318 poly info??

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7duce swinger

7duce swinger

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Alright, Can some one school me on 318 poly's.. I always thought there was very little in common between poly's and la's?? I know the la was a lighter version, but thats about it. Do any parts interchange? Intake manifolds exhaust manifolds? Distributors? A guy on the local craigslist, has the dual carb poly intake, that he states will also work on 340's n 318's. Is this true or is he wrong? He wants almost 400 bucks for the intake. Also i keep hearing about 318-3's, and 318-1's, what does all this mean?? Is one block better than the other? someone please chime in thanks guys!..... P.s. sorry if they may sound like dumb questions, just trying to fill my head with some more knowledge!
 
Oh and ive seen on few blocks aawj, and "aaqa" i think it was, what do those mean? Anything special or do they all have the same castings? Thanks fabo!
 
The crankshaft, rods and timing chains interchange, but that's about it. The block, heads, intake are all totally different. The intake is worth about that to somebody doing a ploy engine.

AAWJ and AAQA are foundry marks. 318-1, 318-3 are service designations. 318-3 is truck/industrial.
 
Cool, its good to know new things. Foundry marks, oh, but what exactly do the letters stand for?? My 318 has 318-7 whats the 7 mean, car, marine? any one know? Is it true the timing chain interchanges on 318's and a certain hemi block? I once heard a guy say that aaqa meant that the block had a higher nickel content? Is this guy nuts and doesnt know what hes talking about? thanks for the feedback guys
 
7duce swinger said:
Oh and ive seen on few blocks aawj, and "aaqa" i think it was, what do those mean? Anything special or do they all have the same castings? Thanks fabo!
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My guess is that there were more than one set of cores for the block and they all have to have some identification in case something heppens (quality defect) to be able to tell where they came from so they know which set of tools/cores to fix. Ideally, they are all supposed to be the same, but sometimes there are slight minor differences between one set of tools/cores and the others.
 
7duce swinger said:
My 318 has 318-7 whats the 7 mean, car, marine? any one know? Is it true the timing chain interchanges on 318's and a certain hemi block? I once heard a guy say that aaqa meant that the block had a higher nickel content? Is this guy nuts and doesnt know what hes talking about? thanks for the feedback guys
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Again, the 7 may be an identification for the outer cores for the casting.

About the higher nickel content, I would put my bet on the guy is nuts...
 
7duce swinger said:
I once heard a guy say that aaqa meant that the block had a higher nickel content?
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There is a specification for the metal that is used in the blocks. the foundary has to run within those specifications from batch to batch. If the hardness of the blocks got too high (over 240 BHN) then they would tear up our tooling on the block line that machined the blocks. If/when we caught them running over the hardness spec, we would contain them and send them back to be melted down and made into "good" ones.

The easiest way to tell if the blocks were over the hardness spec was to see if you could knick them with a file. If a file could not mark the metal, they were too hard.
 
Lol, thanks krazy cuda, i just like to know the little things sometimes. casting numbers, stampings etc. as for the guy being nuts, yes he looked it. Same as my neighbor, Says some off the wall things sometimes(ford guy) i laugh when he says ford and mopar parts interchange :D
 
7duce swinger said:
Alright, Can some one school me on 318 poly's.. I always thought there was very little in common between poly's and la's?? I know the la was a lighter version, but thats about it. Do any parts interchange? Intake manifolds exhaust manifolds? Distributors? A guy on the local craigslist, has the dual carb poly intake, that he states will also work on 340's n 318's. Is this true or is he wrong? He wants almost 400 bucks for the intake. Also i keep hearing about 318-3's, and 318-1's, what does all this mean?? Is one block better than the other? someone please chime in thanks guys!..... P.s. sorry if they may sound like dumb questions, just trying to fill my head with some more knowledge!
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Intake manifolds exhaust manifolds? No way, no how
Distributors? YES!

A guy on the local craigslist, has the dual carb poly intake, that he states will also work on 340's n 318's. Is this true or is he wrong?

He is a jack *** and a know nothing fool that should be exposed, tar and feathered and sent to a happy homo house for unga bunga till dead. Tell'em so as well. Know nothing **** stains like him should be bashed in the skull with a pentastar shaped hammer until the beg to be killed and then shown no mercy. You should treat him like a leaper. Run away, far away. But before you run, wet him down in fuel and light the match and save someone else from him bull **** and spare a brother some grief.

And then we'll do this to his rotting corpse for his family to see, just to be sure it is done again. "happy homo house for unga bunga till dead."

Also i keep hearing about 318-3's, and 318-1's, what does all this mean?? Is one block better than the other?

It doesn't matter since your going to either rebuild it or just use as is.

318-3 were truck engines. But it also means NOTHING since regular car engines also received the same engine without the "3". No one block is better than the next.
 
rumblefish360 said:

318-3 were truck engines. But it also means NOTHING since regular car engines also received the same engine without the "3". No one block is better than the next.
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I'm not sure this is correct????? Seems to me some of the truck engines had different heads and even used 18mm spark plugs

I'm sure you are right about the block per se, but the heads are different
 
On Poly's, the knowledge runs shy. On "LA" engines, I could be wrong but would bet $500 I'm right. Which only means I'm sure, not 100% correct.

"LA"'s

The size spark plug hex has remained the same for many years.
All engines are the same from car to truck. Year to year changes do occur. Sometimes, a engine, like a cops engine, will come with extras for longevity like a double roller chain and windage tray and forged cranks while passenger cars came with cast cranks, single chain and no windage tray.

Poly engines went through some odd changes in it's time. The 318 size was not really a long running size. Ummm, 10 years *I THINK* it was. Most changes were in the crank or intake for performance.

As far as I have seen, all 318 Poly heads have been identical. Though sometimes noting the plugs size was not in the workings of the day. Just parting it out was.
 
318 poly engines are not junk a little wider at the top then a LA motor but make good power for what they are,,,


aftermarket speed parts are hard to find but they are out there,,,that dual carb intake is a one year only option on a plymmouth fury,,some where around 1958 or 59 if its a factory intake he is selling

there use to be a group i think on the H.A.M.B. that were in to the ploy motors,,, the mid fifties poly motors have nothing in common with the 318 poly except the dizzy on some models,,,and they are some kool motors as well,,
 
67Dart273 said:
Well I tell ya, Rumble, there are numerous posts of 318-3 heavy truck engines using 18mm "Ferd" plugs, so SOMETHIN' has to be different.

Here's Summit's listing for a '74 M350, 318:

http://www.summitracing.com/search/.../Model/M350/Engine-Size/5-2L-318/?Ns=Rank|Asc
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Industrial / Medium Duty application. Things begin to get funky when you get into Medium Duty and Industrial Duty applications. I've got an 8-Bolt Forged LA 318 Crankshaft in the garage somewhere that came out of a Medium Duty LA 318 (D600 Flatbed, I believe. Had a 5-Speed manual with a 2-Speed Rear)

The same applies for Stationary & Outboard stuff too. Some boats used LA Small Blocks with special exhaust manifolds that cycled water (from the lake/river/whatever) through them to help propel the craft.

Some 361's, 400's, 413's and 440's (example) have special heads with extra water jackets and relocated water pumps in medium duty applications where the fan and water pump are mounted up high (above and in front of the intake)
 
Hey Rob, tell them about the cast 2x4 intake we exchanged for money.

Bill S
 
Ooooo, you mean this bad mabba jammba intake I modified?
Oh yea, well, he he he he he, it will be going on a Poly in the future.
I'll be building various sized Poly engines to play with. I'll start with a 318 and stroke from there.

Do note that the poly intakes sides were it bolts up to the head are a bit flat looking. But take note to the port arrangement and how it is different from a "LA" intake.

Also, the mod was made to fit a throttle butterfly as large as a 750 carb. IDK about a 800. I'll try my Edelbrock 800 carb to see if it opens up while on top.

The intake came with machined throttle bores. Very small. The pictured 600's would not fit. IDK about the Edelbrock 500's. None on hand yet.

You can see the machining done. The spacers, from Edelbrock are designed to be used in order to seal the carb to the intake. A carb alone would leak since the walls are now very very thin and unable to seal a carb.

I need one more spacer to either mill the spacers divider away or just get an open one. This would allow both sides of the intake to "Talk" to each other. This may or may not help, build dependent I believe. But helpful I think it will be.
 

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fstfish66 said:
318 poly engines are not junk a little wider at the top then a LA motor but make good power for what they are,,,,
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Oh no bro, there basically the same block. While a "LA" head can not go on this for actual use, the blocks are dimensionally the same. Minus a few freeze plugs and a weird water passage that would leak like a siv with a "LA" head on top.

I have put a "LA" head and intake on top of a Poly just to demonstrate what I said above. They fit and bolt down. But can not be used on the Poly block. Not unless your a heck of a welder that is.

Click this; http://api.viglink.com/api/click?fo....php?t=40020&jsonp=vglnk_jsonp_13461161636163
 
Thanks rumble, im not trying to rebuild or buy another motor. What i meant was, what do all the casting numbers mean and such. I need to be a little more clear next time. I mostly thought if one block had better oiling, better cooling, or was thicker. Not which one would give me more power etc.. thanks.. The guy with the intake i had already talked to him about it last year. I told him that i was pretty sure it wouldnt work but was not positive. Last time he had it listed as " this intake will go on all sb mopars" now he has it as " it is a poly intake, but will work with 340 sb mopar - 318 sb mopar" just wasnt 100% sure so i thought id ask here to let him know, hes still wrong. When i asked him, he said he was quite positive it would fit and work on "every" mopar smallblock. Quite interesting info here thanks for all the feedback.
 
Well, a thicker cylinder sleeve is better for power since there will be less flexing of the cylinder bore.
 
My dad used to say that the poly's were also good for econo runs. They had good power and economy.
 
rumblefish360 said:
Run away, far away. But before you run, wet him down in fuel and light the match and save someone else from him bull **** and spare a brother some grief.
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Hey Rob, why don't we just put it this way:


Light a fire, you keep a man warm for the night...

But light a man on fire, you keep him warm for THE REST OF HIS LIFE....
 
Haha well i dont wanna light em on fire, but i will let em know he is very wrong. He even painted it so that i wouldnt find it ! I remember his phone number and email address though.
 
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