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Big Block Max RPM #2700333
09/24/19 05:47 AM
09/24/19 05:47 AM
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MASSACHUSETTS
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Chip Offline OP
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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 cool

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?

Re: Big Block Max RPM [Re: Chip] #2700349
09/24/19 06:53 AM
09/24/19 06:53 AM
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n20mstr Offline
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Originally Posted by Chip
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 cool

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.....
Re: Big Block Max RPM [Re: n20mstr] #2700357
09/24/19 07:20 AM
09/24/19 07:20 AM
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Marion, South Carolina [><]
an8sec70cuda Offline
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Originally Posted by n20mstr
Originally Posted by Chip
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 cool

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)

iagree


CHIP
'70 hemicuda...8 sec street car
'69 road runner 440 w/ Indy SRs
'69 road runner 440-6, 4 speed...Dad's ride
'71 Demon 340 resto project
'06 GMC 2500HD LBZ Duramax...toy hauler
'16 Grand Caravan SXT...baby hauler
Re: Big Block Max RPM [Re: an8sec70cuda] #2700374
09/24/19 08:10 AM
09/24/19 08:10 AM
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Chip Offline OP
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Indy 440-1 Heads Ported at Brandywine with 750 lift roller cam 1.5 ratio T&D rockers

Re: Big Block Max RPM [Re: an8sec70cuda] #2700375
09/24/19 08:11 AM
09/24/19 08:11 AM
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So. Burlington, Vt.
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fast68plymouth Offline
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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
Re: Big Block Max RPM [Re: fast68plymouth] #2700400
09/24/19 09:28 AM
09/24/19 09:28 AM
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S.E. South Dakota !
bigdad Offline
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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
Re: Big Block Max RPM [Re: bigdad] #2700408
09/24/19 09:51 AM
09/24/19 09:51 AM
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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
Re: Big Block Max RPM [Re: JERICOGTX] #2700410
09/24/19 09:52 AM
09/24/19 09:52 AM
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S.E. South Dakota !
bigdad Offline
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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
Re: Big Block Max RPM [Re: bigdad] #2700412
09/24/19 10:06 AM
09/24/19 10:06 AM
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MI, usa
dvw Offline
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I run 10.5x31 with a 4.30. 7100@145mph. Your converter is slipping way to much. At 10.70s you're a what? 124 mph?
Doug

Re: Big Block Max RPM [Re: Chip] #2700414
09/24/19 10:07 AM
09/24/19 10:07 AM
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Originally Posted by Chip
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 cool

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 10:08 AM.

1970 Duster
Edelbrock headed 408
6.143@110.85 mph
9.73@135.05 mph shifting at 6700 RPM
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: Big Block Max RPM [Re: pittsburghracer] #2700451
09/24/19 11:43 AM
09/24/19 11:43 AM
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Chip Offline OP
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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...

Re: Big Block Max RPM [Re: Chip] #2700456
09/24/19 12:00 PM
09/24/19 12:00 PM
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MI, usa
dvw Offline
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Not tighter. More efficient. All the progressive numbers are way off. What converter is in it? At that power level and weight you should be 9.60 or better.
Doug

Re: Big Block Max RPM [Re: Chip] #2700459
09/24/19 12:13 PM
09/24/19 12:13 PM
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Keymar, MD
DusterKid Offline
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Was the car hooking? My car had a 1.53 60' when I went 11.50s...For the power your making your 60' should be 1.3x something I'd think.

Re: Big Block Max RPM [Re: DusterKid] #2700461
09/24/19 12:17 PM
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n20mstr Offline
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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.....
Re: Big Block Max RPM [Re: n20mstr] #2700465
09/24/19 12:44 PM
09/24/19 12:44 PM
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Chip Offline OP
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Thanks for the feedback.

Running footbrake also....no box

I will test again this weekend.

Re: Big Block Max RPM [Re: Chip] #2700467
09/24/19 12:46 PM
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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 12:47 PM.

....BAD A$$ STREET CAR.....
Re: Big Block Max RPM [Re: Chip] #2700514
09/24/19 03:34 PM
09/24/19 03:34 PM
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Oregon
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Originally Posted by Chip
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.

Re: Big Block Max RPM [Re: Chip] #2700522
09/24/19 03:56 PM
09/24/19 03:56 PM
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Originally Posted by Chip
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
6.143@110.85 mph
9.73@135.05 mph shifting at 6700 RPM
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: Big Block Max RPM [Re: AndyF] #2700568
09/24/19 06:31 PM
09/24/19 06:31 PM
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Chip Offline OP
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Originally Posted by AndyF
Originally Posted by Chip
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

Re: Big Block Max RPM [Re: Chip] #2700614
09/24/19 09:09 PM
09/24/19 09:09 PM
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So. Burlington, Vt.
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fast68plymouth Offline
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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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