Valve Spring question..
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Valve Spring question..
When buying valve springs - what parameter gives you the maximum lift of a certain spring???
How do I determine what spring is right for my application?
I'm thinking that - if I keep my '68 - I want to upgrade my springs and put a larger solid cam into the car (over .600 lift).. Now I'd like to find the right spring that would handle the additional lift... My current springs are only good to my current lift of .545
Here is an example of specs for a spring:
Outer Diameter Outer 1.560
Outer Diameter Inner 1.146
Inner Diameter Inner .766
Damper YES
Seat Pressure @ Installed Height 194# @ 1.950
Open Pressure and Height 485# @ 1.320
Coil Bind 1.210
Average Spring Rate 462 #/IN
Which one of those parameter gives me the maximum lift??
[Modified by GrandSportC3, 7:39 PM 2/5/2004]
How do I determine what spring is right for my application?
I'm thinking that - if I keep my '68 - I want to upgrade my springs and put a larger solid cam into the car (over .600 lift).. Now I'd like to find the right spring that would handle the additional lift... My current springs are only good to my current lift of .545
Here is an example of specs for a spring:
Outer Diameter Outer 1.560
Outer Diameter Inner 1.146
Inner Diameter Inner .766
Damper YES
Seat Pressure @ Installed Height 194# @ 1.950
Open Pressure and Height 485# @ 1.320
Coil Bind 1.210
Average Spring Rate 462 #/IN
Which one of those parameter gives me the maximum lift??
[Modified by GrandSportC3, 7:39 PM 2/5/2004]
Race Director
Joined: Apr 2000
Posts: 17,673
Likes: 199
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Re: Valve Spring question.. (GrandSportC3)
Installed height minus coil bind I believe. 1.95 - 1.21 = 0.74 in.
Many more things to consider with springs and you should use what the cam manufacturer suggests.
You could get the correct lift and pressures open and closed but there is also spring harmonics to worry about and the springs the cam manufacturer recommends should cover that. :D
Many more things to consider with springs and you should use what the cam manufacturer suggests.
You could get the correct lift and pressures open and closed but there is also spring harmonics to worry about and the springs the cam manufacturer recommends should cover that. :D
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Re: Valve Spring question.. (MotorHead)
Installed height minus coil bind I believe. 1.95 - 1.21 = 0.74 in.
Many more things to consider with springs and you should use what the cam manufacturer suggests.
You could get the correct lift and pressures open and closed but there is also spring harmonics to worry about and the springs the cam manufacturer recommends should cover that. :D
Many more things to consider with springs and you should use what the cam manufacturer suggests.
You could get the correct lift and pressures open and closed but there is also spring harmonics to worry about and the springs the cam manufacturer recommends should cover that. :D
Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Re: Valve Spring question.. (GrandSportC3)
The open pressure height it the maximum recommended hieght to run a spring to and still get good life out of it. The closer you run a spring to coil bind the more heat it will generate and the shorter the life it will have.
1.950 Seat Height minus
1.320 Open Height
------
0.630 maximum recommended lift for good valve spring life.
1.950 Seat Height minus
1.320 Open Height
------
0.630 maximum recommended lift for good valve spring life.
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Re: Valve Spring question.. (Pete79L82)
The open pressure height it the maximum recommended hieght to run a spring to and still get good life out of it. The closer you run a spring to coil bind the more heat it will generate and the shorter the life it will have.
1.950 Seat Height minus
1.320 Open Height
------
0.630 maximum recommended lift for good valve spring life.
1.950 Seat Height minus
1.320 Open Height
------
0.630 maximum recommended lift for good valve spring life.
