How can I calculate what spring height I need for my new cam?
04-17-2003, 08:03 PM
#1
Registered User
Thread Starter
Join Date: Jun 1999
Location: Williamson,WV,USA
Posts: 90
How can I calculate what spring height I need for my new cam?
I bought a bigger cam for my car, and the valve springs are mashing flat. The install height is 1.885, the cam is 654in, 652ex. 254in, 260ex. Is there a formula to calculate what spring install height that I need?
04-18-2003, 08:47 AM
#2
Registered User
Join Date: Oct 2001
Location: smog zone adjacent to a great lake
Posts: 1,462
Not really a formula, just simple math really. You need a spring that has enuf travel plus and additional minimum .05-.06" 'cushion from coil bind. I like to work backwards. For instance, as an example:
A spring has a 'coil bind' dimension of 1.150". Take your lift, (.650") add the .05" cushion to get .700". Add this to the coil bind dimension you get a necessary (for that spring) installed hgt. (minimum) of 1.850. Now ask yourself, does that spring give adequate seat pressure installed at 1.850" to determine if the spring with those specs is usable for your application. Working from the installed hgt. side of things, does little cuz it does not include the coil bind dimension, which is the important limiting criteria to anchor from.
A spring has a 'coil bind' dimension of 1.150". Take your lift, (.650") add the .05" cushion to get .700". Add this to the coil bind dimension you get a necessary (for that spring) installed hgt. (minimum) of 1.850. Now ask yourself, does that spring give adequate seat pressure installed at 1.850" to determine if the spring with those specs is usable for your application. Working from the installed hgt. side of things, does little cuz it does not include the coil bind dimension, which is the important limiting criteria to anchor from.
Thread
Thread Starter
Forum
Replies
Last Post
dbusch22
Forced Induction
6
10-31-2016 11:09 AM