318 and 360 small block question

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ethan santin

ethan santin

Buck eye jim you gotta go
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Hello there FABO,

I wanted to ask people on here who have some knowledge about building small block 318's and 360's, what their opinions and recommendations would be on building a reliable motor for a daily driver. What are the advantages and disadvantages of both small blocks? Which motor would you recommend for a reliable, daily driver build? Any kind of information on either blocks would be greatly appreciated. I would also like to hear about any tips or pointers you have picked up from any kind of experience you have had with building either one of these motors. Please share photos if you would like, thank you for reading.

Ethan
 
Both are great. They will both weigh roughly the same and are virtually identical on the outside. The 360 comes with 42 extra cubic inches so it will have more torque and is probably the better "bang for the buck" motor but the 318 won't be far behind it. In my opinion, whichever one you can get easier will be the way to go.
What kind of "build" do you want to do? If you just want to warm them over then both will hit 300hp easily. If you want 500+hp then the 360 will get there easier because of the extra cubes but by that point you're likely doing a serious build anyway and either motor is capable of getting there
 
318’s are more plentiful and cheaper in initial cost. Make sure you check availability and cost of parts for a rebuild as in pistons, rings, bearings, gaskets and the like. Earlier year blocks, 1974 and earlier have thicker cylinder walls and can be over borded larger. But this does not mean all earlier blocks can be, you have to sonic test for thickness like you should any block before rebuilding.

That being said, a 360 even at a stock rebuild will have more torque and power than a 318 for a comparable level rebuild. If you have a heavy vehicle, truck, B or C body, you will more than likely want a 360.
 
Either is great for daily driver. I have a lot of LA360 stuff so i stick with the LA series mostly. I think if I was starting over i would go with the magnum series 318/360. Benefits of the roller cam and tend to be more plentiful. My favorite block is the late 80's early 90's pre-magnum blocks it have the roller cam but uses the LA heads.
 
Seems reliability is more important to you than power, if that’s the case either can be built similarly for very good reliability. Although you can have your cake and eat it too, junkyards are full of 5.9 magnum engines and they have a few benefits over the La for reliability. Hydraulic Roller cam, thin ring packs, hypereutectic pistons, just to name a few. Don’t overlook the 5.2 magnum either. They are more plentiful than the 5.9 and almost as good. Slightly less hp/Tq but same reliability.
 
Unless you have real desire to do a 318, you would be better of with a 360.

For any given power level a 360 will be more streetable have better idle, part throttle etc.., plus better at daily driving street rpms 1500-3500+ and will need less gear, stall for similar performance, Also can build about 13 % more power for a similar streetability.

Sure you could build a strong 318 too but there no point if it really don't matter to you.
 
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You mentioned "daily driver" but didn't mention anything about hot rodding/high HP. I'll proceed by saying "unless I know what it is going in, I cannot give a recommendation".

Huge difference between a early A body and a '74 3/4 ton club cab Dodge pickup.
 
True but even dead stock 2bbl 318 vs 2bbl 360 most would rather the 360, maybe could make a gas mileage argument for a 318 at that point, I'd still rather the 360 even if it cost a few mpg. Even if performance ain't a big deal it kind of is at least a little or otherwise most modern non performance cars wouldn't produce the power they do .
 
273 said:
True but even dead stock 2bbl 318 vs 2bbl 360 most would rather the 360, maybe could make a gas mileage argument for a 318 at that point, I'd still rather the 360 even if it cost a few mpg. Even if performance ain't a big deal it kind of is at least a little or otherwise most modern non performance cars wouldn't produce the power they do .
Click to expand...
Mileage is not different, apples to apples comparison.
My dad bought a 78 power wagon, 360, 4-speed, 3.55 club cab short box, new, recorded every gallon of gas put in it, 14.5 mpg is what it got.
I bought a 78 power wagon, 318, 4-speed, 3.55 standard cab short box, used off the original owner 49,000 miles it got 14.5 mpg.
Both trucks totally stock, including tire size.
The 360 has more power, gets the same mileage, pulling a slightly heavier truck.
People here need to quit spreading bad info that the 360 gets worse mileage than the 318.
 
273 said:
True but even dead stock 2bbl 318 vs 2bbl 360 most would rather the 360, maybe could make a gas mileage argument for a 318 at that point, I'd still rather the 360 even if it cost a few mpg. Even if performance ain't a big deal it kind of is at least a little or otherwise most modern non performance cars wouldn't produce the power they do .
Click to expand...
In a heavier vehicle, or towing, or cutting more wind (like a van), the 360 will actually get better MPG in most cases. But trotting around town in a Dart, or warming an engine on a cold winter day, the 318 will get better MPG. That's why it matters what vehicle and the purpose of the vehicle. Few things that favor the 318 in my opinion:
  1. Neutral balanced. That to me is always a win vs externally balanced for more than one reason.
  2. In most situation, a little better MPG.
  3. Usually a little cheaper. People value 360's more and understandably so. But still, "usually" the 318 will be cheaper - For sure in the LA's, and even some in magnums.
  4. While it is "close", the 318 is a tad lighter.
So to me, there is no "cut and dried" choice between the two without knowing the vehicle or absolute intended purpose.
 
sireland67 said:
Mileage is not different, apples to apples comparison.
My dad bought a 78 power wagon, 360, 4-speed, 3.55 club cab short box, new, recorded every gallon of gas put in it, 14.5 mpg is what it got.
I bought a 78 power wagon, 318, 4-speed, 3.55 standard cab short box, used off the original owner 49,000 miles it got 14.5 mpg.
Both trucks totally stock, including tire size.
The 360 has more power, gets the same mileage, pulling a slightly heavier truck.
People here need to quit spreading bad info that the 360 gets worse mileage than the 318.
Click to expand...
I agree in a Power Wagon situation. My experience is in lighter cars, the 318 does get better mpg.
 
I find most older cars get like an 15 ish average driving mpg give or take a few mpg.
To me not something I'd overly worry about.
 
273 said:
I find most older cars get like an 15 ish average driving mpg give or take a few mpg.
To me not something I'd overly worry about.
Click to expand...
Yeah, they pretty much average about that, now a days a modern car does not get all that much better, considering fuel injection etc.
 
i'll follow up the question from @318willrun with: what are you starting with? do you have a motor at all or just one that's clapped out? do you want headers and a 4bbl carb and it sound mean? what are your expectations: does it have to get really good mileage, do you need enough vacuum to pull power brakes, do you want it to idle sewing machine smooth and quiet?

all of these are considerations.

@TT5.9mag had a wonderful suggestion of 5.9 (or 5.2) magnum motor as a base.

really you can't go wrong with either motor. the 360 has a slight edge in making power because of the extra cubes, however with the power numbers you're most likely looking for the added cost of a 360 probably wouldn't be worth it.
 
ethan santin said:
Hello there FABO,

I wanted to ask people on here who have some knowledge about building small block 318's and 360's, what their opinions and recommendations would be on building a reliable motor for a daily driver. What are the advantages and disadvantages of both small blocks? Which motor would you recommend for a reliable, daily driver build? Any kind of information on either blocks would be greatly appreciated. I would also like to hear about any tips or pointers you have picked up from any kind of experience you have had with building either one of these motors. Please share photos if you would like, thank you for reading.

Ethan
Click to expand...
From my experience in rebuilding both engines, a bunch depends on you, the car it’s in and what is expected from the engine/car combination. While you did state some practical and honest goals, I’ll take that description and run with it.

For mileage considerations only, the 318 wins and will do it well.
For a bit more get up and go, the extra stroke of the 360 is a huge thing.
Ether engine will do great.

My ‘79 Dodge Magnum I purchased off of the original owner came with a 318/904/2.76 set up. He kept all records! Even when the light bulb rod the radio went out, twice, even the name of the guy who repaired it. Insane records!

He stoped recording miles after only 10 years with just over 323,000 miles. I asked why and he told me for the next 4 years, his daughter used it for collage with weekend trips back home. Collage was an easy 200 miles away. Then his son 4 years later at the same collage. He told me he hates flying so twice a year, the family would load up and take a trip to visit one of the states and tour it. He’s been to every state in the continental union and drive through Canada. From there, after his son got done with collage, he daily drive it for work, which I knew the exact firehouse he worked in since it was down the block from where I worked. (Weird huh?!) The drive was a daily 80 mile trek he did 5 days a week for the next 10 years. Poor car suffered NYC rush hours. Horrible- not joking.

I got the car and it was just fine. Needed an oil pump, tune up & that’s it.

On a 360 I had in another Magnum, it was basically dead stock. A 4bbl Carter AFB was used and dual exhaust was out on. The best mileage I got out of that with 2.76 gears was 20 Hwy. I have no idea how many miles were on that 1st Magnum of mine. It came to me well over 20 years old with the odometer reading 70/80K on it, but I don’t think it was the first time it’s seen those numbers ether.

The only price difference I see worth mentioning between the two engines is possibly piston price. That would not be a lot ether.

My tip for a stock or nearly stock engine is just simply good machine work and care during assembly. Keep the compression under 8.5-1 for an easy use of 87 octane. Use a factory cast iron 4bbl intake and what ever carb you use, (Carter AFB/AVS are my favorites behind a good TQ.) take the time to tune it as best you can. Same with the distributor. The use of a 4bbl carb can indeed, easy enough, get great mileage. The amount of mileage available is a multi prong issue starting with your right foot. Then how well the distributor and carb are dialed in. Again, take your time on it.
I highly suggest a “H” pipe dual exhaust even if you’re going to run exhaust manifolds. Longer the muffler the quieter it’ll be.

I have found some good mileage gains from a multi spark system. I can’t suggest a MSD anymore due to their incredibly high failure rate with me. My suggestion is get a factory chrome box or equal in the car, work with it until you can afford a superior multi spark system. Below is where I would go.
An American company built right here in Florida using as many American part they can get there hands on if it passes there quality standards.

Welcome To Daytona Sensors™

A word on camshafts, keep it small and easy, it’ll last longer. Regrinds of the factory stock 2 & 4 barrel cams are available through Mellings which you can purchase through Summit racing.
 
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