Pushrod questions
09-08-2005, 03:41 AM
#1
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Pushrod questions Couple questions.
1. I've heard people say that if you get hardened pushrods (stock motor) then you should upgrade your springs otherwise if you overrev then you'll bend/bust a valve etc. Why would upgrading springs and stuff prevent breaking parts like that? Is it because the springs are so much stronger that they pull the valve out of harms way so fast that the piston wont hit it, eliminate floating, all that?
2. I think that I may have bent a pushrod not from a mechanical overrev but from an accidental free rev bouncing off the limiter for a second. My old hurst was a PITA. Before I replaced it with the pro 5.0 it would have enough "hang up" between gears that I made a shift and let out the clutch and hit the gas but the shifter had hung up between gears and the engine free revved off the limiter for a split second. (It didnt happen all the time, I had another guy drive it and he noticed it was only every once in a while) That was a couple weeks ago. That night and after that I think that everytime I drove the car I had the windows down until the other night. I drove it windows up and could hear a ticking when I push the gas. I listened under the hood and it's barely audible at idle but easily noticeable when I give it a little throttle. I have a set of Comp 7.4"s on the way. I think one might have a little bend. I figure I'll pull the stockers and check them if none are bent then I'll still be upgrading. I'll need them when I get a cam anyway. If it's not the pushrods I'll track it down somewhere else. I've had no issues with the pro 5.0. Sooooo...
My question/s is: I know I torque the rockers down to 22 ft/lbs, what do I torque the valve cover bolts to?
Should I torque in 2 steps? Once to 18 ft then to 22 ft?
I'm not going to rotate the engine while I reinstall the rockers, once I start the car the rocker assembly will be a little noisy and need to re-pressurize due to the bleed off from the uninstall but will go away after a few minutes. Is this correct?
Thanks.
1. I've heard people say that if you get hardened pushrods (stock motor) then you should upgrade your springs otherwise if you overrev then you'll bend/bust a valve etc. Why would upgrading springs and stuff prevent breaking parts like that? Is it because the springs are so much stronger that they pull the valve out of harms way so fast that the piston wont hit it, eliminate floating, all that?
2. I think that I may have bent a pushrod not from a mechanical overrev but from an accidental free rev bouncing off the limiter for a second. My old hurst was a PITA. Before I replaced it with the pro 5.0 it would have enough "hang up" between gears that I made a shift and let out the clutch and hit the gas but the shifter had hung up between gears and the engine free revved off the limiter for a split second. (It didnt happen all the time, I had another guy drive it and he noticed it was only every once in a while) That was a couple weeks ago. That night and after that I think that everytime I drove the car I had the windows down until the other night. I drove it windows up and could hear a ticking when I push the gas. I listened under the hood and it's barely audible at idle but easily noticeable when I give it a little throttle. I have a set of Comp 7.4"s on the way. I think one might have a little bend. I figure I'll pull the stockers and check them if none are bent then I'll still be upgrading. I'll need them when I get a cam anyway. If it's not the pushrods I'll track it down somewhere else. I've had no issues with the pro 5.0. Sooooo...
My question/s is: I know I torque the rockers down to 22 ft/lbs, what do I torque the valve cover bolts to?
Should I torque in 2 steps? Once to 18 ft then to 22 ft?
I'm not going to rotate the engine while I reinstall the rockers, once I start the car the rocker assembly will be a little noisy and need to re-pressurize due to the bleed off from the uninstall but will go away after a few minutes. Is this correct?
Thanks.
09-08-2005, 06:44 AM
#2
TECH Senior Member
Originally Posted by LSWannabe
Couple questions.
1. I've heard people say that if you get hardened pushrods (stock motor) then you should upgrade your springs otherwise if you overrev then you'll bend/bust a valve etc. Why would upgrading springs and stuff prevent breaking parts like that? Is it because the springs are so much stronger that they pull the valve out of harms way so fast that the piston wont hit it, eliminate floating, all that?
1. I've heard people say that if you get hardened pushrods (stock motor) then you should upgrade your springs otherwise if you overrev then you'll bend/bust a valve etc. Why would upgrading springs and stuff prevent breaking parts like that? Is it because the springs are so much stronger that they pull the valve out of harms way so fast that the piston wont hit it, eliminate floating, all that?
2. I think that I may have bent a pushrod not from a mechanical overrev but from an accidental free rev bouncing off the limiter for a second. My old hurst was a PITA. Before I replaced it with the pro 5.0 it would have enough "hang up" between gears that I made a shift and let out the clutch and hit the gas but the shifter had hung up between gears and the engine free revved off the limiter for a split second. (It didnt happen all the time, I had another guy drive it and he noticed it was only every once in a while) That was a couple weeks ago. That night and after that I think that everytime I drove the car I had the windows down until the other night. I drove it windows up and could hear a ticking when I push the gas. I listened under the hood and it's barely audible at idle but easily noticeable when I give it a little throttle. I have a set of Comp 7.4"s on the way. I think one might have a little bend. I figure I'll pull the stockers and check them if none are bent then I'll still be upgrading. I'll need them when I get a cam anyway. If it's not the pushrods I'll track it down somewhere else. I've had no issues with the pro 5.0. Sooooo...
My question/s is: I know I torque the rockers down to 22 ft/lbs, what do I torque the valve cover bolts to?
Should I torque in 2 steps? Once to 18 ft then to 22 ft?
I'm not going to rotate the engine while I reinstall the rockers, once I start the car the rocker assembly will be a little noisy and need to re-pressurize due to the bleed off from the uninstall but will go away after a few minutes. Is this correct?
Thanks.
Thanks.