Dartswinger70
Well-Known Member
I read somewehre that someone was glad to see an LA under the hood when they came out. What was better about the LA vs the Poly it replaced? I seem the think the HP on the Poly was 230,and the LA 318 was 235 etc.
There was a dual-quad version, too; if I remember correctly...There was a four barrel version of the poly 318 available 59 through 62. Had 260 hp. Besides the four barrel carb and dual exhaust, it also had a mildly hotter cam, with 248 degrees duration vs. the 240 of the 318 poly two barrel. That 248 degrees of duration, coincidentally, is that same as the later 273 four barrel.
There was a dual-quad version, too; if I remember correctly...
All of the above is Really good information! I knew none of this before. Thanks much.The 318 poly is the reason early 273's had an alternator bracket with four head mounting holes. Two are for the poly 318, two are for the 273. Both motors used the same bracket. Many other parts same, too, including timing cover, pulleys, crank and rods.
Very cool! Can we have some more pictures?By the way, the 1956 dealer installed dual quad intake and hot cam could also be installed in a 277, which upped the hp from 200 to 230.
And while I'm discussing arcane and mostly useless info about a motor family that hasn't been produced for well over 50 years, one more thing I only learned recently:
If you get a timing cover gasket set for a small block, you'll notice that there is one extra water pump gasket that doesn't fit whatever small block - A or LA - you might have. Turns out that the 56 motor has a different timing cover, that places the water pump higher on the motor than 57 and later. In other words, the 56 water pump and timing cover are unique to that year. Reason being that the 57's were lowered several inches from 56, and so the radiator was lower to clear the hood, so the water pump had to be lowered too. And the 57 water pump was also re-designed. So the water pump gasket changed.
I only found this out recently when I put a new timing chain in my 56. Its timing cover is cast iron, and I was thinking I might change to a later aluminum timing cover. But no - that would have lowered the water pump, which would have lowered the fan to where it wouldn't be in the right place for the radiator. So, I finally found out what the extra water pump gasket is that's in every small block timing kit I've ever bought.
I kept the 56 timing cover and water pump, but I did swap in a 65 poly 318 crank damper (the 56 didn't come with one) and pulley, and bolted a 273 timing tab to the bottom of the water pump. That tab clears the damper by probably an inch. Still usable, but it doesn't hug the damper like it does on a later A/LA.
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Very cool! Can we have some more pictures?
The engine man! lolI've posted a few pix of the car here and there on this site. Be happy to post more. What do you want to see?
BTW, I bought the 56 Plymouth at Mopars at Big Daddy's twenty years ago. Doesn't seem possible I've had it that long.
The cam specs may have been the same between the 248 and 273, but the cams can't be interchanged between A and LA. The port layouts are different, therefore the cam lobes are sequenced differently. Same core, different lobe layout.
If you want engines, Rusty? Here you go-The engine man! lol
The engine man! lol
yes, I had one of the manifolds years ago, 290 hp.There was a dual-quad version, too; if I remember correctly...