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Long Live The King
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Discussion Starter #1 (Edited)
I was cleaning the garage today and came across an old dyno sheet from the A-460 headed 565. This is the dyno sheet from 2007 after I put the second set of A-460 heads on it with 2.4" Ti intakes and the new style (tall) A-460 intake. Both dyno sheets are with a 9375 1050 I brought back in '91 ( it was an old used carb then) and sent it to the original Barry Grant for a rebuild in the Spring of '91. It went on the 512" my brother and I had.

Before the 2007 "fresh-up" I sent it to C&J Engineering for a cleaning and rebuild. Progressive linkage, primary PV.


It was pulling 1.7" - 1.8"vac.

We ended up with the jetting at 80 primary with a 4.5" PV and 86's in the secondary. We ended up pulling 10 jet sizes out of it on the dyno that day. My buddy "Mummert" (who posts in here from time to time did the heads and was tuning with me that day) The more jet we pulled out the better all the numbers kept getting.

This is a 2012 dyno sheet after a complete rebuild with 13:1 compression and T&D 1.8 rockers:


Jetting was 84 primary 90's.

I have other Dominators and they don't produce this consistent A/F's and don't even come close to the BSFC #'s. I'm assuming the brake specifics start from the metering plates and end at the boosters as far as the Carb goes. (And then you have the engine combination: heads, comp, cam, exhaust etc.)

From the carb: from metering plates to boosters, and Air Speed plays a role in this helping atomization. Would this carb produce the same range of numbers on a 7,200 rpm 420" smblk ? Could it be Cloned to put two of them on a 7,000 rpm 600". Would the air speed be cut nearly in half from the 7,200 rpm 565 ? ( more on that question later) How does that impact atomization ?

So, I had thought the original Barry Grant had converted this carb to a 2 circuit:
Carb parts:











****

A related question:
a 600" engine at 7,000 rpm has an air requirement of approx 1,215 cfm x 110% = 1,336 cfm

How do you think two 1,000 cfm 4150's would perform compared to two 1,050's or 1,200's ?

Lot's of part throttle driving between 3,200 - 4,200.
 

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A related question:
a 600" engine at 7,000 rpm has an air requirement of approx 1,215 cfm x 110% = 1,336 cfm

How do you think two 1,000 cfm 4150's would perform compared to two 1,050's or 1,200's ?

Lot's of part throttle driving between 3,200 - 4,200.


What about 2 smaller 4150s on the 600" @ 7000 build? Something like 2 x 950HP with the 1.38" venturi. I think they flow about 830cfm. One 950Hp can support 300" at 7000, so what about 2 on 600". I don't know. Just putting it up there for discussion.
 

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Long Live The King
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Discussion Starter #3 (Edited)
Worth the discussion or two 1,000 HP’s.

It wouldn’t be a 600” reving to 8,000.
 

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Not going to mention the 2 builders.Had a 1080HP 541 cu-in on dyno .made same HP and TQ with in 1-2 HP.Same staggered jetting.On the track same day ABAB test one carb was 7 hundreths quicker.Quicker in 60ft and at shift recovery.Bill C.
 

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The Liquor Makes Me Think
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Would the 1.7-1.8"hg have anything to do with it? aren't carbs built for efficiently in that range?
 

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Long Live The King
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Discussion Starter #6 (Edited)
The C&S 1100 Aerosol Billet pulled the same vac and BSFC #'s in the high .3's - .41, but made less power back on the first dyno sheet.


Pro Systems 1,200 and another 1,200 same vac and high .4's- .51
 

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Long Live The King
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Discussion Starter #8
Float bowl extensions:

 

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What was the fuel lbs/hr on the first dyno sheet?

What was the weather / dyno correction factor for each dyno sheet.

BSFC is calculated from Uncorrected HP and fuel lbs/hr

Stan
 

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What plays into any carbs differences is how well the fuel is atomized and how equally it is subsequently distributed to all 8 cylinders, along with the correct fuel curve. Booster design, metering block emulsion package, and even venturi to bore ratio all affect it. And then the manifold design, runner and plenum texture, flow velocity...
 

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Long Live The King
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Discussion Starter #13 (Edited)
What other manifold did you compare with this TFS manifold?
No back to back testing on the dyno with these two: Original A-460 and Hi-Rise. The newer style hi-rise certainly has better distribution. I've been told they can be worth 20+ hp over the "low" rise. I wouldn't doubt it:




The thought behind the original post " What makes one carb more efficient than the next?"

At some point the 13:1 comp 565 is going to get reworked and become a pump gas 11:1 600" (4.6 x 4.5") when it gets done it will be the time to try these on the dyno. I wondering if I can just get another 1,050 to try to match the one I already have and bolt them on and see what happens, or would two 950HP or 1000HP's do better for a 600" that will not see more than 7,200 and have lots of part throttle driving:




I don't know how it will run, but it will sure look good. (sitting on 528" pump gas engine from a few years back)


Suppose I could run the Predators on it: :smt115



In any case, I'm very interested as to how these two manifolds will perform against each other. ???????
 

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Long Live The King
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Discussion Starter #14
What plays into any carbs differences is how well the fuel is atomized and how equally it is subsequently distributed to all 8 cylinders, along with the correct fuel curve. Booster design, metering block emulsion package, and even venturi to bore ratio all affect it. And then the manifold design, runner and plenum texture, flow velocity...
Thanks ....
 

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Long Live The King
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Discussion Starter #15
What was the fuel lbs/hr on the first dyno sheet?
I'm seeing 44.3 gph at peak tq. 6,000. At 6,900 it shows 57.7 gph & 7,000 62.4 gph. VP C12 sp g .717

What was the weather / dyno correction factor for each dyno sheet.
I need to find the folder with all the runs in them

BSFC is calculated from Uncorrected HP and fuel lbs/hr

Stan
....
 

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Long Live The King
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Discussion Starter #16
What other manifold did you compare with this TFS manifold?
Speaking of intake manifolds. Yesterday I came across my old catalog from Price Motorsports . They have listed a set of adapter plates for the A-460 heads to 429 intakes. So you could adapt a 429 TR or a dual plane intake to work with the heads.

I wonder what application that worked well for ?
 

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If you are going to use the same cam and lower the compression in the 600 cuin, the power will peak at a lower rpm and so the power might peak in the high 800's at around 6500 rpm (?), useing those thoughts I got this output from pipemax roughing in your engine.

- Induction System Tuned Lengths - ( Cylinder Head Port + Manifold Runner )
1st Harmonic= 36.629 (usually this Length is never used)
2nd Harmonic= 20.789 (some Sprint Engines and Factory OEM's w/Injectors)
3rd Harmonic= 14.514 (ProStock or Comp SheetMetal Intake)
4th Harmonic= 11.424 (Single-plane Intakes , less Torque)
5th Harmonic= 9.269 (Torque is reduced, even though Tuned Length)
6th Harmonic= 7.798 (Torque is reduced, even though Tuned Length)
7th Harmonic= 6.730 (Torque is greatly reduced, even though Tuned Length)
8th Harmonic= 5.919 (Torque is greatly reduced, even though Tuned Length)
Note> 2nd and 3rd Harmonics typically create the most Peak Torque
4th Harmonic is used to package Induction System underneath Hood


And if it peaks at 7000 rpm like the 565 with a higher VE, I got this output.

- Induction System Tuned Lengths - ( Cylinder Head Port + Manifold Runner )
1st Harmonic= 34.135 (usually this Length is never used)
2nd Harmonic= 19.374 (some Sprint Engines and Factory OEM's w/Injectors)
3rd Harmonic= 13.526 (ProStock or Comp SheetMetal Intake)
4th Harmonic= 10.646 (Single-plane Intakes , less Torque)
5th Harmonic= 8.638 (Torque is reduced, even though Tuned Length)
6th Harmonic= 7.267 (Torque is reduced, even though Tuned Length)
7th Harmonic= 6.272 (Torque is greatly reduced, even though Tuned Length)
8th Harmonic= 5.516 (Torque is greatly reduced, even though Tuned Length)
Note> 2nd and 3rd Harmonics typically create the most Peak Torque


All this is assuming that the intake runners flow as much as the head does.
 

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Long Live The King
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Discussion Starter #18 (Edited)
current thoughts: .. Heads need just a tad bit of work. might go to 2.45" intake

Compression 11:1 - 11.25:1

Cam that has been in 565 was just a tad big for that combo. should
work fine for a 600" pump gas deal. cam ran @ 4* advanced.

Might "manipulate the ex. side by changing T&D rockers from 1.8
to 1.7 or 1.6.

At this point in time :My best EWAG (Educated WILD ASS GUESS)

Single 4 = 1.6hp per cubic inch @ 6,800 = 960 hp +/- 8 hp. Should get close to 800 lbs ft at 6,000.

Either T/R with dual 1,050's @ 6,800-7,100 1,015 hp +/- 10. Better than 820 lbs ft at 6,000


Just my current thoughts on it.
 

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598.286 Cubic Inches @ 6800 RPM with 107.00 % Volumetric Efficiency PerCent

Required Intake Flow between 410.6 CFM and 436.0 CFM at 28 Inches
Required Exhaust Flow between 266.1 CFM and 305.2 CFM at 28 Inches

600 RPM/Sec Dyno Test Lowest Low Average Best
Peak HorsePower 880.1 916.3 934.4 952.5
Peak Torque Lbs-Ft 752.8 783.7 799.2 814.7

HorsePower per CID 1.471 1.532 1.562 1.592
Torque per Cubic Inch 1.258 1.310 1.336 1.362

BMEP in psi 189.7 197.5 201.4 205.3
Carb CFM at 1.5 in Hg. 1260 1401 1472 1543

Target EGT= 1307 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 99.6 to 101.0 Octane required range
Air Standard Efficiency = 62.22586 % for 11.000:1 Compression Ratio

Peak HorsePower calculated from Cylinder Head Flow CFM only
600 RPM/Sec Dyno Test Lowest Average Best Potential
Head Flow Peak HP = 847.3 949.2 1051.0




598.286 Cubic Inches @ 6800 RPM with 111.00 % Volumetric Efficiency PerCent

Required Intake Flow between 430.6 CFM and 457.5 CFM at 28 Inches
Required Exhaust Flow between 279.1 CFM and 320.1 CFM at 28 Inches

600 RPM/Sec Dyno Test Lowest Low Average Best
Peak HorsePower 931.0 969.3 988.4 1007.6
Peak Torque Lbs-Ft 795.1 827.8 844.1 860.5

HorsePower per CID 1.556 1.620 1.652 1.684
Torque per Cubic Inch 1.329 1.384 1.411 1.438

BMEP in psi 200.4 208.6 212.8 216.9
Carb CFM at 1.5 in Hg. 1307 1454 1527 1601

Target EGT= 1290 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 100.4 to 101.0 Octane required range
Air Standard Efficiency = 62.22586 % for 11.000:1 Compression Ratio

Peak HorsePower calculated from Cylinder Head Flow CFM only
600 RPM/Sec Dyno Test Lowest Average Best Potential
Head Flow Peak HP = 920.7 1011.5 1102.3


Have you measured the intake tract length so you know whick maniflod to use?

And have you thought about trying to see if a C-460 manifold would fit/or be made to work?
 

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Long Live The King
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Discussion Starter #20
A C-460 single intake would have to be Spliced/sectioned to fit on A-460 heads. I looked at that some 15 years ago.

it should be able to make 1.6 hp per cube with a single 4 but it won't be done with my 1,050. Not sure if the 1,200 will flow enough air, but it will have a better chance than will the 1,050.
 
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