what gives you torque? (advice for a dummie)

[CB]

When driving my 69 I really enjoy the car.
Only if I could get the 275's spinning when I floor it
It has  a stock (but tired) 383  and no H or X exhaust.

What do you guys suggest to do first?
thanks

[andy74]

CUBIC INCHES MY MAN!

[Chryco Psycho]

there are a lot of factors , often just installing a looser torque converter will make all the difference by allowing the engine up into its powerband before loading the engine 

[Duey]

When driving my 69 I really enjoy the car.
Only if I could get the 275's spinning when I floor it
It has   a stock (but tired) 383   and no H or X exhaust.

What do you suggest to do first?
thanks

Technically, torque is produced by internal combustion pressures acting on the upper surface of the piston...the more pressure, the greater force on the piston that gets translated from linear force in the cylinder bore to rotational force at the crank.

Like Chryco said, you likely have a stock converter 1800-2200-ish that is not letting the engine quickly get to its peak (or at least higher) torque RPM before hooking up.

Remember, a 383 is only 13% less displacement than a 440 and its internals let it wind up faster.  If anything, a low-deck B motor would do well with a slightly higher stall converter than an RB motor, all other things being equal.  (That's the engineer in me talking, not the huge amount of experience that Neil has...  )

Cheers,
Duey

[firefighter3931]

The length of the stroke is the biggest difference betwen a 383 and a 440 aside from the obvious cubic inch discrepency. Shorter stroke motors won't make as much torque as a longer stroke engine. As mentioned above, a looser converter will flash higher when you hammer the throttle and get the engine into it's powerband quicker....which makes the car feel faster.

Ron

[CB]

so replacing the converter will give that extra punch.
With the old glasspacks I don't think they give to much restriction.
What about new cam/intake?

[gsmopar]

How much are you wanting to spend?  I think that might give us a better scope for our suggestions.  Glass packs may appear free flowing, but you'll find some improvments if upgrade to a dynomax or magnaflow (even flowmasters are better than glasspacks).  For a weekend warrior street/strip setup, I'm a big fan of the old .509 purpleshaft with a good carb and intake.  If you have a little more cash the EB heads are an easy install and would really wake up any big block.  What rear gear are you running?

Later,

Greg

[morepower]

intake, carburetor, camshaft, headers and complte exhaust system with less restrictive mufflers and an x pipe for scavening would really wake up that 383 if all properly matched..article in MM a few years ago...113hp with jus replacing those things....And gears...3.55-3.91 for street use

[firefighter3931]

What do you suggest to do first?

Before i did anything to that motor it would be checked out for compression and leakdown. There's no point in throwing bolt ons onto a tired motor. 

Ron

[Ghoste]

And then you need to formulate a realistic plan and budget accordingly.  If all you want to do is spin the tires there are probably cheap ways to make the suspension unload itself (although they aren't very safe) and you can have all sorts of tire chirping fun.  But, if you want to go fast, you need a plan.

[Chryco Psycho]

if you are thinking of changing the cam you need to match the cam & converter to work together... so we need to pick a cam first & match a converter

[CB]

Before i did anything to that motor it would be checked out for compression and leakdown. There's no point in throwing bolt ons onto a tired motor. 
Ron

I think Ron has right, to check if the engine is still healthy before poring $ into it.
What are the right values to look for?

It isn't just chirping the tires I want but a car that pulls the bricks out a split second after you take off. Speed isn't really important.

If I start looking for a cam, what is recommendable?

thanks!

[Ghoste]

Ha, ha.  That's it, you're hooked!  Get out the wallet now baby cuz the fun is just beginning.
In all seriousness though, I've read some great tuning advice from the guys on this site.  Moparts may have the reputation but some of those guys don't like to give up too much.  It seems like some people that hang out here don't care how many secrets they give away.

[firefighter3931]

  It seems like some people that hang out here don't care how many secrets they give away.

Life's too short to worry about keeping secrets, inmo.   I've had some good teachers in the past and figured stuff out on my own as well. If i can help someone avoid making the same mistakes i've made then sharing that knowledge is well worth it.   I'd much rather see someone out enjoying their ride than have it sitting in a garage out of frustration.   I agree with Ghoste, there is a wealth of knowledge on this board and a willingness to share. I have learned lots from other members on this site and value that information....knowledge is power. I like reading threads and thinking : "Cool, i didn't know that" then filing it away in my pea brain, lmao.

Back to CB's question: Do a quick diagnostic check and post the compression #'s as well as the current list of parts on the car, transmission, stall converter, rear end gearing etc... and we'll help sort it out.

Ron

[Runner]

i always find the saying "it revs faster" an interesting statment. i dont understand how a motor that makes less torque and less horse power can "rev faster".    for example im sure a honda will rev faster than my 452 if we are free reving the engines.......   however it just isnt going to happen when the same load is applied to each engine.  the one that makes the most torque is going to "rev faster" simply becasue it can get the load rotating faster. i think the only real time this applies is when both engine are close in cubic inches.    then the one with the lighter rotoating assembly has that much less load that it has to get moving .    now i might be wrong and feel free to correct me if i am, but ive heard that thrown around alot.

  any time you add stroke to a motor, your basically adding leverage.  and if you had a bigger bore you get more force being applied to that leverage. i wont argue what is better a big bore short stroke motor , or a long stroke small bore motor becasue i dont know.  the 440 has a bigger bore than a 383 ( force) and more stroke (leverage).

        i love 383s, i think they are the red headed step child of mopar engines.  no one gives them any repsect and they did most of the meat and potatos work in the muscle car wars for us, but to get that short stoke motor to bake tire its going to need the right combonation of parts (gears and converter).

[RD]

in that case runner, the proper terminology should be:

"it is easier to rev the 383 faster due to the shortened stroke and lighter internals if all other things are equal between that motor and a 440".

its just the gearheads way of saying it in a shorter phrase, i knew what he meant without him having to say the entire lung squeezing sentence.

[Runner]

in that case runner, the proper terminology should be:

"it is easier to rev the 383 faster due to the shortened stroke and lighter internals if all other things are equal between that motor and a 440".

its just the gearheads way of saying it in a shorter phrase, i knew what he meant without him having to say the entire lung squeezing sentence.

     not with the load of the drive train on them, the 440 will rev quicker than the 383. the motor that makes more power revs faster.     (assuming both engines are put together simular)

     ive had /have decent running 383s (12.49@109MPH)

    

[bull]

As firefighter pointed out, torque is directly related to length or distance of stroke. This is why a diesel engine can have a low horsepower rating but still pull stumps out of the ground as easily as you can take the lid off a new pickle jar. However, if you read the definitions for torque and horsepower they are almost identical because the two are directly related.

But yea, if an engine is tired, it's tired. You need to be sure you have a strong and healthy base before you add on a bunch of performance stuff or it will end up looking like Charlie Brown's Christmas tree.

[bull]

i always find the saying "it revs faster" an interesting statment. i dont understand how a motor that makes less torque and less horse power can "rev faster".    for example im sure a honda will rev faster than my 452 if we are free reving the engines.......   however it just isnt going to happen when the same load is applied to each engine.  the one that makes the most torque is going to "rev faster" simply becasue it can get the load rotating faster. i think the only real time this applies is when both engine are close in cubic inches.    then the one with the lighter rotoating assembly has that much less load that it has to get moving .    now i might be wrong and feel free to correct me if i am, but ive heard that thrown around alot.

  any time you add stroke to a motor, your basically adding leverage.  and if you had a bigger bore you get more force being applied to that leverage. i wont argue what is better a big bore short stroke motor , or a long stroke small bore motor becasue i dont know.  the 440 has a bigger bore than a 383 ( force) and more stroke (leverage).

        i love 383s, i think they are the red headed step child of mopar engines.  no one gives them any repsect and they did most of the meat and potatos work in the muscle car wars for us, but to get that short stoke motor to bake tire its going to need the right combonation of parts (gears and converter).

FWIW, I don't think 383s are the red-headed step child, simply because they've been around a long time and proven themselves worthy on many fronts. That's funny because I've always considered the 400 and 360 to be the low-compression-red-headed-Johnny-come-latelys and have little respect for them, but it's just personal opinion. Lots of people swear by them, but I've always been a big 383 fan.

Anyway, the HP vs. torque discussions rely heavily on the use and application. For instance, take one of these high revving, high horsepower Indy cars and hook it up to a fifth wheel horse trailer full of cows. Now step on the throttle and see how far up a 6% grade you get before the engine implodes or you melt the tires off. Obviously the opposite illustration works for a Cummins turbo diesel on the circle track at Indy but diesel engines rely on torque (as in stroke) and gearing more than horsepower to do their assigned work. Today's performance horsepower ratings have more to do with light loads and higher RPMs. New ricer cars are fast because they rev fast and carry light loads. The faster the engine spins the faster the torque converter, transmission, axles and wheels spin and the faster the car goes. But put eight 250-lb. guys guys in an Acura and eight 250-lb. guys in a turbo diesel Dodge pickup and see who gets to the top of that 6% hill faster. Our old Chargers are fast because they nicely combine torque, horsepower and RPMs, and therefore work well in a wider range of applications compared to the smaller, high RPM cars, even though the horsepower ratings might be similar. In other words you really can hook a loaded horse trailer to a Charger and pull a hill. A large cube engine with a long stroke can actually do some practical work compared to a small, high-revving four banger with a short stroke. That's why I have a bit of a problem with the way car companies come up with modern hp ratings. Car companies rate their little engines at high horsepower based on a formula that states the speed at which their engine can supposedly move a certain number of lbs. a certain number of feet in a certain length of time. The original hp formula created by James Watt states that one horse can do 33,000 foot-pounds of work every minute. When creating a hp standard he said a horse can pull 330 pounds 100 feet in a minute, or 33,000 foot-pounds per minute. However, car companies are basically fudging the hp ratings because small engines can rev higher and therefore increase the resulting horsepower based on that formula without actually doing any real work. Even though the hp ratings are technically true by formula, they are using the speed portion of that equation to their advertising advantage, even though the car is worthless for anything but moving light loads from point A to point B quickly.

[RD]

FWIW, I don't think 383s are the red-headed step child, simply because they've been around a long time and proven themselves worthy on many fronts. That's funny because I've always considered the 400 and 360 to be the low-compression-red-headed-Johnny-come-latelys and have little respect for them, but it's just personal opinion. Lots of people swear by them, but I've always been a big 383 fan.

Anyway, the HP vs. torque discussions rely heavily on the use and application. For instance, take one of these high revving, high horsepower Indy cars and hook it up to a fifth wheel horse trailer full of cows. Now step on the throttle and see how far up a 6% grade you get before the engine implodes or you melt the tires off. Obviously the opposite illustration works for a Cummins turbo diesel on the circle track at Indy but diesel engines rely on torque (as in stroke) and gearing more than horsepower to do their assigned work. Today's performance horsepower ratings have more to do with light loads and higher RPMs. New ricer cars are fast because they rev fast and carry light loads. The faster the engine spins the faster the torque converter, transmission, axles and wheels spin and the faster the car goes. But put eight 250-lb. guys guys in an Acura and eight 250-lb. guys in a turbo diesel Dodge pickup and see who gets to the top of that 6% hill faster. Our old Chargers are fast because they nicely combine torque, horsepower and RPMs, and therefore work well in a wider range of applications compared to the smaller, high RPM cars, even though the horsepower ratings might be similar. In other words you really can hook a loaded horse trailer to a Charger and pull a hill. A large cube engine with a long stroke can actually do some practical work compared to a small, high-revving four banger with a short stroke. That's why I have a bit of a problem with the way car companies come up with modern hp ratings. Car companies rate their little engines at high horsepower based on a formula that states the speed at which their engine can supposedly move a certain number of lbs. a certain number of feet in a certain length of time. The original hp formula created by James Watt states that one horse can do 33,000 foot-pounds of work every minute. When creating a hp standard he said a horse can pull 330 pounds 100 feet in a minute, or 33,000 foot-pounds per minute. However, car companies are basically fudging the hp ratings because small engines can rev higher and therefore increase the resulting horsepower based on that formula without actually doing any real work. Even though the hp ratings are technically true by formula, they are using the speed portion of that equation to their advertising advantage, even though the car is worthless for anything but moving light loads from point A to point B quickly.

yeah what he said.        j/k bull

[Runner]

acually the reason diesel engines have a lot of torque compared to thier hp ratings is because hp ratings is simply a formula calcualted from the dynos measured amount of torque. horse power numbers and torque numbers ALWAYS are the same at 5250 rpm.    if you could spin a b cummins to 5250, the hp and torque would be the same.  theres other things s well, like the fuel they use, the compresion ratio ect.

    as far as a engine  "reving faster" a 383 compared to a 440 is just a bad comparison. because the 440 will simply make more power if both engines are biult right. the comparison started coming around  when people started stroking 400's.  a 450 stroker ends up with a lighter rotating assembly than the 446-448 (.030-.040 overbore 440) due to the fact that the 446 has has a talled deck at 10.72 inches were as the 383-400 deck is 9.98 inches .    that means that you have to have either 3/4 inch more rod or a talled piston, all of witch are recipicating weight, and that makes your bob weight way more on the tall deck.   


   a great comparison for this would be the new 431 strocker motors everyone is starting to biuld.    the 431 will have a lighter bob weight than a 426 wedge thats bored .030 over (also a 431) . both engines will be 4.28 bore and both will be 3.75 stroke. one is in a 10.72 deck motor (rb) and the other is in a 9.98 deck motor.

     parts selection is also a big factor, big old trw forged pistons are ALOT heavier than the moden pistons of today( diamond, ross ect)

   i say a 440 with the same parts will always rev faster than a 383.

[bull]

Hey Runner, did you get my last pm about Joseph?

[Silver R/T]

converter, better heads  (ported), cam, build up trans with shift kit.

[Ghoste]

Is it inaccurate to say that torque measures the amount of work and hp measures the rate at which that work is performed?

[Duey]

Is it inaccurate to say that torque measures the amount of work and hp measures the rate at which that work is performed?

Nope, Ghoste...you're bang on....that's exactly what they are. 

Work is defined as: force applied in the direction of motion times the distance travelled ( F x d ) (d - distance in the case is torque is actually theta - angular (vice linear) displacement)


Power is defined as: the rate at which work is done - force times distance divided by unit time ( F x d / t)


This had been part of the great HP v. Torque debate...one (torque) leads to the other (power) being capable of being developed and expended.  Note that if you don't have enough physical force in the system to counter the opposing force (inertial of a big car, for instance) you can't even get moving to then have the force-distance product evaluated over time (i.e.  without torque, no power can be produced.)

So, torque is what gets you moving, and must continue to be made as the vehicle accelerates.  I know some may pick away at this, but mathematically, all lots of HP means is that your engine is still capable of producing torque as the RPMs increase...this is a good thing since it is the ongoing application of force (torque) that is what accelerates a mass (remember F=ma, or rearranged, a = F/m? )

Cheers,
Duey

[firefighter3931]

Nice explanation Duey !   While the stroke and rod ratio have an impact on torque production....the heads and cam also have a large role as well. The factory heads can become a limiting factor due to the (small) cross sectional area within the port and it's subsequent volume. A stock iron head is actually quite small, comparatively speaking, for a 440ci engine. That is why the oem cam profiles are all specced out on wide LSA's...to flatten out and widen the powerband. Throw a bigger head on the same motor and you can extend the powerband and increase the horsepower.

Stock 440's made peak hp at 4700 rpm. Designing an engine package to pull hard to 6k will make more power (hp) and keep the tq #'s intact. It's all in the combination.  

Ron