42 cfm gain @ .500. That's very good! Mild street engines are typically around .500 lift. Those heads would make a fantastic, little street engine! Probably, hurt some feelings!😃
2:00 Its not 'chunky' but it looks like the air is fanning out more, which, if one is looking at fuel mixing and vaporization, this seems like its capable of breaking up droplets better.
With and average 285 cam 240@fifty 10:1 cr 1.8-1.9 hp per cfm which seems an average 1.15-1.3+ lbs-ft per cid type build gets, so like 450-480 hp, A more max effort guessing 2-2.3+ hp per cfm.
Good numbers. The J heads can achieve 270. The z can get up to 290. The exhaust flow is your limitation on ultimate power output. 2.4 hp/cfm is good. But with the exhaust power output would be limited to 2.0-2.2hp/exhaust cfm. The j head flowing 270....max effort with 12.5:1 compression and tunnel ram can make 550hp. The exhaust holds it back. Lots more flow available on the z heads Charles. Can you get 290?
No, this is as far as these heads go. Now if someone bought them from Rob and wanted me to do them up that would be cool. They need guides. Good info and thanks Tom.
Great work on the cast iron, and 250 cfm can support 500 + HP. Do you have any videos on sbc swirl port head porting? Would be cool to increase the flow on those while maintaining the swirl. 220 cfm out of a set of the above would be great for a 425 HP stump puller! Perhaps a sbc 400 block with a sbc 307/327 crank to get just over 350 cubes. Short strokes like smaller cc runners, helps to fill the cylinder more efficiently. Cool videos.
Headbytes made a video about porting the 193 swirl head. However, many people said he committed fraud. I used to have a 1990 Chevy Silverado, and sometimes I think about TBI engine tricks. I wondered what a 383 stroker and roller cam could do.
Eric Weingartner has a program where you send him a head and he flows it and critiques it. I am not doing that at this point. I would do it for local guys. Thanks
