318 or 360?

-
George Lawicki said:
Im a bit confused between the Magnum and LA motors LA motors were 2001 and earlier? and Magnum motors 1992 and up???
Click to expand...
5.2 Magnum motors began in 1992, 5.9s in '93- they replaced the LA series at that time; so the last production LA318 was in 1991, the last LA360 in 1992.
Just remember: the Magnums use the same type motor mount as LA340/360 engines- as I said in my first response, make SURE you've got your mounts before you start.
 
Last edited:
George Lawicki said:
Im a bit confused between the Magnum and LA motors LA motors were 2001 and earlier? and Magnum motors 1992 and up???
Click to expand...

I think 92 was the dividing year,
Magnum has a few changes the make it different engine family.

block wise is pretty much the same, it’s basically a head package, the main things that make it different for swap, is it’s balanced different than a 360, and the intake bolt holes are a different angel and the belt is a serpentine system, which if you go with older timing cover you can use LA style accessories.

In stock form the magnum heads make a lot more power than LA.

If you google magnum 5.9l vs LA 360 I’m sure you can find a more detailed information.

basically it’s mainly flex plate balance and intake the main issues when swapping.
 
I'm not up to date on the 74/6 model, but if it has a 7.25 rear axle, you may want to upgrade to a 8.25 or something equal first.
 
I’d also look for 904 with the deeper 1st gear, 2.74:1.

Especially if you plan on using high rear end gear like a 3.23 or 2.96.
 
If you run headers, don’t buy the cheapies that go below the steering linkage on the drivers side. They usually get smashed flat the first month. There is so little room in an a body, I prefer exhaust manifolds for a streeter.
 
273 said:
Nothing wrong with a LA 318, but if you have the option of a low 200 hp 318 or a 300-320 hp 5.2l/5.9l and you looking for cheap decent street friendly power , why pick the LA318?
Click to expand...

Cost and simplicity. Never had a problem getting around 300 or better out of them, for cheap.
 
George, here's a few pics of the progression of a 2001, 5.9 Magnum. I started with an engine from a 2001 Ram Van. Stripped it down and took it to a machine shop to have new rings, bearings (main, rod, and cam), and he honed the bores and polished the crank.

I sent the original cam to Oregon Cam Grinding for a regrind. Got Doug's headers and Edelbrock heads on black Friday sales. Went with the Edelbrock Air Gap intake. I kept the v-belt setup to keep the old school look. For that I sourced a 1970 timing cover and used the water pump, alternator, and power steering pump and brackets from my old 273 engine.

I was 56 years old when I started and this is the first time beyond swapping heads. FABO and a number of members here helped me out tremendously. The scariest thing was degreeing the cam, but like the entire build, I took my time and triple checked everything!

IMG_20190915_171121.jpg

IMG_20191101_103354.jpg

IMG_20191130_213532.jpg

IMG_20200518_125355.jpg
 
No replacement for displacement. You can fabricate mounts to fit. Manifolds or headers let your conscience be you guide


Tim
 
Something that no one has touched on is power at stall.
With a 2000 stall for example the bigger engine will annihilate the LA318.
If you are stuck with hiway gears, the bgger engines will again stomp the LA318.

You can build up an LA318 to make power at 5000, but it can never compete with a 360/5.9 at 2000, well unless you supercharge it
So in other words, you can save the cost of a hi-stall and performance gears, simply by choosing a bigger engine.
And if choosing between a a stock LA360 and a stock 5.9 Magnum, it's a no-contest, 5.9 for the win.
But if doing a full-boogie rebuild, the winning is a lil more complicated. For your application either is a good score.
But if you have to change the rear end, then the 5.2 Magnum might be back on the table, depending on what gear ratio is in the replacement rearend.
But the LA318 in stock form I would not consider in any case; no matter how cheap.
Now if you stumbled on a hi-compression version, with NOT stock heads,and good ring-seal, for cheap,well, that's another story.
 
AJ/FormS said:
Something that no one has touched on is power at stall.
With a 2000 stall for example the bigger engine will annihilate the LA318.
If you are stuck with hiway gears, the bgger engines will again stomp the LA318.

You can build up an LA318 to make power at 5000, but it can never compete with a 360/5.9 at 2000, well unless you supercharge it
So in other words, you can save the cost of a hi-stall and performance gears, simply by choosing a bigger engine.
And if choosing between a a stock LA360 and a stock 5.9 Magnum, it's a no-contest, 5.9 for the win.
But if doing a full-boogie rebuild, the winning is a lil more complicated. For your application either is a good score.
But if you have to change the rear end, then the 5.2 Magnum might be back on the table, depending on what gear ratio is in the replacement rearend.
But the LA318 in stock form I would not consider in any case; no matter how cheap.
Now if you stumbled on a hi-compression version, with NOT stock heads,and good ring-seal, for cheap,well, that's another story.
Click to expand...

I look at displacement as another form of gearing, eg.. a 360 with 3.55 gear Is like a 318 with 4.10 gears. Or a 408 with 3.23 if all putting out similar HP.
 
AJ/FormS said:
Something that no one has touched on is power at stall.
With a 2000 stall for example the bigger engine will annihilate the LA318.
If you are stuck with hiway gears, the bgger engines will again stomp the LA318.

You can build up an LA318 to make power at 5000, but it can never compete with a 360/5.9 at 2000, well unless you supercharge it
So in other words, you can save the cost of a hi-stall and performance gears, simply by choosing a bigger engine.
And if choosing between a a stock LA360 and a stock 5.9 Magnum, it's a no-contest, 5.9 for the win.
But if doing a full-boogie rebuild, the winning is a lil more complicated. For your application either is a good score.
But if you have to change the rear end, then the 5.2 Magnum might be back on the table, depending on what gear ratio is in the replacement rearend.
But the LA318 in stock form I would not consider in any case; no matter how cheap.
Now if you stumbled on a hi-compression version, with NOT stock heads,and good ring-seal, for cheap,well, that's another story.
Click to expand...


What would you give more importance to gears or stall ?
 
Stall for sure; but kindof depends on where you are starting from, and where you are going.
I mean if you already have a 2600 on the street, with 3.91s , then a 3200 would not be on my radar,...... unless I had a 318.

But if somebody bolted an 1800 onto a 360 with 2.76s, that 1800 is gonna be the first thing I ditch.

The thing is, a streeter is a 2-gear car; first just to get moving, and with an automatic,you can't trap anywhere near the right rpm at 60 mph, in second gear......... unless you have a really tiny cam.
Think about realistically, what would be the biggest street gear you would install. Would it be 3.73s? Ok then with 27" tires, your rpm at 60 would be 4030@no slip, say 4600 with 15% slip. And say the power plateau is 300rpm, so you can have a cam that power peaks at 4300. Any bigger than that, is gonna trade away low-rpm performance,and you won't get to the power-peak at legal road speeds.
So if yur stuck with 3.73s and a 4300rpm power peak, what do you do?
You install the biggest darn CID engine you can fit or afford.
And then,
You have to figure out how to make first gear hook up. Here a 3800stall is a poor choice. Here an 1800 might just do it
 
Last edited:
But most guys are gonna use 3.23s with an automatic, cuz now you can cruise 65=2600/zeroslip.
So now, 60 in second is 3800@zeroslip, say 4200@10% slip. You can still use that 4300rpm cam, but you'd be giving up 300 to 400 rpm at the top, and of course, it's more cam than you need for fuel-economy.
But a cam with a 4200 power peak is already pretty small, being a stock smogger-teen cam. So what do you do? Well if stuck with a 318, then you are gonna need some stall to get moving. And more stall if you wanna be quick. But a better solution is just to get a bigger engine.

In a 3600pound car, do you need a 360/5.9?.... that depends;
A 360 with 3.23s and a 2800stall will just annihilate the tires in first gear. A 2000 stall and a 318 cam in that 5.9, will still annihilate the tires in first gear.
The stock LA318 with bolt-ons has about the right amount of power at low rpm with about a 2800stall and 3.23s. It just doesn't have enough in second gear, to really be fun. It's not bad in a straight line...... but second gear, IMO, is just too soft.
So it kindof depends on what your goals are.
By choosing a 360/5.9, you got all the bases covered ...... I mean you don't have to floor it every time you take off,lol. And it has great! second-gear power, lol, especially the 5.9, in stock for stock comparison.

IMO a hi-compression 340 with a 318/360 type cam, and nice heads would be just right. And since I already built such a combo, and that 340combo is my second-favorite all-time build, I can say that,lol. I called it my big-bore teener.
 
AJ/FormS said:
Stall for sure; but kindof depends on where you are starting from, and where you are going.
I mean if you already have a 2600 on the street, with 3.91s , then a 3200 would not be on my radar,...... unless I had a 318.

But if somebody bolted an 1800 onto a 360 with 2.76s, that 1800 is gonna be the first thing I ditch.

The thing is, a streeter is a 2-gear car; first just to get moving, and with an automatic,you can't trap anywhere near the right rpm at 60 mph......... unless you have a really tiny cam.
Think about realistically, what would be the biggest street gear you would install. Would it be 3.73s? Ok then with 27" tires, your rpm at 60 would be 4030@no slip, say 4600 with 15% slip. And say the power plateau is 300rpm, so you can have a cam that power peaks at 4300. Any bigger than that, is gonna trade away low-rpm performance. Any bigger,and you won't get to it at legal road speeds.
So if yur stuck with 3.73s and a 4300rpm power peak, what do you do?
You install the biggest darn CID engine you can fit or afford.
And then,
You have to figure out how to make first gear hook up. Here a 3800stall is a poor choice. Here an 1800 might just do it
Click to expand...

AJ/FormS said:
But most guys are gonna use 3.23s with an automatic, cuz now you can cruise 65=2600/zeroslip.
So now, 60 in second is 3800@zeroslip, say 4200@10% slip. You can still use that 4300rpm cam, but you'd be giving up 300 to 400 rpm at the top, and of course, it's more cam than you need for fuel-economy.
But a cam with a 4200 power peak is already pretty small, being a stock smogger-teen cam. So what do you do? Well if stuck with a 318, then you are gonna need some stall to get moving. And more stall if you wanna be quick. But a better solution is just to get a bigger engine.

In a 3600pound car, do you need a 360/5.9?.... that depends;
A 360 with 3.23s and a 2800stall will just annihilate the tires in first gear. A 2000 stall and a 318 cam in that 5.9, will still annihilate the tires in first gear.
The stock LA318 with bolt-ons has about the right amount of power at low rpm with about a 2800stall and 3.23s. It just doesn't have enough in second gear, to really be fun. It's not bad in a straight line...... but second gear, IMO, is just too soft.
So it kindof depends on what your goals are.
By choosing a 360/5.9, you got all the bases covered ...... I mean you don't have to floor it every time you take off,lol. And it has great! second-gear power, lol, especially the 5.9, in stock for stock comparison.

IMO a hi-compression 340 with a 318/360 type cam, and nice heads would be just right. And since I already built such a combo, and that 340combo is my second-favorite all-time build, I can say that,lol. I called it my big-bore teener.
Click to expand...

I 99% agree but I always think you can go up a few steps or two above stock low power cam, without effecting bottom end.

A stock 5.9l with 4bbl and headers is Base HP/TQ even without headers you'd only lose 10 hp or so.
This engine hits the marks you where talking about peak hp at 4400 rpm and it's pretty flat from 3800-5200 rpm +.

screenshot_20171212-101519-png-png-png-png-png.png




I plan on stepping my 380 hp crate engine down by going rpm air gap and 264hr-12 cam or similar, 210/220 .512" 112. since they dyno over 400 hp I think it might now be at it's actual rating of 380 hp but I don't care It's got to at least get 1hp per cid and work better with my 2.96 gears 2800 stall.


If your wondering the mod #'s is a comp 275 roller and eddy heads on the stock short block.
 
Last edited:
You must log in or register to reply here.
-

Back
Top