Oct 15, 2013 the 67' 440 'HiPo' Cylinder Heads, and called them the 40 Horsepower Heads. Back then they were all the rage. You could pick them from your local Mopar Dealership Parts Department for a crazy low cost, something like $125 for a set. The Heads and a 'Street Hemi' grind Hydraulic Camshaft, pretty much guaranteed.
The 318 engine is absolutely the best all-around small block Mopar, in my opinion. It can easily make 400 plus horsepower and still has great street manners. If you're building for fuel economy, the 318 beats the Mopar 340 and 360, hands down.
The 318 was produced in three versions: polysphere, LA series, and Magnum. Each are good engines, but for performance use, you should stick with the LA or Magnum because performance parts for the 318 Poly are hard to find. This article focuses on the LA version. Why build a 318 when it's just as cheap to build a 360? For one thing, if you already have a 318, it's not 'just as cheap' to build that 360.
First, you'll need to get a 360 core, which will set you back $250 or more. The 318 and 360 engines are balanced differently, so you'll also need a new flywheel or flex plate and torque converter. Then there is fuel economy.
Almost 12% smaller than the 360, the 318 should get about 12% better mileage, all else being equal.When it comes to building for power, the 318 is also a great choice. I'm not an engineer, so I can't explain the details, but there are many aspects of an engine besides outright displacement that contribute to its power potential: bore to stroke ratio, connecting rod length, port volume, etc. Suffice to say that the stars were aligned for the 318, and all the design specifications come together to produce an engine with excellent power potential for its size. A street-worthy 318 can easily make 400 horsepower, about what a lot of street 360s put out. If you've never rebuilt a small block Mopar, you really need this book. Has all the information you need to know. It covers stock type rebuilds, so if you're looking for high performance info, it's best to consult with an engine builder who has experience with the Chrysler LA small blocks.
They aren't the same as Chevys and you won't get maximum performance if you just copy what works on a Chevy. Please note there is another book available titled How to Hot Rod Small-Block Mopar Engines which I do not recommend, as much of the information is out-dated and a lot of the parts mentioned are no longer available. Overview: Even though almost all Mopar 318s came from the factory in low performance two-barrel trim, the 318 can be built into a great street performance engine. Blocks can be a little harder to find than 360 cores, depending on where you live, but it's worth the effort to track one down. I recently had a 318 rebuilt to replace the 273 in my 66 Barracuda. Here is how it was done.
I used a 1986 block. These have the advantage of having factory provisions for a hydraulic roller cam, but the disadvantage of thinner cylinder walls than earlier castings. Fortunately my block cleaned up with a.020' bore. Most blocks require.030' which is the maximum you should go on these thin wall blocks. Another problem with the later blocks is that they're prone to cracking between the center head bolt and the water jacket. My block was cracked. It's easily repaired, but adds about $100 to the cost of the re-build.
Machine work included boring and honing with torque plates (very important), line honing the main bearing saddles, and decking the block. For a street engine, that's all you need. Since this is a street engine, I decided to use the stock cast crankshaft instead of a custom forging. Mine required grinding and cleaned up at.010/.010 on the rod and main journals. The stock Mopar 318 crank is actually a pretty good piece and is good for at least 6500 rpm, far higher than I'll be spinning mine. I decided to go with Scat I-beam rods. They're probably not necessary in this application, but if a rod lets go it will ruin your whole day, as well as your engine.
![943 943](/uploads/1/2/5/4/125489727/682801710.jpg)
I figure they are cheap insurance. I should also mention they're only a little more than Eagle rods but made out of better steel.
If you're putting after-market rods into a small block Mopar, I'd recommend Scat over Eagle. Stock pistons aren't the right choice, even in a mild build. I used Keith Black KB-167 hypereutectic pistons. These are much stronger than stock pistons and give a higher compression ratio. On my engine, the compression ratio worked out to 10.1:1. For rings, I used KB's matching moly ring set.
I used high swirl 318 (#302) castings. These are by far the best cylinder heads to use on a mild 318 (I know, some people prefer the 360 heads). They have high-velocity ports that give good flow with just a little work and a closed, high-swirl combustion chamber that helps prevent detonation.
I upgraded from stock valve sizes to 1.88' intake and 1.60' exhaust valves. I also had the shop do a 3 angle valve job and bowl blend. At this performance level, more extensive porting isn't necessary. I'm running a Comp Cams 268XE cam that has 224/230 duration and.477/.480 lift on the intake and exhaust. This should give me good power without sounding too racy.
In retrospect, I should have gone with their XE275HL cam which is designed specifically for Mopar's larger lifter diameter, but the cam I have should be OK. I used to think the Edelbrock Performer would be perfect for this combination, but after talking to several people, I've decided that the Weiand Action Plus is a better manifold, so that's what I went with. I had the shop block the exhaust crossover when they installed the manifold. If I was going for all out performance, I would have run a Holley 750 vacuum secondary carburetor. Since I wanted some semblance of economy, I decided to run an Edelbrock 650 cfm Thunder carburetor. I also like the fact that I can tune it without pulling the fuel bowls as is required with the Holley carbs. Headers are a great idea with benefits in power and economy.
At this power level, though, it kind of depends. On most Mopars, headers are probably worth the money.
On an early A-Body, it might take a long time to recoup the cost. However, since my engine looks so pretty, I decided to splurge on a nice set of TTI headers. Just don't ask what they cost, it's still painful to think about it. Since I was kind of going all-out anyway, I replaced the stock rocker arms with Comp Cams stainless steel rollers. I also replaced the stock oil pan with a Milodon pan and matching pickup, and bought a nice set of polished aluminum valve covers.
Ignition will be a Mopar Performance electronic distributor with an MSD-6A control box. Overall, it should be a good combination. If I was starting over, I would have had the heads done by Shady Dell Speed Shop and taken the time to find an earlier block.Well, there you go, a recipe for a Mopar 318 that should give great performance and decent economy.
I can't wait to get my Barracuda back and see how this thing actually runs. If you like it (or not), leave a blurb in my guest book. The best intake by far for a 318 running 'high swirl' cylinder heads is the Weiand 8007 Action Plus Intake Manifold. Running a large port intake with 318-style ports causes a 'damn' in the intake path where the intake mates to the head because of the port mismatch.
Most intakes designed for the 318 ports are economy type manifolds that aren't really intended for high performance. The Weiand 8007 Action Plus is the only high-rise, high performance intake designed specifically for the 318 sized intake ports. I have one on my Barracuda and I love it.If you're running 340/360 heads, the best intake is probably the Edelbrock Performer RPM (don't run it with 318 heads though).
I really interesting option would be the single plane 2-bbl intake manifold that Mopar put on the 273 and some early 318. I think that with porting and Extrude Honing this manifold could be made to flow pretty well. Combine it with a tuned over-size 2-bbl carb from one of the low end big blocks and you'd have one heck of a sleeper.
Blueprinting an engine is the process of measuring, fitting, and balancing all the parts of an engine during the rebuilding. Blueprinting an engine improves its fuel economy, dependability, and most importantly its performance.An engine is a complex piece of machinery, and explaining all the steps necessary to blueprint one is beyond the scope of this lens.
In fact, it is a subject that could take up a whole book. As it turns out, there is one: by Rick Voegelin. If you are interested in what it takes to blueprint an engine, I highly recommend this book.What I like best is that it's written on a level easily readable by someone with even limited mechanical experience.
Instead of just stating what should be done, it also explains the 'why' and 'how' of engine blueprinting. It is also very clear on what steps can be accomplished by the home mechanic and what steps are better left to a competent machine shop. There is a ton of good information in this book.
I wore out my first copy and bought a second. In the Good Old Days, piston selection was simple. Cast pistons were for Grandma cars and forged pistons were for everything else. Today there is a third option, hypereutectic pistons. Not all engines have all piston types available, but the Mopar 318 is one of those engines that has been blessed with a decent assortment of pistons to choose from. By selecting the right piston for your application, you'll ensure that your car runs at its best, you'll be a hit with all the babes, and the envy of all your rivals.Cast pistons are the cheapest pistons you can buy.
They are also the weakest, so you need to really consider what you're going to use your engine for before choosing to run cast pistons. Cast pistons for the 318 are made by Federal Mogul. A set will cost you around $100 from Summit Racing. Regardless of the year of your 318, use the Federal Mogul Z526P pistons which are listed for the 1985 through 1989 318. These will give you about a half point higher compression ratio than the Z285NP pistons listed for the 1967 through 1984 318 and will fit the earlier engine just fine.
Cast piston advantages: Inexpensive, tight piston-to-wall clearance, quiet when cold. Cast piston disadvantages: Low compression, limited selection, not as strong as other choices.Hyperteutectic pistons are most likely your best choice for a high performance street or mild (no nitrous) racing engine.
Hypereutectic pistons for the 318 are available from Speed Pro and Keith Black. The Speed Pro pistons cost $147.12 for a set from Summit Racing. They are more of a stock replacement style piston, but will give you a little higher compression ratio than either of the cast piston choices for not too much more money.
They are also much stronger than regular castings and have a friction reducing coating on the skirts. If I were building a budget 318, these would be my pistons of choice. For a high performance street 318 I like the KB167 piston from Keith Black.
It's still a flat top, but with a higher deck height than the Speed Pro hypereutectics. It will give you a compression ratio between 9.2:1 and 10.4:1 depending on what heads you're running. They're also heat treated to T6 hardness, making them very strong. They cost $310.69 from Summit and are in my opinion the best pistons to use in a street engine. Hypereutectic piston advantages: Much stronger than standard castings, tight piston-to-wall clearance, quiet when cold, better ring and oil control than forgings.
Hypereutectic piston disadvantages: 5/64' ring package, shouldn't be used with heavy shots of nitrous.Forged pistons are the strongest pistons available, and therefore the best, right? Probably not, at least not for a street engine. While it's true that forgings are the strongest, they are also the most expensive. Also, because forged pistons expand more than cast pistons, they must be installed with a larger piston to wall clearance. This allows the piston to rock slightly in the bore when the engine is cold, which is noisy and also affects oil control.
There are some very good reasons to run forged pistons, but most of them don't apply to a street engine, not even a really hot Street 318. Unless you're running big shots of nitrous or lots of boost, you'll probably be happier with a set of KB167's.
If you DO need forged pistons for you application, I'd suggest skipping the less expensive offerings from Keith Black, TRW, etc., and going with a good set of custome forgings from Aries, JE, Mahle, Ross, Wiseco, etc. Forged piston advantages: Extremely strong, (potentially) much lighter weight. Forged piston disadvantages: Expensive, large piston to wall clearance, noisy when cold, poor oil control (compared to cast pistons).When buying a set of pistons, you should always go with the smallest oversize possible. Some people think the more you over-bore the better, but with a thin wall casting like the small block Mopars use, boring too much hurts power because it lets the cylinder walls flex more under load. You should also have your block bored and honed with torque plates installed to help ring seal and power.
If you're into Mopar engines, you will like this book very, very much. It has over 30 articles reprinted from the pages of Hot Rod and Car Craft magazines. It covers small block, big block, and Hemi engines.
It has two excellent articles on the 318. The first is very useful because they start out with a bone stock 318 and then add parts to it a step at a time to increase the performance. At each step they put it on a dyno so you can see the effect of that step on power output. Very educational.
The second article related to the 318 is on how to stroke it to a 348. This is a very cool modification to the 318 that I'd like to try some day.
It's even easier now since Scat makes a 3.58' stroke crank that drops into the 318 (as well as the 340) without having to grind down the main journals. So much useful information. I recently bought a 74 scamp w/318 LA eng. I'm not a car guy, just saw it, loved it, and have been slowly learning how to fix it up. It is so overwhelming and embarrassing trying to learn what to do when I have no idea what certain names of parts are or where they go. You've given me a great base to start from. I've been googling and youtubeing everything you wrote about.
Thank you so much for taking the time to write this. Other car guys might already know this info, especially for chevys, but for me, it was almost biblical in a sense. Thank you again!! I can easily attain most of the part mentioned, and know what its intended for and referenced to. Absolutely love the 318. My 1972 challenger with a 318 would run mid 15 quarter miles in stock form. Got 18-20 mpg freeway too.
My 1981 ramcharger with 318 ran great, but the most impressive was a lifted 91 w150. Brother drove it through college, i drove it through college. Did not get proper maintenance due to lack of funds at that time. Used and abused, sold it with over 200k on the clock and I still see it running around town. I plan on a mild build for the challenger 318. Just want a fun car for cruising.
The la blocks where developed past the earlier a blocks which stood for alloy la standing for light alloy. The 318 and 340 are almost exactly the same except for bore size and the 318 used cheaper parts. To do a successful 318 build used a 340 forged crank 340 rods will fit as wellthe windage tray and a high pressure oil pump use the push rods out of 340 as well stock where forged and shot peened as well.
![943 943](http://vehicle-photos-published.vauto.com/bf/6f/2a/4c-adf4-45e7-b79f-390728bcca19/image-11.jpg)
Now there are fast burn 318 heads you can get to raise compression. Also i would use a 340 timing cover on a 318 gives you a better high performance front main seal oh and it is a direct bolt on.
Port match the j heads to a eldelbrock rpm airgap manifold and some nice hedman headers. I use a fuel cooler and oil cooler as well on the car. You do this the engine will easily clear 500hp.not 400.the 340 was the base also of the nascar nhra and other race builds.
Hello mopar fans, i am alabama born and raised, raised to help people and a a retired mechanic at 50 due to open heart surgery. I lost my home and numerous other items waiting on disability.
I gave away several engines to people to build for power like a 68 lincoln/ford 429 dove-c engine which never had the valve covers off till i pulled them perfect runner as is//(wished i still haddit lol) 1 set of 4bbl 340 mopar heads and a set of 302 cast 318 heads and a 67 413 4bbl chrysler running perfect never built engine. Now after disability had came about 30 months later you see why i wished i had all my junk back. Instead of buying another 50 grand f-150 which i had to selli bought a one owner 86 d100 dodge 318 pick up.
If you see where i am going i wished i had the 302 cast or the 340 heads back for the old dodge ram. I am not a indian giver and would never ask for anyone to give em back but if anyone knows of any 302 cast heads for cheap or at least reasonable shoot me an email at [email protected]. I am on a fixed income which sux after busting ass all my life but the lord let me live. My old 429 is now planted in a 72 mustang mach pushing nearly 750 hp and all my mopar stuff left the state to tennessee. Thanks guys. Reposting this original one that I thought I had deleted!.G'day all.I have personally owned & built more Aussie Chryslers than anyone in the world to my knowledge (Just over 300 owned now to date since 1978) It was a 'Fireball' 318 2Bbl that really got me hooked & was my 2nd Australian Valiant in 1982.
Hi there, John from portland oregon. I just wanted say 318 is in my opinion is a great motor. I have a 69 barracuda notchback with a 318 with a 340 cam and I put the magnum heads on it.she run very good the older 318 are better too rebuild. I would for shure build a 318 over a 360 just because it is an internally balacend engine and you Can spin one high if built right.
I do have a 69 340 I plan on building took me along time too get the block from a friend of mine he has a 69 340 dart had the exstra block. I paid a lot just for the block. My plans are 340 fast efi and passion performance 5speed it's a new trans there Working on. All can say for shure if have a 318 build it for performance and it will run with the best of them. The mopar 318 suffers from a bad image just like the 307 chevy does. Its a mindset and if you hear someones opion (spelt that wrong) long enough you begin to get brainwashed. A car with a 340 in it will always get more money if the person sells it because on the image and reputation, the 318 is mopars best motor ( in my opion) but because chysler never meant it to be a high performance engine, everyone buys into the mind set.
The 318 if you corrrect it 3 major concerns which is cam, compression and flow (heads and carb) it BEATS THE 360 hands down because it has the same stroke as the 340.I have beaten many 340s and 360s with my 318 and i hear all the EXCUSES, well my 340 0r 360 just wasn't running well that day. BS its all reputation and mindset, someone tells us that a 318 can't beqat a 340 or 360 everyone believies it because they want to be led and they are looking for answers and are brain washed went to comes to the 318. Its a great engine with a very bad rep when it comes to performance, WHY BECAUSE CHRYLSER GUYS SAID SO A ND YOY BELIEVE IT.
I'm looking at buying a 1976 Dart with a 318, but I like it to become my summer daily driver. With high gas prices, I was trying to figure out a way to convert it to Port Fuel Injection. Therefore I would get performance (stability) and fuel economy. I haven't been able to find a complete system out there. Is there something (intake manifold, etc) I can get at the junkyard to build a system myself. Which manifold would you recommend?
The electronics I can get from EZ-EFI, but it's the mechanical side that seems to be a problem with the 318. Yes, I'm a Mopar fan. My family has had a string of 318-powered cars and trucks, and are still impressed that it is possibly the most tolerant and reliable powerplant we've dealt with.
Torquey, good mileage AND it makes gobs more power with a little attention.I do think you'll have cause to regret one of your changes though: Part of the 318's efficiency comes from heating the fuel, which is facilitated by that exhaust passageway you blocked off. That's why the performance intake kept that layout. For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: Show Details NecessaryHubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.LoginThis is necessary to sign in to the HubPages Service.Google RecaptchaThis is used to prevent bots and spam. AkismetThis is used to detect comment spam. HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.Amazon Web ServicesThis is a cloud services platform that we used to host our service.
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. FeaturesGoogle Custom SearchThis is feature allows you to search the site.
Google MapsSome articles have Google Maps embedded in them. Google ChartsThis is used to display charts and graphs on articles and the author center. Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature.
Google YouTubeSome articles have YouTube videos embedded in them. VimeoSome articles have Vimeo videos embedded in them. PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account.
No data is shared with Facebook unless you engage with this feature. MavenThis supports the Maven widget and search functionality. MarketingGoogle AdSenseThis is an ad network. Google DoubleClickGoogle provides ad serving technology and runs an ad network.
Index ExchangeThis is an ad network. SovrnThis is an ad network. Facebook AdsThis is an ad network. Amazon Unified Ad MarketplaceThis is an ad network. AppNexusThis is an ad network. OpenxThis is an ad network. Rubicon ProjectThis is an ad network.
TripleLiftThis is an ad network. Say MediaWe partner with Say Media to deliver ad campaigns on our sites.