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Posted:
Tue Jul 26, 2005 7:18 amby sheppard00
on the 302 head it gives me a peak rpm of 5200
and an air speed of 653fps
Posted:
Thu Jul 28, 2005 9:25 amby hollywood63
Sheppard,
I have a dumb question what does the symbol between the word bore and the number 2 stand for.
:p
Art
Posted:
Thu Jul 28, 2005 11:39 amby cspeier
Shepard
If your saying that the port velocity of your port is 650 fps.. It will never work, ever! That's way to fast. It needs to be 1/2 that. In the old days that's what I thought. The faster the port the better. That thinking is totally wrong. I took a port that flowed 350 at 450 fps. Nice oval port round Dart/Buick head. We killed it to 340 at 290-310 fps and the car went an easy .10 faster and more RPM! I kind've bet any of the pros. like Curtis, would agree. Try it..
Posted:
Thu Jul 28, 2005 6:05 pmby larrycavan
Posted:
Fri Jul 29, 2005 12:56 amby cboggs
Chad is right, . ( hi Chad )
On a flowbench flowing at 28" h2o, .. I shoot for air speeds
around 280fps to a max of 350fps. Anything faster then 350fps
will choke under dynamic running conditions.
Now if the 650fps is based on the dynamic conditions of a running
engine, .. it's about the max.
anything past Mach .55 will choke, ..
Curtis
Posted:
Fri Jul 29, 2005 7:07 amby sheppard00
(.00353 x RPM x stroke x bore^2)/min cross sectional area = Max Port
will someone use this formula on one of thier heads and see how it comes out... check it for me. I got it from someone else and don't have a probe to check air speed my self..
thanks
mark sheppard
Posted:
Fri Jul 29, 2005 8:45 amby cspeier
Mark
Your math is correct, but the only way to know port speed is by a velocity probe. This is what I suggest. Look on this forum you can easily find everything you need to build you a manometer and pitot. You can find plans to build, which is peanuts in cost, a vertical manometer. I personally purchased a Performance Trends pitot tube and a 36" Dwyer manometer.
I'll promise you, you'll learn more about port flow and the dynamics of a port when you use it than ever grinding and flowing! Before probing, I've had SSR speeds of 400+ and couldn't figure out why the head either didn't flow or stoped flowing. The pitot is the ONLY way to find your high flow areas to know were you need to grind. If you need any help, email me and I'll send a photo of what I use. Your head will benefit from this.
Chad
Posted:
Sun Jul 31, 2005 8:57 pmby sheppard00
a pic would be nice... and a little explination on how to use it would also be helpfull.. thanks
mark
Posted:
Fri Aug 26, 2005 12:26 pmby 114-1125072539
Posted:
Sat Aug 27, 2005 11:10 pmby larrycavan
Hi Ron,
Welcome to Bruce's little corner of the world. 20 years ago I discussed the potential of a V8 ZX Kawaski motor with a friend of mine. I see you've turned that into reality. I like the way you think.
Larry
Posted:
Sun Aug 28, 2005 10:13 pmby 114-1125072539
It's a bizzare world, But a rules change will keep the V-8 out of competition. However, a new light has dawned. The largest displacement single engine Funnybike, with the most Boost is under construction. But since I can only have 16 valves instead of 32 ,I'll need to develop some better than normal ports to slay the competition.
Ron