Stock Pushrods with PAC 1218 springs?
TECH Regular
Joined: Jul 2011
Posts: 452
Likes: 2
See the formula derived by Euler for columns:
http://en.wikipedia.org/wiki/Buckling
The Area Moment of Inertia (I) is a big player in column stiffness. As vettenuts has said, the pushrod OD and wall thickness determine the overall I value. Also, Modulus of Elasticity (E) is a factor ... so material properties does also play a role. Increase both I and E and you have a much stiffer pushrod.
http://en.wikipedia.org/wiki/Buckling
The Area Moment of Inertia (I) is a big player in column stiffness. As vettenuts has said, the pushrod OD and wall thickness determine the overall I value. Also, Modulus of Elasticity (E) is a factor ... so material properties does also play a role. Increase both I and E and you have a much stiffer pushrod.
No doubt...I'm sure the one piece construction of aftermarket pushrods also plays a role, albeit the two major factors are the ones you listed...I actually want to do a stress analysis of stock pushrods vs aftermarket ones but I cannot find a definitive answer on the wall thickness of a stock pushrod...I may have to sacrifice one for the greater good lol...most stock type aftermarket pushrods have an 80 thousandth wall thickness...I'm going to use a stock spring with the stock pushrod and probably use a comp magnum pushrod and 918 spring in the compairison...
TECH Regular
Joined: Jul 2011
Posts: 452
Likes: 2
When I upgraded the valve springs in my 2002 Z06 with PAC 1518 valve springs and the Comp Cams trunnion kit, I also upgrade the pushrods to Mantons. Vettenuts was the guy who recommended the Mantons. I went with the Series 3 #304, 11/32" dia x 0.120" wall. If you search this forum you'll find some of my old threads.
http://www.mantonpushrods.com/
http://www.mantonpushrods.com/
See the formula derived by Euler for columns:
http://en.wikipedia.org/wiki/Buckling
The Area Moment of Inertia (I) is a big player in column stiffness. As vettenuts has said, the pushrod OD and wall thickness determine the overall I value. Also, Modulus of Elasticity (E) is a factor ... so material properties does also play a role. Increase both I and E and you have a much stiffer pushrod.
http://en.wikipedia.org/wiki/Buckling
The Area Moment of Inertia (I) is a big player in column stiffness. As vettenuts has said, the pushrod OD and wall thickness determine the overall I value. Also, Modulus of Elasticity (E) is a factor ... so material properties does also play a role. Increase both I and E and you have a much stiffer pushrod.
No doubt...I'm sure the one piece construction of aftermarket pushrods also plays a role, albeit the two major factors are the ones you listed...I actually want to do a stress analysis of stock pushrods vs aftermarket ones but I cannot find a definitive answer on the wall thickness of a stock pushrod...I may have to sacrifice one for the greater good lol...most stock type aftermarket pushrods have an 80 thousandth wall thickness...I'm going to use a stock spring with the stock pushrod and probably use a comp magnum pushrod and 918 spring in the compairison...
