Need some advice 318 POLY vs 318 LA

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The polys are wider than a LA engine, but not as wide as a BB engine.

I just helped put a poly in a 1966 B-body and saw the sizing.

the intake manifold is much larger and heavier than the LA engine.
 
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I was wrong on my earlier post sorry. Below is the correct weight from when I did it (thread on B Bodies)

There's a lot of conjecture about the weight of a 318 poly. "As heavy as a 440" some have claimed (a 440 weighs 670 lbs according to the info. I've found). Hughes Engines "estimates" it at 600+ lbs.
Anyway, mine is out, about to receive a stroker crank, and I weighed it.
I used 2 bathroom scales, with 150kg (330 lbs) capacity each, with a piece of timber between them to put the engine on.
The engine with exhaust manifolds, cast iron intake, forged crank, stock rods, 0.060 bore, cast pistons, fuel pump, water pump, engine mounts, but without starter, carb, fan or alternator weighed 550 lbs.
I weighed it a few times, shifting the scales and the timber to centralize the the weight, and it kept coming up the the same. I never did get both scales reading half each (275 lbs), depending on where the scales were it would always favor one or the other, but I'm confident it was fairly accurate.
The load leveller (11 lbs) and timber (5 lbs) were also in that weight.
Lighter than I expected, but still pretty heavy pulling around on the engine crane.
20220313_111213-jpg.jpg
 
66 Sat said:
I was wrong on my earlier post sorry. Below is the correct weight from when I did it (thread on B Bodies)

There's a lot of conjecture about the weight of a 318 poly. "As heavy as a 440" some have claimed (a 440 weighs 670 lbs according to the info. I've found). Hughes Engines "estimates" it at 600+ lbs.
Anyway, mine is out, about to receive a stroker crank, and I weighed it.
I used 2 bathroom scales, with 150kg (330 lbs) capacity each, with a piece of timber between them to put the engine on.
The engine with exhaust manifolds, cast iron intake, forged crank, stock rods, 0.060 bore, cast pistons, fuel pump, water pump, engine mounts, but without starter, carb, fan or alternator weighed 550 lbs.
I weighed it a few times, shifting the scales and the timber to centralize the the weight, and it kept coming up the the same. I never did get both scales reading half each (275 lbs), depending on where the scales were it would always favor one or the other, but I'm confident it was fairly accurate.
The load leveller (11 lbs) and timber (5 lbs) were also in that weight.
Lighter than I expected, but still pretty heavy pulling around on the engine crane.
View attachment 1716009497
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Thanks for that! Definitely not the pigs they're made out to be.
 
The scales I used were cheap and I wouldn't be surprised if it was out by 20 or 30 lbs.
From memory the period articles I've read discussing the transition from A engine to LA the weight difference was always about 45 lbs. With the starter, fan, alternator it could run close to 600 lbs but folk who say they pulled out a poly and dropped in a 440 and the nose went up without touching the torsion bars are tripping.
 
after 30 years of going to car shows I am always excited to see something out of the ordinary. I LOVE seeing a cool poly!

I had a friend from Vancouver BC who used to come south when these was a spring car show outside Seattle on Sunday and Mopar Drags at Bremerton Raceway in Bremerton WA on Sunday. He would drive his 64 Plymouth B-body down with a 318 poly, custom cam and the factory 2 x 4 manifold found on police cars. He would run consistent 13 flats all day and often win the Mopar brackets and then drive to the show the next day and take class, pack up and drive the car home. My pick for one of the best all around enjoyable cars I've ever seen
 
I LOVE how the earlier ones look. Like the Spitfire engines. Just badassary!
SPITFIRE.jpg
 
I've read they can safely be bored to 4.00" and still have good cylinder wall thickness.
 
Bewy said:
One of the few mistakes Mother made...was discontinuing the Poly. In this country they were much sought after for Midget speedway racing.
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Why exactly ? I assume it had to do with a class rule .
 
mbaird said:
I dont know why they arent used more often in Rods ? I get SO tired of seeing small block chevy crate motors in $100,000 customs !
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It does get old when there are SO many other cooler and obscure choices.
 
RustyRatRod said:
It does get old when there are SO many other cooler and obscure choices.
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The absolute most boring looking engine ! I did see a BOSS 429 in a custom once … that was cool ! And a 30s custom truck with a 440 and cross rams hanging out over the running boards … wicked cool !
 
Doesn't surprise me.....
Both 313 & 318 Polys were in Chry cars sold here. They were all 2bbl, 9:1 CR. Mate had a 59 Belvedere 4 door hardtop, TF trans. Full chassis in those & TF was cast iron, you can imagine how heavy it was....
Engine had a lot of miles on it, absolutely stock/original, running on 7 1/2 cyls because one plug would oil up. His mate had a Ford Falcon, 302W bored out to 311. Ford must have been 400-600 lbs lighter. They had a drag race. At 80 mph, the Ford drive looked out his window, only to see a red front fender at his door....
 
RustyRatRod said:
I LOVE how the earlier ones look. Like the Spitfire engines. Just badassary!
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I'm sure you realize that's a Chrysler poly, either 301 or 331 or (if I remember correctly) 354. Chrysler block, Chrysler exclusive poly heads. They went into the low line Chrysler Windsor/Saratoga. Nothing interchangeable with the 318 poly.

There also was a Dodge poly, in 241, 259/260, 270, 315 and 325 cubes (the latter two being raised deck). Confusingly, some early Plymouth V8's (all 55's and some 56's) ran Dodge poly motors. Also 57 DeSoto Firesweeps. Likewise, virtually nothing interchangeable with the 318 poly.

The first true Plymouth designed V8 was the 277 poly, introduced in 56. That's what's in my 56 Belvedere. It looks just like a 318. There were also 301, 303, 313 and 326 versions. 303 and 313 were Canadian (303 also used in 56 Fury), 326 was 59 Dodge only. Here's my 277, stock 200 hp power pack (4 barrel and dual exhaust) except for a 500 Edelbrock carb replacing the original WCFB, and a Mallory Unilite ignition:

277 with Edelbrock.jpg
 
65 Cuda 340 said:
I'm sure you realize that's a Chrysler poly, either 301 or 331 or (if I remember correctly) 354. Chrysler block, Chrysler exclusive poly heads. They went into the low line Chrysler Windsor/Saratoga. Nothing interchangeable with the 318 poly.

There also was a Dodge poly, in 241, 259/260, 270, 315 and 325 cubes (the latter two being raised deck). Confusingly, some early Plymouth V8's (all 55's and some 56's) ran Dodge poly motors. Also 57 DeSoto Firesweeps. Likewise, virtually nothing interchangeable with the 318 poly.

The first true Plymouth designed V8 was the 277 poly, introduced in 56. That's what's in my 56 Belvedere. It looks just like a 318. There were also 301, 303, 313 and 326 versions. 303 and 313 were Canadian (303 also used in 56 Fury), 326 was 59 Dodge only. Here's my 277, stock 200 hp power pack (4 barrel and dual exhaust) except for a 500 Edelbrock carb replacing the original WCFB, and a Mallory Unilite ignition:

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Sure. Those were the early polys, the 318 we first referenced in this thread are the later ones. I like um all. lol
 
64-5 273's used 318 poly crank and rods, timing cover, brackets and pulleys. That's why the early 273 alternator bracket has two sets of head mounting holes: one set for the 273, other for the 318 poly. Also why the early 273 timing cover has one unused bolt hole on the driver's side - the poly 318 used it, the 273 doesn't.
 
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65 Cuda 340 said:
64-5 273's used 318 poly crank and rods, timing cover, brackets and pulleys. That's why the early 273 alternator bracket has two sets of head mounting holes: one set for the 273, other for the 318 poly. Also why the early 273 timing cover has one unused bolt hole on the driver's side - the poly used it, the 273 doesn't.
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I sure WISH the early A came with the poly engine instead.
 
RustyRatRod said:
Sure. Those were the early polys, the 318 we first referenced in this thread are the later ones. I like um all. lol
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Yeah, I was really posting for those who don't know about all the poly motors. Lotta confusion about fifties Chrysler Corp motors.

When I replaced my timing chain, I found out that 56 Plymouth poly motors had a one year only cast iron timing cover, with the water pump sitting higher than later motors. The 57 Plymouths were lower, with a lower hood line, lower radiator, etc. so the 57 poly water pumps sat lower to put the fan in the right place. The 56 water pumps are also unique to that year.

Going by memory, the 277s were 56 and 57 only, 301's were 57 only. After that, except for the 59 Dodge 326 with its .040 over bored 318 and hydraulic lifters, all American Plymouth poly motors were solid lifter 318's. Interestingly, Chysler Corp. stayed with solid lifters for the new 273 LA motors. So when you hear someone say, yeah, the Commando 273 had a hot solid lifter cam, you can say, yeah, the two barrel motors also had solid lifter cams that were only a little milder than the hi-po 273s.

Finally, the 61 and earlier 318 poly motors used an extended crank that the torque converter bolts to directly, without a flex plate. The back of the blocks are also different. You'd need some kind of adapter to hook one up to an aluminum Torqueflite. 62 and later, not a problem.

Here's a pic of the front of my 277 when I was putting it back together after installing the timing chain. Did a little cleaning/painting while I was at it. My 277 did not originally have a vibration damper; I put one in from a 65 318 poly, along with the fan and crank pulleys, and the 318 poly timing tab (also used on 273's). Fan is a NOS 56 Plymouth fan. Notice the gap between the damper and the timing tab. The tab closely hugs the damper on the LA (and later A) motors, mine is probably an inch away.

20181117_153554.jpg
 
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65 Cuda 340 said:
Yeah, I was really posting for those who don't know about all the poly motors. Lotta confusion about fifties Chrysler Corp motors.

When I replaced my timing chain, I found out that 56 Plymouth poly motors had a one year only cast iron timing cover, with the water pump sitting higher than later motors. The 57 Plymouths were lower, with a lower hood line, lower radiator, etc. so the 57 poly water pumps sat lower to put the fan in the right place. The 56 water pumps are also unique to that year.

Going by memory, the 277s were 56 and 57 only, 301's were 57 only. After that, except for the 59 Dodge 326 with its .040 over bored 318 and hydraulic lifters, all American Plymouth poly motors were solid lifter 318's. Interestingly, Chysler Corp. stayed with solid lifters for the new 273 LA motors. So when you hear someone say, yeah, the Commando 273 had a hot solid lifter cam, you can say, yeah, the two barrel motors also had solid lifter cams that were only a little milder than the hi-po 273s.

Finally, the 61 and earlier 318 poly motors used an extended crank that the torque converter bolts to directly, without a flex plate. The back of the blocks are also different. You'd need some kind of adapter to hook one up to an aluminum Torqueflite. 62 and later, not a problem.

Here's a pic of the front of my 277 when I was putting it back together after installing the timing chain. Did a little cleaning/painting while I was at it. My 277 did not originally have a vibration damper; I put one in from a 65 318 poly, along with the fan and crank pulleys, and the 318 poly timing tab (also used on 273's). Fan is a NOS 56 Plymouth fan. Notice the gap between the damper and the timing tab. The tab closely hugs the damper on the LA motors, mine is probably an inch away.

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Oh LAWD! The timing covers on all the early polys and hemis were just dreadfully HEAVY. Especially the Chrysler Firepower truck motors. I just BET by swapping over to the Hot Heads cast aluminum timing cover and the Big Chevy aluminum water pump that I got rid of 75 pounds off the front of that thing. It was ridiculous. VERY heavy duty, though.
 
RustyRatRod said:
Oh LAWD! The timing covers on all the early polys and hemis were just dreadfully HEAVY. Especially the Chrysler Firepower truck motors. I just BET by swapping over to the Hot Heads cast aluminum timing cover and the Big Chevy aluminum water pump that I got rid of 75 pounds off the front of that thing. It was ridiculous. VERY heavy duty, though.
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Yeah, I was seriously considering swapping to an LA aluminum timing cover until I found out that wouldn't work. Well, it would fit the motor OK, but the fan would end up in the wrong place, maybe even hit something.

FWIW, the new timing chain and the Mallory distributor are LA pieces that just dropped right in. LA fuel pumps OK, too, although I'm running a NOS 318 poly fuel pump - a rebuildable Carter that looks like today's Carter street/strip pump except for 5/16 inlet/outlet instead of 3/8.

And here is a 57 301 poly (which has a 318 bore, 277 stroke, i.e., 3.91 x 3.125):

57 belvedere 301.jpg


Edit: Looks like the timing cover on this is cast iron, too. Not sure when they went to aluminum. Also note that, like my 277, each valve cover has three bolts. I believe it was 58 that the center bolt was dropped and A motors from then on only had two bolts per valve cover.
 
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65 Cuda 340 said:
Yeah, I was seriously considering swapping to an LA aluminum timing cover until I found out that wouldn't work. Well, it would fit the motor OK, but the fan would end up in the wrong place, maybe even hit something.

FWIW, the new timing chain and the Mallory distributor are LA pieces that just dropped right in. LA fuel pumps OK, too, although I'm running a NOS 318 poly fuel pump - a rebuildable Carter that looks like today's Carter street/strip pump except for 5/16 inlet/outlet instead of 3/8.

And here is a 57 301 poly (which has a 318 bore, 277 stroke, i.e., 3.91 x 3.125):

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Yeah, I used an LA double roller and the chain tensioner on mine. You have to modify the tensioner, but it's easy.
 
Professor Fate said:
Oh, they fit- it's a squeeze, but they fit even in an early A.
@A56 posted these in another thread. Too cool!
View attachment 1716009384

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AND it's a four speed to boot!
And the recall wheels.
Overall, just a big ol' heapin' helping of awesomeness!
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Is this your A body with a poly? If so what all was required to make it fit? I have a 67 Cuda and been thinking about building a Poly 318 stroked. I see the motor mounts bolt right up. My concern is the power steering unit. I measured a 64 B body and they are about an inch from the steering sector. That car is 1" wider inside fender to fender than my 67 Cuda. I think it will fit but hoping you can help me out?
 
Dmopower said:
Is this your A body with a poly? If so what all was required to make it fit? I have a 67 Cuda and been thinking about building a Poly 318 stroked. I see the motor mounts bolt right up. My concern is the power steering unit. I measured a 64 B body and they are about an inch from the steering sector. That car is 1" wider inside fender to fender than my 67 Cuda. I think it will fit but hoping you can help me out?
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No, it's not mine. As I said, they were pictures that another member posted in a different thread. Sorry I can't help with the particulars of the swap.
 
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