lets see if we can locate a 1968 318 camshaft in useable condition (all the lobes intact) from there it can be stuffed into the existing 360 and just runnin it up with the prop installed and watchin the tach will tell of any gains or losses, not like i have a dyno anywhere handy, but yes playin with cam timing may be of benifit.....USA specifications
273 V8318 V8 (LA)318 V8 (A)340 V8
Gross horsepower, 1968
(1962 for 318-A)190 @4400 230 @ 4400 200-260 @ 4,400275 @ 5000 Net horsepower, 1972-73150 @ 4,000 240 @ 4,800 Net horsepower, 1977145 @ 4,000(not made)Torque, lbs.-ft. , 1968260@ 2000 340 @ 2400 340 @ 3200 Torque, lb-ft, 1972260 @ 1,600290 @ 3,600Torque, lb-ft, 1977245 @ 1,600Compression ratio, 19689.0 to 19.2 to 19.0 to 110.5 to 1Compression ratio, 19738.6 to 18.5 to 1Bore, inches3.633.913.914.04Stroke, inches3.3123.3123.313.312Carburetor type (1968-73)2-bbl.2-bbl.2 or 4 bbl (1960s)4-bbl.ExhaustSingleSingle(not avail.)DualFuelRegularRegular(not avail.)Premium
The 318
was used as a police engine, mainly in the M-bodies (Diplomats and Gran Furys), but its performance was unexceptional. It was, in many years, the largest engine available in Valiants and their descendents, the Diplomat and Gran Fury. It was used extensively in trucks as well.
A new, more reliable manifold heat control valve was used starting in 1969, featuring replaceable bushings for the valve shaft and a replaceable stainless steel internal seal to shield the bushings. Manifold heat control valve solvent can be squirted through the vent holes to keep the valve operating freely.
From its introduction in 1967 through its conversion to EFI, the 318 was generally treated as a two-barrel workhorse. With the 340 and 360 around, the 318 kept its "economy carb" from 1968 through 1978, when it got a Thermoquad four-barrel option to make performance acceptable with California emissions systems (in some years, the only choice in California was a four-barrel). A Carter two-barrel was the official replacement for the Imperial electronic fuel injection system. Starting in 1981, the four barrel was available in trucks regardless of location.
For 1977, F-bodies and B-bodies sold in high-altitude areas had altitude-adjustable carburetors; and the TorqueFlite torque converter was modified for better gas mileage and torque, with increased oil flow. The spark advance on these cars was also modified.
Lean Burn was also set for a late 1977 launch on the 318 (except in California).
In 1978, Chrysler noted with regard to the 318 and 360:
Exhaust-valve seats are induction-hardened on all engines for lead-free fuels. In the hardening process, seats reach a temperature of 1700°F and are then allowed to air-cool. This hardens the valve­seat surfaces to a depth of .05" to .08". The exhaust-valve stems are chrome-plated for increased resistance to wear.
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[/ame]The heat valve in the right exhaust manifold diverts hot gases to the floor of the intake manifold to vaporize the fuel mixture when the engine is cold. During warm-up, a thermostatic spring allows the heat valve to open to the exhaust pipe-so gas flow through the intake manifold crossover passage is decreased.
All 1978 Chrysler V-8 and 6-cylinder engines have an adaptor to receive a magnetic probe for timing the ignition magnetically (you can still set the ignition with a timing light); magnetic settings are more accurate.
Chrysler's most compact V-8 ­ designed to be rugged and dependable - is equipped with the second-generation
Electronic Lean-Burn System for 1978. Features include:
- Hydraulic valve lifter (tappets)-no periodic adjustments required
- Induction-hardened exhaust-valve seats
- Cast ductile iron crankshaft
- Aluminized steel exhaust and tail pipe
The 318 V-8 has proved its reliability over the years as the best seller in Chrysler Corporation's lineup of V8 engines. Now, it offers the increased dependability of electronic spark-plug timing and ignition controls. (A four-barrel version to meet California emission requirements is available on LeBaron and Cordoba in California).
1976 figuresSlant Six Valiant318 V8 Valiant360 V8 Valiant440 Fury Low speed pass 475 feet / 11.0 sec 460 feet / 10.5 sec 405 feet / 8.6 sec 400 feet / 8.4 sec High speed pass 2090 feet / 24.8 sec 1480 feet / 16.2 sec 1245 feet / 13.3 sec 1130 feet / 11.7 sec [It now has a] carburetor over a half pound lighter than the previous carburetor, designed for solid-fuel operation. This means a solid, continuous stream of fuel is fed to the primary discharge nozzles by the metering system. The fuel is mixed with air upon entering the nozzles. The solid-fuel metering produces precise carburetion for good driveability with lean fuel-air mixtures.
In 1980, Chrysler altered the 318s block, cam, exhaust manifold, and rear main bearing cap to save weight. They advertised the following specifications:
Bearings, CamshaftSteel-backed Babbitt, five, replaceable
Bearings. Connecting-Rod, LowerAluminum on steel.
Bearings, Crankshaft, MainV-8: five babbitt (except #3 aluminum), replaceable.
Oil grooves in upper and lower # 1 bearing, in upper half of all others.
Journal
Dimensions1
2.50" x 0.872"
2
2.50" x 0.872"
3
2.50" x 1.51V
4
2.50" x 0.872"
5
2.50" x 1.322"
For 1981, Chrysler introduced a
propane 318 system in the M-body cars. Factory engineered, built, and warranteed, it proved to be very popular for propane.
318 throttle-body / roller-cam engines (by Vince Spinelli and Jack Perkins)
In 1985, Chrysler finally switched from standard hydraulic lifters (and matching camshaft) over to a roller hydraulic lifter and a new matching camshaft. The roller design allowed for a steeper cam profile, and thus a more precise valve-train actuation, but the primary impetus seemed to be longevity. [
Story of developing the roller cams]
The throttle-body fuel-injected 318 motor had a few changes for its model year (1988), which would come to the 360 in 1989. This low pressure system gained a twin-bore throttle body with dual fuel injectors; the new throttle body had a 32.5% increase in throttle area. The engine also
used new roller tappets and revised valve timing, increasing power output of the 318 by 20% (and also boosting the 360 when its turn came). Oil capacity was reduced to five quarters (with filter change).
The heads were different; the basic casting is the same, but the fine points were not. To make better use of the fuel injection, swirl intake ports were introduced. To accommodate a slightly changed pushrod angle (the new roller lifters were taller than the standard hydraulics), the push rod guide holes in the cylinder heads were changed from roughly 0.5 inches to a published 0.66 inches (
Dodge DW Series Truck Factory Service Manual, 1988). Upon measurement, this was confirmed to within an accuracy of 0.01 inches. Push rod length changed from about 7.5 down to 6.78, and diameter shrunk from 0.360 to 0.3125 (again to accommodate the changed push rod angle).
[See the Magnum section, later in this page, for details on the "5.2" or 318 Magnum engines.]
318 Engine Troubleshooting
Duane D. Hughes wrote:
My 1976 318 stumbled and sagged badly until it was fully warmed up, even when new, a classic sign of a lean mixture. A friend who worked at a Dodge dealer advised me to raise the metering rods about 1/16 th of an inch, which can be done without disassembling the carb. I did this on three different cars with Carter carburetors, and it worked each time.
That car also pinged at light, not heavy, load, and on the slightest grade at highway speeds. I read that truck 318s had an adjustable vacuum advance on the distributor, accessible through the little hole where the vacuum line attaches to the vacuum advance unit. Sure enough, it had a screw to adjust the advance. Just a little playing around to get the right setting, and Voila! No more pinging. No change in mileage, either.
From: Bruce Martin wrote: One very common fault with the otherwise wonderful 318 is that the exhaust crossover in the intake manifold (which warms the base of the carb) becomes clogged. This is common so it should be among the first things you check. (This problem was addressed on the Magnum engines)
Ted Devey adds two more steps:
- Examine the reluctor teeth in the distributor for possible damage, nicks etc. which can happen if the gap gets too small. If there is damage to the teeth, replace the reluctor.
- Several years ago I dismantled the Carter 2-barrel carburetor and reassembled it with the jet assembly upside down. There is no obvious wrong way.
Timing marks and removing the crank seal (360 but 318 is probably similar)
The timing marks are located on the lower driver's side of the timing chain cover. If the car has extra brackets bolted on the bottom of the timing chain cover, they may hide the timing marks from being easily seen. Some early LA engines may have had the timing marks on the passenger side but certainly by 1977 they should all be on the driver's side.
(Thanks, valiant67)
When the timing chain cover seal is leaking, the harmonic balancer will need to be removed. It will require a 1 1/4" socket and a puller to remove the balancer. You will then be able to replace the crank seal (and maybe add a wear sleeve to the crank if the surface is worn).
The 340: high performance in a small package
Probably the best development for performance enthusiasts was the production of the 340 V-8 in 1968. It had high-flow heads, big ports, a two-level intake manifold, and a six-barrel option (three two-barrel carbs).
Click here for a full page on the 340.
There were many differences between the 340 and 318 apart from the bore of a similar block. The 340, from '68 to '71 at least, is the smallblock equivalent of the Hemi. It has great power when put in the right car (a '68 Barracuda, for example), and has more than enough appeal to keep the Brand-X guys wishing they'd boarded the Mopar Express before the light turned green.
355 Racing Engine: NASCAR, Drag Racing, and IROC
Starting around 1975, Chrysler produced a version of the LA engine specifically designed for racing, and not available in any passenger car. NASCAR had recently started penalizing of any engine over six liters (366 cubic inches). In 1975, Dodges equipped with the 355 V8 won 14 of 30 Grand National races, and Richard Petty was in the winners circle 13 times with 355-powered Dodges.
Sometime around 1978, a drag-racing version of the engine was developed, also at 355 cubic inches.
Marc Rozman wrote:
When I ran my 440, a guy we called
Fast Eddy [Poplawski], part of the race group, who ran a 355 racing motor [for drag racing; never used in a production car], tunnel ram, dual quads. He had a Chevy manifold on a Mopar, he made up little wedges that make a manifold fit the angle on the heads on the small block Chrysler. Back then, Ted Flack and Howard Comstock where the guys driving those cars. Ted Flack was a dyno operator at one time, and he made the grade and became an engineer later on. Sharp guys.
They were still running the [NHRA] Pro Stocks, and if you look in the records you can see the Flack and Comstock cars, including a Dodge Dart Sport. They were doing development work on that motor still.
Ed Poplawski wrote:
The 355 engine was a bored and stroked 340 production 6-barrel engine block (LA) that we modified for racing use. The modern 355 that we did in 2001 when we got back into NASCAR racing is a purpose built race engine which has nothing in common with any of our old or new LA engines.
[The 355 block was common to all racing applications before 2001.] Back then the engine block of choice was the 340 6-barrel block. However, by the late 1970s, 6-barrel blocks were hard to come by and we were scrounging the local junk yards trying to find blocks. It was the same thing for the Pettys. To be honest, we were using standard 340 blocks for dyno development and saving the 6bbl blocks for the race cars.
The reason we wanted to use the 6bbl block was because we had added material to the bulkheads for strength so we could use 4 bolt main caps. Otherwise the only difference between the engines, like you mentioned was carburetion, camshaft, cylinder heads and headers. The NASCAR engine could only use a flat tappet cam (we used a mushroom tappet) and a single 4 bbl carb. The NHRA drag engines could use roller cams and multiple carburetion intake manifolds depending on the class.
Headers were chosen depending on the type of racing we were doing and the engine speed at which we were running. For example, for 1978 our goal for Daytona that year was 600 HP and the engine peaked at 7200 rpm. The 8bbl drag engines peaked at 9600 rpm so therefore the header size and length was a lot different. The IROC engines were basically NASCAR 355 engines. Also, we used dry sump oil systems in NASCAR so there were some internal modifications done to the block to make this work. Those were the major differences between all the series.
For 1976, Dodge had a complete W2 package, developed under John Wehrly;
Willem Weertman credits Larry Rathgeb with creating a Kit Car which included that engine for racers. The Kit Car had a 340, 355, or 360 cubic inch engine (it varied by model year). The 355 had a slightly larger bore than most LA engines, with a stroke between the 340 and 360 (see chart at beginning of page); it did well in short-track venues. The engine had forged aluminum pistons, stress-relieved blocks with thickened bulkheads, and four-bolt instead of two-bolt main bearing caps. Weertman wrote that this package reached more than 600 hp, gross, with a single four-barrel carburetor.
In 1979, Mopar Performance started selling their X block, a heavy duty racing small block which would displace 340 cubic inches used as is, or could be bored out, as Larry Shepard suggested, to 355 cid (Shepard also warned against using a used Kasper prototype block). These were painted orange and a large X was cast into the end. It had standard and four bolt versions. The same block was used in Pro Stock during 1979 and in NASCAR racing , as well as ARCA oval track racing in the 1990-91 seasons. There were numerous features in this block to add strength.
The engines were also used when Chrysler sponsored the IROC (International Race of Champions) series, which uses identical cars; drivers ran with Dodge Daytonas converted to rear wheel drive, with the 355 under the hood.
When NASCAR added a truck series in 1996, Dodge entered with an updated version of the 355, including cylinder heads. The engine was finally retired in 2001. [
Read a 355 development story]
The 360
The 360 first appeared in 1971, with a two barrel carb. It had a cast crank and external balancing, and was the only LA engine without a 3.31" stroke (3.58"). In 1972, it was rated at 175 hp @ 4,000 rpm, and 285 lb-ft of torque @ 2,400 above the 318 but well below the smaller 340. According to engine leader Willem Weertman, the goal of the 360 was to replace the old
B-series 361, providing something between the 318 and 383; but to do so at lower cost. They could not raise the block decks to help with a longer stroke, because the budget did not include altering the automated block and assembly lines to that extent. Weertman and others worked around that, using the same connecting rod as the 318, but reducing the height of the piston from the pin to its top, and cutting the radius of the crankshaft counterweights so there would be room at the bottom of the stroke. While that solved the space issues, the engine was now out of balance, so weights were added to both ends of the crankshaft assembly. That meant redesigning the torque converter flex plate and flywheel, and adding an offset weight to the vibration damper on the front of the crank.
The 360 was relatively tame through 1974, when it received some 340 performance parts and a Carter Thermoquad four-barrel carb in an effort to replace the 340 as a performance engine (starting in 1985, a GM-Rochester Quadrajet replaced the Thermoquad).
In its final years, the 360 was Chrysler's performance truck engine, making the
Grand Cherokee5.9 Limited the fastest SUV and powering top-of-the-line
Dakotas and
Durangos. The 360 was also used in
patrol cars and the
Volare Roadrunner. In 1987, a number of 360s were used in Diplomats and Gran Furys; some say that some of these engines were labelled as 318s, but that's a tough one to track down.
Vince Spinelli and Jack Perkins added: There are squad car heads, and there are interceptor heads. Squad car (cruiser) heads are 360 heads with little to no modification depending on whom you talk to. Interceptor heads are high compression heads, identical to standard 318 heads of the era, but with a smidge tighter combustion chamber. Compression works out to high 9s to 1, as opposed to the standard 318 head at about 8.5 to 1. Interceptor heads also have slightly large valve aperatures.
Dave Lyle expanded on this: These were J heads, and they were the same as regular 360 heads, except for bigger intake valves (1.88) and better springs.
In 1978, Chrysler wrote that the 360s valve timing, valve lift and length of time the valves remain open are carefully engineered for low emissions, power, and smooth operation at all speeds. Hydraulic valve lifters require no periodic adjustments. ... The camshaft is designed to seat the valves smoothly to decrease the possibility of valve bounce and the stress it causes in valve stems. In 1978, the 360 gained dual concentric throttle return springs in addition to a torsion throttle spring.
1978CarburetorHorsepower (net)Torque (lb-ft)318 Fed.Carter 2-barrel145 @ 4000245 @ 1600318 (CA)Carter 2-barrel135 @ 4,000235 @ 1,600360Carter 2-barrel155
@ 3600275 @ 2000360 E584-barrel.220 @ 4,000280 @ 1,6004004-bbl190@ 3600305
@ 3200400 HD4-bbl 190 @ 3600305
@ 3200
The 1978 California version came with an air pump, which could be ordered elsewhere with the N96 emissions control package.
In 1989, the 360 switched to roller cams and throttle-body fuel injection (see the 318 section); and see the Magnum section, later in this page, for details on the "5.9" or 360 Magnum engines.
All 360 production was moved in Mexico in 1980, according to Rodolfo Rodriguez. United States use of the 360 ended in December 2002.
Designed for aluminum engine blocks? (Mike Sealey)
There is some evidence that the 273 was originally meant to be an aluminum-block engine, and was to power a stillborn A-body DeSoto.
Motor Trend and other enthusiast magazines future products sections mentioned the development of both compact Dodges and DeSotos and a V8 engine sharing many internal parts with the 318, but displacing about 270 cubic inches and using an aluminum block.
Motor Trend ran artist's conceptions of the proposed Dodge and
DeSoto compacts. Their sketch of the Dodge accurately predicted its use of the "Lancer" name, its grillework, and the character line that curves back toward the front of the car in the middle of the front door on production Lancers. The taillight and rear fender treatment looked rather more like that of the
1960 Dodge Polara than what actually went into production.
The DeSoto sketch showed a Valiant-based car, with a grille that widened at the bottom and extended under the headlight clusters much like the fullsize 1960 DeSoto, and taillights modeled off the Valiant/Lancer rear fender, but with three small lights in a row along the fender edge, paying homage to the traditional DeSoto three-light fin treatment. MT speculated that this new compact DeSoto would carry the name "Adventuress." While this would have made for a slick tie-in to the larger, sportier Adventurer, I doubt that with gender attitudes being what they were at the time DeSoto would have gone with something that overtly feminine. (Especially after the tiny number of Dodge LaFemmes sold just a few years earlier.)
Preproduction lead times (and the notable differences between the A and LA engines, particularly in regards to head and intake/exhaust system design) being what they are, development of the 273 would have had to start around 1959-60.
Aluminum engine blocks were seen as the Big New Thing in this era, and while many remember the Corvair's use of aluminum and the Buick/Olds/Pontiac aluminum-block 215 V8, few remember the brief production of aluminum blocks by manufacturers other than GM. Chrysler made an
aluminum-block Slant Six as an option, apparently only in 225 configuration. It would be safe to assume that aluminum V8s were also under development, if for no other reason than to compete with GM.
Across-engine specifications
1994 Engine
Vehicles
Power (bhp)
Torque
5.9 (360)Ram 1500 and 2500, Van, Wagon
230@4,000
330@3200
5.9 (360)Dodge Ram 3500
230@4,000
330@2,800
5.2 (318)Dakota, Ram Van, Ram Wagon
220@4400
295@3200
5.2 (318)Ram Pickup
220@4400
300@3200
3.9 V6Dakota, Ram Van, Ram Wagon
175 @4800
225@3200
3.9 V6Ram Pickup
175 @4800
230@3200
Identifying LA Series V-8 engines and parts interchange
LA engines have the distributor at the rear, and the displacement is on the left front of the block, below the left cylinder head. LA valve covers are held on by five screws on the outside of the covers. If you remove the valve covers (the gaskets tend to go after 10-20 years), do not tighten these screws too far, and follow the instructions for 2.2 valve cover replacement in the FAQ. (But use a rubber gasket instead of RTV alone).
Robert Jones wrote: "All head gaskets for 318 LA series engine, even from Chrysler, are made to fit all bore sizes ranging from the 318 to 340. The fire ring is much larger on a 340 and the gasket thickness is closely matched to a 360 spec gasket so the compression is significantly reduced on replacement. Example: 1976 Plymouth Volare factory timing spec was 2 degrees (in Canada... was very snappy) and after I had changed the gaskets I found I couldn't make it ping even with as much as 10 degrees advance whereas 6 degrees was almost undriveable."
Dave Wordinger wrote: "The 1964-1965 273 head had the had the intake manifold bolt holes drilled at a different angle than the other LA heads, but will bolt to any LA block. The 1970 340-6 had the pushrod holes relocated. All other LA heads are interchangeable. The heads don't care what kind of camshaft or lifters you are using. The 1964-1967 273 had mechanical lifters. All 1968 and newer LA engines had hydraulics."
David William Elder wrote: "If you compare an early (such as 1968) 340 crank to a 318 crank of the same vintage you can clearly see the 340 casting is beefier. I think the two are the same numerically speaking but as far as strength the 340 is clearly the winner. The same goes for the connecting rods. The 273-318 connecting rods are similar to the 340s but a different casting with less 'beef'. I have actually seen some mid-70s truck and stationwagon 318s that came from the factory with 340 Six-Pak rods."
Mark DuVerger wrote: "The 273 rods are not the same as a 318, they measure the same and look identical but are lighter; all 273 rods are full floating rods, 73 and up 318s are press fit rods for the wristpin. The 273 will rev alot faster than a 318, or a 340."
Ed Prichard wrote: "Any intake that fits an LA 318 will also fit a 273. They will also fit 340s and 360s as well. But it is easier to find a "non-smog" intake for a 273 or 318 than a 360."
See the
starter page for information on starter interchangeability.
Magnum Engines (318/5.2, 360/5.9, 3.9 V6)
Chris Theodore said:
[After Chrysler bought AMC,] they tried to merge the two cultures, and so I was in charge of Jeep and Truck Powertrain. The first thing we started on were the Magnum engines, since the old
318 and 360 were still carbureted, and hadnt been improved in ages.
... Then they wanted to integrate the two groups so they picked five guys from the Chrysler side and five guys from the AMC side, and moved me to Highland Park and some of the Chrysler Highland Park guys to the
Plymouth Road facility. We were all kind of like fish out of water.
The main differences to the new 5.2l and the old 318 are in the block and heads. The new block has roller lifters, with a new lifter angle, and has bosses for the lifter retainers. The heads are high-swirl / high-flow heads, and the Magnum has a better intake. Some changes were made to commonize the 5.9, 5.2, and
3.9 V6 engines.
Gary Howell: "The Magnum blocks are physically the same as the earlier LA engines, except the oil passage for the shaft mounted rockers is not drilled, because the Magnum engines oil through the push rods. The boss is there if you need to use the old style heads."
Steve W. added, LA rods are not interchangeable with Magnum pistons. I just learned this while attempting to hang some MP stroker 360/403 pistons onto 1986 360 LA rods. The big end of the LA rod is 1.20 inches wide, while the MP stroker piston I am using has a pin width of 1.16 inches measured with a digital caliper.
In 1996, as Dodge moved to the JTEC powertrain computer, the LA engine series gained OBD II on-board diagnostics, and EGR was dropped (late in the year for the 360).
Maybe you can joggle the cam timing for more low end?
By the way some industrial engines had a different crank flange
You don't need to run the engine reverse rotation, do you?
so far it seems I'm lookin for a 1968 318 camshaft in useable shape, it dont gotta be brand new, i can install new lifters on it, if it has lifters in proper sequence is a plus...so far from what I have seen thats the one makin the biggest torque at the lowest rpm's, I went to a few sites with the oliver combines and can't see the dodge 318 engine being mentioned so for
