To get or not get pushrods?
08-01-2006, 08:24 PM
#1
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To get or not get pushrods? Ive had about a 50/50 consensus when asking this question. Relatively small cam----
222/222 .566"/.566" on a 112LSA and will be shifting around 6300rpm with 6500rpm limiter. Comp 918 springs to boot.
Ive heard about half say hardened pushrods would be bad here cuz they arent necessity at that load and if you overrev and kiss a piston youve caused a lot more problems than if you overrev and bend some pushrods. At what point do the stock pushrods break and not bend.
The other half of the argument is obvious. Can I have some input? Thanks.
222/222 .566"/.566" on a 112LSA and will be shifting around 6300rpm with 6500rpm limiter. Comp 918 springs to boot.
Ive heard about half say hardened pushrods would be bad here cuz they arent necessity at that load and if you overrev and kiss a piston youve caused a lot more problems than if you overrev and bend some pushrods. At what point do the stock pushrods break and not bend.
The other half of the argument is obvious. Can I have some input? Thanks.
Last edited by Rynofasho; 08-01-2006 at 08:36 PM.
08-02-2006, 12:31 AM
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[B. Pushrods
What they are:
What they do: transfer the motion of the cam to the rockers
What to look for:
- New pushrods aren’t absolutely necessary but they are highly recommended.
- The pushrod was never designed to be a fusible link in the valvetrain. Several years ago we even had a member (might have been in the old LS1.com days) that was an engineer from Jesel (don't recall his ID) and he was adamantly opposed to the notion that the LS1 pushrods were designed to break in the event of a mechanical over-rev. The job of the pushrod is to accurately transmit the motion of the cam lobe (via the rocker arm) to the valve. If it’s flexing under load, then its simply not doing its job.
Look at it this way; you CAN mechanically over-rev any engine - pushrod, OHC, rotary, or otherwise - and cause damage. There is nothing unique or special about the LS1 pushrods making them fusible.
This is like saying that you broke your ring gear on a missed shift so therefore everybody should continue using the weak 10-bolt rear ends. Just a silly, backwards argument IMO - especially when you're considered an aggressive cam with heavier valve springs (Fulton 1)]
This was taken from the sticky at the top of the page.
What they are:
What they do: transfer the motion of the cam to the rockers
What to look for:
- New pushrods aren’t absolutely necessary but they are highly recommended.
- The pushrod was never designed to be a fusible link in the valvetrain. Several years ago we even had a member (might have been in the old LS1.com days) that was an engineer from Jesel (don't recall his ID) and he was adamantly opposed to the notion that the LS1 pushrods were designed to break in the event of a mechanical over-rev. The job of the pushrod is to accurately transmit the motion of the cam lobe (via the rocker arm) to the valve. If it’s flexing under load, then its simply not doing its job.
Look at it this way; you CAN mechanically over-rev any engine - pushrod, OHC, rotary, or otherwise - and cause damage. There is nothing unique or special about the LS1 pushrods making them fusible.
This is like saying that you broke your ring gear on a missed shift so therefore everybody should continue using the weak 10-bolt rear ends. Just a silly, backwards argument IMO - especially when you're considered an aggressive cam with heavier valve springs (Fulton 1)]
This was taken from the sticky at the top of the page.
08-02-2006, 01:28 PM
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Get them.
Any flex in your valvetrain will cause a loss of lift and potential damage.
Imagine a pushrod flexing while in use.When the pushrods go into compression you would be losing lift and if you lose lift you are losing power.Then once the rebound occurs (like a spring) this could cause the pushrod to lose contact with the lifter or the valve to open farther than intended and smack a piston and all kinds of havoc can ensue.
Also the constant flexure due to exceeding the limits of the stock pushrods will cause them to fatigue and "go off" more quickly.
Any flex in your valvetrain will cause a loss of lift and potential damage.
Imagine a pushrod flexing while in use.When the pushrods go into compression you would be losing lift and if you lose lift you are losing power.Then once the rebound occurs (like a spring) this could cause the pushrod to lose contact with the lifter or the valve to open farther than intended and smack a piston and all kinds of havoc can ensue.
Also the constant flexure due to exceeding the limits of the stock pushrods will cause them to fatigue and "go off" more quickly.