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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2445719
02/03/18 05:10 PM
02/03/18 05:10 PM
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Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
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Need more specifics about the combo.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: fast68plymouth]
#2445748
02/03/18 06:06 PM
02/03/18 06:06 PM
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Joined: Apr 2008
Posts: 84
ohio
2264PLY
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OP
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Posts: 84
ohio
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Hedman 1 3/4 primary tube, Holley list 4780 Performer RPM intake 906 heads KB flat top pistons stock dist. with electronic conversion.Currently have 1 Mr Gasket spring in the dist. At idle its at full advance 34 degrees. I'm looking for someone who's had a similar experience and what changes remedied the situation. Certainly welcome thoughts and opinions.
Last edited by 2264PLY; 02/03/18 06:13 PM.
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2445752
02/03/18 06:13 PM
02/03/18 06:13 PM
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Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
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Of you have an adjustable valvetrain, I'd strongly suggest going to a solid cam.
If that's not an option, and you're going to stick with a hyd...... I'd look at taking 20-25deg @.050 out if it.
Something along the lines of a Comp XE274 or XE275HL.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2445766
02/03/18 06:30 PM
02/03/18 06:30 PM
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Joined: Apr 2008
Posts: 84
ohio
2264PLY
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OP
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Joined: Apr 2008
Posts: 84
ohio
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Currently stock rockers. A close friend with similar 440 with a stick difference being rpm heads roller rockers with the XE275HL. I didn't ride in his car but we were talking about it and he expressed the same feelings. I definitely respect his opinion.His car did have a 3.91 gear.His engine was also professionally built. He pulled the engine out of his '71 300 which was an automatic and put it in a "69 B body.He felt the motor definitely worked better in front of the automatic. I was thinking the same way you are about the duration. After talking with him I started to wonder about that. Going to a solid cam makes sense.
Last edited by 2264PLY; 02/03/18 06:33 PM.
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2445807
02/03/18 07:20 PM
02/03/18 07:20 PM
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Joined: Jan 2003
Posts: 25,726
Rio Linda, CA
John_Kunkel
Too Many Posts
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Too Many Posts
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Posts: 25,726
Rio Linda, CA
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IMHO, too much cam and too big of a carb for good throttle response.
If you want really snappy throttle response, a carb with small bores will give it.
The INTERNET, the MISinformation superhighway
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2445857
02/03/18 08:53 PM
02/03/18 08:53 PM
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Joined: Jan 2003
Posts: 8,160
Plymouth, MI
Blusmbl
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master
Joined: Jan 2003
Posts: 8,160
Plymouth, MI
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Could also try advancing the current cam a few degrees if you don't have piston to valve clearance issues.
I ran a Mopar .509 4* advanced in a low compression 440 stick car, even occasionally running it with 2.76's it wasn't objectionably bad.
'18 Ford Raptor, random motorcycles, 1968 Plymouth Fury III - 11.37 @ 118
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2445880
02/03/18 09:44 PM
02/03/18 09:44 PM
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Joined: Oct 2007
Posts: 4,205
New York
polyspheric
master
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master
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Posts: 4,205
New York
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Assuming you want to keep your axle?
Lighter flywheel
3.09:1 1st gear
Boffin Emeritus
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2446074
02/04/18 05:19 AM
02/04/18 05:19 AM
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Joined: Aug 2003
Posts: 43,096
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,096
Bend,OR USA
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There are a bunch of things that can make a motor not accelerate well like to rich at part throttle, valve lifters with not enough preload or to much preload, degreeing the cam off of the exhaust lifter instead of the intake lifter  , not enough advance at low RPM on the ignition timing, to cold on the heat range on the spark plugs and probably some others that aren't coming to mind right now  How tall are your rear tires now? Is your NP 833 a 2.65 low gear set or is it the later 2.2? low gear set  As already suggested using a lower first gear ratio like the stock 3.09 low gear set makes a bunch of difference on the street Been there done that years ago when the early A body trans. where plentiful in our local SO CA junk yards  I put one of those gear sets in a friend of mines 1970 Duster 340 4 speed street race car that ended up with a set of 5.57 rear gears in the Dana 60 , you needed to be on your game on the first three gear changes in that rascal   It flat hooked and book with a set of 13x30x15 drag slicks on a set of 12 inch rims  It showed a bunch of BB Chevy the tail lights on lots of occasions
Last edited by Cab_Burge; 02/04/18 05:26 AM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2446093
02/04/18 10:44 AM
02/04/18 10:44 AM
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Joined: Jan 2003
Posts: 9,982
Frostbitefalls MN (Rocky&Bullw...
gregsdart
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master
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Posts: 9,982
Frostbitefalls MN (Rocky&Bullw...
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Calculate the cranking compression to see how much that cam is hurting you for starters. Best off idle will be helped a great deal by coming up with a combo of cam, compression, and cam installed centerline that will be as high as the fuel you use can take.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: 2264PLY]
#2446099
02/04/18 10:55 AM
02/04/18 10:55 AM
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Joined: Feb 2005
Posts: 4,310
Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,310
Prospect, PA
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What is your cylinder pressure? Get that first so we know what your working with.
My friend's 68 4 speed GTX w/ 3.54 drove like it was on ice in 1st gear. Small cam, fairly low cylinder pressure, good factory heads, factory spreadbore intake and matching carb. Car was a blast on the street. That being said, it really wasn't that fast at the track, so don't confuse the two, as they may or may not be the same thing.
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: Cab_Burge]
#2446373
02/04/18 05:56 PM
02/04/18 05:56 PM
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Joined: Sep 2014
Posts: 4,457
Washington
madscientist
master
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master
Joined: Sep 2014
Posts: 4,457
Washington
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There are a bunch of things that can make a motor not accelerate well like to rich at part throttle, valve lifters with not enough preload or to much preload, degreeing the cam off of the exhaust lifter instead of the intake lifter , not enough advance at low RPM on the ignition timing, to cold on the heat range on the spark plugs and probably some others that aren't coming to mind right now How tall are your rear tires now? Is your NP 833 a 2.65 low gear set or is it the later 2.2? low gear set As already suggested using a lower first gear ratio like the stock 3.09 low gear set makes a bunch of difference on the street Been there done that years ago when the early A body trans. where plentiful in our local SO CA junk yards I put one of those gear sets in a friend of mines 1970 Duster 340 4 speed street race car that ended up with a set of 5.57 rear gears in the Dana 60 , you needed to be on your game on the first three gear changes in that rascal It flat hooked anjd book with a set of 13x30x15 drag slicks on a set of 12 inch rims It showed a bunch of BB Chevy the tail lights on lots of occasions The 70 and later 4 speeds has a 2.44 first.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: madscientist]
#2446385
02/04/18 06:24 PM
02/04/18 06:24 PM
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Joined: Aug 2003
Posts: 43,096
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,096
Bend,OR USA
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The 70 and later 4 speeds has a 2.44 first. [/quote] Not true  Only the T/A and AAR Cuda 4 speed cars had the close ratio stock in 1970, all 1971 and later 4 speed cars had them until Corporate decided to go to the NP833 O.D. trannys in what ever year that was
Last edited by Cab_Burge; 02/04/18 06:24 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Throttle response and Low speed performance in a 440 stick.
[Re: Cab_Burge]
#2446424
02/04/18 07:27 PM
02/04/18 07:27 PM
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Joined: Sep 2014
Posts: 4,457
Washington
madscientist
master
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master
Joined: Sep 2014
Posts: 4,457
Washington
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The 70 and later 4 speeds has a 2.44 first. Not true Only the T/A and AAR Cuda 4 speed cars had the close ratio stock in 1970, all 1971 and later 4 speed cars had them until Corporate decided to go to the NP833 O.D. trannys in what ever year that was [/quote] My point is there never was a 2.2 first gear 833. Ever. Look at what I quoted.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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