![\"IMG_0662\"](\"https:\/\/datsunworks.com\/Blog\/wp-content\/uploads\/2015\/10\/IMG_0662.jpg\")
<\/a><\/p>\nThe before column is a raw port with only the machine work for the port matching done. The after has been cleaned up really quickly with a double cut round burr and then I hit it with a cartridge roll on a mandrel. All I did was remove the sand casting texture, blend the steps between the seats and ports, and remove the additional material from the halve guide bosses.<\/p>\n
<\/p>\n The clear acrylic manifold Had a 3.5″ bore.<\/p>\n They applied modeling clay to the intake ports to smooth the air entry and they held a tube against the exhaust port to simulate a header.<\/p>\n Here is the before port. You can see the steps between the valve seats and the ports are still there and the valve stem bosses are too long.<\/p>\n Here is my piss poor after port. You can see there is plenty of room for improvement with my porting abilities:)<\/p>\n This is a flow comparison chart don by Bryan Blake of BMC. If I trust anyones numbers it would be his. As you can see my head is well above the stock KA and really close to Bryan’s ported KA.<\/p>\n <\/p>\n They are just initial numbers but they do follow what I hoped to see based on my port volumes. When I was designing it I looked up the kind of volumes the K20 head gurus were running and I tried to hit those marks. Especially on the intake. The exhaust is fairly close to the stock K20 in shape but the intake is mine from scratch. I started with the stock entry and exits and made it look pretty in between.<\/p>\n","protected":false},"excerpt":{"rendered":" So I took the head down to Scott’s Racing engines to get it Flow tested. The before column is a raw port with only the machine work for the port matching done. The after has been cleaned up really quickly with a double cut round burr and then I hit it with a cartridge roll … Continue reading <\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n