Hot Rod 340 builds and dyno test.

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I'm not buying it.
My totally stock 1970 Swinger 340, in 1971,with about 12000 miles on it, went 98 in the qtr, which I think is representative of most all totally stock 340Darts. At 3330 pounds that is 246.66 hp, according to the bulletin book. So either the scales at the track that day lied about me and my car being 3330 or I remember it wrong. I was 130 back then so even if I gross the weight up to 3460, the power comes out to 256.
As an aside,thru 3 gears (3.55s) from 25 to 85mph, that car was one of the fastest cars around,in my town,bar none. ( after 85mph. the BB cars would start to overtake me, and by mid 90s I was getting nervous. By 100, I was occasionally seeing rear bumper. So I made it a point to not race past 90,lol)
If my 340 had made 320; then @3330#, it shoulda gone 108. At 3460 it shoulda gone 106.

HR says that engine was "nearly stock spec"
I call BS, with a capital BS

I say, put that engine in a chassis and run it up the track and see what's what.
They even tell you; put
 
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They even tell you
"With the simple addition of 1 7/8-inch headers, output jumped to 352.1 horsepower at 5,300 rpm and 395.9 lb-ft of torque. In a 3,200-pound A-Body with 3.91 gears and traction, mid-thirteen second e.t.s are guaranteed."
Try and find a vintage track test where a 3200# A-body, plus driver, with a stock 340 and headers went mid 13s.
Besides at 3460 race weight and a street chassis; 13.5 ET is 282 to 320hp....... according to the bulletin book.
With 350hp, it should be closer to 12.9
Here's the point;
My 360 went 12.9@106, with Eddies and a true 10.9Scr and a 223/230/110 @.050 cam, @3650#...... The 106 says 338hp. The 12.9 says 310hp in a SS chassis,or about 343 in a street chassis. So I'm saying my tune was about as good as it gets.
Now compare the two;
360 with 10.9Scr Eddies,TTIs,with full-length dual 3" pipes, the 223/230/110 cam, AG/750DP.
340 unspecified compression,iron heads,210/220/114 cam,Factory intake and carb.
Ima guessing that those full-length dual 3" pipes musta sucked my power way down to; 340 "nearly stock spec" level,lol

Chit; I shouldda never bought them Eddies, nor that POS 223/230 cam, nor the Ag, nor the 750DP, nor all the machining to get the 10.9Scr.
What I shoulda done was, get me one of them "nearly stock spec" HR built 340s, and I wouldda been a couple of thousand dollars richer,
lol
 
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AJ/FormS said:
They even tell you
"With the simple addition of 1 7/8-inch headers, output jumped to 352.1 horsepower at 5,300 rpm and 395.9 lb-ft of torque. In a 3,200-pound A-Body with 3.91 gears and traction, mid-thirteen second e.t.s are guaranteed."
Try and find a vintage track test where a 3200# A-body, plus driver, with a stock 340 and headers went mid 13s.
Besides at 3460 race weight and a street chassis; 13.5 ET is 282 to 320hp....... according to the bulletin book.
With 350hp, it should be closer to 12.9
Here's the point;
My 360 went 12.9@106, with Eddies and a true 10.9Scr and a 223/[email protected] cam @3650#...... The 106 says 338hp. The 12.9 says 310hp in a SS chassis,or about 343 in a street chassis. So I'm saying my tune was about as good as it gets.
Now compare the two;
360 with 10.9Scr Eddies,TTIs,with 3" full-length duals, the 223/230 cam, AG/750DP.
340 unspecified compression,iron heads,201/220 cam,Factory intake and carb.

Chit; I shouldda never bought them Eddies, nor that POS 223/230 cam, nor the Ag, nor the 750DP, nor all the maching to get the 10.9Scr.
What I shoulda done was, get me one of them "nearly stock spec" HR built 340s, and I wouldda been a couple of thousand dollars richer,lol
Click to expand...
Yep! Ya screwed up! LOL The bottom line I think is who really cares about maximum horsepower. If you are class racing then you will pay thousands $$$ for just a dozen ponies. ET racing doesn't care either. but everybody want's a good running engine that can smoke some tires when you want. Add headers if you want more and don't mind the price and what it takes to install. ETC.
 
The article is OK in the sense of what can be done with a well machined 340. You aren't getting there with an OEM machined 340 or parts.

The rockers if a true 1.5 ration will show a bunch more valve than the 1.40-1.43 stock stamped stuff. Not slinging the OEM spring and having beehives help with valvetrain weight.

Looks like a pretty clean throat cut on those heads too...

Lots of little things that add up.

Mid-high 90's was a good mph for a stock 340 A body car back then.
 
I always smirk at "nearly stock" because the list of differences from actual stock makes for more cubic inches and increases efficiency. Just once I would like to see a 318 block bored out to 4.04 and then old used factory 340 parts installed.
 
Yah'no, I used to look at that HR chanel, like those guys were the gods of automotivedom. And they might be, IDK. But by the time we see their stuff in print, a lot of critical information gets left out, and what they do publish is buried in the ink somewhere, and you have to search for the tidbits.
So something,IMO, is going on there that just makes me wanna distrust their results, and sometimes even conclusions. And I'm just Joe-Average, so if I'm getting this vibe, I gotta wonder if I'm losing it.
However, they certainly are an entertaining bunch. If for no other reason, I would continue to watch that show for it's purely comedic value. And I especially like how they appear to all get along well, being respectful one towards another.

BTW
I am in no wise saying they fudge any numbers, or that their dyno does. No, not at all. I just think I sense a disconnect between their data and the real world. Where said disconnect exists, or if it exists, I cannot tell.
But it might be in the statement " nearly stock spec"
 
Well I can only give you actual on track numbers and the specs of my '71 stock 340 Cuda from 1983. Weight 3600lbs+/- a few at the line. Additions from stock were>
Ally dual plane intake, (can't remember which one), 750DP, DC. .484/284 purple, small tube hdrs. Stock springs with clamps on front seg, long shocks and pinion snubber, 3.55's w/8x26 slicks, 3500 verter, used to pick a wheel up...would run consistent to within 1/200ths at 13.31's@101, that = 302.44flyhp w/alternator etc.

Add to that a few yrs on>

Same stock 2.02 heads, Holley Strip Dominator int. 850DP, DC. 590" solid, 1.75" race hdrs, 4200 verter, 4.30's..10x28 g/years and perhaps 50lbs lighter, car went 12.39@108+ as a best and consistent 12.4's = 366hp.
 
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Hot Metal said:
Well I can only give you actual on track numbers and the specs of my '71 stock 340 Cuda from 1983. Weight 3600lbs+/- a few at the line. Additions from stock were>
Ally dual plane intake, (can't remember which one), 750DP, DC. .484/284 purple, small tube hdrs. Stock springs with clamps on front seg, long shocks and pinion snubber, 3.55's w/8x26 slicks, 3500 verter, used to pick a wheel up...would run consistent to within 1/200ths at 13.31's@101, that = 302.44flyhp w/alternator etc.

Add to that a few yrs on>

Same stock 2.02 heads, Holley Strip Dominator int. 850DP, DC. 590" solid, 1.75" race hdrs, 4200 verter, 4.30's..10x28 g/years and perhaps 50lbs lighter, car went 12.39@108+ as a best and consistent 12.4's = 366hp.
Click to expand...

See there ya go; that's what it takes to run mid 13s.
As in not; a 210/220/114 cam, not an AVS 580, not "nearly stock spec"!
A 210/220/114 (I can't say about the brand they used) cam is usually a great torque maker at 10.5Scr, but it's pretty much done by 5000/5200, so honestly how much power can stock iron heads make at those rpms, with a 114 cam. Well with a little bowl work, beehives,roller-tipped rockers, and headers.....apparently...350
 
toolmanmike said:
Yep! Ya screwed up! LOL The bottom line I think is who really cares about maximum horsepower. If you are class racing then you will pay thousands $$$ for just a dozen ponies. ET racing doesn't care either. but everybody want's a good running engine that can smoke some tires when you want. Add headers if you want more and don't mind the price and what it takes to install. ETC.
Click to expand...
I agree. Where were you in 1999,lol, when I needed that sage-ism..
After The 292/508 debacle, I had a rude awakening; lots of power from 5000 to 6500plus, is super great .......when you're speed is such that you're in that zone......which with 3.55s is from 43mph to 55, in first gear.......And 95% of the time I was never there. The problem was getting up to 43 mph. And the 292 cam is not real helpful down there. 3.91s would have brought the numbers to 39 to 51.
So after moving it twice, I realized chasing a horsepower number might not have been one of my better ideas.( Yeah I know it wanted a deeper starter gear, but doing the math, I decided a new smaller cam was a better option for me.)
So then I chased torque instead, with a 223/230/110 @.050 cam. And that combo was by far my favorite for my application. I spent a lot of time and money fitting that gang-busters engine to my driving style, and in the end, I was very sad;
when, one day she dropped 2 lobes.
And enter the current cam; 230/237/110; a reasonable compromise,I thought,
A reasonable amount of torque from right off idle,in a stick-car, makes for a way more fun driver.You don't need BB type torque either, as I found out. Too much just eats rubber. My 230 cam dropped a lot of very-low rpm torque compared to that 223 cam. I know it's only 1 cam-size; but for the longest time I was very disappointed, and spent a lotta time trying to get some of it back. But the boost at the top was also unexpected, as it rivaled the 292/108. So, in the end,IMO, with the 3.09 low gear,it was a good compromise. .......except it sucks gas bigtime.
 
AJ/FormS said:
I'm not buying it.
My totally stock 1970 Swinger 340, in 1971,with about 12000 miles on it, went 98 in the qtr, which I think is representative of most all totally stock 340Darts. At 3330 pounds that is 246.66 hp, according to the bulletin book. So either the scales at the track that day lied about me and my car being 3330 or I remember it wrong. I was 130 back then so even if I gross the weight up to 3460, the power comes out to 256.
As an aside,thru 3 gears (3.55s) from 25 to 85mph, that car was one of the fastest cars around,in my town,bar none. ( after 85mph. the BB cars would start to overtake me, and by mid 90s I was getting nervous. By 100, I was occasionally seeing rear bumper. So I made it a point to not race past 90,lol)
If my 340 had made 320; then @3330#, it shoulda gone 108. At 3460 it shoulda gone 106.

HR says that engine was "nearly stock spec"
I call BS, with a capital BS

I say, put that engine in a chassis and run it up the track and see what's what.
They even tell you; put
Click to expand...

They were measuring flywheel hp in that article, and you're calculating wheel hp which is lower because of drivetrain losses.
 
toolmanmike said:
Yep! Ya screwed up! LOL The bottom line I think is who really cares about maximum horsepower. If you are class racing then you will pay thousands $$$ for just a dozen ponies. ET racing doesn't care either. but everybody want's a good running engine that can smoke some tires when you want. Add headers if you want more and don't mind the price and what it takes to install. ETC.
Click to expand...

Well yes I guess so, but my Cuda in the early days with the .484 cam spec I posted up would just bring the front way up and take off when I went on it, and thats with crappy true bias street tyres. Thats what I thought was cool with that car, not laying rubber, it would do that with the L/lock easy, I think it had std worn front shocks on it, and it was much the same with the now limited street driving with the upgraded solid cam and 4.30's, that was evil on the street!!
 
Nice build to prove what you can get from a stock build and what headers could do to add power, but the issues I have with articles like this is, they are comparing their modern dyno to however Chrysler rated them. Secondly the engine was built by a performance shop, not a mass production line where corners are cut, tolerances are loosy goosy, and folks just did their shift.

To make this a honest comparison to other makes, they should spec build the 350 Olds, 350 Poncho, 351 Winsdor and Cleveland, 343 AMC, and 350 Chebby and run them on the same dyno.
 
BS on the what it takes to run 13's

Dart 3250# 340 214/224 cam, stock heads, ld340, 750VS, headers, 3.91's 13.30 at 103

I know another car that has the same cam with ported J heads on a 360... 11.80 at 114

Demon 360 3300# with XE268H, ld340, 750DP, Headers, 2800 converter... 12.75 109 3.23 gears and a 26" tall tire. :)

The biggest tell is the MPH. ET is too dependent on chassis/converter/gear. If your car runs 13.50 with a 112 trap, you have a chassis issue. The MPH shows whether the engine is making power, it's that simple.
 
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crackedback said:
Dart 3250# 340 214/224 cam, stock heads, ld340, 750VS, headers, 3.91's 13.30 at 103
Click to expand...

And that mph/weight computes to 284flyhp, which again is nowhere near as suggested by that article. Mph does show the hp/weight however it needs to be in synch with the ET as well to show a more accurate hp output. That car@284hp/3250 should be in the 13.13's, get that to ET there and then see if he still pulls 103, would probably lose 1mph which would still make a close hp no.
The issue here for working out hp/weight/mph is when you get a car that really does 60ft like a stocker, an example of that is of a legal A/SAA stocker we have here that runs 9.96@130mph, that normally would be 134>5 for an average brkt car, hp/weight calcs goes out the window there, 9.96 would be 710fhp and the 130mph is just 624fhp against the weight.
 
AJ/FormS said:
I don't think the bulletin book ever heard of anything but flywheel hp.
Click to expand...

Ok?

All I said was you're comparing your hp as calculated from drag strip times (which gives you rear wheel hp, after drivetrain losses) with their flywheel dyno hp (which doesn't and will be higher).

Bulletin book is using physics to calculate actual wheel hp...you get similar results using the Wallace calculator:

ET-MPH-HP Calculator
 
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451Cuda said:
Ok?

All I said was you're comparing your hp as calculated from drag strip times (which gives you rear wheel hp, after drivetrain losses) with their flywheel dyno hp (which doesn't and will be higher).

Bulletin book is using physics to calculate actual wheel hp...you get similar results using the Wallace calculator:

ET-MPH-HP Calculator
Click to expand...
I get what you're saying,
But in the Bulletin book, it is no where stated that these numbers were related to RWHP. And since the charts have been around since the 60s, I assumed they were flywheel. And since the numbers have, for me, always correlated to flywheel hp, that's what I assumed they had to be. Further,if those charts are RWHP, there would be no way to predict your mph using those charts,and using your engine dyno results, (unless you fudged the powertrain loss, with a pick-it-from-a-hat factor), so they would be kindof useless, for anyone wishing to hit a specific mark.
If you're right, then I've been wrong for a lotta years.
On the bright side my engine just gained about 75 hp.
 
AJ/FormS said:
I get what you're saying,
But in the Bulletin book, it is no where stated that these numbers were related to RWHP. And since the charts have been around since the 60s, I assumed they were flywheel. And since the numbers have, for me, always correlated to flywheel hp, that's what I assumed they had to be. Further,if those charts are RWHP, there would be no way to predict your mph using those charts,and using your engine dyno results, (unless you fudged the powertrain loss, with a pick-it-from-a-hat factor), so they would be kindof useless, for anyone wishing to hit a specific mark.
If you're right, then I've been wrong for a lotta years.
On the bright side my engine just gained about 75 hp.
Click to expand...

Your right on that aj, all manufacturers engine ratings are at the flywheel. Why would a manufacturer publish rwhp? Doesnt make sense, they want the person buying it to hear the larger power number. You think chrysler would of sold a bunch if they said it only made 250 hp to the wheels lol no, when they say hp or torque they always give you engine flywheel specs because that is the largest number they can use to advertise
 
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DFX 340 Duster said:
I always smirk at "nearly stock" because the list of differences from actual stock makes for more cubic inches and increases efficiency. Just once I would like to see a 318 block bored out to 4.04 and then old used factory 340 parts installed.
Click to expand...
Did something lile that, well...kinda more my own version.

318 bored 4.040
Kb243 pistons
.024 above deck
273 Closed chambered heads 1.88/1.50
Cfm 220 int/160 exh flow roughly
Chambers blended and valves unshrouded.
9.6 comp.
.470 lift 262adv 110
Ootb Performer w/600 Holley
Doug's headers

305 hp @5200
380 peak tq
 
MOPAROFFICIAL said:
Did something lile that, well...kinda more my own version.

318 bored 4.040
Kb243 pistons
.024 above deck
273 Closed chambered heads 1.88/1.50
Cfm 220 int/160 exh flow roughly
Chambers blended and valves unshrouded.
9.6 comp.
.470 lift 262adv 110
Ootb Performer w/600 Holley
Doug's headers

305 hp @5200
380 peak tq
Click to expand...
That's a nice combo there.
 
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