How Much HP Can You Get Out a 318

[rumblefish360]

Don't put good money into an engine that wasn't designed to produce big HP. Swap it out with a 340. You'll be happier in the end.

Another person with a "I-d-10-T" issue.

Besides the higher compression pistons in which a 318 can be out fitted with easy enough, the 4bbl. carb, intake and the very modest cam size of the OE 340, tell me what is it that is designed into the engines core parts that make it "designed" where the 318 is not.

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You sometimes have to use what you have and 340's are not cheap just to buy one that needs rebuilt.

Exactly! I'm all for bigger cubes to make the job easier. However at the price, I'm not on board with this idea and the posters target goal.

After a sonic check of the 318, you could go far with the bore. Less is better for strength, longevity & power concerns.

Use of hard block helps a good bit with high levels of HP & TQ.

 

[Ragman]

L O V E that car!!!!!!!!!!!!!
Talkin' about the faded out Plymouth. Talk about a sleeper!
Rag

 

[Dako]

Here's what they did in HOT ROD Magizine on the cheap. http://www.hotrod.com/howto/113_0304_318_small_block_build/viewall.html

375-400HP for $1,500 sounds reasonable to me...

 

[jbearden]

A buddy of mine that I drag race with built a 318 just out of curiosity.With W2 heads,a 4.00 crank,4.00 bore(you can bore the early 318's that much.),roller cam,12.5:1 and so on,he ran 10.60's in a 3000 lb 70 Dart on race fuel.He twisted the piss out of it too!Don't expect to see that out of your car unless you plan to move the rear forward,set the engine back,build a full roller 904 and the other things he's done to his car.But he accomplished his goal of running 10's with a naturally aspirated 318.You can get quite a bit out of it,but why when you can get more out of a 360?If you really want some power,put a big block in it.No replacement for......you get it.

 

[RustyRatRod]

Well that ain't a 318 no more. It's a 402. Kinda defeats the purpose of the discussion.

 

[ply64post]

318

Well that ain't a 318 no more. It's a 402. Kinda defeats the purpose of the discussion.

x2

 

[jbearden]

Still a 318 block.Still getting that power out of it.It's the same as anyone that's running a stroker motor but having the factory engine callouts on it,claiming to have something they don't.If that's the case then a .030 over block isn't the cu in it was when it left the factory and shouldn't be talked about because that would make it a 323.I think the original question was how much hp can you get out of a 318?That's just one example that I know of.I guess I could just say what everyone else has already said with simple power adders.Yeah,let's just go with that.Cam,intake,carb,heads and headers.There ya go.Or just put some forced induction on it.Just remember that the 318 was rated at 235 with a 2 bbl while the 340 was rated at 275 with a 4 bbl and was only 22 cubic inches smaller.A good intake and carb,headers and exhaust system on a stock 318 will take you well above a factory rated 340.You can get power out of it.Just depends on what you want to do with it.I still say go with a big block since you have plenty of room.

 

[kb67mopar]

Personally I'd pick up a 273 for a song, drop in the steel crank, up the compression a bit but keep it on pump gas, run the 273 rocker arms and adjusters, put in a solid lifter cam, a set of heads updated with 2.02" intake valves and go huntin. (I am guessing by 72 it was a forged crank right?) The parts for those small blocks are pretty darn cheap and all available used. heck I sold my 273 for $150, my edelbrock 4bbl intake for $100 and a 780 holley carb for $50....now start searchin.

 

[RustyRatRod]

I took it to mean how much HP can you get out of a stock stroke 318 and I think everyone else did too. In other words, I think the OP meant how much can you ge tout of a 318 without breaking the bank with a stroker. If I'm off base, maybe the OP can put me on track, but that was my interpretation of the question. Sure, you can bore it to the water jackets and stick a 4.125" crank in it if that's your thing, but all of that requires a lot of expensive parst and machine work that I just don't think the OP was talking about here. Of course I could be mistaken.

 

[193rdsow]

I took it to mean how much HP can you get out of a stock stroke 318 and I think everyone else did too. In other words, I think the OP meant how much can you ge tout of a 318 without breaking the bank with a stroker. If I'm off base, maybe the OP can put me on track, but that was my interpretation of the question. Sure, you can bore it to the water jackets and stick a 4.125" crank in it if that's your thing, but all of that requires a lot of expensive parst and machine work that I just don't think the OP was talking about here. Of course I could be mistaken.

One more reason to NOT sink money into a 318 is resale value. In the end when you decide to sell/upgrade etc, you'll get all your money back out of a 340/440 rather than a 318. I have owned many different Mopars over the years including a 318 Challenger that I tried to improve on. The 318 was not DESIGNED to be an HP motor. It was designed to take the family on vacation, get fairly good gas mileage and last 150K before needing a valve job. The 340 was designed for high RPM HP and yes, it will cost you more up front to buy one, but in the end, you'll need to sink a lot of money into a 318 to get the same performance from a stock 340. Swap out to a 440? I'd do that in a heartbeat. The problem is, new K frame etc. tons of HP and torque but not as easy as simply dropping in a 340. If you can afford an upgraded cam, aluminum intake and a set of headers for a 340, you'll smile every time you hit the gas pedal!

 

[RustyRatRod]

If we all looked at this hobby as to what we can "get out of it" when we're done, it would surely die.

 

[satman72]

One more reason to NOT sink money into a 318 is resale value. In the end when you decide to sell/upgrade etc, you'll get all your money back out of a 340/440 rather than a 318. I have owned many different Mopars over the years including a 318 Challenger that I tried to improve on. The 318 was not DESIGNED to be an HP motor. It was designed to take the family on vacation, get fairly good gas mileage and last 150K before needing a valve job. The 340 was designed for high RPM HP and yes, it will cost you more up front to buy one, but in the end, you'll need to sink a lot of money into a 318 to get the same performance from a stock 340. Swap out to a 440? I'd do that in a heartbeat. The problem is, new K frame etc. tons of HP and torque but not as easy as simply dropping in a 340. If you can afford an upgraded cam, aluminum intake and a set of headers for a 340, you'll smile every time you hit the gas pedal!

Ya know, If I built that junker 318 from hot rod magazine and was putting out 400+ horsepower & torque for 1500 bucks, I'd be willing to bet that I would be smiling everytime I hit the gas pedal as well.

No one is saying that a 340 SB or a BB would not be better. That isn't the point.

The question is simple; What can I do with a 318! Not a 340, not a 360, not a Big Block, not a hemi, not a chevy, not a roll of Charmin toilet paper!!!!

"WHAT CAN I DO WITH A 318"????WHY IS THAT QUESTION SO HARD TO UNDERSTAND?????

 

[old tired rebel]

I love the mileage my 18 gets and it doesn't take much to wake them up. Right now I have a factory Van Truck intake on mine with a Edelbrock 600. My next step is going to be headers and then a wieand intake with a AVS carb, there goes the gas mileage.

 

[kb67mopar]

Next car I build is getting a 318 poly....and I will probably never build a car with a 440. I love that you can change the earth's rotation with the torque of a big block but really if I can't afford to fill the tank for a trip the store...then there is no point.

Its the reason people keep 318's around...that and the fact they are bullet proof, live forever and can be potent. Its probably the best all around motor dodge ever made. I guess thats why they used it all the way up until like 2003.

 

[RustyRatRod]

A LOT can be done with a 318. All the mags have shown you how, plus, people were doin it before the editors of those mags were even born. I love it when people holler about 700 HP. Most of those people have probably never felt an honest 400 HP. You can build a 12 second street car real quick with a hot 318. And I mean 12 ohs if you do it right and still have some driveability. Just use what you have. It'll be fine. Oh and to the ignorant ones who say Chrysler never made a performance 318, what's this? Same bore, same stroke, just in a little different package. And what's that? A FACTORY dual quad intake. And what did police cars use all through the 1980s? 318 4 barrel police package motors. They were not passenger car engines.

 

[Dako]

I spy...a Poly! :hello2:

Off the show room, with that dual quad, it was rated at 290hp...and that was before any tinkering took place.

 

[satman72]

Another thing to consider... the small block is a lot lighter than the big block. 150 to 200 lbs less weight on the front end makes a difference. Sure it's a lose something, gain something scenario. In the end it comes down to the individual... what do I want, what can I get for what I can afford, what do I have available.

I would be willing to bet that If I spent 5-6 grand on doing a 318, I could probably shame a basic hemi or 440 that cost more.

 

[RustyRatRod]

For a Mopar beginner such as a young gun, it should be a question of logistics. Are there more 440s, 383s, 340s or 318s available? The 318 by FAR out numbers all the rest and is way cheaper because of that and the fact that everybody thinks they're a boat anchor.

 

[67Satty]

I gave away the 318 that came in my Satellite when I swapped the 440 in. I gave it to a guy in exchange for helping me take it out. I kinda wish I would have kept it, not for the satellite, no regrets swapping in a 440, but for a future project like an A Body or A100 Van or something. The '67 318s had close-chambered heads and forged steel cranks too.

 

[RustyRatRod]

That's right. They also had something else a lot of people don't know OR overlook. The 318s up till about 69 or 70 all had the smaller, LIGHTER 273 rods. Those are the same rods that Mopar Performance made all through the 1970s and have now been long discontinued that everybody wants. They are much lighter than the standard 318, 340, 360 rod and properly prepped, they are just as strong. I'll put it like this.............. Anybody that says any of the old school Mopar engines ain't any good has more ghey in them than I wanna be around.