318 vs 360 Engine

[mtran2000]

Which engine do most prefer?

Gas mileage better in 318 but more power with 360.

Which is more reliable and has greater longevity?

[neon_rt]

They are essentially the same engine with most (depends on the year) of the parts interchangeable. Reliability is the same.
On the non-Magnum (pre-93) engines I would always select the 360. The pre-Magnum 318s didn't have enough power and spend most of their time straining against the load. My Dad has had both 318 and 360 powered B-series vans, the 360 consistantly got 2-3 more MPG than the 318s. We lived in a hilly area and had the vans loaded to capacity most of the time. The 360 vans could stay in high gear while the 318 had to shift down a lot to keep up.
In the Magnum series, there is not a lot of difference between the 318 and 360 for power. The 360 has a more low RPM torque, so the response from a dead stop when load heavily or towing is better. At highway speed the difference is minimal. The 318 can turn more RPMs than the 360, depending on the gears and speed, the 318 can can hold it's own against the 360, sometimes even bettering it on uphill pulls. It's all in the gears.

[BleedDodge]

That's what I would have said too.

A 340 would probably change your mind real quick though.

[wafrederick]

If you replace a 318 with a 360,replace the torque converter too.The torque converter for the 360 has a counter weight on it and the 318 does not.

[slantsixness]

I have a bone stock 1972 318-3 2 barrel pulling a 10,000 pound Winnebago motorhome and I get 15 mpg at highway speeds, and I'm not alone or guessing at this figure.

I have never seen a 360 get better gas mileage than a 318 in my life in ANY car or truck.

It's probable that the 318 neon rt had was in serious disrepair before it was replaced with a 360.

the 318 is no speed demon, nor will it pull anywhere near as much weight as a 360, but it's more reliable, with better mpg and runs cooler.

Even with a weighted flexplate or weighted torque converter, the 360 still has a balancing problem unless you use the 360 harmonic balancer too. Even after that, the 360 (pre-magnum...) still has a small vibration (around 2800rpm usually) that is absent on the 318s.

There are 5 different versions of the 318. What I have is the 318-3 truck motor from 1972. It's pretty well bulletproof, where most other 318 "car" or "light truck" engines seem less "beefy".

Just a freindly FYI....

Slantsixness

[stamar]

ive got a 318 in a short wheelbase b250 conversion with fuel injection

and i dont think ive gotten 15 mpg

its only got85k miles on it. i cant imagine why yours gets better.

any secret?

[slantsixness]

Originally Posted by stamar

ive got a 318 in a short wheelbase b250 conversion with fuel injection

and i dont think ive gotten 15 mpg

its only got85k miles on it. i cant imagine why yours gets better.

any secret?

Secret is mine is a 2bbl carb. a really teenie weenie little 2bbl carb!

[neon_rt]

You mention 15mpg at "Highway speed" what is your def of highway speed.
Mine is 60-65mph highway. On hills it is 60-65mph up to and including WOT. Freeway speed 70-80mph.
15mpg sounds like you drive more economical than I have patience for (honk,honk, get that thing out of the way, road hog ).

[dieselcaddy]

I have a 91 B250 Conversion Van that my grandparents bought new. I was 16 then and went with them to look at the models they had. They ended up ordering one and I remember the salesmen telling my grandpa that he didnt want the 360 because the fuel injected 318 did just as good, while the 360 just sucked more gas. My whole family has driven chrysler products for a long time due to the fact most of them work at the plant in Saint Louis and I have always heard the 360 sucked more gas and couldnt take getting overheated. After my grandparents van came in we went on a trip out west in it and it got 18 mpg on the highway running 60-65. NeonRT is right though, it doesnt like hills and seems to bounce from 4-3 a lot. The temp gauge would nudge up there on some of the hills too on our trip. My grandpa complained to the dealer when we got back about it, but nothing was done about it. He couldnt beleive that it came factory with a one core radiator. I also have their 86 Fifth Avenue that has a 318 2-bbl in it and I have gotten as much as 24 on the highway, but that is running about 60 mph with it. I could imagine a van could get the 15 mpg running the 2-bbl. The conversion van my grandparents bought now has 160,000 miles on it and 13 is all it can muster. I havent had it on the highway though for quite a while.

Blaze

[altair20]

I have a 1978 Dodge maxi-van with the 318 - 2bbl carb, 3 speed auto. very VERY highway gears - 12mpg in town, and 15 mpg on highway. That was the biggest van dodge makes. My dad ordered this van brand new from the factory in St Louis, it's got 200,000+ on it, and it CONSISTENTLY makes those numbers. Loaded, unloaded, makes no difference to it.

[turbovanman]

I have a 75 B250 with a raised roof I put on, it weighs 5000 lbs, I weighed it at the scales. It came with a 318, auto, shit Carter 2 bbl, no egr and never got better than 12, even with headers and I added 12 inches to the collectors which made a big difference in towing grunt, dual exhaust, ram air-power went up but fuel stayed the same. With 3.3 rear gears, it still screams at 3500 rpm at 65mph. I tow with it and even that never changed the MPG. Switched to a 4 barrel and Edelbrock dual plane manifold, worse due to the Holley being a pig, installed an Edelbrock 600 cfm, worst of 9 and best of 12. Installed Qjet from a Chevy engine, could only get 1/2 throttle dueto linkage isues and got 14. Engine is tired so install a .030 360, real X heads with 2.02 valves, minor port work, RV cam, rejetted Edelbrock and guess what, 10 friggin MPG. worst of 8-9 towing a heavy bike trailer. Dynoed at 420 ft/lbs of torque though. Tried Demon, shit btw and finally running a Dodge Qjet, now average 10-12 again.

[stamar]

when my 89 tbi 318 was running better it got 12 mpg. loaded with 100s of pounds or empty. around town or on the freeway.

It defied the laws of thermodynamics really.

[slantsixness]

"Highway speed" in a 34 year old Winnebago is 55-65 mph. if you push it to 70, ther mpg drops to around 12, and if slower than 55 but greater than 35, it settles at 16 mpg.

Stop and go around town is around 12mpg.

Tom

[cossey]

i have a '97 dodge ram with a 318. My dad owns a '95 dodge ram with a 360. i know that the 318s get better gas milage. i dont haul alot of stuff around so i get about 19-20 mpg hwy. my dad on the other hand just drives his to work and gets about 15-16 mpg hwy. his has more torque but mine will catch back up and fly by his. alot of it is the transmissions. his is built for hauling loads and mine is for running to work. personally i prefer the 318s.

cossey

[bratt]

we have 3 dodge ram 3500 with the huge 5.9L 360 motor
2 are fuel injected and 1 was TBI motor

well, the gas mileage is horrible but so was our old ford clubwagon van.

the power is good. we can haul anything up our steep mountain climb. one time my brother was having problems with his 27foot Motorhome. the motorhome would not climb the hill because it was not tuned.

I took the 96 dodge ram van down there and pushed it up the mountain with ease. On the steepest part of the hill the 5.9L v8 motor powered the 27foot motor home up the hill no problem.

We have pulled many boats behind it and trailers. I never felt any hesitation when doing so.
The 5.9L v8 had a lot of power.

one of the vans has overheated many times due to a small pressure coolant leak that we have be lazy to fix. The van can overheat and still work. I have about 250,000 on all 3 of them. One is close to 300,000miles and it works good. We have really abused these vans and the motor has always survived the abuse.

The transmissions however are another story, one tranmission died on me because of a clogged valve body I think, the entire tranny was rebuilt but ever after that it would not go into reverse.

Another transmission had a front seal leak and we still have that trans.
One trans has a small leak in the rear seal even after a new rear seal was installed. wierd huh!

I never had a 318 or have I ever driven one!