Not trying to argue, but you will end up with an engine that runs really rich because the carbs will be dumping fuel but not enough air. It will have NO bottom end torque at all, the tunnel ram kills bottom end power and topping it with that much carb will do even more. You will have to spin the hell out of it to get it to move. I ran this through my dyno software using the specs you have listed. With 900 cfm you are looking at 399hp at 7500 rpm. With a 660 cfm carb it maxes out at 391. Seriously, the problems you will have are not worth 8 hp at the top end of your power band, which you are never going to hit anyway. That motor will come apart if you spin past 6500 for very long. We are not trying to stifle you, but help you. really look at this with an open mind. you can still run the tunnel ram, which looks awesome, but you need to downgrade the carbs.
you posted 254-264cfm on the finished heads. 8:1 compression big cam tunnel ram 2 x 450cfm carbs 260cubic inches 2800-3200 rpm stall verter. I applaud you for sticking to your guns, but brother, they're not loaded... my p.o.s. edelbrock small block Chrysler heads only flow around 250 cfm at my cam's max lift. 415 cubic inches at 6500rpm with 10.5:1 compression pulling through an 850 double pumper. Measured 618cfm when we put the turbine on top of the carb. Now i know you're planning on spinning more revs, but does anyone wanna calculate what cfm my extra 155 inches would translate to at 6400 rpm compared to 260 cubic inches at that engine's rpm (8,000 was it?) the cubes vs rpm should be able to be directly compared, but the other thing you're fighting isn't as easily calculated: 8:1 compression really sucks. Actually anything that low is definitely NOT going to suck enough air on the intake to cause a quick pressure drop to get some flow going. Dont remember your cam specs, but i remember the word "big"- so now we've got a high flow head, with a valve opened long and wide, on top of a piston that wont suck much, but under a massive plenum of atmosphere, trying to draw through carburetion that demands high flow...AND let's not forget your verter and gears just aren't going to let her rev up to put that short stroke to use. The converter you picked will DEFINITELY stall at the extreme BOTTOM end of the advertised range of that part number because a low torque mill wont stretch out a stall (and you already know you're not building a high torque mill). Light weight cars also cause the stall to happen in the lower end of the range -(falcons aren't super light, but they're still light). I'm confident in this -UNLESS you spec'd that converter with a VERY good company that knows your whole combo, and quoted that rpm range for YOUR combo. I'm just waiting for the post about wanting to use a traditional single point distributor and a vacuum shifted transmission j/k I hope it works for you, but unless you've got some trick up your sleeve that you've not revealed, it sounds like someone's selling you a bag of parts that might look good but just aren't a matched combination. Or maybe they're just being polite about the recipe being suggested. I dont want you to think we're just picking on you- we love to see someone bring out a rippin little car. It's just that alot of this doesn't add up. I've been wrong before and i'll be wrong again, (i'm sure everyone here can say the same) but i'd be very surprised if so many here are wrong on this one. keep us posted. -rick
Well my local circle of engine builders says the combination will work the converter was made for my combination but u never know u guys might be right i hope not though we will see how it turns out engine is almost finished
Even if it does to out to be the wrong set up and just pouring fuel into the engine, all of your work on the heads and intake will not be wasted as you could use them on a bigger SBF. Or raise your compression to 12:1 and run ethanol.
you may not even have to use another mill- lower compression loves boost-turbos/roots and if the compression is now a little higher, then a centrifugal blower would work to- and still be considered traditional. I've got a bigass VR4 Paxton for my 61 Falcon gasser- I may even paint it blue to look like the blowers of the day...
I love the car and the plan, I just don't think its gonna work like you want it to. my point was that you can run the same setup with two smaller carbs.
If the tunnel ran was a shared-plenum design, I would say block off the rear carb and use it as a dummy, but that wouldn't work on this intake, not vey well anyway. Two 350 cfm carbs would be a lot better. You haven't cracked those carbs open, you should be able to swap them out for some 350s. Give it a try, but I don't think you will be happy with it. I think the car will be killer once you get it right.
Desktop Dyno is made by Comp Cams and has always been within a few percent of the actual dyno results on the engines I have personally built. It is probably the most accurate program available.
In all seriousness, there is a lot of experience talking to you here, you should at least listen with an open mind. We all have to learn a few things the hard way, at 16 you are probably going to be hard-headed, but you'll come around once you actually get it fired up. By the way, my 650 hp Mopar 383 runs on a 900 CFM Proform carb. That motor spins to 7k, has a .600" lift solid roller and CNC ported Edelbrock Victor heads that flow in the 300s at max lift, and 260 at .300. Just saying.
265.904 Cubic Inches @ 7800 RPM with 105.0 % Volumetric Efficiency PerCent Required Intake Flow between 201.7 CFM and 212.7 CFM at 28 Inches Required Exhaust Flow between 151.7 CFM and 166.3 CFM at 28 Inches 600 RPM/Sec Dyno Test Lowest Low Average Best Peak HorsePower 390.2 406.2 414.2 422.2 Peak Torque Lbs-Ft 290.9 302.9 308.8 314.8 HorsePower per CID 1.467 1.528 1.558 1.588 Torque per Cubic Inch 1.094 1.139 1.161 1.184 BMEP in psi 165.0 171.8 175.1 178.5 Carb CFM at 1.5 in Hg. 630 701 737 772 Target EGT= 1435 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test Octane (R+M)/2 Method = 87.7 to 88.9 Octane required range Air Standard Efficiency = 58.05734 % for 8.500:1 Compression Ratio Peak HorsePower calculated from Cylinder Head Flow CFM only 600 RPM/Sec Dyno Test Lowest Average Best Potential Head Flow Peak HP = 407.8 462.0 516.3 ----- Engine Design Specifications ----- ( English Units ) ( per each Valve Sq.Inch area ) Engine Size CID = 265.904 Intake Valve Net Area = 2.864 CID per Cylinder = 33.238 Intake Valve Dia. Area = 2.956 Rod/Stroke Ratio = 1.796 Intake Valve Stem Area = 0.092 Bore/Stroke Ratio = 1.338 Exhaust Valve Net Area = 1.919 Int Valve/Bore Ratio = 0.505 Exhaust Valve Dia. Area = 2.011 Exh Valve/Bore Ratio = 0.417 Exhaust Valve Stem Area = 0.092 Exh/Int Valve Ratio = 0.825 Exh/Int Valve Area Ratio = 0.680 Intake Valve L/D Ratio= .264 Exhaust Valve L/D Ratio= .320 CFM/Sq.Inch = 68.2 to 71.9 CFM/Sq.Inch =75.5 to 82.7 Curtain Area -to- Valve Area Convergence Intake Valve Lift inch= .485 Curtain Area -to- Valve Area Convergence Exhaust Valve Lift inch= .400 Intake Valve Margin CC's Exhaust Valve Margin CC's 1.00 CC = 0.0206 1.00 CC = 0.0304 0.50 CC = 0.0103 0.50 CC = 0.0152 0.25 CC = 0.0052 0.25 CC = 0.0076 0.10 CC = 0.0021 0.10 CC = 0.0030 ------- Piston Motion Data ------- Average Piston Speed (FPM)= 3731.00 in Feet Per Minute Maximum Piston Speed (FPM)= 6084.56 occurs at 75.454 Degrees ATDC Piston Depth at 75.454 degree ATDC= 1.2652 inches Cylinder Volume= 240.1 CC Maximum TDC Rod Tension GForce= 3170.03 G's Maximum BDC Rod Compression GForce= 1789.46 G's ------- Current Camshaft Specs @ .050 ------- IntOpen= 15.00 IntClose= 41.00 ExhOpen= 51.00 ExhClose= 5.00 Intake Duration @ .050 = 236.00 Exhaust Duration @ .050 = 236.00 Intake CenterLine = 103.00 Exhaust CenterLine = 113.00 Compression Duration= 139.00 Power Duration = 129.00 OverLap Duration = 20.00 Lobe Center Angle (LCA)= 108.00 Camshaft Advanced = 5.00 degrees -Recommended Camshaft Valve Lift- Minimum Normal Maximum Intake = 0.535 0.577 0.634 Exhaust = 0.494 0.532 0.585 Max-effort Intake Lift = 0.665 Max-effort Exhaust Lift = 0.613 Minimum Intake Valve Lift to prevent Choke = .577 Lift @ 7800 RPM Minimum Exhaust Valve Lift to prevent Choke = .532 Lift @ 7800 RPM - Induction System Tuned Lengths - ( Cylinder Head Port + Manifold Runner ) 1st Harmonic= 26.548 (usually this Length is never used) 2nd Harmonic= 15.068 (some Sprint Engines and Factory OEM's w/Injectors) 3rd Harmonic= 10.519 (ProStock or Comp SheetMetal Intake) 4th Harmonic= 8.280 (Single-plane Intakes , less Torque) 5th Harmonic= 6.718 (Torque is reduced, even though Tuned Length) 6th Harmonic= 5.652 (Torque is reduced, even though Tuned Length) 7th Harmonic= 4.878 (Torque is greatly reduced, even though Tuned Length) 8th Harmonic= 4.290 (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 Plenum Runner Minimum Recommended Entry Area = 2.151 to 2.420 Sq.Inch Plenum Runner Average Recommended Entry Area = 2.473 Sq.Inch Plenum Runner Maximum Recommended Entry Area = 2.526 to 2.990 Sq.Inch Minimum Plenum Volume CC = 793.1 [typically for Single-Plane Intakes] Minimum Plenum Volume CID= 48.4 [typically for Single-Plane Intakes] Maximum Plenum Volume CC = 4357.4 [typically for Tunnel Ram Intakes] Maximum Plenum Volume CID= 265.9 [typically for Tunnel Ram Intakes] ------- Operating RPM Ranges of various Components ------- Camshaft Intake Lobe RPM = 5463 Exhaust Lobe RPM = 5793 Camshaft's Intake and Exhaust Lobes operating RPM range = 3545 to 5545 Note=> Lobe RPMs are only BallPark estimations Minimum Intake Valve Lift to prevent Choke = .577 Lift @ 7800 RPM Minimum Exhaust Valve Lift to prevent Choke = .532 Lift @ 7800 RPM Current (Intake Valve Curtain Area -VS- Time) Choke RPM = 6925 RPM Current (Exhaust Valve Curtain Area -VS- Time) Choke RPM = 7511 RPM Intake Valve Area + Curtain Area operating RPM Range = 5017 to 7017 RPM Intake Valve Diameter RPM Range = 4925 to 6925 Intake Flow CFM @28in RPM Range = 5771 to 7771 ___________________________________________________________________________ Best estimate RPM operating range from all Components = 5589 to 7589 Note=>The BEST Engine Combo will have all Component's RPM Ranges coinciding ___________________________________________________________________________ --- Cross-Sectional Areas at various Intake Port Velocities (@ 28 in.) --- 155 FPS at Intake Valve Curtain Area= 3.120 sq.in. at .512 Lift 164 FPS at Intake Valve OD Area and at Convergence Lift = .485 202 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 2.394 sq.in. at 7800 RPM 350 FPS Velocity CSA= 1.382 sq.in. at 7800 RPM Port Sonic-Choke with HP Loss 330 FPS Velocity CSA= 1.467 sq.in. at 7800 RPM Port Sonic-Choke with HP Loss 311 FPS Velocity CSA= 1.556 sq.in. at 7800 RPM Smallest Useable Port CSA 300 FPS Velocity CSA= 1.613 sq.in. at 7800 RPM Recommended Smallest Port CSA 285 FPS Velocity CSA= 1.698 sq.in. at 7800 RPM Recommended Smallest Port CSA 260 FPS Velocity CSA= 1.861 sq.in. at 7800 RPM Recommended Port CSA 250 FPS Velocity CSA= 1.936 sq.in. at 7800 RPM Recommended Port CSA 240 FPS Velocity CSA= 2.017 sq.in. at 7800 RPM Largest Intake Port Entry CSA 220 FPS Velocity CSA= 2.200 sq.in. at 7800 RPM Largest Intake Port Entry CSA 210 FPS Velocity CSA= 2.305 sq.in. at 7800 RPM Torque Loss + Reversion 200 FPS Velocity CSA= 2.420 sq.in. at 7800 RPM Torque Loss + Reversion --- Cross-Sectional Areas at various Exhaust Port Velocities (@ 28 in.) --- 148 FPS at Exhaust Valve Curtain Area= 2.574 sq.in. at .512 Lift 190 FPS at Exhaust Valve OD Area and at Convergence Lift = .400 234 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 1.629 sq.in. at 7800 RPM 435 FPS Velocity CSA= 0.877 sq.in. at 7800 RPM Sonic Choke at Throat Area 350 FPS Velocity CSA= 1.090 sq.in. at 7800 RPM Port Sonic-Choke with HP Loss 330 FPS Velocity CSA= 1.157 sq.in. at 7800 RPM Port Sonic-Choke with HP Loss 311 FPS Velocity CSA= 1.227 sq.in. at 7800 RPM Smallest Useable Port CSA 300 FPS Velocity CSA= 1.272 sq.in. at 7800 RPM Recommended Smallest Port CSA 285 FPS Velocity CSA= 1.339 sq.in. at 7800 RPM Recommended Smallest Port CSA 250 FPS Velocity CSA= 1.527 sq.in. at 7800 RPM Recommended Port CSA 240 FPS Velocity CSA= 1.590 sq.in. at 7800 RPM Recommended Port CSA 225 FPS Velocity CSA= 1.696 sq.in. at 7800 RPM Largest Exhaust Port Exit CSA 210 FPS Velocity CSA= 1.817 sq.in. at 7800 RPM Largest Exhaust Port Exit CSA 190 FPS Velocity CSA= 2.009 sq.in. at 7800 RPM Torque Loss + Reversion 180 FPS Velocity CSA= 2.120 sq.in. at 7800 RPM Torque Loss + Reversion ---- Some Useful Formulas are: ---- Average_CSA = Port_Volume_CC / (Port_CenterLine_Length * 16.387) Port_Volume_CC = Average_CSA * Port_CenterLine_Length * 16.387 Port_CenterLine_Length = Port_Volume_CC / ( Average_CSA *16.387 ) FPS = ( Flow_CFM * 2.4 ) / Average_CSA Flow_CFM = Average_CSA * FPS * .4166667 Average_CSA = ( Flow_CFM * 2.4) / FPS Valve Intake Exhaust Curtain Area 300 FPS Velocity Minimum Head Lift Choke Choke Square Inches Cross-Sect Area Flow @ 28 In inches RPM RPM Intake Exhaust Intake Exhaust Int Exh .050 676 733 0.305 0.251 0.140 0.110 17.5 13.8 .075 1014 1100 0.457 0.377 0.210 0.165 26.2 20.7 .100 1353 1467 0.609 0.503 0.280 0.221 35.0 27.6 .125 1691 1834 0.762 0.628 0.350 0.276 43.7 34.5 .150 2029 2200 0.914 0.754 0.420 0.331 52.5 41.4 .175 2367 2567 1.067 0.880 0.490 0.386 61.2 48.3 .200 2705 2934 1.219 1.005 0.560 0.441 69.9 55.2 .225 3043 3301 1.371 1.131 0.629 0.496 78.7 62.1 .250 3382 3667 1.524 1.257 0.699 0.552 87.4 68.9 .275 3720 4034 1.676 1.382 0.769 0.607 96.2 75.8 .300 4058 4401 1.828 1.508 0.839 0.662 104.9 82.7 .325 4396 4768 1.981 1.634 0.909 0.717 113.7 89.6 .350 4734 5134 2.133 1.759 0.979 0.772 122.4 96.5 .375 5072 5501 2.286 1.885 1.049 0.827 131.1 103.4 .400 5410 5868 2.438 2.011 1.119 0.883 139.9 110.3 Valve Intake Exhaust Curtain Area 300 FPS Velocity Minimum Head Lift Choke Choke Square Inches Cross-Sect Area Flow @ 28 In inches RPM RPM Intake Exhaust Intake Exhaust Int Exh .425 5749 6234 2.590 2.136 1.189 0.938 148.6 117.2 .450 6087 6601 2.743 2.262 1.259 0.993 157.4 124.1 .475 6425 6968 2.895 2.388 1.329 1.048 166.1 131.0 .500 6763 7335 3.047 2.513 1.399 1.103 174.9 137.9 .525 7101 7701 3.200 2.639 1.469 1.158 183.6 144.8 .550 7439 8068 3.352 2.765 1.539 1.213 192.3 151.7 .575 7777 8435 3.504 2.890 1.609 1.269 201.1 158.6 .600 8116 8802 3.657 3.016 1.679 1.324 209.8 165.5 .625 8454 9168 3.809 3.142 1.749 1.379 218.6 172.4 .650 8792 9535 3.962 3.267 1.819 1.434 227.3 179.3 .675 9130 9902 4.114 3.393 1.888 1.489 236.1 186.2 .700 9468 10268 4.266 3.519 1.958 1.544 244.8 193.1 ************** Metric Units ****************** 4.357 Liters @ 7800 RPM with 105.0 % Volumetric Efficiency PerCent Required Intake Flow between 95.2 L/S and 100.4 L/S at 71.12 CM Required Exhaust Flow between 71.6 L/S and 78.5 L/S at 71.12 CM 600 RPM/Sec Dyno Test Lowest Low Average Best Peak KiloWatts 290.9 302.9 308.9 314.9 Peak Torque Ntn-Meter 394.4 410.6 418.7 426.8 Kilowatts per Liter 66.8 69.5 70.9 72.3 Torque N/M per Liter 90.5 94.2 96.1 98.0 BMEP in Kpa 1137.4 1184.2 1207.6 1231.0 Carb L/S at 38.1 MM Hg 297 331 348 364 Target EGT= 779 degrees C at end of 4 second 600 RPM/Sec Dyno accel. test Octane (R+M)/2 Method = 87.7 to 88.9 Octane required range Air Standard Efficiency = 58.05734 % for 8.500:1 Compression Ratio ( Metric Units ) ( per each Valve Sq.CM area ) Engine Size Liters = 4.357 Intake Valve Net Area = 18.478 CC per Cylinder = 544.674 Intake Valve Dia. Area = 19.070 Rod/Stroke Ratio = 1.796 Intake Valve Stem Area = 0.593 Bore/Stroke Ratio = 1.338 Exhaust Valve Net Area = 12.379 Int Valve/Bore Ratio = 0.505 Exhaust Valve Dia. Area = 12.972 Exh Valve/Bore Ratio = 0.417 Exhaust Valve Stem Area = 0.593 Exh/Int Valve Ratio = 0.825 Exh/Int Valve Area Ratio = 4.388 Intake Valve L/D Ratio= .264 Exhaust Valve L/D Ratio= .320 L/S/Sq.CM = 4.991 to 5.263 L/S/Sq.CM = 5.521 to 6.051 Curtain Area -to- Valve Area Convergence Intake Valve Lift MM= 12.319 Curtain Area -to- Valve Area Convergence Exhaust Valve Lift MM= 10.160 Intake Valve Margin CC's Exhaust Valve Margin CC's 1.00 CC = 0.0206 1.00 CC = 0.0304 0.50 CC = 0.0103 0.50 CC = 0.0152 0.25 CC = 0.0052 0.25 CC = 0.0076 0.10 CC = 0.0021 0.10 CC = 0.0030 ------- Piston Motion Data ------- Average Piston Speed (M/S)= 18.95 in Meters per Second Maximum Piston Speed (M/S)= 30.91 occurs at 75.454 Degrees ATDC Piston Depth at 75.454 degree ATDC= 32.1373 MM Cylinder Volume= 240.1 CC Maximum TDC Rod Tension GForce= 3170.03 G's Maximum BDC Rod Compression GForce= 1789.46 G's ------- Current Camshaft Specs @ 1.270 MM ------- IntOpen= 15.00 IntClose= 41.00 ExhOpen= 51.00 ExhClose= 5.00 Intake Duration @ 1.27 = 236.00 Exhaust Duration @ 1.27 = 236.00 Intake CenterLine = 103.00 Exhaust CenterLine = 113.00 Compression Duration= 139.00 Power Duration = 129.00 OverLap Duration = 20.00 Lobe Center Angle (LCA)= 108.00 Camshaft Advanced = 5.00 degrees -Recommended Camshaft Valve Lift- MM Minimum Normal Maximum Intake = 13.601 14.647 16.112 MM Exhaust = 12.539 13.506 14.856 MM Max-effort Intake Lift = 16.881 MM Max-effort Exhaust Lift = 15.565 MM Minimum Intake Valve Lift to prevent Choke = 14.647 MM Lift @ 7800 RPM Minimum Exhaust Valve Lift to prevent Choke = 13.506 MM Lift @ 7800 RPM - Induction System Tuned Lengths MM- ( Cylinder Head Port + Manifold Runner ) 1st Harmonic= 674.316 (usually this Length is never used) 2nd Harmonic= 382.720 (some Sprint Engines and Factory OEM's w/Injectors) 3rd Harmonic= 267.189 (ProStock or Comp SheetMetal Intake) 4th Harmonic= 210.300 (Single-plane Intakes , less Torque) 5th Harmonic= 170.630 (Torque is reduced, even though Tuned Length) 6th Harmonic= 143.551 (Torque is reduced, even though Tuned Length) 7th Harmonic= 123.892 (Torque is greatly reduced, even though Tuned Length) 8th Harmonic= 108.967 (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 Plenum Runner Minimum Recommended Entry Area = 13.878 to 15.612 Sq.CM Plenum Runner Average Recommended Entry Area = 15.956 Sq.CM Plenum Runner Maximum Recommended Entry Area = 16.299 to 19.288 Sq.CM Minimum Plenum Volume CC = 793.1 [typically for Single-Plane Intakes] Minimum Plenum Volume Liter= 0.7931 [typically for Single-Plane Intakes] Maximum Plenum Volume CC = 4357.4 [typically for Tunnel Ram Intakes] Maximum Plenum Volume Liter= 4.357 [typically for Tunnel Ram Intakes] ------- Operating RPM Ranges of various Components ------- Camshaft Intake Lobe RPM = 5463 Exhaust Lobe RPM = 5793 Camshaft's Intake and Exhaust Lobes operating RPM range = 3545 to 5545 Note=> Lobe RPMs are only BallPark estimations Minimum Intake Valve Lift to prevent Choke = 14.647 MM Lift @ 7800 RPM Minimum Exhaust Valve Lift to prevent Choke = 13.506 MM Lift @ 7800 RPM Current (Intake Valve Curtain Area -VS- Time) Choke RPM = 6925 RPM Current (Exhaust Valve Curtain Area -VS- Time) Choke RPM = 7511 RPM Intake Valve Area + Curtain Area operating RPM Range = 5017 to 7017 RPM Intake Valve Diameter RPM Range = 4925 to 6925 Intake Flow CFM @28in RPM Range = 5771 to 7771 ___________________________________________________________________________ Best estimate RPM operating range from all Components = 5589 to 7589 Note=>The BEST Engine Combo will have all Component's RPM Ranges coinciding ___________________________________________________________________________
What is your point? Desktop Dyno can do that too. At this point I am going to stop arguing with a 16 year old that thinks he knows everything. Good luck on your build. Make sure you buy a lot of spark plugs, you'll be changing them out quite often.
265 inches? Read those camshaft specs again, and repeat after me "4,000 stall, 4000 stall, 4,000 stall 4,000 stall, 4000 stall, 4,000 stall 4,000 stall, 4000 stall, 4,000 stall" the 14th line of your post reads "peak hp calculated from cyl head cfm only" - meaning "that's what the heads COULD support" good luck with your "raised" compression ratio with the head shave of 8.5:1 on 87-89octane. I have a feeling you're not gonna hit that 105%Volumetric efficiency...
He has made up his mind about what set up he wants to run. The results will be, well, unavoidable. So how about some more pictures of the progress you've made? You should look into the 347 kits for that Mexican 302. Then put it in something very, very light.
so many pictures to upload but im too lazy... car is getting caged and tubbed in these next couple of weeks
man, that's gonna be cool. but you gotta check out the 2 door falcon wagon at www.boernestagekustoms.com for inspiration
Looking good, I cant wait to here your dyno numbers, I bet that engine has a nice sound to it. Good Luck Jon
Looking forward to some video- that's a pretty burly cam on such a small mill, i bet she's got a nasty idle... rick
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