Does anyone remember what the reliability of the big and small block mopar engines were when they first came out?

[451Mopar]

Reliable if maintained. Other than oil / filter changes, the ignition points would need regular adjustments / replacements.
Having carb problems running rich could really cause issues with fowling plugs, washing down the cylinders, and if not driven hard once in awhile, excessive carbon buildup in the rings, crossover, and such. PCV valve replacement every so often.
In unmodified cars the transmissions lasted, if a stall converter or towing, really should add a transmission cooler.

 

[BeepBeepRR]

They tried to re imagine the V8 and came up with the 4.7l magnum That engine is a pile of crap. Sure you may have a few people who swear by them but the junkyards are full of Durangos, Dakotas and Dodge Rams that have had these engines. When they swapped from the 5.2 and 5.9 hell even the 3.9 magnums they went to crap. I just worked on my friends 318 Magnum Ram and it has almost 400k on the clock. I bet it would be hard to find a 3.7 or 4.7 that has made it that long. This may be an unpopular opinion but while newer engines are more efficient than the older engines there is a trade off. Plastic parts, Plastic timing chain tensioners, plastic intakes, plastic everything. Plastic is not a sustainable or reliable wear part. I'd stick with the older stuff which was mechanical and more reliable.

With that said the invention and use of roller cams and lifters has made new stuff top notch but they still have failure issues as well. Look at the MDS Hemi engines for instance. They are problematic. I guess the beauty is in the eye of the beholder..

 

[451Mopar]

They tried to re imagine the V8 and came up with the 4.7l magnum That engine is a pile of crap. Sure you may have a few people who swear by them but the junkyards are full of Durangos, Dakotas and Dodge Rams that have had these engines. When they swapped from the 5.2 and 5.9 hell even the 3.9 magnums they went to crap. I just worked on my friends 318 Magnum Ram and it has almost 400k on the clock. I bet it would be hard to find a 3.7 or 4.7 that has made it that long. This may be an unpopular opinion but while newer engines are more efficient than the older engines there is a trade off. Plastic parts, Plastic timing chain tensioners, plastic intakes, plastic everything. Plastic is not a sustainable or reliable wear part. I'd stick with the older stuff which was mechanical and more reliable.

With that said the invention and use of roller cams and lifters has made new stuff top notch but they still have failure issues as well. Look at the MDS Hemi engines for instance. They are problematic. I guess the beauty is in the eye of the beholder..

I recall the hype (1990's?) of the new 4.7L having a timing chain and beehive springs, and I think a strong bottom end, but the performance was not good, and neither was the fuel economy.
I have never seen what they could do if modified? The Hemi came out right after the 4.7L and I think anyone looking for performance just ignored the 4.7L and got a Hemi.

 

[BeepBeepRR]

I recall the hype (1990's?) of the new 4.7L having a timing chain and beehive springs, and I think a strong bottom end, but the performance was not good, and neither was the fuel economy.
I have never seen what they could do if modified? The Hemi came out right after the 4.7L and I think anyone looking for performance just ignored the 4.7L and got a Hemi.

The 4.7l engines are blown head gaskets waiting to happen. I have seen one 4.7l on dakotart.com that had some cams and a turbo that would rip. But the majority of the 4.7l engines were and are junk in my opinion. My buddy bought a Dakota from our neighbor and I told him not to buy it but he did anyway. Turns out that it had the 4.7l engine both head gaskets blown and 2 pistons with holes in them. I told him to scrap it he decided to pay some craigslist guy to rebuild the engine.... I use that term REBUILD very lightly.

 

[440 4 speed]

I drove a 440 GTX as a daily driver in the 70s, a '62 Imperial with a 413 in the 90s, and a '66 Imperial with a 440 later in the decade. Nearly 200,000 miles combined, and no issues with any of them. I'll never forget a business trip one week in January, arriving back at Chicago's O'hare airport in single digit weather after the '66 Imperial had been sitting for nearly a week in the long term parking lot. The look on my colleagues' faces when the 440 fired on the second crank was priceless.
View attachment 1732165

 

[440 4 speed]

I drove a 440 GTX as a daily driver in the 70s, a '62 Imperial with a 413 in the 90s, and a '66 Imperial with a 440 later in the decade. Nearly 200,000 miles combined, and no issues with any of them. I'll never forget a business trip one week in January, arriving back at Chicago's O'hare airport in single digit weather after the '66 Imperial had been sitting for nearly a week in the long term parking lot. The look on my colleagues' faces when the 440 fired on the second crank was priceless.
View attachment 1732165

1966 went to a New Year’s Eve party. -30F about 1:30 AM. Had mom’s 61 Pioneer 313. Time to leave I ended up boosting a 63 and 64 Ford with 352’s. A 64 Impala 283.
Just sold the Pioneer 4 years ago to a fellow who has a nice 60 Plymouth New York State Police car with lights etc. A 61 Plymouth that is finished and some other 60-61’s. Think he’s going to start on the Pioneer this winter.
The car has 147,000 miles on it.
The first slant six 60 Plymouth sold in our area was to a fellow that had a lumber mill. No electricity. Driven on the bush trails and logging roads. After a year others realized that was a good engine. People started buying a car with that funny engine.
.

 

[Donakey]

I don’t know if this relates to the conversation but when I was a kid the older teenagers got a free 80’s Dodge Truck. They took it jumps where we would all ride our bikes and drove the truck with no coolant. The 318 had a red glow and it was still running. I couldn’t believe it . I will always remember how the 318 kept going even when the block was that hot the whole thing glowing red!

 

[440 4 speed]

As a geezer, always heard how reliable the 318/727 were durable, hard to kill, and knew a couple people who beat the living snot out of them. Though back then the 318 was considered as boat-anchor material for anyone upgrading.

1961 318’s with a 4 bbl were rated at 260 hp and moved quickly.

 

[DanielSlocum]

I think the engines and drive trains were great if properly maintained. I think the old big gear reduction starters were junk and often failed in just 2-3 years.
Ballast resistors failed often and most Mopar guys carried a spare as i still do. Mopars were often more cold blooded/slow to warm up properly than some other brands,making many women hate to drive them. I believe those minor problems lost Chrysler a lot of customers. Performance/accelleration was always 2nd to none as many people were very slow to learn the hard way.

 

[autoxcuda]

-Small block Mopar engines have one of the longest timing chains of any V-8 of that era. They tend to get loose due to that length.
-Chrysler 727 and 904 transmissions tend to leak out of shift shaft selector seals.
-Small blocks can corrode cast aluminum timing chain covers at two outer upper circular ports. Later design cover where made thicker in these problem areas.

 

[1967coronet]

I drove and beat them back in the 70s.
My vote for tuff can't kill it V8 engines would be the 383 mags and the daily driver 318s.
Some of the 383s I was around just amazed me for durability and performance box stock.

 

[Runcharger]

318's were great but sometimes the heat crossover would plug up, slantys did indeed crack exhaust manifolds, 383's were great, later ones had a nylon timing gear that would break down, later 440's had the nylon timing gear issues as well.
Some guys could break them but that was generally from stupidlty abusing them.

 

[64BEL]

In 1978 our '69 Fury II had 157,000 miles on it. I put a brick on the gas pedal trying to blow up the 318. No joy! Took the water out of the rad, it would die and just restart after cooling off, was about the take the oil out and Dad came around the corner and stated "just pull the f'n motor already and put in that 440/4 speed you have sitting on the garage floor, I can't hear the customers in the butcher shop" !

 

[MarPar]

225 slant six will outlive cockroaches after a nuclear war

I've got mine ready!!

 

[AR67GTX]

A funny story, in the late 70’s in Colorado Springs my brother and I determine my Mom’s 6 cylinder 2-door green Scamp had ate its nylon distributor gear so we got a replacement, installed it and re-timed the leaning tower of power. So my brother, my girlfriend and I set out to go for a test drive and make sure it was running OK. Well, one thing led to another and before long we were on the road to the top of Pikes Peak. All was going well but slower and slower as we went. Finally, as we neared the summit and the last hill/hump before the parking lot at the overlook, we were down to a crawl, blowing black smoke like a diesel and backing up traffic behind us. I mean a turtle could outrun us at that point and it looked like we might not make it over that last hump into the parking lot. So my brother said don’t let off of it and he crawled out of the rear window, and pushed us the last few feet over the hill to where we could coast into the parking lot. We figured the old Scamp was good to go now and somehow the brakes got us back down OK. My Mom was not amused when she heard the story. They were tough little cars.

 

[moparedtn]

I've never intentionally tried to kill an engine in my life. That's just inane...
Tell you what though, I concur with the /6 and the 318. Both tougher than nails - and the /6
still appears on many of those "greatest engine designs of the 20th century" lists.
It's damn near a perpetual motion kind of deal, it runs so effortlessly....
No, it's no powerhouse, but it just plain runs forever.

As far as the HP engines go, I surely beat on my share of them over the years (and to be honest,
Fred gets leaned on sometimes to this day, too) but I don't ever remember any of them failing me.
Sure, they developed leaks over time and some of them surely needed a rebuild, but I don't recall
any outright just laying down or throwing rods or any such nonsense.

Are the newer ones tighter, more efficient? Sure, 50 years of further engineering will do that - but
for outright beating a mule of an engine, give me an old 440 any day.

 

[68BabyBlue]

Mopars were often more cold blooded/slow to warm up properly than some other brands,making many women hate to drive them. I believe those minor problems lost Chrysler a lot of customers.

I grew up with Mopars, so to me their cold blooded temperment was just something I dealt with, I'd never experienced anything different. My wife grew up with other makes, and when we got married in 1977, she quickly came to despise my slant six Valiant and 440 GTX because of the warm up issues. As soon as I could afford it, a bought her a new brand X vehicle. Happy ending, we've been married 47 years, and I still own a GTX. But she always asks why I have to run that thing for so long before I back it out of the garage.

 

[6PKRTSE]

I would say they must have been flawless with all of the so called numbers matching everything running around these days..... lol.

 

[440 4 speed]

I drove and beat them back in the 70s.
My vote for tuff can't kill it V8 engines would be the 383 mags and the daily driver 318s.
Some of the 383s I was around just amazed me for durability and performance box stock.

1968 a Dad bought a new Bee 4 spd for his sons to share. Destroyed 2 engines that winter. Chrysler cancelled any further warranties. Turned out that the boys were doing cold starts in the winter. Up to-30F and running it up to at least 4000 rpm. Collapsing piston’s.
Dad wasn’t happy to say that least.

 

[69 Charger]

I have been looking at new cars lately and trying to compare engines which made me start thinking how this process went for mopars back in the day. For instance did the 383 have less issues than a 318? Was the 440 more reliable than the 340/360.

Same thing with transmissions? I’d imagine the 727 was preferred but can’t seem to find a lot out about these statistics for the back in the day. I know what I’d prefer now but just wondering if that was the same back then.

I am the original owner of my '69 Charger with 383 HP and A833 4-speed. It racked up 178,283 miles with no engine problems at all. It was off the road from 1996 to 2022 when it began restoration due to some needed body work. During professional rebuild of the engine in 2023, it needed only a new timing gear/chain, a new cam and new rings. The cylinders were only honed, original pistons were reused. The transmission was opened up and examined by an AAMCO mechanic with years of experience who was about to retire. He said he had never seen a 4-speed that looked that good after so many miles, just replaced the seals and gaskets and buttoned it up. Didn't even need new bearings.
This car was a family car for 27 years, so I always treated it for reliability, not max performance, and it has never been abused. I have been its only driver. Perhaps all that is not typical, but it shows what can be achieved.