Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Engine Masters Critique my 383 SBC Build
View Single Post
  #21 (permalink)  
Old 11-11-2008, 02:51 PM
techinspector1's Avatar
techinspector1 techinspector1 is offline
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,325
Wiki Edits: 326

Thanks: 843
Thanked 1,154 Times in 953 Posts
973kgt's goal for this build is 500/500. I wanted to play around with it with an additional goal of 400 ft/lbs @ 2000 with the lowest possible SCR. I tried upwards of 2 dozen camshaft/SCR combinations to get there. Best results were achieved with a custom grind cam, although a couple of off-the-shelf grinds were close. I tried lobe separation angles from 106 to 112 and settled on 110 for the best numbers between hp and torque. A 106 cam made incredible torque from idle, but never reached the 500 mark and was pretty much all done at 3000. Maybe it's possible to make the 106 cam work and I just don't know how to do it.

Anyway, here's the combo....
383, 10.30:1 static compression ratio. Cylinder volume 783.85 cc's, combustion volume 84.28 cc's, combined volume 868.13 cc's. Heads are 65 cc's, so another 19.28 cc's have to be found between the piston, gasket and piston deck height to reach the 10.30:1 SCR used in this combo. If we shaved the heads for 63 cc chambers, used KB197 pistons with a 12cc dish and a Fel-Pro 1003 gasket (recommended for aluminum heads and iron block) with dimensions of 4.166" X 0.041" and a zero deck, the SCR would work out to 10.31:1 and the squish would work out to 0.041". Sounds pretty close to me. 5.7" rods. (6" rods picked up 3 hp and 2 ft/lbs)
Canfield 195 aluminum heads 2.055"/1.60"
Flow figures: (from 973kgt)
.100 61/51
.200 128 103
.300 191/143
.400 238/170
.500 251/189
.600 254/200
Intake manifold: Dual plane max flow (RPM or equivalent)
Carb: 780 CFM
Cam: Hydraulic Roller.
Intake & exhaust lift at valve 0.560" (1.6 rockers)
Intake & exhaust lift at cam 0.350"
Primary timing seat to seat (0.006") 31/63/77/29
Duration 274*/286* @ 0.006", 230*/236* @ 0.050".
Intake centerline 106*, exhaust centerline 114*, lobe separation angle 110*, overlap 60*.
Secondary timing (0.050") 9/41/52/4
Installed retarded 1*
True seat to seat timing @ 1* retarded 30/64/76/30, ICA 107*, ECA 113*, LSA 110*, overlap 60*.
Lifter acceleration rate 3.10

RPM HP TQ VE BMEP
1500 102 359 67 141
2000 155 407 74 161
2500 197 415 77 164
3000 253 443 83 175
3500 317 476 89 188
4000 377 495 94 195
4500 432 504 98 199
5000 470 494 100 195
5500 496 474 99 187
6000 501 438 95 173
6500 470 380 89 150

Last edited by techinspector1; 11-11-2008 at 03:32 PM.
Reply With Quote