More work on the cylinder heads. I'm enlarging the intake port minimum cross section area because this will increase the peak torque rpm, and will correct a too high velocity at the pushrod pinch at peak horsepower rpm.
On a side note, the combustion chamber volume was 58cc per Edel spec; then after unshrouding the valves and polishing the chambers they are at 61cc. BUT I HAD TO MILL THE HEADS 0.010 to reduce the cc's back to 61.
Now for increasing the cross section area at the intake port pushrod pinch.
For clearance to the pushrods for LA block with Edel magnum heads, ended up having to drill the OEM holes out to just over 5/8 diameter, then epoxied 5/8 diam brass tubes in the pushrod holes; then pushed the tubes flat to give a little more cross section to the port.
As cast cross section area at pushrod pinch was 0.88 wide X 2.1 tall = 1.68 sq. inches.
With brass tubes flattened, area is (1.0 X 0.6) round tubing + (1.08 X 1.5) flattened tubing = 2.22 sq. inches total. So the cross section area increased 32%.
From the speedtalk forum:
Proper port velocities mean superior power range and torque spread characteristics. Too much port velocity will limit peak power... independent of cfm flow numbers for the port.
Intake port velocity limit condition is 0.55-0.60 times speed of sound (Mach 1 is speed of sound). For 0.55 mach, this is equal about 660 feet per second including temperature compensation and various personal opinions.
Peak volumetric efficiency (VE) occurs in the range of 0.3-0.5 mach. VE drops rapidly at speeds of 0.6-0.8 mach. 0.3 mach = 335 ft/sec.
Equation for intake port limiting port velocity = (0.00353 * rpm * S * B*B) / CA
where rpm is peak engine rpm, S is stroke, B is bore, CA is minimum cross section area.
For as-casts Edel magnum head:
limiting velocity = (0.00353 * 6000 * 3.58 * 4.03 * 4.03) / 1.68 = 733 ft/sec
So the port velocity at 6000 rpm is definitely into velocity limit condition.
Try again at 5000 rpm gives answer = 611 ft/sec which is a good velocity, so port will flow well at 5000 rpm, but not at 6000 rpm.
Now modify the intake port minimun cross section area which is at the pushrod pinch, so limiting port velocity at 6000 rpm = 0.00353*6000*3.58*4.03*4.03)/2.22 equals 555 ft/sec. So with modified port, the velocity is good at 6000 rpm, just below the 0.55 mach limit condition of 660 fps. AT 3000 rpm the port velocity would be 273 fps, and by 3500 rpm velocity is 324 fps...just getting into peak volumetric efficiency. So at highway cruising speed of 70 mph with 3.23 axle gears and 24 inch tall tires, engine speed is 3200 rpm, just getting into peak VE range.
Now check for what rpm peak torque (PT) occurs at. PT = CA * 88,200/vol of 1 cyl.
Peak horsepower will be about 1400 rpm above peak torque.
For as-cast Edel intake port, PT = 1.68 * 88,200 / 45.6 = 3250 rpm, and peak hp = 4650 rpm. Both kinda low considering for street use would like to see peak hp at about 6000 rpm.
Now check modified port. PT = 2.22 * 88,200 / 45.6 = 4294 rpm, about 4300 rpm, so then peak hp = 5700 rpm which is making full use of a street engine rpm range.
When I switched to 1.6 rocker ratio, I thought the 0.05 duration of the voodoo cam was maybe a little too much for power brakes. The voodoo specs are 271/279 seat duration, with 226/234 @ 0.05 for 1.5 rocker ratio, then add 3 degrees for 1.6 rocker ratio would be 229/237 @ .05 lift, which from forum searching is a little much for power brakes and good street manners. LSA was 110 degrees.
I'll be using 1 3/4 diameter headers and free flow exhaust, so I decided to go with a single pattern hydraulic flat tappet cam from Engle, part # K56H. I bought the cam several months ago not realizing the Engle company would be sold last month, so was lucky.
Engle specs are: 272/272 seat duration, 110 lobe seperation angle, 223/223 dur. at 0.05 lift and .504 valve lift for 1.5 rocker; then add 3 degrees for 1.6 rocker gives 226/226 at 0.05 lift and .537 valve lift. Now subtracting 2% for the 59 degree lifter angle gives valve lift of 0.526 inch. Not too radical, should not wear out valve guides real fast, and the 226 duration @ 0.05 shoud work well for power brakes.
On the dodge charger forum, many folks liked the Engle K56H cam in their big block 383. Some said the 383 with its short stroke acts like a small block, so the K56 should work well in a small block; with less cubes maybe a little rougher idle.
Photos show drilling out the pushrod holes, then intake ports with brass tubes flattened and 60 grit finish applied to entire intake port to promote liquid fuel drops atomized back into airstream. Last pic shows intake/exhaust bowls.
