At what point are people moving to a thicker wall pushrod over the normal chromoly 0.080”? I was looking to fit a set of Pac 1203 valve springs on a set of Champion iron heads and had come across a lot of information about pushrod deflection. Looking at Pacs site it seems the valve springs will be around 175lbs on the seat and a little bit over 500lbs open. I had plans on using the FullThrottle XR5 214/214 camshaft, combination in my signature, if there will be significant gains across the power band over the current XR3 215/220. From what I gather there is a whole lot more left in my setup by increasing the boost past 32psi.
Pushrod wall thickness and spring pressure
- Thread starter ATL_87GN
- Start date
No disintegrations
Well-Known Member
- Joined
- Dec 27, 2015
I would prefer the stronger heavier pushrods to the lighter possibly more flimsy ones. Better control of the valves should be the result. You're prob not chasing every last rpm, I assume?
- Joined
- Nov 30, 2009
Go to the Trend Performance website for info on pushrod deflection , valve float , bounce & valve loft , or call them directly .
https://blog.trendperform.com/spintron-secrets-valve-float-bounce-and-loft-explained
https://blog.trendperform.com/spintron-secrets-valve-float-bounce-and-loft-explained
- Joined
- Aug 1, 2003
smith bros catalog has a recommended pushrod for spring pressure shart and shows 5/16 .080 CM for up to 700lbs open
on my combo with champion aluminums isky dual springs , 224 solid roller billet cam, jesel rockers .612" lift open pressure 568 (258 closed) .120 taller valves and pushrods over 9" length i went with their 5/16 .116 wall CM rods
on my combo with champion aluminums isky dual springs , 224 solid roller billet cam, jesel rockers .612" lift open pressure 568 (258 closed) .120 taller valves and pushrods over 9" length i went with their 5/16 .116 wall CM rods
That’s what I’ve been trying to find. I really didn’t find much searching on here about it.
- Joined
- Aug 1, 2003
fwiw theres more in your current cam, i heard same thing when i got the cam that it was not good enough and done at 130
in my 86GN i was running over 140 with the 215/220 on cleaned up irons (no runner porting) with a single pac spring t+D 1.55s 5/16 .083 prods
ptc 18 , th400 3.23 gears 275pros ,234cu eagle crank external, K1 rods JE 20, 71hpq on alky +93 3450lbs at 29psi , at 24psi it was still running into the 9s at over 137 with a soft 1.5 60'
stall was 2650 @0 , shifts were 5600-5700 , coupled at 5150 , trapped at 5850
in my 86GN i was running over 140 with the 215/220 on cleaned up irons (no runner porting) with a single pac spring t+D 1.55s 5/16 .083 prods
ptc 18 , th400 3.23 gears 275pros ,234cu eagle crank external, K1 rods JE 20, 71hpq on alky +93 3450lbs at 29psi , at 24psi it was still running into the 9s at over 137 with a soft 1.5 60'
stall was 2650 @0 , shifts were 5600-5700 , coupled at 5150 , trapped at 5850
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