

    I owned an Australian assembled right hand drive 1959 Desoto Firesweep, it would have been a 1958 equivalent in US and Canada, it was fitted with a 361 cu block that if I remember correctly developed a claimed 309 bhp, it had a push button torqueflite auto, air and steer, however the air was not factory but a very neat aftermarket wide slim underdash unit.
    A light green with dark green top and those beautiful 3 bullet tail lights on each fin, the Desoto had the best looking front grille and rear tail styling of the forward look Chryslers IMHO.

  • @hoost3056
    @hoost3056 Před 4 měsíci

    The Poly came back in the modern era as the 4.7 SOHC V8. The principle was the same.
    I will say this......the Poly has one of the best sounds ever produced by a V8. There's a stroker on CZcams that will make you smile.

  • @bobroberts2371
    @bobroberts2371 Před 4 měsíci

    One data point. I have a 1956 Plymouth with a 277 / Powerflight. Decades ago the crankshaft broke under another persons ownership and the car was sidelined. From what I understand, broken cranks on the 277 were an issue.

  • @79tazman
    @79tazman Před 4 měsíci

    My grandfather worked for Chrysler in Windsor his first job was the engine plant not sure what year he started but it was in the 50's for sure when he retired he worked in the big van plant on Pillette Road he also worked in the main plant back in the 70's when they were building the Cordoba's and the Lil Red Express trucks.

    • @angieshaw8877
      @angieshaw8877 Před 4 měsíci

      Whatever happened to the Cordova?...
      MoPars answer to GM/Chevy
      MonteCarlo
      ...both of the early-mid 70s...
      @lds/aes

  • @garymckee8857
    @garymckee8857 Před 4 měsíci +1

    Timing Chains fit 318, and the early Chrysler Hemi

  • @adotintheshark4848
    @adotintheshark4848 Před 4 měsíci

    The LA 273 could be had in the '65 Plymouth Valiant and Barracuda. That's probably the earliest use of that engine. Also, I owned two vehicles that had the A-318. A '62 Dodge Power Wagon 4x4 and a "65 Belvedere I inherited from my parents. Both were high mileage and both used a little oil, but didn't break down. Excellent, informative video I might add!

    • @Poly318
      @Poly318  Před 4 měsíci +1

      @adotintheshark4848, thanks. The 1965 Belvedere has wonderful lines.
      The LA273 was released for the 1964 model year optional in Plymouth Valiant and Barracuda and Dodge Dart models. The 273 Super Commando was released in 1965, which is a great engine and the start of factory performance LAs.

    • @jimstrict-998
      @jimstrict-998 Před 4 měsíci

      ​@@Poly318 273 Super Commando usually referred to as the "Formula S".

  • @jarepair7429
    @jarepair7429 Před 4 měsíci +2

    They forgot to mention the self driving 1958 model named Christine.

  • @louislepage5111
    @louislepage5111 Před 4 měsíci +1

    Its a crying shame that Chrysler didn't develop this engine further performance development 😮

  • @markanderson1519
    @markanderson1519 Před 4 měsíci

    Great video. One of the interesting things that I noticed is that some poly engines have a much more pronounced sawtooth shape to the valve covers than others. I wonder if the big sawtooth poly's are the semi-hemi engines or if there is some other explanation.

    • @Poly318
      @Poly318  Před 4 měsíci +1

      @markanderson1519, thanks. Yes, the Dodge/Chrysler Hemi-block poly heads have four very deep, symmetrical waves in the heads and valve covers pictured at 0:30. On the other hand, all A-block heads have a shallower sawtooth wave pattern with four peaks like my head at 0:20.

  • @tomlewis4345
    @tomlewis4345 Před 4 měsíci

    We had a 59 Plymouth wagon with the 318 in it and you couldn’t keep main bearings in it. It ran pretty good and was pretty quick but the front sump oil pickup starved the oil pump under hard acceleration.

    • @Poly318
      @Poly318  Před 4 měsíci +2

      The 1959 A318 wagon engine was a center sump oil pan, and a front-sump pan won't clear the crossmember. Only trucks and some industrial A-blocks received a front sump, and that design was used through 1967 without widespread reports of oiling issues. The A-block cars used the 4-quart center-sump design from 1959 - 1967 with no reputation or service bulletins of oiling problems with the pan/pickup, so I suspect something else was wrong with the engine.

    • @tomlewis4345
      @tomlewis4345 Před 4 měsíci

      @@Poly318 Ithink it was something other than the oil sup because of other 318s would live forever and rattle like a junk yard.

  • @alexgrindnshine2522
    @alexgrindnshine2522 Před 4 měsíci

    These poly engines are really cool. Not sure how many people know that the modern 4.7L sohc engine has valve placement that looks almost identical to these old poly heads. I wish Chrysler would have kept with this design. Were they the first to bring this canted valve arrangement to the market out of the big three? Will Poly heads bolt onto an LA block?

    • @Poly318
      @Poly318  Před 4 měsíci +2

      @alexgrindnshine2522, yes, Chrysler Corporation pioneered what they named the polyspherical valve and chamber arrangement at the time GM was experimenting with the wedge arrangement in the small block and Ford with the peanut-shaped chamber in the Y-block, both with inline valve configurations.
      A-block heads can be fitted onto an LA short block, but it's not a direct interchange and much more work than simply using an LA 2.5" main journal crankshaft in the A-block for stroking. Most of the A-block's coolant ports are either missing or misaligned and need to be drilled into the LA block for optimal cooling. A-block heads use two oil drain-back galleries drilled through the head down through the block into the crankcase that the LA doesn't have, so you either need to rely on the A-block intake push rod holes for drainage--which keeps a quart or more of oil tied up in each cylinder head for it to pool high enough to reach the push rod holes--or you have to tap into the A-block's head and run drain-back lines into the oil pan. The LA block up toward the deck needs to be ground for A-block push rod clearance. LA flat-top pistons will either need to have valve reliefs cut in to match the A-block intake valve, or A-block pistons can be fitted. An A-block camshaft must be used, which fits without modification. Either A-block or LA lifters can be used, although A-block lifters are shorter.

    • @alexgrindnshine2522
      @alexgrindnshine2522 Před 4 měsíci

      @@Poly318 thank you for all the great info.

    • @Poly318
      @Poly318  Před 4 měsíci +1

      @alexgrindnshine2522, I'm happy to share.

  • @JosephCowen-ru7up
    @JosephCowen-ru7up Před 4 měsíci

    Did I miss the bit on the 273 LA or Low Deck A engine ?

    • @Poly318
      @Poly318  Před 4 měsíci +1

      You did not. There was never a "low deck" or "raised deck" A-block since only one deck height was used for the 1956 - 1967 A-block at 9.603", plus or minus a few thousands depending on machining tolerances. The 273 is based off the A-block short block but is in the Light A (LA) engine family and not the focus of this video. I mention the LA273 around 15:11 as an aside but don't go into much detail.

  • @kevinsparks1279
    @kevinsparks1279 Před 4 měsíci

    I have a 57 dodge one ton dually with what I thought was a 315ci. poly. Is it a 313? I really like it and feel like it's a rare find and hope to get it restored. Dodge all the way!!!!

    • @Poly318
      @Poly318  Před 4 měsíci

      @kevinsparks1279, domestic Dodge trucks did not receive the A-block until 1959 with the A318. Export trucks offered the A303 in 1957 and then the A313 starting in 1958. The A-block is easy to tell apart from the Hemi-block poly. If your engine has valve covers with four very deep and symmetrical scallops, it's a Hemi-block poly. If your engine has four shallow and asymmetrical scallops, it's an A-block. There are many other differences, but the valve covers are easy giveaways. Another easy one is that the A-block has an intake manifold that seals the valley, like an LA or small block Chevy intake manifold, whereas the Hemi-block poly uses a separate valley cover underneath the intake manifold with a gap between them.

    • @jimstrict-998
      @jimstrict-998 Před 4 měsíci

      ​@@Poly318The red 315 Dodge truck engine pictured for 1959 is a true hemi.

  • @jonathanmorrisey5771
    @jonathanmorrisey5771 Před 4 měsíci

    Where does the 241 cid from 1955 fit in?

    • @Poly318
      @Poly318  Před 3 měsíci

      @jonathanmorrisey5771, the 241 Hemi and Hemi-block poly is not in the A-block family covered in this video.

    • @davidpowell3347
      @davidpowell3347 Před 3 měsíci

      @@Poly318Did 1955 Plymouth offer both "poly" based on the Dodge hemi block and "poly" based on the new A block?

    • @Poly318
      @Poly318  Před 3 měsíci

      @davidpowell3347, no, the A-block was not offered until the 1956 model year. 1955 Plymouth used the Dodge V8.

  • @deanstevenson6527
    @deanstevenson6527 Před 4 měsíci +1

    🥝✔️

  • @hotrodray6802
    @hotrodray6802 Před 4 měsíci +1

    The B block was introduced in 1958 at 350 cubic inches.... In 59 grew to 361.

    • @jimstrict-998
      @jimstrict-998 Před 4 měsíci

      Another correction is for the 1959 361 Golden Commando.
      That would be 395 gross TORQUE, rather than HP, unless
      we're talking about a dual-quad
      version.

    • @Poly318
      @Poly318  Před 4 měsíci +1

      @hotrodray6802, The B350 and B361 were both available in 1958.

    • @Poly318
      @Poly318  Před 4 měsíci +1

      @jimstrict-998, You're correct. I meant to say ft.lbs. torque, but horsepower snuck out. They were advertised 305 HP. Thanks for pointing that out.

  • @jammerz63
    @jammerz63 Před 4 měsíci +1

    He forgot the 325 dodge.

    • @Troy440Dodge
      @Troy440Dodge Před 4 měsíci +3

      The Dodge 325 Red Ram is covered.

    • @Poly318
      @Poly318  Před 4 měsíci +3

      I discuss the A-block Dodge Red Ram 326 at 09:00 minutes. The Dodge 325 is a Hemi and Hemi-block poly engine and not in the A-block family discussed in this video. The A-block version was a 324.49 c.i.d. advertised by Dodge and listed in service manuals as a 326 to differentiate it from the Hemi and Hemi-block poly 325.

    • @Troy440Dodge
      @Troy440Dodge Před 4 měsíci +4

      @@Poly318 My mistake on the engine identification. As a retired mechanic specializing in Mopars, I've encountered only two 325 Dodge engines. I will admit that the 318 is the toughest engine ever built. In all generations. And one of the most underestimated as a performance build.

  • @raginroadrunner
    @raginroadrunner Před 3 měsíci

    Chrysler shot themselves in the ass when they dropped this motor. Bad bad move.