300 inch amc class motor

General engine tech -- Drag Racing to Circle Track

Moderator: Team

KnightEngines
Guru
Guru
Posts: 1730
Joined: Fri Jan 09, 2009 8:51 pm
Location: Australia

Re: 300 inch amc class motor

Post by KnightEngines » Wed Nov 08, 2017 11:44 pm

Pipemax wall of text incoming, I pulled a bunch of specs out my ass, but this is a ballpark of what you need - nothing too hard here, you can do this sh\t no probs.
Based off 7800rpm peak & 108% VE - which you can do.
Flow requirements are including manifolds! - factor in 10-15cfm drop from manifold & you're safe enough.



319.961 Cubic Inches @ 7800 RPM with 108.0 % Volumetric Efficiency PerCent

Required Intake Flow between 249.7 CFM and 263.9 CFM at 28 Inches
Required Exhaust Flow between 188.6 CFM and 206.5 CFM at 28 Inches

600 RPM/Sec Dyno Test Lowest Low Average Best
Peak HorsePower 551.6 574.2 585.6 596.9
Peak Torque Lbs-Ft 410.6 427.5 435.9 444.4

HorsePower per CID 1.724 1.795 1.830 1.866
Torque per Cubic Inch 1.283 1.336 1.362 1.389

BMEP in psi 193.5 201.5 205.4 209.4
Carb CFM at 1.5 in Hg. 780 868 912 956

Target EGT= 1189 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 111.9 to 112.8 Octane required range
Air Standard Efficiency = 65.74910 % for 14.000:1 Compression Ratio

Peak HorsePower calculated from Cylinder Head Flow CFM only
600 RPM/Sec Dyno Test Lowest Average Best Potential
Head Flow Peak HP = 520.3 579.8 639.3

----- Engine Design Specifications -----
( English Units ) ( per each Valve Sq.Inch area )
Engine Size CID = 319.961 Intake Valve Net Area = 3.306
CID per Cylinder = 39.995 Intake Valve Dia. Area = 3.398
Rod/Stroke Ratio = 2.067 Intake Valve Stem Area = 0.092
Bore/Stroke Ratio = 1.373 Exhaust Valve Net Area = 2.231
Int Valve/Bore Ratio = 0.505 Exhaust Valve Dia. Area = 2.324
Exh Valve/Bore Ratio = 0.417 Exhaust Valve Stem Area = 0.092
Exh/Int Valve Ratio = 0.827 Exh/Int Valve Area Ratio = 0.684
Intake Valve L/D Ratio= .313 Exhaust Valve L/D Ratio= .337
CFM/Sq.Inch = 73.5 to 77.7 CFM/Sq.Inch =81.2 to 88.9
Curtain Area -to- Valve Area Convergence Intake Valve Lift inch= .520
Curtain Area -to- Valve Area Convergence Exhaust Valve Lift inch= .430


Intake Valve Margin CC's Exhaust Valve Margin CC's
1.00 CC = 0.0180 1.00 CC = 0.0263
0.50 CC = 0.0090 0.50 CC = 0.0131
0.25 CC = 0.0045 0.25 CC = 0.0066
0.10 CC = 0.0018 0.10 CC = 0.0026

------- Piston Motion Data -------
Average Piston Speed (FPM)= 3900.00 in Feet Per Minute
Maximum Piston Speed (FPM)= 6303.31 occurs at 77.092 Degrees ATDC
Piston Depth at 77.092 degree ATDC= 1.3398 inches Cylinder Volume= 292.7 CC
Maximum TDC Rod Tension GForce= 3219.18 G's
Maximum BDC Rod Compression GForce= 1964.95 G's


------- Current Camshaft Specs @ .050 -------

IntOpen= 31.00 IntClose= 57.00 ExhOpen= 66.00 ExhClose= 28.00
Intake Duration @ .050 = 268.00 Exhaust Duration @ .050 = 274.00
Intake CenterLine = 103.00 Exhaust CenterLine = 109.00
Compression Duration= 123.00 Power Duration = 114.00
OverLap Duration = 59.00 Lobe Center Angle (LCA)= 106.00
Camshaft Advanced = 3.00 degrees

-Recommended Camshaft Valve Lift-
Minimum Normal Maximum
Intake = 0.601 0.647 0.712
Exhaust = 0.540 0.582 0.640
Max-effort Intake Lift = 0.746
Max-effort Exhaust Lift = 0.671
Minimum Intake Valve Lift to prevent Choke = .647 Lift @ 7800 RPM
Minimum Exhaust Valve Lift to prevent Choke = .582 Lift @ 7800 RPM


- Induction System Tuned Lengths - ( Cylinder Head Port + Manifold Runner )
1st Harmonic= 30.254 (usually this Length is never used)
2nd Harmonic= 17.171 (some Sprint Engines and Factory OEM's w/Injectors)
3rd Harmonic= 11.988 (ProStock or Comp SheetMetal Intake)
4th Harmonic= 9.435 (Single-plane Intakes , less Torque)
5th Harmonic= 7.655 (Torque is reduced, even though Tuned Length)
6th Harmonic= 6.441 (Torque is reduced, even though Tuned Length)
7th Harmonic= 5.559 (Torque is greatly reduced, even though Tuned Length)
8th Harmonic= 4.889 (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 = 2.664 to 2.997 Sq.Inch
Plenum Runner Average Recommended Entry Area = 3.063 Sq.Inch
Plenum Runner Maximum Recommended Entry Area = 3.128 to 3.702 Sq.Inch

Minimum Plenum Volume CC = 954.3 [typically for Single-Plane Intakes]
Minimum Plenum Volume CID= 58.2 [typically for Single-Plane Intakes]
Maximum Plenum Volume CC = 5243.2 [typically for Tunnel Ram Intakes]
Maximum Plenum Volume CID= 320.0 [typically for Tunnel Ram Intakes]


------- Operating RPM Ranges of various Components -------

Camshaft Intake Lobe RPM = 6996 Exhaust Lobe RPM = 7121
Camshaft's Intake and Exhaust Lobes operating RPM range = 5028 to 7028
Note=> Lobe RPMs are only BallPark estimations

Minimum Intake Valve Lift to prevent Choke = .647 Lift @ 7800 RPM
Minimum Exhaust Valve Lift to prevent Choke = .582 Lift @ 7800 RPM

Current (Intake Valve Curtain Area -VS- Time) Choke RPM = 7834 RPM
Current (Exhaust Valve Curtain Area -VS- Time) Choke RPM = 7771 RPM

Intake Valve Area + Curtain Area operating RPM Range = 5675 to 7675 RPM

Intake Valve Diameter RPM Range = 5834 to 7834

Intake Flow CFM @28in RPM Range = 5775 to 7775
___________________________________________________________________________

Best estimate RPM operating range from all Components = 5738 to 7738

Note=>The BEST Engine Combo will have all Component's RPM Ranges coinciding
___________________________________________________________________________


--- Cross-Sectional Areas at various Intake Port Velocities (@ 28 in.) ---
141 FPS at Intake Valve Curtain Area= 4.247 sq.in. at .650 Lift
176 FPS at Intake Valve OD Area and at Convergence Lift = .520
218 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 2.752 sq.in. at 7800 RPM
350 FPS Velocity CSA= 1.711 sq.in. at 7800 RPM Port Sonic-Choke with HP Loss
330 FPS Velocity CSA= 1.816 sq.in. at 7800 RPM Port Sonic-Choke with HP Loss
311 FPS Velocity CSA= 1.927 sq.in. at 7800 RPM Smallest Useable Port CSA
300 FPS Velocity CSA= 1.998 sq.in. at 7800 RPM Recommended Smallest Port CSA
285 FPS Velocity CSA= 2.103 sq.in. at 7800 RPM Recommended Smallest Port CSA
260 FPS Velocity CSA= 2.305 sq.in. at 7800 RPM Recommended Port CSA
250 FPS Velocity CSA= 2.397 sq.in. at 7800 RPM Recommended Port CSA
240 FPS Velocity CSA= 2.497 sq.in. at 7800 RPM Largest Intake Port Entry CSA
220 FPS Velocity CSA= 2.724 sq.in. at 7800 RPM Largest Intake Port Entry CSA
210 FPS Velocity CSA= 2.854 sq.in. at 7800 RPM Torque Loss + Reversion
200 FPS Velocity CSA= 2.997 sq.in. at 7800 RPM Torque Loss + Reversion


--- Cross-Sectional Areas at various Exhaust Port Velocities (@ 28 in.) ---
151 FPS at Exhaust Valve Curtain Area= 3.134 sq.in. at .580 Lift
204 FPS at Exhaust Valve OD Area and at Convergence Lift = .430
252 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 1.882 sq.in. at 7800 RPM
435 FPS Velocity CSA= 1.090 sq.in. at 7800 RPM Sonic Choke at Throat Area
350 FPS Velocity CSA= 1.354 sq.in. at 7800 RPM Port Sonic-Choke with HP Loss
330 FPS Velocity CSA= 1.437 sq.in. at 7800 RPM Port Sonic-Choke with HP Loss
311 FPS Velocity CSA= 1.525 sq.in. at 7800 RPM Smallest Useable Port CSA
300 FPS Velocity CSA= 1.580 sq.in. at 7800 RPM Recommended Smallest Port CSA
285 FPS Velocity CSA= 1.664 sq.in. at 7800 RPM Recommended Smallest Port CSA
250 FPS Velocity CSA= 1.897 sq.in. at 7800 RPM Recommended Port CSA
240 FPS Velocity CSA= 1.976 sq.in. at 7800 RPM Recommended Port CSA
225 FPS Velocity CSA= 2.107 sq.in. at 7800 RPM Largest Exhaust Port Exit CSA
210 FPS Velocity CSA= 2.258 sq.in. at 7800 RPM Largest Exhaust Port Exit CSA
190 FPS Velocity CSA= 2.496 sq.in. at 7800 RPM Torque Loss + Reversion
180 FPS Velocity CSA= 2.634 sq.in. at 7800 RPM Torque Loss + Reversion

AMXstocker1
Pro
Pro
Posts: 221
Joined: Fri Jun 10, 2016 5:39 pm
Location: Oklahoma City, Oklahoma

Re: 300 inch amc class motor

Post by AMXstocker1 » Wed Nov 08, 2017 11:55 pm

Looks like a plan if this class last long enough for us to get the combo together. If not well have a fun bracket car. I have pipemax and engine pro did the group buy in not long ago on speed talk, those programs really make me want to start building my own intakes and headers and seeing if i can find gaines by just spending some time with a tig torch.

KnightEngines
Guru
Guru
Posts: 1730
Joined: Fri Jan 09, 2009 8:51 pm
Location: Australia

Re: 300 inch amc class motor

Post by KnightEngines » Thu Nov 09, 2017 12:11 am

You can, but not as big as you may expect!

I don't think you have to get funky, roughly 1.3HP/ci is easy enough if you got enough head, & I reckon you do.

mag2555
Guru
Guru
Posts: 2062
Joined: Sun Sep 18, 2011 11:31 am

Re: 300 inch amc class motor

Post by mag2555 » Thu Nov 09, 2017 7:13 am

Will the spark plug location in those AMC heads not choke off the flame travel with over 12.5 comp?

AMXstocker1
Pro
Pro
Posts: 221
Joined: Fri Jun 10, 2016 5:39 pm
Location: Oklahoma City, Oklahoma

Re: 300 inch amc class motor

Post by AMXstocker1 » Thu Nov 09, 2017 6:51 pm

With the 427 we can get over 12.5 with a flattop but without the sweep area id imagine its going to need a ilttle dome.

Diodedog
Member
Member
Posts: 58
Joined: Mon May 30, 2016 2:03 pm

Re: 300 inch amc class motor

Post by Diodedog » Thu Nov 09, 2017 7:48 pm

AMXstocker1 wrote:
Thu Nov 09, 2017 6:51 pm
With the 427 we can get over 12.5 with a flattop but without the sweep area id imagine its going to need a ilttle dome.
A lot of dome for sure.

Post Reply