Spring is finally here, after a seemingly endless wet and cool winter. On our daily walk about a month or so ago, I spotted this ’65 Valiant at a stop light. It’s been a while since I saw something like this that might be a daily driver. There used to be a number of old Falcons and such around, when it was hip, and the cars were cheap and easy to come by.
As the light turned green and it took off, I couldn’t help but notice some not very nice sounds, presumably from the engine.
It was a engine-speed related clunking or clanging; like really loose bearing s or such. Hopefully it was something more benign.
Institute for Alternative Facts
Slant sixes are not as bullet proof as their reputation would have you believe. I have rebuilt a few of them due to bearing issues. But, a great engine nonetheless…
Still looks in good overall shape, time to either do a major overhaul or find a good used engine, install it and freshen up the rest of the car .
Or if originality is of less import, drop in a 318.
No car/engine is bullet proof. We here at CC pretty much know that.
Some have better up-run-times, but maintenance, driving habits, long haul vs stop-and-go histories, and age… , well, you know, lots of things go into the thoughts of what is better and what is worse.
My 1971 225 slant six had a cracked exhaust manifold within the first two years and the brakes were terrible when wet. But no issues with the motor itself during the short time I drove it.
Having said this, one of the reasons I bought the Duster was that I thought the slant six was bullet proof.
As 3SpeedAutomatic noted in an earlier post comment today, Go Figure!
My slant six lasted 9 years but eventually dropped a bearing and I got a rebuild.
The car was hard on shock absorbers too, and alternators, none of which were due to my lead foot. Or I would like to believe.
Nonetheless loved that car. 74 Dart Sport.
As others noted, bulletproof is a relative term. The slant-six was pretty rugged, but you have to expect a 58-year-old engine to need a wee bit of attention.
We had a similar ’65 Valiant 100 2-door sedan, although in a lighter shade (Medium Blue Metallic, while the featured car looks to be Dark Blue Metallic). The front view, showing the car signaling left, reminds me of one of Dad’s concerns before buying the car – namely, that the front parking/directional lamps being mounted low & under the bumper wouldn’t be that visible to other drivers.
I am 58, and getting a bit slanted already!
lololol “Amen” there!! I’m “62”, clan and rattle endlessly.
Some years ago I met a gentleman who had formerly owned a rural Ford dealership. After selling the dealership, he kept his hand in as a sales rep at a used car “supercentre” in a local auto mall.
He seemed like a good fellow, but described every used Ford on the lot as being “bulletproof”, even those with dubious transverse V6 engines with internal waterpumps. I was rather skeptical, as there was not a Slant Six among them. Sort of the automotive equivalent of grade inflation, I suppose. ;>)
Seriously, despite the Slant Six’s fine reputation (for example, Phil Edmonston, Canada’s amicable version of Ralph Nader, described a ’70s Dart or Valiant with the six as being ‘the closest thing yet to perpetual motion’), I was surprised to discover that it had only four main bearings. And yet, they seemed very robust.
Yeah, only four main bearings, each the same size as those in some of Chrysler’s largest, most powerful V8s of the era. It’s almost as if tsk-tsking over the Slant-6 only having four main bearings when everyone knows any real linear-6 engine has seven of them, popularised by the likes of Jan Norbye, is…I donno, like, a silly myth or something.
I’m reminded of the hash BMC made of their C-series six when they went from four to seven bearings. Too much internal friction and the thing wouldn’t rev. Part of what made the MGC a disaster. Four big bearings can beat seven smaller ones. And if its taken until 2023 for this 1965 Valiant’s bearings to get loose, that’s pretty good longevity in my book.
It’s like decrying GM and Hemi V8s for still using pushrods. It might not be ‘best practice’ from a theoretical engineering point of view, but it sure gets the job done.
Even Slant 6’s need oil. If it burns or leaks oil and the owner never checks it, it won’t take long to do bearing damage on any engine. I had one that got to the point of consuming 1 quart per 50 miles. The previous owner had overheated it several times due to a radiator leak (he kept a couple gallons of water in the car to top it off when it got hot). I’m sure that didn’t help. It would keep the mosquitoes at bay…
Could easily be something simple. I’ve heard fan belts make noises that would make one swear the water pump and alternator bearings had gravel in them.
…or the radiator fan, aided and abetted by worn or broken engine mounts. Or loose torque converter bolts. Or…
My old man had a Holden 6 with a fanbelt that was too stiff the car rattled badly on cold start but only for a minute or so then quiet, it sounded like bad lifters eventually the cure was found for a customer car and dad immediately booked his one in, quiet thereafter.
Slant 6s do throw internals out Ive seen the results but generally they were good engines, gutless compared with the hemi 6 that replaced them down here but a good one runs smooth as butter, the only slant 6 I bought ran beautifully the car was pretty much toast from rust and general neglect but the engine was good, I owned a few later Hemi versions but early cars were getting rare by the late 80s.
Back in the ’80’s, my cousin called from somewhere in New Jersey; never quite able to put life together, he was returning to PA from a road trip into Harlem to buy some weed through a sliding window, when his Duster broke down with a steaming, pinging power plant. I opened the hood to find that a macaroni-soft lower rad hose had sprung a leak. I’d brought along some odds and ends, and was able to tape it up temporarily and fill it with water so he could drive home. Miraculously, it sounded fine when he drove away (I remember being impressed that there seemed to be no ill effects), so fine that he didn’t take it to a mechanic, and he eventually ran it out of coolant a second time, killing it.
How much you want for the 1965 Plymouth Valiant?
My old, dependable, Slant 6 powered ’65 Valiant that served me very well for over 20 years. Though I loved that drivetrain combo, it was time to take the car to a higher level. 2018 saw me install a 505 cubic inch big block Mopar engine resulting in mid 10 second 1/4 mile times. The shock from the Chevy/Ford boys was worth it !!
My obnoxious, loud, licensed, insured tough street car. I drive it on a weekly basis to do some grocery shopping, really…what fun !!!!
Maintenance helps, we regularly ran ours over 150,000, without incident, and years ago I knew a Cab company who got 200,000+ out the ones he ran.
The term “bullet proof” gets thrown around a lot, but if you run your motor hard, and are lackadaisical about the care and maintenance, you’re going to ruin any engine. Nowadays we expect a car motor to last over 200,000 miles without major work, usually we don’t even have to “break the seal” on the basic block during our entire ownership period. My ’96 Mustang with a 4.6 has over 215,000 miles and should be good for many more. My old 5.0 Explorer had over 265K when I sold it and it was running good up to then. Back in the ’60’s a typical V8 would need a valve grind “freshening up” at around 50 thou, and a complete overhaul around 100 thou. Modern engines are so improved, but auto transmissions are still lucky to go over 150K.
I suppose that an engine can be called bullet proof if it gets close to meeting modern expectations. There are several recent motors that are notorious for being fragile and short lived, early Jag V8s, and Cadillac NorthStars come to mind, but I’m sure there are more.
Well said Jose ;
Loose tolerances on the initial build of older American engines tended to result in short service life before needing routine overhaul or complete rebuilding .
Older Gernam engines, and VW’s in particular rarely needed anything until 150,000 miles, depending on maintenance and few Americans ever did anything until the engine failed to start or stopped running then blamed the manufacturer .
I’ve seen many really loose and sloppy engines run very well after overhaul, the best of these were used in Hot Rods or Commerical rigs where they’d get run very hard but always properly maintained .
I’d be very upset if a slush boxfailed before 250,000 miles but then I hot change the ATF and filter .
This isn’t a yes/no deal; the Slant-6 was unusually durable by the standards of the day.
Of course. And it seems a number of commenters have taken my tongue-in-cheek headline way too seriously or literally. It’s a 58 year old car. And it’s still running. Yea!!
I managed to kill the slant-6 in a 1964 Belevedere. Mind you, it had over 300k miles on it, a high-volume oil leak from the valve cover, and I was 23 when it passed into my hands…
I had several leaning towers of power. They lasted through my teen years, and oil changed oil, plugs, and tires. Sold it to my best friend after high school. Wish I had keep it. Had bucket seats, push button transmission on the dash. Since then I had purchased 1975 swinger with a slant six. Looking to hop up the engine, cam, headers, intake from Cifford. Plus on major modification, a windage tray, to keep oil on 1 and 2 rod journals. Traveling the the road, oil goes to the back of the pan leaving lack of oil up front.