Author Topic: More Torque?  (Read 1233 times)

Offline challenger72rt

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More Torque?
« on: June 13, 2006 - 02:33:34 PM »
ok, the torque for a stock 440 was 480 Lb/ft.  Is it possile to get in the neighbourhood of 650 out of a 440, and still be streetable?  If so, what are some mod's that would improve torque?

I plan on having the Chally dyno'd at some point, cuz I am curious as to how much of a difference all of the mod's have made.

When the motor was built, the following was done..

bored 0.060"
10.5:1 pistons (forged/forged rods)
performance Purple Shaft cam
balanced crank (forged)
heads ported and polished, 3-angle valve job
MP Performance dual-plane intake
750 Holley with larger jets
Coyote headers
3" exhaust w' H-pipe


does anybody have any opinions as to what kinda power the motor might be putting out? Also, what else could I possibly do to it to get even more power, and still keep it on the street??

It runs a 4-core rad with a 4-blade fan and an electrical fan on a toggle, but the temp is consistent within 180-190 degrees (optimum performance temp) and it's already a 727 with a Fireball rebuild kit, and 3.91:1 8.75 sure-grip rear.  The whole car is 3,260Lbs.  I already have to run 100 Octane Av Gas.  I'd hate to have to get racing fuel just to get to the corner store!! 

So  A) what would my ballpark power #'s be, and B) what to do to get even MORE power??


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Offline Chryco Psycho

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Re: More Torque?
« Reply #1 on: June 13, 2006 - 05:11:47 PM »
torque & hp ar4e different ways of measuring power so increasing hp will increase torque cam design , stroking ,rod ratio all affect power
 I will not guess on power , too many varibles , first would be exactly what Mopar cam is used
 the biggest error I can see in the package you have is that you are under carbed by at least 150 CFM possibly as much as 300 cfm

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Offline challenger72rt

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Re: More Torque?
« Reply #2 on: June 13, 2006 - 09:16:12 PM »
Under-carbed!  really??  my goodness, I had no idea.  My mechanic who built the motor put on the 750, I just assumed it was the best choice.  Hmmm...something to consider, fer sher!
"Once upon a time I had a really bad Monday"

Offline wart1de

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Re: More Torque?
« Reply #3 on: June 13, 2006 - 09:29:38 PM »
Do you know what cfm your heads flow after being ported?
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Offline chevyconvert

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Re: More Torque?
« Reply #4 on: June 13, 2006 - 11:58:26 PM »
440-6 had 1350 cfm total @ wot for comparison... :2cents:
Eric
'70 Hemi Orange RT/SE 440 Six Pack Pistol-Grip 4 speed
Bay Area California

Offline challenger72rt

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Re: More Torque?
« Reply #5 on: June 14, 2006 - 07:02:44 AM »
no, I don't know, unfortunately.  I'm not even sure of total compression.  I know it's high enuff that I can't use 94 Octane without a really good octane booster, or the car won't run for crap!
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Offline Chryco Psycho

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Re: More Torque?
« Reply #6 on: June 14, 2006 - 08:24:02 AM »
virtually any 440 needs 850 cfm , more with ported heads & I have often seen gains of 40 hp going from an 850 to a 1050

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Offline challenger72rt

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Re: More Torque?
« Reply #7 on: June 14, 2006 - 09:55:46 AM »
Greeeeeeaaaaattt!!!  MORE money I don't have!  ;)

Guess I'll have to start savin' my empties!
"Once upon a time I had a really bad Monday"

Offline moper

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Re: More Torque?
« Reply #8 on: June 15, 2006 - 06:06:31 AM »
Did you expect to get 170 pound feet for free? Much more important than "how much" is "when". A 440 I tossed together 3 years ago is pump gas (no avgas :puke:), idles at 800rpm, and makes peak torque of 550 pound feet at 3500 rpm. HP is just shy of 450 at 5200 with a Crane hydraulic cam, the iron factory 6bbl, and the "terrible" 516 iron heads. It's enough to make the car ('71 440+6 iron sixpac, 4sp, 3.54 Dana) hard to drive on radial tires thru 3rd gear, and runs 106 in the 1/4 mile (car is 4200lbs w/driver). 

The fastest way to get huge torque low down, is to add stroke length to the crank. The MP cam you have can be replaced with something much better. The carb is ok for a street car, and even a mild race car if the RPMs are limited to below 5500, but I'm sure you could get better performance with a slightly larger one, and learning to tune a Holley well. Dominators are not street carbs, and shouldnt even be dreamed about unless you own a chassis dyno with a wide band O2 sensor...lol. You didnt mention ignition, but I'm sure if it runs "forged 10.5:1" pistons, your ignition curve is not right if it pings with factory heads. Also, the factory sixpacs are really about 980cfm. 2bbls are not flowed the same way as a 4bbl is. To compare apples to apples, you would need to flow them using the same tests... Also, Demons and Avenger carbs are wet flowed, and that represents a truer reading of the airflow capacity than the Edelbrock and 4150/3310 old school holleys that were dry flowed to get the figures. A 3310 "750cfm" vaccum sec Holley really maxes out at about 690cfm when wet flowed. The Street Avenger Holley vaccum sec 680cfm carb is just shy of that (true to the advertised rating) when wet flowed. The liquid displaces air in the resulting measurement. I'd say you have some tuning to do, then you can really say if it's not good enough for your tastes. And tuning is fairly cheap in monetary use.