NEWB Q. Why do the pushrods bend?
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NEWB Q. Why do the pushrods bend?
Why do the rods bend if you bounce the rev limiter? I would have imagined the rev limiter being at a "safe" point to where it would protect everything. I know they are soft and that is a good thing to prevent valve and other damages. I've just always wondered this.
Thanks!
Brandon
PS... yes I searched.
Thanks!
Brandon
PS... yes I searched.
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Originally Posted by BrandonSS
Why do the rods bend if you bounce the rev limiter? I would have imagined the rev limiter being at a "safe" point to where it would protect everything. I know they are soft and that is a good thing to prevent valve and other damages. I've just always wondered this.
Thanks!
Brandon
PS... yes I searched.
Thanks!
Brandon
PS... yes I searched.
#3
Usually when the valves are BANGING into the pistons....probably due to valve float (loss of valve control) at high RPM. Its better the pushrod bends than the valve but sometimes its both.
Last edited by Tony Mamo @ AFR; 03-08-2005 at 10:22 PM.
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I agree and understand why its better. But missing a shift and sending the rpms to 6-6200 just doesnt seem like it should bend a push rod. So the stock rev limiter is useless? Well I wouldnt say useless b/c if it were to go higher then a lot more problems would happen... but you get what I'm saying.
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Originally Posted by BrandonSS
I agree and understand why its better. But missing a shift and sending the rpms to 6-6200 just doesnt seem like it should bend a push rod. So the stock rev limiter is useless? Well I wouldnt say useless b/c if it were to go higher then a lot more problems would happen... but you get what I'm saying.
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Originally Posted by P Mack
He's asking why pushrods bend when you bounce off the rev limiter, no mechanical overrev and no valves hitting pistons. That's a good question. I guess the stock valvesprings aren't good enough for the stock rev limiter?
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Ive run headlong into the revlimiter dozens of times without bending a pushrod. In theory, the rev limiter should be at a safe point before damage occours from valve float. If you truly bent pushrods without mechanically over-revving the motor via missed shift or other error, then there is a problem with your valvetrain besides the anemic pushrods. My guess would be that if youre really hard on your valvesprings, taking it up into the high RPMS constantly, driving the car hard when its cold, etc... My guess is that the valvesprings have lost some seat pressure and are not able to close the valves quickly enough, causing the valve float and thus bending your pushrods when the piston taps the valve. Just one possibility though...
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If it hit the valves he would know it would probably bent the valve a little! It doesn,t have to hit the valve to bend a push rod. I always run a compression check when I used to bent a lot of push rods and the compression on every cylinder was the same!