Big Block Max RPM
#2700333
09/24/19 06:47 AM
09/24/19 06:47 AM
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Joined: Dec 2018
Posts: 76 MASSACHUSETTS
Chip
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OP
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Joined: Dec 2018
Posts: 76
MASSACHUSETTS
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First race weekend eva at 58 years old in my 1970 Barracuda with a 440 stroked to 500-inch...check mark in the bucket list Ran a best 10.72 but was letting up...testing, newbe, and car was hitting the rev limit. I had a 7000 module limit in my MSD 7AL-3. Car weighs 3150 with me in it, has a 430 Dana rear, 3 speed 727, 31x15 big tire...i know there is more in it. Max torque 653 @ 5500-rpm and max hp 766 @ 6600rpm How high to you guys rev your big blocks?
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Re: Big Block Max RPM
[Re: Chip]
#2700349
09/24/19 07:53 AM
09/24/19 07:53 AM
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Joined: Aug 2003
Posts: 4,679 On the parachute mount
n20mstr
master
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master
Joined: Aug 2003
Posts: 4,679
On the parachute mount
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First race weekend eva at 58 years old in my 1970 Barracuda with a 440 stroked to 500-inch...check mark in the bucket list Ran a best 10.72 but was letting up...testing, newbe, and car was hitting the rev limit. I had a 7000 module limit in my MSD 7AL-3. Car weighs 3150 with me in it, has a 430 Dana rear, 3 speed 727, 31x15 big tire...i know there is more in it. Max torque 653 @ 5500-rpm and max hp 766 @ 6600rpm How high to you guys rev your big blocks? It really depends on what head is on your engine. However, if you made 766 @ 6600, id bet shifting at 6800-7000 and going thru the stripe at 7000 would work well. You may want to re think your gearing. 3.70? might work better. Any case if you made your most power at 6600, going much past it is not going to help, even if the engine has light weight components that can rpm higher.(steel or alum rod)
....BAD A$$ STREET CAR.....
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Re: Big Block Max RPM
[Re: n20mstr]
#2700357
09/24/19 08:20 AM
09/24/19 08:20 AM
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Joined: Jan 2003
Posts: 13,365 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
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First race weekend eva at 58 years old in my 1970 Barracuda with a 440 stroked to 500-inch...check mark in the bucket list Ran a best 10.72 but was letting up...testing, newbe, and car was hitting the rev limit. I had a 7000 module limit in my MSD 7AL-3. Car weighs 3150 with me in it, has a 430 Dana rear, 3 speed 727, 31x15 big tire...i know there is more in it. Max torque 653 @ 5500-rpm and max hp 766 @ 6600rpm How high to you guys rev your big blocks? It really depends on what head is on your engine. However, if you made 766 @ 6600, id bet shifting at 6800-7000 and going thru the stripe at 7000 would work well. You may want to re think your gearing. 3.70? might work better. Any case if you made your most power at 6600, going much past it is not going to help, even if the engine has light weight components that can rpm higher.(steel or alum rod)
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: Big Block Max RPM
[Re: an8sec70cuda]
#2700375
09/24/19 09:11 AM
09/24/19 09:11 AM
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Joined: Jan 2003
Posts: 14,499 So. Burlington, Vt.
fast68plymouth
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So. Burlington, Vt.
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766hp@3150lbs....... Assuming a 10-12% loss for atmospheric conditions and parasitic losses....... 675-690hp. Should be good for about 140-141mph. Assuming the typical 10% converter slip, 4.10’s would put you in the 7000rpm range.
That isn’t a problem as long as the valvetrain is set up for that, along with the oil system.
4.30’s seems like it would be a bit too much gear if everything is working as it should.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Big Block Max RPM
[Re: fast68plymouth]
#2700400
09/24/19 10:28 AM
09/24/19 10:28 AM
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Joined: Feb 2004
Posts: 34,909 S.E. South Dakota !
bigdad
Still Posting A Lot
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Still Posting A Lot
Joined: Feb 2004
Posts: 34,909
S.E. South Dakota !
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My 470
I shift it at 6500 , runs thu the lights at 6500
tires are 14x31 Goodyears, gears at 4.30's
last weekend , it did nice wheelstand , short time was 1.38 4 -- ran 10.49 @ 124.8
me in car it weighs 3280 full of fuel
The lips of fools bring them strife, and their mouths invite a beating.Proverbs 18:6
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Re: Big Block Max RPM
[Re: bigdad]
#2700408
09/24/19 10:51 AM
09/24/19 10:51 AM
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Joined: Jan 2003
Posts: 10,027 MN
JERICOGTX
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I Live Here
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I think you need a new convertor. should not be going through the traps at that high of RPM, with those gears.
69 GTX
68 Road Runner
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Re: Big Block Max RPM
[Re: JERICOGTX]
#2700410
09/24/19 10:52 AM
09/24/19 10:52 AM
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Joined: Feb 2004
Posts: 34,909 S.E. South Dakota !
bigdad
Still Posting A Lot
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Still Posting A Lot
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S.E. South Dakota !
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those tires roll out at 97 inches, they are short ..going to put taller ones on next year
The lips of fools bring them strife, and their mouths invite a beating.Proverbs 18:6
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Re: Big Block Max RPM
[Re: Chip]
#2700414
09/24/19 11:07 AM
09/24/19 11:07 AM
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Joined: Feb 2005
Posts: 20,174 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,174
PA.
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First race weekend eva at 58 years old in my 1970 Barracuda with a 440 stroked to 500-inch...check mark in the bucket list Ran a best 10.72 but was letting up...testing, newbe, and car was hitting the rev limit. I had a 7000 module limit in my MSD 7AL-3. Car weighs 3150 with me in it, has a 430 Dana rear, 3 speed 727, 31x15 big tire...i know there is more in it. Max torque 653 @ 5500-rpm and max hp 766 @ 6600rpm How high to you guys rev your big blocks? What was your mph on the 10.72 pass What was the 60 foot and 1/8 mile times.
Last edited by pittsburghracer; 09/24/19 11:08 AM.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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Re: Big Block Max RPM
[Re: DusterKid]
#2700461
09/24/19 01:17 PM
09/24/19 01:17 PM
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Joined: Aug 2003
Posts: 4,679 On the parachute mount
n20mstr
master
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master
Joined: Aug 2003
Posts: 4,679
On the parachute mount
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I would be calling Ultimate, or PTC, or ATI, or some other reputable converter company with your dyno info and other car information to get the "correct" converter for your application.
....BAD A$$ STREET CAR.....
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Re: Big Block Max RPM
[Re: Chip]
#2700467
09/24/19 01:46 PM
09/24/19 01:46 PM
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Joined: Aug 2003
Posts: 4,679 On the parachute mount
n20mstr
master
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master
Joined: Aug 2003
Posts: 4,679
On the parachute mount
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just an idea, is the trans full?? and what pan is on it?
you could also put some hyd fluid in it, but that's just a bandaid
Last edited by n20mstr; 09/24/19 01:47 PM.
....BAD A$$ STREET CAR.....
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Re: Big Block Max RPM
[Re: Chip]
#2700514
09/24/19 04:34 PM
09/24/19 04:34 PM
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Joined: Jan 2003
Posts: 31,041 Oregon
AndyF
I Win
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I Win
Joined: Jan 2003
Posts: 31,041
Oregon
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Indy 440-1 Heads Ported at Brandywine with 750 lift roller cam 1.5 ratio T&D rockers With -1 heads and a solid roller cam you might still be making power at 7000 rpm. Usually the power is dropping by 7000 rpm with those heads and 500 cubes but it all depends on compression, cam, intake and headers. If you have a good intake (ported by someone who knows what they are doing) the power will carry a little further. Most Mopar guys run cast intakes right out of the box which kills off some of the top end power. You'll have to drive the car for awhile to see if those 4.30 gears are what you want. From what I've seen, the 4.10 gears tend to work pretty good with a 500 inch engine but it depends on where the power curve ends up.
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Re: Big Block Max RPM
[Re: Chip]
#2700522
09/24/19 04:56 PM
09/24/19 04:56 PM
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Joined: Feb 2005
Posts: 20,174 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,174
PA.
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R/T .117
60 ft 1.539
330' at 4.274
1/8 at 6.658 at 103.35 MPH
1/4 at 10.723 at 109.48 MPH (but i was letting off)... My dial in was 10.75
Probably need a tighter converter... Well let’s just say you aren’t anywhere near 766 horsepower on that pass especially at an East coast track. Heck my sons heavier (3200) pounds stock crank Edelbrock headed 360 is quicker than that and he’s no where near that horsepower
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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Re: Big Block Max RPM
[Re: AndyF]
#2700568
09/24/19 07:31 PM
09/24/19 07:31 PM
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Joined: Dec 2018
Posts: 76 MASSACHUSETTS
Chip
OP
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OP
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Joined: Dec 2018
Posts: 76
MASSACHUSETTS
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Indy 440-1 Heads Ported at Brandywine with 750 lift roller cam 1.5 ratio T&D rockers With -1 heads and a solid roller cam you might still be making power at 7000 rpm. Usually the power is dropping by 7000 rpm with those heads and 500 cubes but it all depends on compression, cam, intake and headers. If you have a good intake (ported by someone who knows what they are doing) the power will carry a little further. Most Mopar guys run cast intakes right out of the box which kills off some of the top end power. You'll have to drive the car for awhile to see if those 4.30 gears are what you want. From what I've seen, the 4.10 gears tend to work pretty good with a 500 inch engine but it depends on where the power curve ends up. Indy intake with a 2-inch merge spacer. Dominator 4500, 1050 cfm, Carb tune by BLP...TTI headers... 410 gears may be best. Thanks, Chip
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Re: Big Block Max RPM
[Re: Chip]
#2700614
09/24/19 10:09 PM
09/24/19 10:09 PM
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Joined: Jan 2003
Posts: 14,499 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,499
So. Burlington, Vt.
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.750 lift roller cam with a 1.5 rocker.
Cams with that much lift using 1.5 rockers usually have quite a bit of duration. Any other cam specs you can share?
I’d get a few more laps on it, hopefully at wot for the entire 1/4 mile, before I thought about changing anything significant.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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