Best 273 and 318 builds (NO 360's please)

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That's awsome! I can't wait to hear how it all turns out! I haven't heard a first hand account from anyone yet who's done the 318-390/396 stroker build.
 
I did a /6 to a 318 swap because I had a teen in my '72 when I was 18 yrs old. And besides, a basket case 318 was in the trunk of the '72 duster that my wife got me for Christmas in 2010.
.040 over, K.B flat top pistons, Comp Cam 20-223-3 cam - 268/280 with .477/.480, RHS Indy 360 X heads 1.920"/1.624", Comp Cams 137 lb behive springs, Comp Cam roller tip rockers, Edlebrock 9176 Performer intake, Holley dbl pumper 650 carb with metering plates, Holley mech fuel pump, Hooker 9501 ceramic headers coated inside and out, balanced and blueprinted.
 

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mi72duster said:
I did a /6 to a 318 swap because I had a teen in my '72 when I was 18 yrs old. And besides, a basket case 318 was in the trunk of the '72 duster that my wife got me for Christmas in 2010.
.040 over, K.B flat top pistons, Comp Cam 20-223-3 cam - 268/280 with .477/.480, RHS Indy 360 X heads 1.920"/1.624", Comp Cams 137 lb behive springs, Comp Cam roller tip rockers, Edlebrock 9176 Performer intake, Holley dbl pumper 650 carb with metering plates, Holley mech fuel pump, Hooker 9501 ceramic headers coated inside and out, balanced and blueprinted.
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That's a very nice build. Good to see somebody lavishing a bit of $$$ and effort on a little 318. And with the stock stroke you'll not get your post edited...:eek:
 
MoparAnglia said:
That's a very nice build. Good to see somebody lavishing a bit of $$$ and effort on a little 318. And with the stock stroke you'll not get your post edited...:eek:
Click to expand...
Thanks Mopar...The hardest part of the build was hiding the cost from my wife....lol
 
mi72duster said:
I did a /6 to a 318 swap because I had a teen in my '72 when I was 18 yrs old. And besides, a basket case 318 was in the trunk of the '72 duster that my wife got me for Christmas in 2010.
.040 over, K.B flat top pistons, Comp Cam 20-223-3 cam - 268/280 with .477/.480, RHS Indy 360 X heads 1.920"/1.624", Comp Cams 137 lb behive springs, Comp Cam roller tip rockers, Edlebrock 9176 Performer intake, Holley dbl pumper 650 carb with metering plates, Holley mech fuel pump, Hooker 9501 ceramic headers coated inside and out, balanced and blueprinted.
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How does that engine run,Im building a motor just like it for a friend. One thing different going with airgap.
 
dart76 said:
How does that engine run,Im building a motor just like it for a friend. One thing different going with airgap.
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Runs sweet. No problems at all. I really haven't opened it up to hard yet. I only have a 7 1/4 rear end so I'm waiting to see what it will do after I swap to an 8 1/4 sure grip I have.
 
I have been real pleased with my 318 performance. I did not do much other than new roller cam, port and polish heads, high volume oil pump, new air intake, 600-cfm holley and electronic ignition. Something I did was to dress up the engine was new after market alternator bracket. I plan to install a similar bracket for the PS Pump. I plan to take it to the strip once or twice but I doubt if I will ever see anything but low 14's or high 13's without a new rearend. It is more a toy to cruise to the local car shows. Do a search on serpentine in the January time frame or advanced search for all words in title in photo gallery for 1973 Duster 318 .
 
Just got my '70 318 block back from Carlson Machine in Salmon Arm, BC Canada eh....

bored .030 over
4.00" cast scat crank
scat I beam connecting rods
kb847 pistons
302 ported heads w 360 valves
Comp Cams Mutha' Thumpr, 287TH7

pushing for 400hp in my 70 swinger clone
 
666mopower666 said:
Just got my '70 318 block back from Carlson Machine in Salmon Arm, BC Canada eh....

bored .030 over
4.00" cast scat crank
scat I beam connecting rods
kb847 pistons
302 ported heads w 360 valves
Comp Cams Mutha' Thumpr, 287TH7

pushing for 400hp in my 70 swinger clone
Click to expand...

Nice, stroker with 302 heads, that thing will be a torque monster. 400Hp should not be hard to acheive. I don't really agree with that cam though, I think the XE series is better. In my opinion the xe274 would make the same HP with more torque. But hey go with what ever you want, everyone wants different things out of their cams, I have a xe284 in my 318 and love it even though EVERYONE says its too big for my set up... haha
 
Just got done putting my little teen back together, shes a blast to drive. Loud, wild, and fast.

318 bored .040" over
.020" head gasket
61cc J heads with 2.02X1.60 valves
234/244 @050" .488/.510" lift
Weiand high rise stealth intake
Holley 750 DP
1 5/8 hooker headers
Roller rocker arms

Hooked up to a A833 4 speed with aluminum flywheel
Car is fun and loves to rev to 6,500+ RPM!!!
 
My IDEA.. a 273 - The stock forged crank
I have a set of good 1970 340 rods - a good set of forged pistons (www.flatlanderracing.com) - LD4B intake (a-body hood clearance) - Avenger EFI throttle body kit - 70's 318 heads with the 273 adjustable rockers - Comp Cams xs268 cam - topped with a Procharger @ 6-8 psi to make up for the low comp.
 
I'd like to build a 360 but my 318 in the car runs so well that I don't know if I see the point
of throwing more money into a 360 build. The 318 holds 60psi at idle. Not a thing wrong with it except for it being bone stock. I'd like more punch. Any reccomendations?

It is a '71 Scamp. 318/904(with low gear set), electronic ignition with orange box and the only other notable mod is an Edelbrock Performer intake/600 Holley carb.

I think headers will give me the most bang for the buck. I still gotta decide what cam and possibly a head swap later. I'm gonna go with 3.55's later.
 
What about this combo:
318 std bore,flat head pistons
302 heads ported,
Cam 276/286 duration-441/441 lift
performer rpm intake
Holley 600( ran on a tuned chevy 350)
Fenderwell headers
would that work?
 
DusterKrazy said:
I'd like to build a 360 but my 318 in the car runs so well that I don't know if I see the point
of throwing more money into a 360 build. The 318 holds 60psi at idle. Not a thing wrong with it except for it being bone stock. I'd like more punch. Any reccomendations?

It is a '71 Scamp. 318/904(with low gear set), electronic ignition with orange box and the only other notable mod is an Edelbrock Performer intake/600 Holley carb.

I think headers will give me the most bang for the buck. I still gotta decide what cam and possibly a head swap later. I'm gonna go with 3.55's later.
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I think a cam would be the biggest bang for your buck. I had almost the exact smae setup as you: 273 4 barrel iron intake with carter 625, orange box, low gear 904... And I put headers on and lost ~.1 sec and gained ~1 MPH in the 1/4. Which translates into, I did gain ~5 HP on the top end and gained some low/midrange, more traction issuses... But I think with a cam you would gain in the 20HP range(with a decent, mild tempered cam) and then if you did headers afterword you would gain 10+ more HP. The cam really is crappy in the 318...
 
Thanks..

I may just leave the 318 in there mostly stock and enjoy it for now. I'm thinking about building a 318 on the side just to be different. I see more people building them now because they are cheap/available and fun to play with!

I'm thinking ...

.030 over for 323 cubes with KB167 pistons and slightly less than 10:1 compression.
*Shaved 360 heads+bowl blended+3 angle valve job
*Solid cam and 273 rockers
*Headers

Some other stuff but haven't fully spec'd it out yet even though I have a pretty good idea. Nothing mega buck at all..
 
steve D in engine masters winter 2006 had a 318 build called cheap as dirt nothing but good basic mopar done right 415 hp great build
 
Years ago (1968) to be exact I used to race my 67 Dart 270 273 Power Pack at Englishtown Raseway Park. I ran in the SS/MA Classes and the Best time on record was 14.2. The engine was untouched except for reversing the Pistons, and stiffer valve springs (Had to change them out every three weeks,or the RPMs would fall off.) 411 gears and I modified the Valve for the reversed shift pattern, Hooker Fenderwells and Goodyear Slick. It was my daily driver, but every Sat night I would tune it up and off to the Track Sun morning. Where I would throw on the Slicks , un cap the headers and go racing. It was a cosistant class winner beating the Mustangs, 326 Tempests,327 Chevys and the 396 Impalas Conv I would face. 273s can be made to run with little work and fun to drive also.
 
Ive been thinking about taking the 5.9 out of my car to have done up into a stroker motor.

In the meantime (and with the kids in school, there will be a meantime) I thought about doing this as a stunt:

take my stock '71 318 shortblock (maybe put rings/hone in it, cylinders are ok)
Put on my 1.9 valve EQ/Iron RAM heads
RPM Air Gap intake
Cam? (would have to know my final comp ratio to make a smart choice, pistons are .100 in the hole...)
1-5/8 headers to 2.5 X-pipe
good oil pan
fresh paint
"yeah, its got a 318" bumper sticker

I've got decent chassis parts on the car, Calvert shocks, Caltracs.

The car does pretty well with the 5.9. Mid-high 1.5 60' times, about 3400 lbs, runs 11.70s with about 320 rwhp.

Any input on what the 'teen would pull off with that combo? Whatever I come up with feels either wildly optimistic or pessimistic.
 
Here is a nice build for a 318 i found on the web.


"DODGE DART Swinger



What Can I Do To My 318?
The mild but spirited 318 combo

The 318 can be an impressive performer. Start by getting the following books: Mopar Performance catalog, Mancini Racing catalog and HP Books How to rebiuld your small block Mopar. So, we'll start with the readily available 1970-1980 318 as a base. These are about 8.5 to 1 compression motors with flat top pistons. These pistons have a compression height of 1.740" from pin centerline to piston top. For the economy back yard performance motor, the factory flat top pistons can be reused. There are also several inexpensive cast pistons on the market to raise the compression up to 9 or 9.5 to 1. If upgrading to these pistons, have the block bored .020" or .030" over at your local machine shop for new oversize pistons.

Heads
For the heads, you have about 3 routes to go here. The original heads can be reworked. Have them checked real close as cracked heads from the late 1970's are not uncommon, especially from the lean burn motors. The small valves will have to be replaced with larger valves from a 360, 1.60" exhaust and 1.88" intake. Mancini Racing has inexpensive stainless valves in stock which are perfect for this upgrade. Have your machine shop recut the valve seats in your heads for the new valves, be sure to get a high performance valve job which has a 70 degree throat cut(some shops use a 65 degree cut which is o.k.). When you get the heads back from the shop, take a look in the throat below the valve seat. Where the throat cut ends at the casting, smooth out this transition with a dremal tool or drill with port polishing sanding rolls. Not too much but smoothing this helps flow a bunch. The best head choice would be the swirl port 318 head (casting 302) made from about 1985 thru about 1991. The 302 casting has a closed chamber that is heart shaped. This is the pre magnum head. Again, treat it like the above 318 head. The 360 head is another chioce. There are tons of these available from the 1970's and are pretty cheap. Keep the small 1.88" valves as port velocity will be higher than changing to the 2.02". Have a competition valve job done, clean up the throat as above. Now the 360 heads have a much larger combustion chamber volume, averaging around 72 cc vs. the 318's 63-65cc. You will have to get these heads milled a bunch to keep what compression you had. Without milling the heads, you'll end up around 7.8 to 1 compression(absolutely no ping though!). So, how much to mill? For each .0048" milled, you remove 1 cc. Looks like you need 7cc removed which is .034". I suggest going to .040" Now as the heads surface is milled, the ports get closer to each other since they are installed on a V engine. Have the intake surface of the heads milled .0095" for each .010" milled from the head/block surface. This will keep the ports in line. Which ones to use? The #302 swirl port castings are the best choice for a mild 318 buildup if you are having them ported. If you are going the un-ported route, go with the 360 heads but have them milled.

Intakes
For the intakes, it depends on which heads you use. If you use the 318 heads which have the small ports, you should use a small port intake for a smooth transition. The Edelbrock Performer is the best choice. If you use the 360 heads, there is only three good choices: MP M1 dual plane, Edelbrock RPM and the factory iron 4 bbl. I would suggest the M1 since it produces more torque and mid range.

Cams
Well, there are a million cam choices out there. The two I would suggest are the following Mopar Performance cams:

P4452759 .430"/.450" lift, 260/268 duration

P4452761 .450"/.455" lift, 268/272 duration

Both of these cams have a lobe seperation angle(LSA) of 110 and a 108 intake centerline(ICL). The "759" cam was developed to make more torque than the original 340 grind with the same horse power. The "761" cam was developed to make the same torque as the 340 grind but more h.p. Make sure you degree the cam in, very important. The 108 ICL is the installed point the factory suggests. My cam choice would be the "761". It will have a lope idle. Be sure to use a dual chain/gear set and match the valve springs to the cam choice. Either of the above cams can use 340 replacement valve springs or Mopar Performance P4120249.

Carb
Again there are tons of choices. The Holley 600 (1850) or 750(3310) vacume secondary is a popular choice. My favorite would be an AVS Carter, they are user friendly. A TQ from a 340 will do well, be sure it is from a 340 or install 340 rear jets(around .126" I think). Carter AFB or Edelbrock Performer carbs are easy to work on, run great and are available new.

Exhaust
Headers are a must. The 318 works well with the economical "fit all" type with 1 5/8" primary tubes. Be sure to use 2 1/4" dual exhaust with high flow mufflers like Walker Super Turbo or Flowmaster Mufflers.

Ignition
The Mopar electronic ignition is a great system Do not use the lean burn system. Recurv the ignition by installing two light springs in the distributor in place of the factory springs. These springs can be gotten from MP as P4007968. Also use the "orange box", P4120505. Set the ignition at 35 degrees total. Use the MP timing tape on your dampener, disconnect the vacume advance, bring up the rpm to 2,500, set the 35 mark on the dampener to the -0- mark on your timing cover. When finished, be sure to reconnect your vacume advance.



DYNO TESTED 318
The proof is in the dyno testing. This engine really performs well and produces the same power as a high compression 340.

Mid 1980's non roller cam 318, rebuilt with stock crank and rods. Arp rod bolts added when the rods were reconditioned. Crank turned .010"/.010". Flat top cast pistons were used. After the block and heads were milled to true up, a 9.2 to 1 compression was achieved. The heads are the #302 swirl port casting from a 1987 318. The heads have the larger 1.88"/1.60" valves installed, competition valve job and were treated to a full professional porting job. Intake is the Edelbrock Performer. Carb is the Holley #3310 750cfm vacume secondary. Headers are basic fit all 1 5/8" primary tube. Cam is the Mopar Performance P4452761 with .450"/.455"lift , 268/272 duration. timing was set at 35 degrees total for the dyno test.

330 horse power @5750rpm.

How does that sound? The exact motor was also dyno run with 360 heads installed and it produced 290 h.p. @5750 rpm. That shows how port velocity is so important. But...290 h.p. is no slouch for a 318. Most of the same information presented here can be applied to the 273."
 
stock good compression 318 short block, good condition 318 heads, (was going to cut in 1.88 intakes but its not my main motor so ill keep it cheap) stock 340 auto cam, 273 4bbl iron single plane intake, 3.91 gears, Cyclone fenderwell headers in a 2900 lb car.. Well see what she does.

273 steel crank and 340 rods?? a balance job will cost more in mallory metal than the motor...unless those pistons are very light.
 
You mean something like this?
Here is mine plan..
never had a 273 before or even a mild 318?

Start with a 273 add a comp cam 268h cam and double roller chain, J heads with the smaller 188 in, and 160 ex valves with heads milled for compression (If I cant find a good set of 302s) and a holly 600 double pumper on a performer manifold (cause I have it) with Mallory electronic dizzy and MSD ignition, {this plan is open to suggestions} but keep in mind it is a TRUE budget motor and will replace the slant in the Duster,... since I also have a 360 project in the works that soon (I hope) go in the 391 geared mini tub'd 67 Dart!
let me know what you think!! since Ive gotten this plan by reading on this site!
thanks
Bruce B.
 
my standard bore, original piston 318 made 165kw/224hp on the rears. jetting was way too rich with black smoke pumping out the pipes and then it was all cut short on the second pull with front uni spitting a cup out and smashing the 904.


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anyway this is nothing more than a rattly old '74 318 twice rings and bearings 250 000km motor
std mellings pump
Heatseeker stage 2 cam 276 degree .420"lift
8 degrees advance valve timing (leaving some top end on the table)
1.6 stainless rollers (.450"lift)
Eddy heads out of the box (240cfm @.450"lift)
Strip Dominator intake with modded 600 Eddy carb
Accel dissy and mallory coil
 
my 1972 Duster Twister went 13.9 @ 102mph with a stock low comp '78 block 273 heads 1.96, 1.6 valves, CCH-302 cam Perfomer intake 600 afb 2800 stall 3.7 gears


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K.O. SWINGER said:
steve D in engine masters winter 2006 had a 318 build called cheap as dirt nothing but good basic mopar done right 415 hp great build
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Sorry to disagree KO, but that result has been established as not just a "happy" Dyno result...but clearly "hysterical".....

I refer you to 71340 post - basically the same as SD and made 70 HP less.

No-one I know of has ever got near that 400 HP result with the same or similar build - and that includes using better heads.
 
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