AJ's Opinion; Just for you 318 streeters
I tried to keep my bias out of this as best as I could.
And now, the rest of the story.
Most of our long wb A-bodies are gonna come around 3400 pounds plus driver. Duster and Demons being lighter. For me that sums to 3650 in my 68 Barracuda tank. Power steering, Power brakes, Four speed with a GVod, and an 8.75 in the back. NO A/C,lol. Heavy everything; springs,bars,shocks, tires; but lightweight wheels.
By my yardstick a 3600pound car then needs a
[email protected]/cube.
but lets say your 318 car comes in at 3200 pounds with you in it. At 1.0 hp per cube=318 hp. You got the power. But that power is at 5200 or more rpm. At 2500 to 3500 where you do most of your driving, you gave up low-rpm power to get that hi-rpm power. So the bottom has gone soft. So you slap a 3000TC on it and 3.91s and everybody is happy, right. Well maybe, if you don't mind 65=3400 rpm, and 9 mpgs.
Say your engine makes 280 ftlbs at 3000 stall, that is 160hp at WOT. Say your car requires 40 hp to cruise at 65mph; that is 25% of available power.
Say you had a 360/318hp which is .88hp per cube. But with the extra cubes comes more low-rpm torque. Furthermore, the much smaller cam required to make the smaller absolute power, also makes more low-rpm torque. So now, you don't need to run the 3000 anymore, nor the 3.91 gears. You still need the same 40 hp to cruise with, so say you choose a 2400TC and 3.23s. Now 65=2750 or so. Suppose this 360 makes the same absolute power of 160hp but now at 2750 rpm. And you are still using 25% of it to cruise with...... but the rpm has dropped from 3400 to 2750. That's down to 81%; good deal. And you still have the same 318 hp at the top, but now maybe it comes in 600 rpm sooner; that's an even better deal.
Of course, with the 360, you could run a lil more than 3.23 gears and a bit more than 2200 stall, and have a whole lotta more fun, versus the 318 which, as to streetability, is as good as maxed out.
Now, you might think that from 3180 pounds to 3600, is only 420 pounds, which is correct, but that 420 pounds at WOT represents 42 hp. And to take a 318 from 318 hp to 360hp
without killing the bottom-end, normally aspirated, is as good impossible, unless your pockets are very deep indeed.
There's lots of ways to get 318hp from a 318. But to get to 360hp is gonna take a very specific plan.
There's lots of more ways to get to 318 hp from a 360, and 360 hp is not very difficult. In fact, the 360 practically falls together at 320 hp. And 360hp is only two cam sizes away. And 400 hp is still only 1.1 hp per cube. Hi compression, good flowing heads, and a 230* cam will get you there at 800ft elevation. At 3600 pounds this is 9pounds per horsepower, and I guarantee you, this is really big street fun. Second gear drifting with 3.23s kindof fun.Two-gear tire-frying, all the way to redline. And sub 8 seconds to 90plus mph, kindof fun..
Now, at 3180 pounds, this would be entirely doable with a 318; see,
I am not a 318 hater.
Now go find a 3180 pound, you in it, A-body, and knock yourself out.
This is why the 340 Dusters and Demons got the reputation; 3300 pound car including driver, lots of tire space, and with close to 300hp, without headers! All you had to do with those cars was install headers, and a bigger carb, and you were in the 13s. Wait, who else was in the 13s? Hyup, stock hemi-Es; Challengers and Cudas.. In that era, 13s was fast.
Chit, a 13 second streeter is still fast today, lol.
