Making power out of the 318

[Dartswinger70]

My advice to the OP if you are a 15 year old kid, and you build your 318 bottom end with 360 heads you'll lower compression but there are things you can do get pistons that com up to deck height as the 318s sit low and mill the heads... get it to 8.5 or 9 to 1 and run it .don't get too crazy because it gets expensive. that's about as far as Id go and really you need a set of stock 318 heads and a replacement piston and it would run that's the least expensive way to go. 318s are about being cheap not dumping your life savings into them.

 

[Dan the man]

Take your time and please, explain to me why you would even consider dumping money into machining/building a LA 318 for performance...and I dont care if you go to that Motor Trend article and copy and paste the whole thing ...Ill wait...

If I already had it, that's one reason, you have to include the additional cost of a 340/360 block. Not everyone needs/wants a tire shredding car. Some folks, like myself just want a car that they can have fun with. I suggest you read 318willrun's articles.

 

[Dartswinger70]

I'm out you guys hang on the web way too much don't you have a car to work on...? parts to buy maybe...?

Ill already been to Mancini today ordered a fuel pump eccentric...its holding up my 340 build...

 

[Dan the man]

My advice to the OP if you are a 15 year old kid, and you build your 318 bottom end with 360 heads you'll lower compression but there are things you can do get pistons that com up to deck height as the 318s sit low and mill the heads... get it to 8.5 or 9 to 1 and run it .don't get too crazy because it gets expensive. that's about as far as Id go and really you need a set of stock 318 heads and a replacement piston and it would run that's the least expensive way to go. 318s are about being cheap not dumping your life savings into them.

Easiest way to raise the compression is to get a set of kb167's, they would be 0.012" down the bore. 360 improve flow but hurt compression as you said. The use of 360 heads increases the cost of the build due to having to have the heads milled so much. I think that he'd be better off in the long run to buy a set of aftermarket heads, by the time he has the guides done, valve job and the possibility of cutting the seats to a bigger size because of excess valve seat wear, milling the heads and milling the intake side of the heads, this is why I think that the use of 360 heads on a 318 can be costly

 

[66fs]

Take your time and please, explain to me why you would even consider dumping money into machining/building a LA 318 for performance...and I dont care if you go to that Motor Trend article and copy and paste the whole thing ...Ill wait...

Thanks, for getting me sucked back into these ridiculous arguments. I've listed and done the easy and cheap parts and combination to make a 318 run with a 340 or 360 soooo many times. You can get a free 360 intake manifold for shipping. You can get 360 heads, clean and magged for cheap, $150 a pair + shipping. Right in the classified section of For A Bodies Only. Get pistons for about 9:1 compression with 72cc chambers, just like a 72-73 340. Do your standard machine work for any V8 rebuild and add torque plate hone and balancing. Get a cam, lifters, springs, double roller timing set in the .450 to .500 lift and 210 to 220 intake duration @ .050. Add a curved distributor, a windage tray, and a good used 318/340/360 TQ carb. Any 318 can run with a 340 or 360. 22 cubic inches less is too small, what a joke.

 

[273]

If my builder told me they couldn't build a decent 318 I wouldn't trust them to build anything.

Buddy likes to strawman his arguments generally insisting that people that want to build or defend building a 318 is cause they think 318 is better than a 340/360 an argument no one has ever made except 66fs he not a 360 fan and goes as far to say a 273 is better, and that's his experience and for him it works, ain't gonna trash on his experience, it might not align with others, but other than that I've yet to see someone say a 318 is better than a 360, just their an capable engine.

 

[273]

it's wild right? i mean, i like HP just as much as the next guy but you absolutely don't need 400 for a nice cruiser.

new hemi 5.7's don't even have 400hp and they absolutly haul balls. in heavier vehicles no less!

i put "i gotta have 400hp" up there with the whole "i want a cam that sounds good" in the category of indoctrinated nonsense from magazine articles, tv shows and forum blather.

Problem with picking a random power number is even 25 hp can change the whole cost of the engine and or driveline. To get that next step might need a whole different engine parts list and different drivetrain.

Eg. A 360 can easily get 275-375hp with a lot of stock parts and driveline, 400+ hp 360 almost everything starts to need or should be modded/upgraded.

 

[Dartswinger70]

Hey OP, good luck whatever you do. Id say with new pistons you are going to have to bore/hone so right there is machine work. just don't be surprised when the bill$ come in. But, it gives you something to work at... what I wanna know is can I clean degrease an engine with a pressure washer...

 

[66fs]

If my builder told me they couldn't build a decent 318 I wouldn't trust them to build anything.

Buddy likes to strawman his arguments generally insisting that people that want to build or defend building a 318 is cause they think 318 is better than a 340/360 an argument no one has ever made except 66fs he not a 360 fan and goes as far to say a 273 is better, and that's his experience and for him it works, ain't gonna trash on his experience, it might not align with others, but other than that I've yet to see someone say a 318 is better than a 360, just their an capable engine.

Not to say a 273 will make more power, and they can depending on the builds, I just like them better. I used to be the king of cheap. To get a cheap engine that revs, I would get the best factory heads and run them on the smallest engine. That way, you don't need a cam to really make an engine run. It works on a Chevrolet and Ford as well, maybe with the exception of a Boss 302. Those heads were too much. I just don't like the 360 and it's longer stroke, I prefer any of the small blocks better. Plus I always had the advantage of running a 4 speed and an 8 3/4 with different pumpkins in an early A Body. With the limitations I put on myself It all works out fine. I have built plenty of 360's for others, just not my cup of tea. By the time I go bigger than a 340, I'm into big blocks.

 

[273]

Not to say a 273 will make more power, and they can depending on the builds, I just like them better. I used to be the king of cheap. To get a cheap engine that revs, I would get the best factory heads and run them on the smallest engine. That way, you don't need a cam to really make an engine run. It works on a Chevrolet and Ford as well, maybe with the exception of a Boss 302. Those heads were too much. I just don't like the 360 and it's longer stroke, I prefer any of the small blocks better. Plus I always had the advantage of running a 4 speed and an 8 3/4 with different pumpkins in an early A Body. With the limitations I put on myself It all works out fine. I have built plenty of 360's for others, just not my cup of tea. By the time I go bigger than a 340, I'm into big blocks.

I like your builds and perspective, people forget the 340 head was designed to work well on a mild 340, a 1.88 valved 360 is fairly under headed, makes sense that there gonna be a great performance upgrade to a 273/318. An Edelbrock head on a 360 is a similar cfm to cid as a stock headed 273 and 340 as would an 1.88 valved J head on a 318 would also have a similar ratio.

 

[barbee6043]

Wow! 309 posts, 13 pages in what 5-6 days. Either the OP has learned a lot or really confused.
I congratulate for all the good people that offer their experience and advice!
All I will add is, there are more than one way to skin a cat (RRR that is a play on words!) and I suggest you just try to take all advice an try to shift thru what will work for you.
Learning is fun and knowledge is power.

 

[mgoblue9798]

so i recently got and 1973 small block 318 i am very new to mopar and was wondering what to do to the 318 i have every thing but the pistons the guy that i got it off of droped one and cracked it, i also have 360 heads that i would like to put on i am thinking about putting kb 167 pistons (0.40 over) in it, stock crank, stock rods and a rad cam with a lot of lope because i am a stupid kid, and stock 360 heads and then some kind of single plane intake and then a 750 double pumper i am really on a tight budget. is all of this possible or unrealistic.

Radical cam and single plane intake don't sound like good choices for a tight budget on a street engine with gas at $3 plus per gallon

 

[volaredon]

Ok I'll say it. I like 318s better than 360s.
I can't figure out especially with the larger combustion chambers, why they further castrated 360s with dished pistons from the factory. I like the idea of a longer stroke, but the stupid low compression (I doubt any actually made the claimed 8.4:1 cr as advertised in any manual from back in the day as built). Probably why they're gas sucking pigs.
Though not "zero deck" every 318 I have seen the heads off of, at least started with flat tops.
I also can't figure out why a 360 is more likely to be sludged up than a 318. In my experience anyway. And I've been inside several of both.
I've never been able afford a 340 so I can't say anything about those. I can't even find a 340. Never have been able to around here even since the 80s.

Yeah, built up the same, I can see the POTENTIAL of a 360 being more potent than the 318. But I have never had a 318 vehicle that simply "ditching the 318 and replacing it with a 360" would have really made much difference in getting what I've needed out of it.
I have a build in my head that id like to try on a 360 one day that would definitely be an improvement over stock, but don't have anything that needs a motor to try what I am thinking of, on.
I will say that I have a 360 magnum in a Durango, and compared to the 4.7 in my pickup, the 360 mag runs circles around the 4.7 when pulling my camper. And the 4.7 js supposed to have 300 HP and 10:1 CR, which is more than the 240-ish my 360 mag is supposed to be....

 

[junkyardhero]

Thanks, for getting me sucked back into these ridiculous arguments. I've listed and done the easy and cheap parts and combination to make a 318 run with a 340 or 360 soooo many times. You can get a free 360 intake manifold for shipping. You can get 360 heads, clean and magged for cheap, $150 a pair + shipping. Right in the classified section of For A Bodies Only. Get pistons for about 9:1 compression with 72cc chambers, just like a 72-73 340. Do your standard machine work for any V8 rebuild and add torque plate hone and balancing. Get a cam, lifters, springs, double roller timing set in the .450 to .500 lift and 210 to 220 intake duration @ .050. Add a curved distributor, a windage tray, and a good used 318/340/360 TQ carb. Any 318 can run with a 340 or 360. 22 cubic inches less is too small, what a joke.

something about getting into an fight with a pig? they'll drag you down and roll around in the mud, but they don't mind getting dirty.

pay no heed to that goofball, he's back on his bullshit again. anytime he gets a whiff of DV, 318 stuff or UTG he just gets spun up.

you know what time it is. we've all built that same motor, or at least most of us have, and it's known that it's a perfectly fine little performer for not a ton of cash and will flat out surprise most.

 

[junkyardhero]

Problem with picking a random power number is even 25 hp can change the whole cost of the engine and or driveline. To get that next step might need a whole different engine parts list and different drivetrain.

Eg. A 360 can easily get 275-375hp with a lot of stock parts and driveline, 400+ hp 360 almost everything starts to need or should be modded/upgraded.

very well said. there's no hard line in the sand on where the tipping point is, but the data available shows that 375/400 is fairly easily attainable with a 360 and not a ton of jack. where as those same numbers from a 318 are exponentially more expensive.

then comes the necessary upgrades to the supporting cast, because who cares if you make 400 horses and can't get 'em to the ground, or blow up parts, or can't take advantage of that power because of a soft converter and 2.76's

there's more to the whole picture than the horsepower number, and unfortunately that's the one thing most people get hung up on.

 

[pittsburghracer]

I got lost and ended up on one of the one hundred 318 posts. I hope I can find my way back to normalcy. Lord help me.

 

[Dale Davies]

Ok I'll say it. I like 318s better than 360s.
I can't figure out especially with the larger combustion chambers, why they further castrated 360s with dished pistons from the factory. I like the idea of a longer stroke, but the stupid low compression (I doubt any actually made the claimed 8.4:1 cr as advertised in any manual from back in the day as built). Probably why they're gas sucking pigs.
Though not "zero deck" every 318 I have seen the heads off of, at least started with flat tops.
I also can't figure out why a 360 is more likely to be sludged up than a 318. In my experience anyway. And I've been inside several of both.
I've never been able afford a 340 so I can't say anything about those. I can't even find a 340. Never have been able to around here even since the 80s.

Yeah, built up the same, I can see the POTENTIAL of a 360 being more potent than the 318. But I have never had a 318 vehicle that simply "ditching the 318 and replacing it with a 360" would have really made much difference in getting what I've needed out of it.
I have a build in my head that id like to try on a 360 one day that would definitely be an improvement over stock, but don't have anything that needs a motor to try what I am thinking of, on.
I will say that I have a 360 magnum in a Durango, and compared to the 4.7 in my pickup, the 360 mag runs circles around the 4.7 when pulling my camper. And the 4.7 js supposed to have 300 HP and 10:1 CR, which is more than the 240-ish my 360 mag is supposed to be....

I am also not a fan of the 4.7/3.7's which should have been stillborn. What a pain when, not if, the head gaskets fail.
The LA and Magnums are reliable and especially so since EFI. With proper service they last seemingly forever. And as you stated, they make torque the SOHC engines have wet dreams over. Now if the bodies stood up that well we would have good vehicles.
An even worse engine is the Ford 4.0 SOHC. Timing chain for the left bank is on the front while for the right bank is on the back. To replace the right chain and guides requires the engine to be removed. And hurting for torque also. They can hardly pull a sick ***** off the piss pot with a 40 yard run.

 

[junkyardhero]

I got lost and ended up on one of the one hundred 318 posts. I hope I can find my way back to normalcy. Lord help me.

careful man, don't stay too long or next thing you know you're scouring the classifieds for some 1.03 t-bars and 17" wheels to go with the LD4B and holly enconomaster you just scored.

 

[Dartswinger70]

There' alot of big talk about 318s especially on Youtube but the way I see it you'll hit a wall with them eventually where you'll have alot of money dumped into it trying to do what...prove it can be made into a 340? no one has really actually done that yet. The one guy on youtube broke the crank revving it too high thus pointing out another weakness. I dont want to hear about the Vizard build till its done then I want to see a list of what was done and how much it would cost in the real world, I also want to see it ran on a dyno real time with HP numbers. I dont care about home porting 318 heads with no proof of any gains...its all talk, internet bench racing I'm not concerned with hypothetical builds that no one will ever do because they complain about "the cost of a 340 or 360 block" and also complain that "318 is better on gas than 360" Truth is the average guy who wants tpo make power that he/she can afford isnt starting with a LA 318 or even a magnum 5.2 theyll go with a 360 /5.9 as a foundation thats what makes sense. I am talking about someone who wants high 300-400 horse in the end. I makes absolutely no sense t o dish out the cash on a 318 only to maybe swap the heads and intake over to a 360/360 stroker bottom end later on down the line this is why youll see 318 builds for 4 grand plus its the guy trying to unload one after they wised up. Usually the cam heads and induction system is what gets parted out the bottom end goes for cheap no matter what machine work was done. i have no issues with 318s at all I've owned a couple and rebuilt a couple, but I usually chime in when people get carried aweay and say "its a 340 it can do what a 340 can do" snake oil salesmen like Yuncle Tonee started that and people parrot it. No amount of internet bullying changes truth.

 

[66fs]

There' alot of big talk about 318s especially on Youtube but the way I see it you'll hit a wall with them eventually where you'll have alot of money dumped into it trying to do what...prove it can be made into a 340? no one has really actually done that yet. The one guy on youtube broke the crank revving it too high thus pointing out another weakness. I dont want to hear about the Vizard build till its done then I want to see a list of what was done and how much it would cost in the real world, I also want to see it ran on a dyno real time with HP numbers. I dont care about home porting 318 heads with no proof of any gains...its all talk, internet bench racing I'm not concerned with hypothetical builds that no one will ever do because they complain about "the cost of a 340 or 360 block" and also complain that "318 is better on gas than 360" Truth is the average guy who wants tpo make power that he/she can afford isnt starting with a LA 318 or even a magnum 5.2 theyll go with a 360 /5.9 as a foundation thats what makes sense. I am talking about someone who wants high 300-400 horse in the end. I makes absolutely no sense t o dish out the cash on a 318 only to maybe swap the heads and intake over to a 360/360 stroker bottom end later on down the line this is why youll see 318 builds for 4 grand plus its the guy trying to unload one after they wised up. Usually the cam heads and induction system is what gets parted out the bottom end goes for cheap no matter what machine work was done. i have no issues with 318s at all I've owned a couple and rebuilt a couple, but I usually chime in when people get carried aweay and say "its a 340 it can do what a 340 can do" snake oil salesmen like Yuncle Tonee started that and people parrot it. No amount of internet bullying changes truth.

Where did the red X go? Absolutely wrong and stupid. Do you think .13 of an inch on a diameter makes any difference at all? Nope. Look at a ruler. Have you built any motors? Have you ever done anything but puff yourself up. High Performance is a combination of head flow, compression, camshaft, ignition, carb/induction, and exhaust. Then your bottom end has to be able to hold up. It absolutely works for any engine. 2.0 Neon, slant six, 273, 318, 340, 360, any big block. I have them and have built them all. You start with the best heads and work down from there. Go bench race with the Chevy boys.

 

[RustyRatRod]

I'm out you guys hang on the web way too much don't you have a car to work on...? parts to buy maybe...?

Ill already been to Mancini today ordered a fuel pump eccentric...its holding up my 340 build...

We're not interested. Goodbye.

 

[RAMM]

so i recently got and 1973 small block 318 i am very new to mopar and was wondering what to do to the 318 i have every thing but the pistons the guy that i got it off of droped one and cracked it, i also have 360 heads that i would like to put on i am thinking about putting kb 167 pistons (0.40 over) in it, stock crank, stock rods and a rad cam with a lot of lope because i am a stupid kid, and stock 360 heads and then some kind of single plane intake and then a 750 double pumper i am really on a tight budget. is all of this possible or unrealistic.

Quick question---Do you have any interest at all in being able to spin/burn the tires ? If yes then you have 2 options: 1. Build the lumpy-cammed 318 but put 4.30-4.56's in the rear.
2. Forget the 318 and find a 360 with more "normal" gearing.

J.Rob

 

[Dartswinger70]

I don't recall my 318 being much of a tire burner now that ya mention it...welp...good luck kid...

 

[Swinger 340]

B

ahhh... the days of picking camshafts and carbs like they were titties: the bigger the better!

Big titties are fine, but you still need the *** behind it. In other words, you will need some head work (stiffer springs), better flowing exhaust and matching carburation and intake. It's the whole package, not just the titties.

 

[Dartswinger70]

Having tore down both 318 and 340 Ill say I agree. It's in the details. People say the 318 is identical, only a little and its externally. So in theory all the little parts you'd have to obtain and swap into a 318 make it expensive to build up. Anyone who knows knows this. For example you are going to buid up a 318 you need heads. OP has 360 heads ,great they are already one step ahead...but wait, there's more...the pistons, the cam...you going to rev up to 5500-6000 is the bottom end going to hold up...etc.? the heads need milled does the block need bored? how bout the crank? Machine work how much will it cost? What are the gains after the money is spent?