Hardened Push Rods - some say use them - some say stay away from them..
06-27-2002, 09:15 PM
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Hardened Push Rods - some say use them - some say stay away from them.. I want to know what you guys (as in a consensus) think about using hardened push rods...
I have been told by a few that they dont use them because the stock rods are weak and act as a fuse for the valve train in case there is too much stress and bend without tearing anything up.. like flatening a lifter or breaking a rocker arm.. etc....
And then others say, thats bull puddy and that you are smart to use hardened push rods cause it will prevent them from bending and force the stressed action to take place without failure..
What do you guys think??
BP
I have been told by a few that they dont use them because the stock rods are weak and act as a fuse for the valve train in case there is too much stress and bend without tearing anything up.. like flatening a lifter or breaking a rocker arm.. etc....
And then others say, thats bull puddy and that you are smart to use hardened push rods cause it will prevent them from bending and force the stressed action to take place without failure..
What do you guys think??
BP
06-27-2002, 09:45 PM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. IMO the stock pushrods were never designed as a "fuse" - that's just silly. If the factory wanted to build in overrev protection they would have used something like an RPM-sensitive "drag CAGS". The fact is that you can miss a gear with ANY manual transmission and cause engine damage regardless of the pushrod construction (even in an OHC engine you could cause damage!). The purpose of the pushrod is to accurately transmit the cam profile to the valve and that's it (well, preferably in as cheap and lightweight a fashion as possible <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> ). When it's prone to flexure it cannot properly do its job.
That's strictly my opinion and the reason I upgraded to hardened pushrods when I did my cam (even though my LS6 springs don't necessarily warrant the change).
That's strictly my opinion and the reason I upgraded to hardened pushrods when I did my cam (even though my LS6 springs don't necessarily warrant the change).
06-27-2002, 10:23 PM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. With my A4 I'll definately go with hardened push rods when the time comes, but if I had a M6 I'd be a little worried about it. If I had to make the decision right now I wouldn't. As you said I'd rather have a missed shift cause me to replace pushrods than something a helluvalot more expensive.
A friend of mine dropped his M6 six in second at 90mph by accident. One of his push rods came out out almost completely broke in half the bottom was straight and the rest was bent pretty severly
You can only imagine what would have happened with a hardened pushrod, it would have transferred all that energy to someplace else.
However, when he did replace them he put in a hardened set. His reasoning was that he didn't want to have to deal with bending pushrods anymore. So go figure. <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />
<small>[ June 27, 2002, 10:24 PM: Message edited by: CamaroSS_2002 ]</small>
A friend of mine dropped his M6 six in second at 90mph by accident. One of his push rods came out out almost completely broke in half the bottom was straight and the rest was bent pretty severly
You can only imagine what would have happened with a hardened pushrod, it would have transferred all that energy to someplace else.
However, when he did replace them he put in a hardened set. His reasoning was that he didn't want to have to deal with bending pushrods anymore. So go figure. <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />
<small>[ June 27, 2002, 10:24 PM: Message edited by: CamaroSS_2002 ]</small>
06-27-2002, 10:44 PM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. Just because you bend a couple pushrods doesn't mean you wont keep winding it up. It still makes power.
06-28-2002, 07:04 AM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. I would ( and have ) rather bend up some
push rods $15 each than bend expensive stuff
from the meeting..
"Mr Piston.. meet Mr Valve "
push rods $15 each than bend expensive stuff
from the meeting..
"Mr Piston.. meet Mr Valve "
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06-28-2002, 07:19 AM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. I would never put a bigger than stock cam in any of these cars without better pushrods. Just IMO.
06-28-2002, 07:48 AM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. Havn't you guys heard of rev limiters?
Last I checked this was a pretty simple way of making sure yourmotor didn't over rev...or am I off track?
Last I checked this was a pretty simple way of making sure yourmotor didn't over rev...or am I off track?
06-28-2002, 08:58 AM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Havn't you guys heard of rev limiters?
Last I checked this was a pretty simple way of making sure yourmotor didn't over rev...or am I off track? </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">A rev limiter is great for a throttle overrev (e.g. you don't shift when you reach redline), but it'll do you no good in a mechanical overrev condition (e.g. putting it in a lower gear by accident - forcing the engine revs to match the wheel speed in that lower gear).
Proper shifting technique goes a long way toward preventing "putting it in 2nd gear at 90mph by accident" <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />
<small>[ June 28, 2002, 08:59 AM: Message edited by: Fulton 1 ]</small>
Last I checked this was a pretty simple way of making sure yourmotor didn't over rev...or am I off track? </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">A rev limiter is great for a throttle overrev (e.g. you don't shift when you reach redline), but it'll do you no good in a mechanical overrev condition (e.g. putting it in a lower gear by accident - forcing the engine revs to match the wheel speed in that lower gear).
Proper shifting technique goes a long way toward preventing "putting it in 2nd gear at 90mph by accident" <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />
<small>[ June 28, 2002, 08:59 AM: Message edited by: Fulton 1 ]</small>
06-28-2002, 11:40 AM
#12
Re: Hardened Push Rods - some say use them - some say stay away from them.. I have seen some pics of big time damage to valves and stuff from running hardened pushrods with stock springs.With much better valve springs
almost everyone seems to run them and I haven't heard of many or any problems.I also found the best way to avoid the 3 to 2 shift..turn your palm towards passenger door and push your elbow up also towards passenger door,your thumb will be pointing towards floor..this position makes it very hard to hit the 3 to 2.I am having some problems with the 2 to 3 at very high rpm but the rev limiter does cut in when you miss third.I also somehow did the 3 to 2,even locked up my rear end a bit with my stock springs and pushrods but must have got lucky since nothing was even slightly bent.Maybe the low miles on the car saved it.the factory garbage springs were still a bit strong.
almost everyone seems to run them and I haven't heard of many or any problems.I also found the best way to avoid the 3 to 2 shift..turn your palm towards passenger door and push your elbow up also towards passenger door,your thumb will be pointing towards floor..this position makes it very hard to hit the 3 to 2.I am having some problems with the 2 to 3 at very high rpm but the rev limiter does cut in when you miss third.I also somehow did the 3 to 2,even locked up my rear end a bit with my stock springs and pushrods but must have got lucky since nothing was even slightly bent.Maybe the low miles on the car saved it.the factory garbage springs were still a bit strong.
06-29-2002, 09:40 PM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. I just installed the TR 230 with 918's and their pushrods. One of the intake springs broke, dropped the valve. The rocker pushed the rod so hard down that it punctured a hole in the lifter. I had to have the head replaced as well as the lifter of course, I may have to replace the cam. Had the stock rods been in it simply would have bent. I am replacing them with stock pushrods. Everyone that has said that they would rather replace rods than heads is 100% correct. I am a perfect example of how a spring can basically **** your motor royally.
06-29-2002, 11:07 PM
#14
Re: Hardened Push Rods - some say use them - some say stay away from them.. Hmm, are you saying that hardened pushrods only exascerbate piston/lifter/valve/rocker damage if a spring breaks?
I've had four springs break in the last year (4 Rev 3115's, three on the original set and one a few days ago on the replacement set). Replaced the Rev's with a complete set of 918's earlier this week.
If these aftermarket springs aren't going to have the same kind of reliability as the stock springs had on the stock valvetrain, I'm thinking I'll revert to stock pushrods...if I don't have custom length pushrods, that is...?
I haven't missed a shift in a long time with my stock shifter, but they didn't include an idiot light on the instrument cluster which says it's time to replace the valvesprings. The first three died after ~18 months and ~22K miles. The last one died after 9 months and <20K miles.
I'll be irritated if my hardened pushrods have caused needless repair expense when the valvesprings died. <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" />
I've had four springs break in the last year (4 Rev 3115's, three on the original set and one a few days ago on the replacement set). Replaced the Rev's with a complete set of 918's earlier this week.
If these aftermarket springs aren't going to have the same kind of reliability as the stock springs had on the stock valvetrain, I'm thinking I'll revert to stock pushrods...if I don't have custom length pushrods, that is...?
I haven't missed a shift in a long time with my stock shifter, but they didn't include an idiot light on the instrument cluster which says it's time to replace the valvesprings. The first three died after ~18 months and ~22K miles. The last one died after 9 months and <20K miles.
I'll be irritated if my hardened pushrods have caused needless repair expense when the valvesprings died. <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" />
06-30-2002, 01:08 AM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. Bent three stock rods broke one missing the 3 > 4 shift in a drag race. Not pretty, but glad it wasn't worse.
06-30-2002, 10:36 AM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. guy you making me worried now <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> the hardened pushrods on their way along with the cam! I haven't missed a shift for a long time but still, bending a pushrod is much much better than f*cking the internals!
should I stick with stock rods or not???
should I stick with stock rods or not???
06-30-2002, 02:03 PM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. Ive been running hardened pushrods for over a year now. I have missed shifts, downshifted and over revved, you name it. I have never damaged anything. I think some people are over reacting. Hardened pushrods are a must in my eyes with any decent size cam.
06-30-2002, 02:54 PM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Cammin BeaSSt:
<strong>Ive been running hardened pushrods for over a year now. I have missed shifts, downshifted and over revved, you name it. I have never damaged anything. I think some people are over reacting. Hardened pushrods are a must in my eyes with any decent size cam.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I feel much much better now
and I feel like <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> LOL
<strong>Ive been running hardened pushrods for over a year now. I have missed shifts, downshifted and over revved, you name it. I have never damaged anything. I think some people are over reacting. Hardened pushrods are a must in my eyes with any decent size cam.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I feel much much better now
and I feel like <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> LOL
06-30-2002, 04:42 PM
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Re: Hardened Push Rods - some say use them - some say stay away from them.. As I tried to point out above, a pushrod is NOT intended to be a sacrificial link in the valvetrain. If it happens to save you from major engine damage during a mechanical overrev then consider yourself lucky because its not by design. Also, assuming that a weak pushrod is "good insurance" is really a backwards argument. The real insurance would be the driver's skill in not missing shifts in the first place.
Stock pushrods are adequate for the stock cams and wimpy springs. However, if you are using stronger valve springs (i.e. greater open spring loads), more aggressive cam lobes, or planning on running higher rpms, then you should be using hardened pushrods. Under the above conditions stock pushrods can flex resulting in a spring-like behavior. This is undesirable in a valvetrain because it prevents the cam profile from being accurately transmitted to the valve, which is the whole purpose of the pushrod. Hardened pushrods will reduce this flexure a great deal and help to stabilize the valvetrain.
Again, there is really no benefit to running hardened pushrods with otherwise stock equipment, but for high performance applications there is a definite benefit.
Stock pushrods are adequate for the stock cams and wimpy springs. However, if you are using stronger valve springs (i.e. greater open spring loads), more aggressive cam lobes, or planning on running higher rpms, then you should be using hardened pushrods. Under the above conditions stock pushrods can flex resulting in a spring-like behavior. This is undesirable in a valvetrain because it prevents the cam profile from being accurately transmitted to the valve, which is the whole purpose of the pushrod. Hardened pushrods will reduce this flexure a great deal and help to stabilize the valvetrain.
Again, there is really no benefit to running hardened pushrods with otherwise stock equipment, but for high performance applications there is a definite benefit.