[gtofreek]

OK. Just got done working some on the cracked 670 head. I angle cut the deck .100"[tilted the head .100" from the intake surface to the exhaust surface] to remove some of the "hook" in the combustion chamber. Also, I wanted to get the spark plug closer to the piston, in an attempt to get the air/fuel charge burned faster, to give it less chance of detonation. Doing this got the spark plug .085" closer to the piston. Deck thickness still looks good. This also made the chamber considerably smaller so I have room to open it up without making it too big. This also will slightly alter the port angle as it enters the cylinder, effectively moving the valve opening more towards the center of the cylinder, slightly. This did slightly improve air flow. Intake picked up at every lift point, while the exhaust picked up a fair amount at low lifts, and lost a slight amount at higher lifts. Angle cutting should also gain me more pushrod clearance with 1.65 rockers. I may not need to grind the pushrod holes out. We'll see. Below are the new flow numbers, followed by the gain or loss. More pics as well.

_______Intake____Exhaust____gain/loss
.100"___85_______57_________+3/+3
.150"___121______80_________+3/+4
.200"___153______99_________+4/+1
.250"___178______116________+5/+1
.300"___199______131________+6/+1
.350"___201______143________-1/0
.400"___206______152________-2/-5
.450"___209______163________-2/-2
.500"___212______168________0/-3
.550"___214______173________+1/-4
.600"___215______181________+1/0
.650"___217______182________+2/-4
.700"___218______186________+3/-2
.750"___219______189________+3/-1
.800"___220_________________+2
______________________gain = +31/-11