318 engine swap!

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Kreutzer

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Hey everybody! I'm new here. Awesome forums!

I bought my first mopar about a month ago. It is a '73 dart swinger 318 with a 3 speed auto transmission (904?). It is all original with matching numbers, but it has 130xxx miles on it. The motor in it has low oil pressure and a noisy valve train. I have an extra 318 I am going to rebuild and install, but I want to make sure the engine will fit my transmission. The guy I bought the motor from said it is from an 87 dakota. I can confirm that the engine is a 318 and was built in 1987 from the casting numbers.

The questions:
Will this motor fit my transmission?
What should I look for when rebuilding the motor?

Thanks!
 
Oil pan/pick up tube is different from a truck to a car. That should be it as far as the installation. You may find that '87 to have a roller cam and close chamber heads. But the 318 is from an '87 Dakota????
 
Good to know, thanks. It has the truck style pan an oil pickup. It does have open chamber heads and flat tappet cam though. Yeah the guy said it was from a dakota... but who knows.
 
that would definitely be a minority not have the roller cam and 302 heads in '87, but who knows.
 
318willrun said:
that would definitely be a minority not have the roller cam and 302 heads in '87, but who knows.
Click to expand...
Car 318s had rollers from '85 model year to '89 unless they were cop cars (with 4bbls). Trucks didn't have roller cams until '88, but they had roller block 318s and 302s from '85-'87, after '88 it's likely the truck's closed chamber 318 heads will have a different cast number though they're functionally the same.

Dakotas got 318s starting in '91. Cop car 318-4s had open chamber heads and a flat tappet cam even in '87. Bigger cam than the 2bbl motors too.
 
If I were you I would look for a 360, it should be about the same price and your 904 would bolt right up. The 318 from a Dakota should bolt up too but the Dakota might have something computerized and your Dart doesn't. Just in case you were wondering the 318 and 360 are made with the same engine block, the 360 is just more powerful but just as plentiful.
A 360 made up to the early 80's is what you would be looking for. Sometimes truck motors have something different somewhere, all depends on the application.
 
leblanc said:
If I were you I would look for a 360, it should be about the same price and your 904 would bolt right up. The 318 from a Dakota should bolt up too but the Dakota might have something computerized and your Dart doesn't. Just in case you were wondering the 318 and 360 are made with the same engine block, the 360 is just more powerful but just as plentiful.
A 360 made up to the early 80's is what you would be looking for. Sometimes truck motors have something different somewhere, all depends on the application.
Click to expand...

I was waiting for someone to say "get a 360".......didn't take long.
 
Lol, well thanks for the input guys but I'm set on using this 318. At least until next summer. I have headers and a dual exhaust for it. I also want to cam it (any suggestions?) or carb and manifold combinations? The car is my daily driver so I don't want a total gas guzzler.
 
You are not making sense.
You can put a little cam in it and a 4bbl and headers and then you will have 360-2bbl power with sub 318 torque.
The only way this can make even a tiny bit of sense is if you already have the teener and the intake and the carb and the headers,etc, as left over parts from other projects.
But the only way you will ever appreciate a 360 is to drop one in there, even a 2bbl, and then you will forget all about the teener,forever. 42 cubes, on paper, is just a 26% increase. But in the real world you would have to put 3.55s in the back, taking out the 2.76s, just to feel the difference off the line, for about 60 ft.The power difference would take maybe three or four cam sizes to keep up at the top.
Really the only way the teener can compare everywhere is to supercharge it.
Having said that, let's talk gas-guzzler. The mods you are considering, when considered all together,will certainly turn your teener into some sort of guzzler. You are gonna shift the power band higher,(that's just the way it works), so you will always be stepping further into the rpms to get the torque you are craving.And that costs gas.
Far better it would be to put a 360 in there(practically a bolt-in), and have gobs more torque than the cammed up teener, right off the line. No cam, no headers, no 4bbl, no gears, no hi-stall,no nuttin'.
I try not to rag on guys and teeners, but this time it was just so clear.
Check this out; Teener core,cam kit,intake,carb,gears, TC,and misc, comes to what? $2000.
And a good running 360LA 2bbl with manifolds,complete? $600? Maybe less.
Let's see; the 360 has; more torque, more horsepower, more performance,more-better gas mileage.
And it has; Less install headaches,less tuning headaches, less than 1/3 the cost.
Money left over. Lotsa money left over.
Hmmmmmmmmmmmmmmmmmmmmmmmm
Sorry for the rant, but post #7 pushed all the wrong buttons.
 
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Sorry I don't know how or why I started two threads... I definetly didnt mean to.

I completely understand that the 360 is cheaper power than the 318 and a superior engine. I don't disagree at all.

Let me clarify. The car came with the exhaust system (uninstalled), and I got this extra 318 for free. I have a very small budget and I promise you I'm not trying milk all the power I can get out of a 318. I just want a reliable v8 in my dart. I was going to order an engine rebuild kit from summit racing. And maybe a cam or try to find an intake and carb on eBay or at my local pick n pull for cheap, just to make it a little more fun than stock. And that would be the extent of my budget.

Bottom line is I don't think I can source a 360 and get it installed on my budget. I can't even find any on Craigslist anywhere near me...
 
If you just want more fun than stock, freshen the heads and chain,(the stock ones usually jump at about your mileage).Put some fresh oil in there and retest the oil-pressure. All you need is 10psi per thousand rpm and about 20 at hot idle. Lots of teeners idle at less, cuz the darn things can be made to idle in gear at 500.
Then put some 3.55s or better in the back.Call it done. Instant smiles.

With stock type gears like 2.76s, if the teener can't spin both tires the secondaries won't even be open by 30 mph.If you put a cam in there it will be worse. Headers won't help much at sub-3000 rpm.
If you put skinny tires on there so the teener can spin both of them, it will give you the illusion that she's fast.And maybe the secondaries open a lil sooner.
But if you put say 3.91s back there, even the 2bbl will spin both 245s.And it will wind up fast, so get ready to shift!
 
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I agree with everyone's saying your always better off to start off with a 360 cause your leaving performance and drivablity on the table but I also believe that true If your building anything smaller than a 440 since it's the largest readily available engine that reasonably fits in our cars. Not that I'm suggesting that swap.

Hp has more to do with engine air flow (cfm) capability not engine size obviously at some point the smaller engines bore size and more likey the realistic operating rpm is gonna put a cap on engine hp ability especially if you want it to be streetable.

Take 318/340/360/383/(400/408)/426/440 think of each engine is a step up from each other.
If you want an engine with streetablity your gonna want idle-5500 powerband making peak power around 5250 rpm which is gonna put you around 1 hp and 1.2 lbs-ft per cid so you can see each step is equal to about 20 hp and 25 lbs-ft. In the torque department you can also think of each step up in engine size needs one less gears size to put them on a level playfeild.

Since your budget doesn't allow to start with a 360. You either except 40 less hp or lose some drivablity and move the powerband up 600-800 rpm which will now required a decent stall converter same with gears either run something like 3.91 or lose the equivalent to 50 lbs-ft or compromise and run a low first gear.

The main problems with starting with a 318 like cam and compression can be fixed in the course of the rebuild. So the main problem is heads and if porting is not an option (check out 1wildandcrazyguy and 318willrun's threads on 318 head porting) your either stuck with factory heads which will give you around a 300 hp ceiling unless ported or use cam and CR to squeeze as much power as you can or go 360/5.9 heads. Some feel the ports are to big but I'd rather go with bigger ports more street friendly than a big cam.

9:1, 600-650 carb, eddy performer or similar intake, comp XE262H cam and headers and duals will get you 280 to 330 hp depending on head choice.
 
Thanks for all the info!

I'm gonna try to get my hands on some porting tools. I know a guy who I think has some.

If I could find 360 heads would that be a bolt on matter?
 
Big chambers in 360 heads + bigger ports + stock 318 pistons = very low compression ratio and poor low RPM cylinder filling = poor low RPM torque = slow and boggy in the bottom end... right where you want it to work for daily driving.

If you are racing and only using high RPMS, and a biiig cam, maybe. But that is not a daily driver by any stretch of the imagination. If you are driving on the street..... that's a very poor combo. But the 360 heads will bolt up if you want to find the above out the hard way.

The temptation is always there to go bigger and look for HP, but that is a mistake for driving around. For a daily driver, 250 HP will be a nice improvement anyway. You should be looking for good low RPM torque and a wide torque band. With the lower stock compression ratio of the 318, then any time you overcam it, the bottom end will be hurt.

If you are concerned about economy but still some nice improvements, stick with a low duration torque cam with 112 LSA and get as much lift as you can, like the mid .400" range. This will help the stock low compression ratio issue. Mild porting will only help it breath better up top, without the damage to the low end torque.

Flat tappet cams are cheaper than roller so the roller is not advantage IMHO on a budget.

Are you planning on rebuilding the bottom end with new pistons, or are you wanting to use the free bottom end as is for budget reasons?
 
Sounds like I should stick with stock heads.

Im just going to freshen up the 318 I got for free. (Not the one in the car). It doesn't have much wear internally, I'm guessing it came out of a wrecked car. I'm using the Pistons it has and replacing all the bearings, rings, gaskets/seals, lifters, oil pump etc.
 
OK, well these 318's had classically low range compression ratios, which helps to keep down detonation under heavy lugging loads (good for trucks, and station wagons full of groceries) and keeps down NOx emissions, but works against low RPM torque. Working on this to get CR up is to your advantage for a daily driver.

- Standard Felpro type head gaskets are thicker than originals so that will drop CR. So see how much it will cost you to have the heads milled down .020" or .030". More would be better, but then you have to pay more attention to milling the intake too to keep them well mated.
- Don't hog out the combustion chambers in your porting.
- Stay mild on the cam: more lift and less duration. Cams like the Lunati Voodoo grinds are oriented to this.
- Spend a few $$ on a timing chain that can be advanced (they can be had for something like $40-45) and then install the cam a few degrees advanced.
- When together, spend a lot of time on the ignition timing and advance mechanisms. Cheap and easy torque and performance.
- With the heads off, carefully measure your pistons' distance below the block deck at their maximum stroke height (TDC). If much more than .085" or so, then you might want to put in some better CR pistons like the Sealed Power H814's or 526NP's, or Silvolite 3247's. That is a few more $$, but $136 for a full set of these Silvolites is cheap torque:
http://www.summitracing.com/parts/uem-3247-std/overview/make/dodge
 

318s have plenty of torque down low. Dogs up top though. After a bit of driving newer trucks it doesn't take long to see what it is you want, what's lacking- and it's not torque under 1000RPM. Under 1000RPM my truck could idle on a hill and with a touch of gas bring a car up the hill with it. Pulled more cars off trailers than on them with it, and often in ice- even pulled a truck with a boat attached up a muddy hill. All with a little stock 318, tall gears, and big tires. A 360, steeper gears, or shorter tires wouldn't have done better because it did excellent. On hills? Never lacked for torque with the low compression teen and 4bbl, loaded or not. Never gave trouble. But a dog up top, no doubt about that. Fewer V8 motors in the last 2 decades have less power up top than old LA 318s.

Just get it running well. Make sure the motor going into it is in good shape. 360 heads would bolt on, you'd see a gain in power over the 318 heads. Gears, daily driver, and fuel mileage don't go together.
 
I think this big port thing is over blown. 340/360 ports aren't that huge, after boring out a 318 you are 17 cubes or less from 340 size and a lot closer to the stand performance 4" bore. I've done it twice before I knew anything about the compression drop and both times made a night and day difference.

Also my cousin resurrected his dad's 340 4 speed duster by put his dad's ported T/A heads and fairly lumpy cam that his dad had laying around and 750 on a LD 340 intake on a smokey low CR 318 bottom end with 3.23 gears and that car was fast and became an animal after installing 3.91 gears. And when his late model with a 340 had a rod noise he took the short block out of the duster and added his late model parts and raced it a couple of weekend didn't win but didn't lose pace with the fast pack either.

Yes if your happy with 300 or less hp 318 heads are prefectly suited for that over that you need to port or move up to 360/5.9 heads. But yes to use 340/360 heads you'll have to deal with the compression problem.
Mainly by installing better pistons.
 
273 said:
I think this big port thing is over blown.I've done it twice before I knew anything about the compression drop and both times made a night and day difference..
Click to expand...

I donoo. Years ago I had the same solid cam in a 318 with 340 J heads, and it wasn't all that impressive. The last summer I had the 67 together it had a nice low miles 318 with "all stock" except that same cam, Performer intake and headers. 318 heads. It ran pretty impressive.

I agree I don't think the big ports are a problem, but the compression drop, in my opinion, IS a problem
 
The increased flow of the larger port heads and valves will increase performance over the loss of the compression drop.... You will still benefit from installing 340/360 heads...

And you will be able to run any crappy pump gas to boot with 7.6 compression....
 
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