Valve Seat Angles and Flow Area

[Stan Weiss]

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

Chad_Darin2.GIF

Chad_Flow_EFA.gif

[RevTheory]

Dumb question, Stan: what is "SAE"?

[user-9274568]

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

[n2xlr8n]

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.

[Stan Weiss]

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

[pcnsd]

Stan,

Do you have a link to the referenced pdf file?

[pastry_chef]

Stan,

Do you have a link to the referenced pdf file?

http://umpir.ump.edu.my/169/1/INTAKE_PO ... WBENCH.pdf

[pcnsd]

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.

[Stan Weiss]

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

[user-9274568]

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

[Rick360]

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

[CGT]

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.

[Stan Weiss]

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

[Rick360]

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

[digger]

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