Re: Valve Diameter, Throat Area, Port Area?
[Re: @#$%&*!]
#559977
12/22/09 02:54 PM
12/22/09 02:54 PM
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Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
B G Racing
master
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master
Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
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Quote:
Just wondering if there are any rules-of-thumb or general guidelines on the relationship between the valve diameter, throat area below the valve, and the minimum area of the port tract.
Thanks in advance and happy holidays. 
This subject can be discussed endlessly,but the most important is a smooth transition from the valve pocket to the port runner and gain as much area and the lest obstruction as possible without weakening or damage the head.
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Re: Valve Diameter, Throat Area, Port Area?
[Re: @#$%&*!]
#559978
12/22/09 04:14 PM
12/22/09 04:14 PM
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Joined: Oct 2004
Posts: 1,752
detroit area
moderncylinder
top fuel
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top fuel
Joined: Oct 2004
Posts: 1,752
detroit area
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Quote:
Just wondering if there are any rules-of-thumb or general guidelines on the relationship between the valve diameter, throat area below the valve, and the minimum area of the port tract.
yes,,, there are
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Re: Valve Diameter, Throat Area, Port Area?
[Re: moderncylinder]
#559982
12/22/09 05:10 PM
12/22/09 05:10 PM
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Joined: Jan 2003
Posts: 6,139
Melbourne , Australia
LA360
master
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master
Joined: Jan 2003
Posts: 6,139
Melbourne , Australia
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From memory it was around 90-93%
Hopefully Jeff corrects me if I am wrong.
As mentioned, Speedtalk is an excellent forum for these kind of questions, do a search there before you ask.
AL....
Alan Jones
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Re: Valve Diameter, Throat Area, Port Area?
[Re: B G Racing]
#559983
12/22/09 05:50 PM
12/22/09 05:50 PM
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Joined: May 2008
Posts: 1,131
Thigh-Gap Junction
@#$%&*!
OP
New user name, Same old jerk!
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OP
New user name, Same old jerk!
Joined: May 2008
Posts: 1,131
Thigh-Gap Junction
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Quote:
This subject can be discussed endlessly
Well, I wouldn't want to start an endless discussion, and certainly not a debate.
[yes,,, there are
The thanks-in-advance weren't meant to be sarcasm in advance... Merry to you.
Quote:
Hey Cory, Does this mean we're going faster next year? 
I know you are. This is about another engine/car entirely. If I get that roller cam for xmas then yes, WE are going to be faster. Still, I don't plan to run under 10 any time soon, unless it's to PO a track manager or something.
Quote:
You need to ask this on SpeedTalk.com; 
Join another forum, no thanks. If moparts fails me I'll just come up with my own ideas. That's my usual way of solving problems anyway. Anyone who's seem my sh1t knows that.
The reason I'm asking is that I have some heads I've been working on that are 1.84/1.56 in the valve size area and I'm changing them to 2.0/1.6 and just want to size the port and throat correctly, or close anyway. Min area in the port is now about 1.8in^2 and the Wallace calculator I tried said max torque at about 4100 rpm, fwiw. There's room to make the port bigger.
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Re: Valve Diameter, Throat Area, Port Area?
[Re: LA360]
#559984
12/22/09 06:54 PM
12/22/09 06:54 PM
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Joined: Oct 2004
Posts: 1,752
detroit area
moderncylinder
top fuel
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top fuel
Joined: Oct 2004
Posts: 1,752
detroit area
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it really depends on chamber style, valve job angles, valve back profile, port floor height, and operating range with a respect to cros ssection and displacemnt.
usually 92% on the intake and 89% on the exh,, with 45 degree seats and atleast a 30 degree top ngle thats .060 or so wide,, nothing flatter for a top or else you make the throat smaller. if its a flat machined chamber you make the throat smaller, if its a 30 degree seat you make the throat smaller,,, if its a 55-58 seat you make the throat larger..
also depends on seat width,, if its a true sreet car you run wider seats to help dissipate heat off the valve head,, so then you make the throat smaller,, if seat widths are .050 or wider, the above 92% intake is for a .035 or so wide seat, exh .045
if you take alot of factory heads and goto oversize valves you can get into trouble going 92% cause the casting wont support it, the bowl cant be made large enough.......
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