340 4 barrel and 340 6 barrel: were they really UNDERrated?

[70SwingerGuy]

THIS stuff is great to see....old timers that raced these when the cars were only a few years old!

AND he has the slips to prove his times!

 

[RustyRatRod]

What I have read is that guys who worked Chrysler's dyno rooms claimed not one 340 came in under 320hp. NHRA factored them to 310hp. Guys on the street said they ran like 350hp 327s. I have also seen tests where pretty much everything else Chrysler sold, with the exception of the 426 hemi, was pretty close to advertised.

Now, consider marketing and other cars/engines in fleet along with racing class and insurance rates. Who would have bought a 383 Dart if the 340 was advertised with more horsepower? Who would have bought a 383 RR/Super Bee for the same reason?

We must have read the same thing. That's exactly what I remember reading. One thing's for sure. They put out more than 275 considering all of the supposedly more powerful victims they outran.

 

[mopar head]

RRR,
I bought a new computer, which I will be setting tomorrow with the help of a couple of mates. I am hoping that the dreaded line will be gone forever.....

I always wondered how people put lines through the text, until it happened to me once. I think I hit Ctrl instead of Shift for a capitol letter.
I think I`ll try it again, nope it just leans the letters forward. Weird.

 

[RustyRatRod]

I always wondered how people put lines through the text, until it happened to me once. I think I hit Ctrl instead of Shift for a capitol letter.
I think I`ll try it again, nope it just leans the letters forward. Weird.

That's called italics.

 

[mopar head]

That's called italics.

Thanks, I learned that in school 50 years ago and forgot

 

[RustyRatRod]

Thanks, I learned that in school 50 years ago and forgot

I don know WHY the stuff that sticks with me does. ......and the stuff that I WANT to stick with me eludes me. lol

 

[nutz]

i never drag raced anything other than a couple of stop light drags
but looked up the time my 2001 audi s4 should run seen #s 13.01 to 13.50 at around 102
other then all wheel drive 6spd its only rated at 250hp
my 86 vette rated at the same 250 hp runs 16s 103 seems slow but nothing run good in 86 ...and even though i had the vette up to 152mph the audi has more pull at over 100
so my stock build 69 dart 340 4 spd should give the audi a run

 

[273]

i never drag raced anything other than a couple of stop light drags
but looked up the time my 2001 audi s4 should run seen #s 13.01 to 13.50 at around 102
other then all wheel drive 6spd its only rated at 250hp
my 86 vette rated at the same 250 hp runs 16s 103 seems slow but nothing run good in 86 ...and even though i had the vette up to 152mph the audi has more pull at over 100
so my stock build 69 dart 340 4 spd should give the audi a run

I just looked up the Vette #'s what I found was 230 hp @ 4000 rpm and 330 lbs-ft @ 3200 rpms, she definitely ain't a revver lol Hard to believe what use to pass as muscle/sport car numbers and people think you can't pep up a 318, the bar has been pretty low for most of history a 5.2l magnum is rated 230 hp @ 4200 rpm.

 

[pomonamissel]

well my time with a boss 302 was limited , it made great power after changing the cam and a better holley and dizzy , and a smaller flywheel . it flew to 155 mph at @ 8500 rpm . but it's running time was very limited , it was apart more than it was together . but it never loss when it ran , lol . but i'll take a nice headed 340 instead of that boss package . i'd rather finish the race then dnf . so now mine sliding a 340 w/eddy heads n rpm intake and a afb into my 64 cuda 4spd tti headers n exhaust system with a few body stiffening mods . it won't handle like my boss , but i'll still drive it's wheels off it , lol . found me a pair of vintage american t70 torq thrusts for the nose , steels and the rear like these .

 

[missing linc]

Chrysler's own 1970 Dart advertising.

6000 RPM for under 3gs.
Apologies for the flash glare, it's in a plastic bag to protect it, and I didn't want to take it out.

 

[nutz]

I just looked up the Vette #'s what I found was 230 hp @ 4000 rpm and 330 lbs-ft @ 3200 rpms, she definitely ain't a revver lol Hard to believe what use to pass as muscle/sport car numbers and people think you can't pep up a 318, the bar has been pretty low for most of history a 5.2l magnum is rated 230 hp @ 4200 rpm.

Yet was leaps and bounds above the 84
Tuned port was the way back to hp
Before that in the 80s nobody had hp
She seen a lot of 5500rpms

 

[nutz]

Chrysler's own 1970 Dart advertising.
View attachment 1716391856
6000 RPM for under 3gs.
Apologies for the flash glare, it's in a plastic bag to protect it, and I didn't want to take it out.

Ill give 3k right now for one
I paid $2500 for my loaded 69 gt dart 273 in 83
I guess they didn't deprecate that much back then

 

[273]

Yet was leaps and bounds above the 84
Tuned port was the way back to hp
Before that in the 80s nobody had hp
She seen a lot of 5500rpms

I'm not overly knocking it, to me it shows how little hp most people could get away with especially in a relatively lite weight A Body. When I was young 225 hp net (260 gross) 5.0l Mustangs were the it car.

 

[fishmens67]

Ode to the mighty 340. an obsolete mill in today's world.

 

[Jim Lusk]

well my time with a boss 302 was limited , it made great power after changing the cam and a better holley and dizzy , and a smaller flywheel . it flew to 155 mph at @ 8500 rpm . but it's running time was very limited , it was apart more than it was together . but it never loss when it ran , lol . but i'll take a nice headed 340 instead of that boss package . i'd rather finish the race then dnf . so now mine sliding a 340 w/eddy heads n rpm intake and a afb into my 64 cuda 4spd tti headers n exhaust system with a few body stiffening mods . it won't handle like my boss , but i'll still drive it's wheels off it , lol . found me a pair of vintage american t70 torq thrusts for the nose , steels and the rear like these .

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It would take very little to make that little A-body outhandle the Boss Mustang. The starting platform is that much better...bigger torsion bars, better rear springs, better shocks, and sway bars...

 

[krazykuda]

Remember those guys that bought into the old rumor of a Wednesday car?
The theory that a car built on a Wednesday was somehow a better built car because on Mondays, they were hung over from the weekend and on Friday, they were looking forward to quitting time and the weekend. Somehow, cars built mid-week supposedly had more attention to detail?

View attachment 1716391228

Sometimes though, an engine runs much better than the rest. Maybe a positive tolerance stack up?
I've driven numerous Chevy 350s. Some were gutless, some hauled ***. One was in a 75 Camaro owned by my Brother's friend. It idled smooth but flat out scrammed. I once had a 318 that wouldn't even peel out in gravel. That one had a timing chain replaced and somehow, it was THREE teeth retarded on the timing sprocket! Once I found that and replaced the chain and sprockets, the dude hauled ***!

I know you say all that tongue and cheek, but I can remember well some cars were just plain faster and quicker than they shouldda been. @krazykuda Karl can attest to it, as well. He worked on the line for Chrysler for a while. He has some stories to tell. In fact, I got one. I had a friend whose father had a 1970 Impala four door. Just a family car. BUT it had a 300 horse 350 in it. Most were garden variety 250 or 270 horse, but this one got the 350/300. Every now and again David, my friend, would be granted use of the car. We'd go out terrorizing people in it. It was the ultimate sleeper. Four door and that GM mint green. We whooped up on many an unsuspecting opponent.

Then, David got a 69 Camaro. 250 horse 350. So one day we were over at David's and he kept looking back and forth at the Impala first, then the Camaro. The family was going on a long weekend vacation, but David, since he now was 18 and had a job, was staying home. Yup. We did an engine swap between that Impala and David's Camaro. The old man never knew the difference, because he never romped on the Impala to really know what it had. But David's car was now a holy terror. Now I fully admit, we were young and stupid. What was actually a 300 horse motor "could" have seem like more "JUST CAUSE" we were young and stupid. But both cars, first the Impala and then the Camaro claimed LOTS of victims "WE JUST KNEW" should have bested us, but didn't.

It isn't so much as what day of the week, it's more of when the holidays were if it matters at all...

As far as horsepower, it's just some run better than others, it may be the tolerance stack-ups working in your favor...

But as far as quality, you want the ones made when there was low absentee... The 'regular' operators on the line do the same job over and over day after day... There is a floater for each section of the line that will fill in when the regular operator is away from the line for a bathroom break if possible... The floater knows each job in that section as they fill in on the days the operator is off...

Then you have the popular long holidays, where the operators take their vacation time... Sometimes more than one per section of the assembly lines... They have to find substitute operators to fill in the lines to keep them assembly lines running... If there are not enough assembly line workers (say before or after a long weekend vacation for the negotiated union vacation day and they cash in a couple of their vacation days [PTO] to get a longer holiday break) to run the assembly line, they borrow operators from other departments... In an engine factory, they borrow the operators from one of the machine lines as the assembly line gets priority... The machine line can be run without an operator as the machine operators usually are required to get the machine running and then do a check part every hour to make sure the machine is running parts to print/spec...

The substitute operators take a little time to get through trhe learning curve for the assembly line job and that is when we saw more defects/repairs on the assembly lines... The regular operators know the job the best and have better quality and speed to keep up with the line...

So on the days where there is high 'absenteeism', there are more repairs and misbuilds because the substitute operators don't know the job as well as the regular operators... Those usually occur before or after one of the extended union negotiated vacation days off when people cash in their personal vacation days to get longer time off in a stretch...

 

[nutz]

and when the molds/machines are new you get a more conistent product
when some of the parts that are on the edge of the production tolerance all come together with the hp gods they build a runner
funny cause my friend would say my vette sounded better then others ...its still all stock other then tire/rims and shocks (still have the stock tires/rims/shocks i took off when it had 6k on it)

 

[plymouth4onthefloor]

I build my 340 6pk in 1998 with domed TRW pistons, Crane cam ca. 220°@50, cold intake, cast iron headers, X Head milled 040, felpro gasket, 10.7 cr with bowl job, 2 1/2 exhaust dynomax turbo muffler the chassis gave me 280hp @ 5500 330 ftlbs @4500. with A833. The 340 rips of the 8 1/4 locked diff, splines on the axle almost gone, no race just street. Top speed 135 mph uphill @ 6000 rpm, speedo reads 150mls. 330 HP calculated to crank

My friend had a crate 360/380hp that one made 275hp on the chassis dyno.

Realistic numbers i think.

 

[KevinCar]

This car of mine is a smidge over 3900 lbs with a 440/495, frame connectors, HD suspension....

View attachment 1716391224

And my 67 Dart 270 hardtop with a 340 727 and 8.75 is 2870# with the jack, spare tire, rally wheels, full interior and half a tank of fuel. although 69-70+ A bodies were heavier with all the luxuries. 68 340 dart was 3220# as rated. 500-600 # difference would be moe accurate for most cars, except cars with many features and additions they would be heavier, A 1969 a12 Superbee 440 4spd was rated at 3620#, dodge dart lo23 426 car weighed 3020#

 

[KevinCar]

He asked about a particular car and a run that we made.

I also posted the numbers that I recollect from when our
340 cars were Brand New and totally stock except for tuning
of course. Also, the first hand results that I had back then in
my experience after stages of modification.

I am responding for to the question asked by the Original Poster
hopefully to be a benefit to my friends on this site.

It really aggravates me when someone says that the 340s were
only good for 5200/5400 new. Mopar in the ads advertised them
at " 6000 RPMS for under $3,000". They were conservative as they
had to warrantee they for 5 years/ 50,000 Miles.

Ya know:
I was there and owned/raced the 340s and every
other Moar back then. I even owned a couple of Dealerships.

I still do race them and I am even right now at the track racing
three at the Nationals today and am between rounds.



I love A Bodys as much as anyone in the World and
particularly the early 340s. It pisses me off no end, when
I see misinformation disseminated on these cars. I will set
the story right every single time.

I do not ever claim to be any big expert or a great mechanic. Often
I ask for help and advise from my many friends on this site and benefit
from it = a Lot.

However, I have been around and raced various Mopar for way over
60 years and it is my chosen Hobby and I do know a few things about
them.

I think you nailed it when you said tuning, we all know 5btdc and factory tuning, proper performance tuning of ign curve, carb etc really wakes up the 340, or any motor. 300hp @3100 # can net high 12s, 375hp could be high 11s given a good track and driver. You guys must be hella tuners on points back in the day to get 375hp tho, but with fuel back then and considering a more true 320 hp from factory. I can see it. Those were the days!

 

[KevinCar]

i never drag raced anything other than a couple of stop light drags
but looked up the time my 2001 audi s4 should run seen #s 13.01 to 13.50 at around 102
other then all wheel drive 6spd its only rated at 250hp
my 86 vette rated at the same 250 hp runs 16s 103 seems slow but nothing run good in 86 ...and even though i had the vette up to 152mph the audi has more pull at over 100
so my stock build 69 dart 340 4 spd should give the audi a run

but then traction and weight, all wheel drive gets going! and 6 spds keeps it in power band. Apples to oranges. Our Kia Stinger gt jb4 is much quicker than our 10.5 compression 340 dart with cam headers and timing but the Kia is no where near as cool or nostalgic to me. i wouldnt daily the Dart, not nearly as efficient, comfortable or safe as a new car.

 

[nutz]

Not sure of the #s
But they all had a/c leather power everything
I have a 06 audi a8 cant get the title for it
Was thinking to strip it and let the kid race it
All alloy body and frame
320 hp v8 and allwheel drive
And it it blows i junk it

 

[Swinger 340]

I had some really good Mopar friends that were super honest and had high end cars. They had a friend (they told me) that had bought a new '71 Duster, 340 4 speed, and tried for a year to get a 13 second pass. They tried different RPM launch's and shift points, they tried adjusting the metering rods and timing (only turning the factory adjustments, no altering), but never got their 13 second pass. They would go 14.0X's to 14-teens. But never got a 13.99.

The 340's were a SCAT PAC. My understanding, that meant they were in the 13.99 or better range. I still have somewhere, ads from the factory that say the 340's are a high 13 car in the "A" bodies. Also $2,800 for a 2800 lb. car. A dollar a pound.

 

[Swinger 340]

And probably a thousand pounds lighter than the B bodies too, great combination for a fast car

Agreed, same motor, different car = different ET's. I have beat several Corvettes (60's) and 5.0 Mustangs. Knowing your car also has a lot to do with lower ET's. While the big boys are back at the line, smoking their tires, I'm at the end, waiting for them to catch up.

 

[Swinger 340]

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That explains it.