do you have Steve Dulcich's hp/tq graph from his 2003 EM 470/Chapman
... My 517 Chapman design was based a lot on what I learned from Steve's 470 motor and discussions with Dyanne and Dan Costello....and it's the flattest/broadest torque and fastest revving wedge I've ever built...by a mile.
No dyno graph, but for those who are interested, here are some of the details of Steve's 470. Lots of clever techniques involved and some smart planning.
Peak HP: 752@ 6,500 rpm
Peak TQ: 641.9@ 5,500 rpm
Avg. HP: 547
Avg. TQ: 598.8
Dulcich 470" 2003 Engine Masters info link a Dulcich 470 Engine Masters info link b .034-inch quench clearance,
12.7:1
Ohio Crankshaft forged steel 3.90-inch stroke
TCI Rattler balancer 7.2" diameter
Manley connecting rods
Ross Pistons
Harland Sharp 1.7 rockers
Comp MM lobe Solid flat tappet cam
259@.050 single pattern
108 LSA - 102.5 intake centerline
Indy 383-13 intake
Tapered 4150-4500 HVH spacer adapter
Barry Grant King Demon RS carb
TTI 2"-2-1/8" step headers
Chapman CNC Victor Heads, 285cc
INTAKE VALVE EXHAUST VALVE
0.050 -36 cfm - 0.050 -30 cfm
0.100 -73 cfm - 0.100 -60 cfm
0.200 -148 cfm - 0.200 -107 cfm
0.300 -214 cfm - 0.300 -158 cfm
0.400 -270 cfm - 0.400 -210 cfm
0.500 -308 cfm - 0.500 -232 cfm
0.600 -332 cfm - 0.600 -250 cfm
0.700 -350 cfm - 0.700 -265 cfm
0.800 -385 cfm - 0.800 -278 cfm
