Why are 318's low HP and torque?

[Haney]

Did the OP ever get the 318 in his car????

 

[Tbone416]

The 1970 factorie hp rateing for the 318 2 barrel dodge was 235 hp and the 1972 340 4 barrel was 245. The 318 had compression the 340 had carb,cam, and a pretty good heads on it. So a 1970 318 with carb,cam,and air sould make closet to the same as hp the 340's

 

[72Dodge]

The 1970 factorie hp rateing for the 318 2 barrel dodge was 235 hp and the 1972 340 4 barrel was 245. The 318 had compression the 340 had carb,cam, and a pretty good heads on it. So a 1970 318 with carb,cam,and air sould make closet to the same as hp the 340's

But wasn't 1972 when net HP ratings began? So you're not comparing apples to apples there.

 

[69 Cuda 440]

The 1970 factorie hp rateing for the 318 2 barrel dodge was 235 hp and the 1972 340 4 barrel was 245. The 318 had compression the 340 had carb,cam, and a pretty good heads on it. So a 1970 318 with carb,cam,and air sould make closet to the same as hp the 340's

T-Bone,

In theory that does make sense.

But, the 1970......318/230 HP,

* 9.3-1 Compression-Ratio
* Small Valve Cylinder Heads {1.78" Intake ~ 1.50" Exhaust}
* Open Combustion Chamber / Small Ports
* Hydraulic Camshaft {.373" Intake / .400" Exhaust}
* Weak Valve Springs
* Small-Port Intake Manifold
* Carter 2-Barrel {285 CFM} Carburetor
* Single-Pipe Exhaust System

First off, the 318/230 HP was 'over-rated' by a good +30 HP, so much so that
the NHRA re-factored them all the way down to 195 HP, and then 185 HP.

 

[rbdart]

I used to run a 73 dart sport , back when I was 18 , It was a 318 bored out 30 tho over with 340 heads /manifold 67 cuda rear end . nothing else . and it was doing mid 10,s in a quarter mile . Sold it when my first son was born . . 30 years later just bought a 71 Dart , 318 ---30 tho over and am starting again . Wish I had never gotten rid of the 73 . Before that I had a 1970 Valient duster(Plain Jane ). Nothing special .

REALLY..???surely ye are jestin man...maybe in the 1/8 mile...do you realize what it entails to run 'mid 10's' even with a bigblk? apparentely not you have no clue...impossible..I've run them all and cut my teeth on mopars...we all know this is bs..get real

 

[Hebrews10:26]

This thread is really out there.lol

 

[SpareParts]

just for the laughs my low hp + tq 318 in the far lane, turbo fox body near lane, both real slow
[ame="https://www.youtube.com/watch?v=hp1rvhJNa1I"]White on Red - YouTube[/ame]

 

[frosty_the_punk]

that sounded amazing, what kinda mph do you pull on the quarter?

 

[YY1]

As long as were:

A- beating a dead horse, and;

B- using oranges-

In 1993, the 5.2 Mag was rated at 235. The 5.9 Mag was rated at 245.

...and that's NET, so 250 is not out of the question at all.

 

[benmopar318]

the Mexican Super Bee (Duster A Body) has a 318 with 270hp

 

[67 Power Wagon]

Odd ball here. OK, my Step son lives across the road from a guy I been "scavenging" from, parts etc to see what he all has, in the midst of this, I see a truck frame, nothing on it, just a frame, with a motor, and transmission.....

The guy, tells me that its a Ram, with a 318.....SO, I uncover the motor (it was covered with a tarp, and was clean looking on the outside of the motor, I did NOT hear it run) But anyway, this "318" did NOT look like any LA 318, I've ever seen, and it surely wasn't the 318 "Poly" either, with the saw-tooth, or scalloped edge valve covers....BUT it surely as a really odd looking 318 IF thats what it is! I can tell ya, its NOT an Mopar "LA" 318.....

What in the hell is this thing then? Tell me, that Chrysler made another "type" or model of the 318........? Can it be? The spark plugs almost look as tho they are turned into the heads, like a 245 straight 6 Hemi, but slightly angled toward the exhaust port.... Damn near vertically inserted into the head.....

Anyone shed some light to this?

 

[bkd]

Take a picture of it would help

 

[67 Power Wagon]

Sadly, i didn't have the camera on me, the next trip, I'll remedy that! Its a pretty good haul from my house to his so... over an hour one way as there is no "easy or fast way" there.....I may be there over the weekend tho, we'll see!

 

[MOUSE]

I built a 318 with 9.5 comp. .30 over, .509 lift cam , 310 dur. , 360 heads that had a little work done and that was one mean little sucker. 4 speed in a 64 cuda. no one could touch it.

 

[m880]

Hello everyone,
I wanted to figure out why 318 engines are rated so much lower than 340 and 360 engines? Other than the smaller cubic inches, is it only the compression that is lacking in order to wake up the 318 engines? Or is it completely different engineering that made it so much tamer? Just a random curiosity I have and I know y'all can tell me what's up! Thanks everyone.

318 was from the get go meant as a reliable engine for daily transportation.It responds to performance mods as good as any engine.Personally i would use either "302" castings or magnum heads.With magnum heads you would be o.k as cast for performance,"302' heads ported work great and still maintain shaft rocker system.Oh i'm back after several yrs use to be waynebo or w5365,can't remember:burnout:

 

[m880]

318 was from the get go meant as a reliable engine for daily transportation.It responds to performance mods as good as any engine.Personally i would use either "302" castings or magnum heads.With magnum heads you would be o.k as cast for performance,"302' heads ported work great and still maintain shaft rocker system.Oh i'm back after several yrs use to be waynebo or w5365,can't remember:burnout:

And if turd 302/5.0 is good the 318 is 16 cibes bigger with better flowing heads than any stock turd head.even the factory gt-40 heads.rayer:

Also 318's are dirt cheap if not free:cheers:

 

[ArizonaKid]

I know the early LA 318's had good compression, 9.5 to 1, if im remembering right, but they got changed in the mid seventies (74?) to 9 to 1, then in 76 or 77 they were changed to 8 to 1, unfortunately, those 8 to 1 motors were the main motor for most mopars at the time, and therefore, the most common, so its not the 318 that was a bad motor, its just the numbers of gas crisis motors that skew the results. :wack:

 

[Tero]

i'm rebuilding my 318. its over pored to .40 and i use stock style pistons. pistons are now 0,096 - 0,104 under deck, needs lots of grinding to get 9.1 comp...

 

[AHcuda]

Boy, just read this entire thread for the first time.
Here is my deal, I have a bone stock 1968 318,in the car and runs good. 80K on it.
Now, I just got the car and want to pep it up a bit, for street & hwy only.

I have options on two motors, both needing rebuilds. A 340 & a E58 360, I can be satisfied just adding some items to the 318 over rebuilding a non running engine.

I want a aluminum intake - Which one ? Performer, M1 or Weiand
600 edelbrock carb-have already
Cam shaft & lifters - which one?
Do I need to do anything to my heads? cut or etc. they are stock 68 heads

I have a 8 3/4 with 3.23 SG and Dougs Headers with full 2 1/2 exhaust w/H pipe.
Stock 904 & converter.
Lets see what you reccomend for me, the rebuilds or keep what I got. I am not looking to race, just a good rumpity sound and smooth performance. As you know its easy to dress up a 318 and most wont know it's not a 340 or 360.

 

[AHcuda]

also, have a question. what is the difference in a LD4B & a LD340 Edelbrock intake?

 

[CPDave]

i'm rebuilding my 318. its over pored to .40 and i use stock style pistons. pistons are now 0,096 - 0,104 under deck, needs lots of grinding to get 9.1 comp...

Well this is probably too late to help, but why ever use stock smog era pistons in any 318 rebuild? The earlier style KBs are a lot closer to 0" deck height with only a surface cut, leaving a lot more meat for a stable cylinder head mating surface and eliminating the need for intake milling to get everything lined up in most cases. Keep in mind all LAs are thin wall castings, it's not like the \6 where you can mill the c**p out of everything and still have a stone ax.

Dave

 

[CPDave]

So, yeah, the 318 was a low output DD work horse for nearly all of it's production run. Even the '80s Police version was an open chamber 87 octane burning taxi motor with a 4 barrel and 1.88/1.6" valves. There is the unicorn '66 318X described in the '66 Barracuda GT FIA Homologation paper work (think D Dart 273 on a 318 bore with 2"/1.65" valves and an aluminum intake manifold); if you run across a '66 Barracuda with a "6" in the 5th digit of its VIN I'd love to hear about it.

But 318s respond to standard hotroding just like any other engine. Make it breath better, squeez the mixture harder, light it off with a powerful arc, and it'll run hard!

My Dart's 318 Built & Tuned by George & Justin Reggio at Maryland Performance Center (http://www.marylandperformance.com/; 301-371-8883) for exampl:

'69 318 block with Hughs Engines main stud girdle; Scat 4340 crank, K1 H-beam rods, and forged pistons. Milodon 7 quate road race pan, Canton Accusum, oil cooler, and Oberg canister filter.

Comp Cams Mech Roller:
Lift: 0.630" 0.630"
[email protected]": 254 260
AdvDur(@0.006"): 284/292
LSA: 107
Int Centerline: 102
Lash: 0.022"/0.024".

QFT 750 road race/circle track Carbuator

LD4B intake with 0.5" semi open spacer

Heads:
"302" castings Ported by Ryan Johnson at Shady Dell Speed Shop
in PA 1.94"/1.60", Final intake port volume: 136 cc

Flow @ 28" of water:
LIFT IN / EX
0.100" 66.1 / NA
0.200" 132.8 / 90.4
0.300" 189.9 / 126.2
0.400" 218.4 / 148.8
0.450" 227.9 / 152.9
0.500" 232.8 / 159.8
0.550" 238.0 / 163.9
0.600" 239.1 / 169.8

Static Compression 10.25:1

Bore 3.960"

Stroke 3.310"

Rod length 6.123"

Exhaust is TTI Early A-Body headers - 3"-in-2.5"-out X-Pipe and small oval case Borla mufflers.

Peak power 6300-6600 Max RPM 6800

In the car (blue lines-post latest rebuild):

On the Pump with the 1.675" dyno headers (smaller than the TTIs in the car):

 

[dancinwulf]

I am rebuilding a 73 340 to put in my 1970 Duster have all the original 73 parts heads and Thermo Quad carb but also have a set of 302 heads I was thinking of putting on it would they be better or should I stick with the stock heads and what about cams any recommendations want it to remain a driver but one with some juice

 

[stroked340]

I used to run a 73 dart sport , back when I was 18 , It was a 318 bored out 30 tho over with 340 heads /manifold 67 cuda rear end . nothing else . and it was doing mid 10,s in a quarter mile . Sold it when my first son was born . . 30 years later just bought a 71 Dart , 318 ---30 tho over and am starting again . Wish I had never gotten rid of the 73 . Before that I had a 1970 Valient duster(Plain Jane ). Nothing special .

LMFAO..sure it did..maybe in the 1/8 mile..

 

[younggun2.0]

LMFAO..sure it did..maybe in the 1/8 mile..

im sure its true. i had a 273 with only 6 plug wires on it. was bored .090 over and used shim gaskets. ran the 3/4 race cam in it with a holley quadrajet. had a rear end out of a boss 302. car ran mid 9's with Vin deisel's autograph on the dash.