|
12-08-2018, 12:30 AM | #1 |
Senior Member
Join Date: Nov 2007
Posts: 615
Likes: 56
Liked 166 Times in 59 Posts
|
math class needed on valve springs
what is the math formula for a known spring rate to calculate seat and open pressure ?
spring rate is 370lbs @ 1.00" closed valve spring installed heigh1.780 open valve spring height 2.237 seat pressure ? open pressure ? thanks in advance |
12-08-2018, 02:21 AM | #2 |
VIP Member
Join Date: Oct 2007
Posts: 1,104
Likes: 412
Liked 250 Times in 101 Posts
|
Re: math class needed on valve springs
|
12-08-2018, 09:57 AM | #3 | |
VIP Member
Join Date: Nov 2001
Location: Florida
Posts: 1,538
Likes: 34
Liked 132 Times in 48 Posts
|
Re: math class needed on valve springs
Quote:
370 rate x .543" lift = 200.91 lbs more than whatever you set/start with the installed height at. You have to have a baseline height/pressure to calculate from, which the spring chart or actual test pressure will provide. That height is a variable based on valve stem length, +/std./- locks & retainers, spring seat machine work, depth of valve job seats.
__________________
LOCOMOTION Racing Last edited by Myron Piatek; 12-08-2018 at 10:03 AM. |
|
12-08-2018, 11:00 AM | #4 |
Member
Join Date: Nov 2014
Posts: 305
Likes: 609
Liked 169 Times in 84 Posts
|
Re: math class needed on valve springs
If you can afford it, this is the cats meow..............
https://www.summitracing.com/parts/l...+5ba26a96cdb6b Wish I had it years ago! |
12-08-2018, 01:43 PM | #5 |
Senior Member
Join Date: Jan 2008
Location: 100th Meridian
Posts: 570
Likes: 116
Liked 280 Times in 139 Posts
|
Re: math class needed on valve springs
What is the valve lift on the int. and exh.?. gsa612
|
12-08-2018, 04:59 PM | #6 |
VIP Member
Join Date: Feb 2014
Location: Lakewood Washington
Posts: 1,407
Likes: 29
Liked 236 Times in 127 Posts
|
Re: math class needed on valve springs
If you can find a comparable spring on the PAC Racing site, this link to their spring rate calculator might help.
https://www.racingsprings.com/index..../?sku=PAC-1224 Edit: Change the part number to your match.
__________________
Dale Shearon 68 Mustang 6394 |
12-08-2018, 06:08 PM | #7 |
Senior Member
Join Date: Feb 2002
Location: Southeast Michigan
Posts: 888
Likes: 63
Liked 224 Times in 103 Posts
|
Re: math class needed on valve springs
The basic formula is F=kX . F is the force , k is the rate , X is the difference in spring height from the length of the spring when it is not loaded .
Last edited by ss3011; 12-08-2018 at 06:09 PM. Reason: Clarify |
12-09-2018, 12:29 AM | #8 |
Member
Join Date: May 2014
Location: E TN
Posts: 442
Likes: 14
Liked 106 Times in 61 Posts
|
Re: math class needed on valve springs
Is the spring rate 370lbs per inch? Is the installed height 1.780? Open height can't be more than closed, what is the free height of the spring?
|
12-09-2018, 11:47 AM | #9 | |
Senior Member
Join Date: Oct 2002
Location: Pittsburgh
Posts: 521
Likes: 246
Liked 550 Times in 106 Posts
|
Re: math class needed on valve springs
Quote:
To add to above, the spring rate is stated as the force generated per unit of compression. Ex: 1,000 Lbf/Inch, 1,700 N/cm etc. Also, its spring FORCE, not pressure. Spring pressure is a common misnomer racers seem to always use, and it just wont die. Its entirely wrong. Its not a pressure, Its a force. |
|
12-09-2018, 10:11 PM | #10 |
Senior Member
Join Date: Nov 2007
Posts: 615
Likes: 56
Liked 166 Times in 59 Posts
|
Re: math class needed on valve springs
|
|
|