Reply to "What's Your Experience/Advice for Ignition Timing with High Swirl Heads?"

Hi George,

Stock flow numbers are from Edlebrock.

Edelbrock #61625 Performer RPM head - Intake runner volume = 190 cc

Camshaft (Comp Cams): Hydraulic roller camshaft (custom grind)

Valve Lift (Int/Exh): .612”/.607”     Duration (@ .050): 230’/236’      LSA: 112’

             Stock                   Ported

.100”          58/54                     79/59

.200”          120/105                166/106

.300”               180/138                229/140

.400”            227/151                275/171

.500”          260/161                297/188

.600”           265/165                299/197

.650”                                              311

.700”                                              314

.750”                                              319

With several assumption made, the engine builder's dyno computer program estimated peak flywheel hp = 518 @ 5900 rpm and peak flywheel Torque = 545 @ 4100 rpm. The torque is above 485 from 2500 rpm to 5400 rpm. It will be interesting to see how close the numbers are to the dyno results.

Mike