Valve Seat Angles and Flow Area

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Stan Weiss
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Valve Seat Angles and Flow Area

Post by Stan Weiss » Tue Mar 06, 2018 10:45 am

I use a much different method for calculating seat area based on seat angle and seat width then what was shown before. This paper has a 3 step method which is very close to what I use to calculate the overall flow area which at most lifts is not the curtain area..

Have had this for sometime and have no link.

INTAKE_PORT_FLOW_STUDY_ON_VARIOUS_CYLINDER_HEAD_USING_FLOWBENCH.pdf

Stan
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Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Valve Seat Angles and Flow Area

Post by RevTheory » Tue Mar 06, 2018 10:52 am

Dumb question, Stan: what is "SAE"?

user-9274568

Re: Valve Seat Angles and Flow Area

Post by user-9274568 » Tue Mar 06, 2018 11:01 am

Stan, I would need to ask Darin how that was written. This is a spreadsheet I got from him many years ago.

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Re: Valve Seat Angles and Flow Area

Post by n2xlr8n » Tue Mar 06, 2018 11:38 am

RevTheory wrote:
Tue Mar 06, 2018 10:52 am
Dumb question, Stan: what is "SAE"?
I'm going to assume it's the Society of Automotive Engineers' formula for discharge coefficient until Stan says otherwise.
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Re: Valve Seat Angles and Flow Area

Post by Stan Weiss » Tue Mar 06, 2018 11:42 am

n2xlr8n wrote:
Tue Mar 06, 2018 11:38 am
RevTheory wrote:
Tue Mar 06, 2018 10:52 am
Dumb question, Stan: what is "SAE"?
I'm going to assume it's the Society of Automotive Engineers' formula for discharge coefficient until Stan says otherwise.
That is correct.

Stan
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Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Valve Seat Angles and Flow Area

Post by pcnsd » Tue Mar 06, 2018 11:39 pm

Stan,

Do you have a link to the referenced pdf file?
- Paul

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Re: Valve Seat Angles and Flow Area

Post by pastry_chef » Tue Mar 06, 2018 11:57 pm

pcnsd wrote:
Tue Mar 06, 2018 11:39 pm
Stan,

Do you have a link to the referenced pdf file?
http://umpir.ump.edu.my/169/1/INTAKE_PO ... WBENCH.pdf
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Re: Valve Seat Angles and Flow Area

Post by pcnsd » Wed Mar 07, 2018 12:44 am

pastry_chef wrote:
Tue Mar 06, 2018 11:57 pm
pcnsd wrote:
Tue Mar 06, 2018 11:39 pm
Stan,

Do you have a link to the referenced pdf file?
http://umpir.ump.edu.my/169/1/INTAKE_PO ... WBENCH.pdf
Thank you for the link. After a quick scan, I will confess that I had hoped for more, still I will pull the equations and logic and see if they are better than what I have.
- Paul

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Re: Valve Seat Angles and Flow Area

Post by Stan Weiss » Wed Mar 07, 2018 10:47 am

Paul,
What I had posted was the calculated MCSA @ each lift point. Using that and its flow I calculated SAE CD and velocity I was only referencing pages 24, 25, 26 of that PDF as a way to calculate the MCSA.

If what you are using is not proprietary. Why don't you post it up so we can have a look and see if it is better or not?

Stan
Stan Weiss / World Wide Enterprises
Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Valve Seat Angles and Flow Area

Post by user-9274568 » Wed Mar 07, 2018 10:54 am

Here is something else that is very beneficial in flow testing. CSA screen based off pitot readings.

Image

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Re: Valve Seat Angles and Flow Area

Post by Rick360 » Wed Mar 07, 2018 2:11 pm

Neither of the spreadsheets in Stan's post are correct in calculating the actual curtain area for different valve seat angles.

There are not enough inputs to calculate it correctly.

Rick

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Re: Valve Seat Angles and Flow Area

Post by CGT » Wed Mar 07, 2018 2:29 pm

Rick360 wrote:
Wed Mar 07, 2018 2:11 pm
Neither of the spreadsheets in Stan's post are correct in calculating the actual curtain area for different valve seat angles.

There are not enough inputs to calculate it correctly.

Rick
Yeah, I noticed that...not the math but the results between the valve angles(differences in window area) are nowhere near what I'm used to seeing using Ricks proprietary software. Therefore the DC figures are junk too.

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Re: Valve Seat Angles and Flow Area

Post by Stan Weiss » Wed Mar 07, 2018 3:02 pm

Stan Weiss wrote:
Tue Mar 06, 2018 10:45 am
I use a much different method for calculating seat area based on seat angle and seat width then what was shown before. This paper has a 3 step method which is very close to what I use to calculate the overall flow area which at most lifts is not the curtain area.

Have had this for sometime and have no link.

INTAKE_PORT_FLOW_STUDY_ON_VARIOUS_CYLINDER_HEAD_USING_FLOWBENCH.pdf

Stan
Reading Comprehension :)

The formulas I quoted came from

"A report is submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Mechanical Engineering with Automotive Engineering"

"The instantaneous valve flow area depends on valve lift and the geometric details of the valve head, seat and stem. There are 3 separates stages to the flow area developments valve lift increases.

Stan
Stan Weiss / World Wide Enterprises
Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

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Re: Valve Seat Angles and Flow Area

Post by Rick360 » Wed Mar 07, 2018 3:28 pm

Stan Weiss wrote:
Wed Mar 07, 2018 3:02 pm
Stan Weiss wrote:
Tue Mar 06, 2018 10:45 am
I use a much different method for calculating seat area based on seat angle and seat width then what was shown before. This paper has a 3 step method which is very close to what I use to calculate the overall flow area which at most lifts is not the curtain area.

Have had this for sometime and have no link.

INTAKE_PORT_FLOW_STUDY_ON_VARIOUS_CYLINDER_HEAD_USING_FLOWBENCH.pdf

Stan
Reading Comprehension :)

The formulas I quoted came from

"A report is submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Mechanical Engineering with Automotive Engineering"

"The instantaneous valve flow area depends on valve lift and the geometric details of the valve head, seat and stem. There are 3 separates stages to the flow area developments valve lift increases.

Stan
Yeah, I saw it and it appears to be the same or similar to the Vizard spreadsheet you posted which is incomplete. Does not have ALL of the variables needed to calculate it fully, but it is simpler. It'd work fine IF the valve is shaped like the one in the picture in that paper, but is incorrect for any type of race valve that I have ever seen or used.

Rick

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Re: Valve Seat Angles and Flow Area

Post by digger » Wed Mar 07, 2018 4:15 pm

There is no way to simple describe it. If you look at cfd results the chamber comes into it as well. Do best you can do is an approximation

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