Are 340’s rare

-
I just keep looking at the original question from the OP and read the slow degradation into the abyss of opinions that really have nothing to do with it . :thumbsup:
 
A56 said:
I just keep looking at the original question from the OP and read the slow degradation into the abyss of opinions that really have nothing to do with it . :thumbsup:
Click to expand...

So you would rather see one or two opinions then the post just dry up and go away. Most of the guys that think this way never contribute anything to the site. This would be one boring website.
 
Sounds like we got some in here who think weight of reciprocating assemblies have no impact on how fast an engine can rev calling other ppl morons? You know like gee pistons go up, reverse direction, go down, reverse direction, go back up, repeat. So gee how can weight of pistons and rods impact ability for engine to rev? Thats a hard one to figure out, real tricky one, right?

Its fairly common knowledge swap in lighter pistons into a 340 its gonna rev faster. No, not aware, never heard of that, don't believe it? Don't think HEAVY *** pistons have a negative impact on engine performance, no? Big *** HEAVY pistons reversing directions doesn't sap some power?? No, not true? Anyone who thinks that is a moron, right?
 
Icetech said:
rare, not really... can always find them for sale.. valuable.. for sure and will only go up in value. 340s have a mystical reputation which will never go away and guys will pay stupid money for one instead of a 360 for 1/8th the price. If you don't need to sell it, oil it up good and put it under a bench for 10 years and it will double in value... no joke. i don't get it myself though.
Click to expand...
I think it is easier to find one now then 50 years ago. I bought a 72' Dodge Van, new and around 74', I began looking for one for it and it took until 79' to find one, but I had to buy the whole car (69' Dart swinger). The cars are now disappearing, but the motors are kept. I have had several since and I'm keeping one now, to install in a pick-up truck, Prowler or anything else unusual. If you never had one, you are missing out on a lot of fun.
 
I have owned a factory 340 car since 1983 and it will remain a 340, as it should. BUT, I have long advocated (since before I owned a Mopar 340 car - I did own a non-Mopar 340 car once upon a time) for building a 360 for a street performance car simply due to the cost difference and ready availability. This was also before most people figured that out. If I had another original 273 four barrel car I'd build the 273, but I don't see an application for a 318 in my world. Due to the relative rarity of the 340 vs. 360 there will always be a price difference.
 
With the 340's being hard to come by and expensive, I don't understand why guys want to Bore and stroke them and run the crap out of them. The last 340 block I saw for sale the guy wanted $600 just for the block. I'm not a fan of the 273's either
 
AJ/FormS said:
Yeah well rpm ain't everything to a streeter. example;
7500 in first gear(TF) with 3.23s comes to 68mph. Did I say still in First gear?
With a power-peak near 7000, what cam do you run, and how's that gonna run in Drive at 30 mph?
No thanks.
I'll take the 408, or 388 (4.04 x 3.79), or even an HO367, with a power-peak around 5400 give or take.
But I gotta say this;
a super-Hi-Compression 340, with a 318 cam, makes a chitload of Bottom-End torque, which is just right for a streeter with 3.23s, or even, a lil less.

I used to get so much flack for having a 360-based small-block. Since it's a 4.04 x 3.58, I started calling it a stroked 340, and that was the end of the criticisms.
Click to expand...

You have some fixed notion that your way of building a “streeter” is the golden ticket. It’s not. It’s your fantasy of what a “streeter” is.

RPM is your friend.
 
340sFastback said:
Sounds like we got some in here who think weight of reciprocating assemblies have no impact on how fast an engine can rev calling other ppl morons? You know like gee pistons go up, reverse direction, go down, reverse direction, go back up, repeat. So gee how can weight of pistons and rods impact ability for engine to rev? Thats a hard one to figure out, real tricky one, right?

Its fairly common knowledge swap in lighter pistons into a 340 its gonna rev faster. No, not aware, never heard of that, don't believe it? Don't think HEAVY *** pistons have a negative impact on engine performance, no? Big *** HEAVY pistons reversing directions doesn't sap some power?? No, not true? Anyone who thinks that is a moron, right?
Click to expand...

It matters, but it’s not some magic squirrel ****. The converter or flywheel on the back of the crank is the biggest RPM retarder on the engine.

RPM and the ability to gain RPM (which is the definition of acceleration) is far more limited by the inability of the heads to feed the engine.

Standing there, blipping the throttle and thinking the engine is really zippy doesn’t mean a thing. What the engine does under load is what counts.

You can’t test for that on a water brake dyno either.
 
Dan the man said:
With the 340's being hard to come by and expensive, I don't understand why guys want to Bore and stroke them and run the crap out of them. The last 340 block I saw for sale the guy wanted $600 just for the block. I'm not a fan of the 273's either
Click to expand...
I built my stroked 340 with a clean std bore '71 block back in 2008 so my original std bore numbers matching 340 could be set aside and not take risk of grenading blowing apart. Back then the 340 block cost me $500 and it was exceptionally clean. That $500 was a very small percentage of overall engine cost and I could say I have 340 block in factory 340 car. Things have changed over time where makes more sense now to use the cheaper 360 block as a starting point.
 
Dan the man said:
With the 340's being hard to come by and expensive, I don't understand why guys want to Bore and stroke them and run the crap out of them. The last 340 block I saw for sale the guy wanted $600 just for the block. I'm not a fan of the 273's either
Click to expand...

In the whole scheme of things, if building a half way serous stroker piece, a 600 dollar block is peanuts. I have more than that in my Victor intake and having it ported.
Just saying.
If 600 bucks is gonna kill me, I would have quit racing a million years ago..lol
 
B3422w5 said:
In the whole scheme of things, if building a half way serous stroker piece, a 600 dollar block is peanuts. I have more than that in my Victor intake and having it ported.
Just saying.
If 600 bucks is gonna kill me, I would have quit racing a million years ago..lol
Click to expand...
$600?
 
william parker said:
How rare are 340’s getting now days? Pulled this solid runner cast crank one out with 727. Not sure to keep it stored or sell.

View attachment 1716228365
Click to expand...
There’s a lot you can do to freshen up that 340. Go back to stock or get crazy n do a 416 CI Stroker.
I’ve alway heard n I had a 360 Stroked to a 408. Lots of low end torque. Google 340 Stroker kit n read up on them.
Happy Moparing
 
All this comparison of 340's and 408's....well I have one of each. Two TOTALLY different animals.

I've had my 71 Demon 340 since 1984. I tell folks the car is a "sheep in wolf's clothing" as the Green Go paint and flat black hood and twin scoops and black stripes scream performance car. But it is not. It is as stock as I could make it other than it has the old purple shaft "hemi-grind" cam in it. It is choked down big-time by the exhaust pipe where it bolts to the manifolds. But I wouldn't trade it as it is supposed to be a 340 car and it is. Just a sweet little car with the proper 340 in it.

The avatar car was birthed in 2019-2020 with its 408. That is one FUN engine. Yep, massive torque and not so much power as it only has Eddie RPM heads with minor bowl blending. But I've said this many times - it's like a young male teenager that just wants to run, run, run. "Please stand on the loud pedal" is what it says every time you're in the car! Oh, it's been to 7500 rpm a few times but not by plan (oops, that would be my fault). But generally it's happiest shifting at 6200 rpm and trapping at about the same rpm. With mid-250's cam duration, if I built it again it would be mid-260's as that 4" arm eats duration. Does it rev fast? Dunno - nothing to compare it to. But it's a barrel of fun for sure as that 6200 point comes up pretty darn quickly. [email protected] PB so far for this "tractor" motor and its non-ported Super Victor intake.

I can't be partial to either one as they are such different things. I enjoy both of them. But for a street/strip car, the fun factor of all that torque from the 408 is hard to beat. (Now if I can just coax a 10.9x from this tractor...!!)

They both got to go to a cruise today. And my wife decided she wanted to drive/roll in with the avatar car. She voted with her right foot!
20240330_144629.jpg
 
Last edited:
Newbomb Turk said:
It matters, but it’s not some magic squirrel ****. The converter or flywheel on the back of the crank is the biggest RPM retarder on the engine.

RPM and the ability to gain RPM (which is the definition of acceleration) is far more limited by the inability of the heads to feed the engine.

Standing there, blipping the throttle and thinking the engine is really zippy doesn’t mean a thing. What the engine does under load is what counts.

You can’t test for that on a water brake dyno either.
Click to expand...


The best dyno is the one with 2 lanes and a timer.
 
B3422w5 said:
Yours ran a lot better than mine.
Had a 69 Dart I owned in 1972 and 73
Had 3.55 gears and cheapy headers.
Best I got out of it was 14.23@ 99 mph, which was a hair quicker than some others back then that ran mid 14’s.
Suspect it was little better gear and the headers.
Click to expand...

that out of a 69 340? my valiant ran 14.2's all day long with a stock 79 360 long block with a performer intake and 600 holley being choked down by 273 manifolds. 3.55 gear too..
 
Last edited:
Newbomb Turk said:
You have some fixed notion that your way of building a “streeter” is the golden ticket. It’s not. It’s your fantasy of what a “streeter” is.

RPM is your friend.
Click to expand...
Thank you for the words of wisdom.
I've had three cams in my engine and can tell you that your notion of rpm being a streeter's utopia is fullofchit.
For every minute of rpm a street engine sees on the rev-limiter, in second gear, it will likely spend many, many hours at under 4000 rpm. and if the Bottom end sucks for lack of cylinder pressure, well, that is your fantasy.
 
abodyjoe said:
that out of a 69 340? my valiant ran 14.2's all day long with a stock 79 360 long block with a performer intake and 600 holley being choked dowm by 273 manifolds. 3.55 gear too..
Click to expand...

That's why I have long advocated for the 360. It got a bad reputation due to being released at the beginning of the smog era and not having a performance option until 1974. I remember conversations in the early 1980s with people degrading the 360 as worthless. I knew they were mistaken...
 
In late summer of 1970, I bought a slightly used Swinger 340/4-speed/3.55s. It was totally stock.
That car, the following summer, on the E70-14 polyglass tires ran a best of 14.4 at 98 mph; spinning those crappy tires thru two gears, at least.
It wasn't the fastest nor the quickest 340 at the track, but I got a trophy that day for being the fastest/quickest in my class.
Back in High School, it was the car to beat on the street, and I feared nothing, at least up to 85 mph, lol.
 
You must log in or register to reply here.
-

Back
Top