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Thread: Looking to build a safe 9k RPM head

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Posts: 11-18 of 18
2011-05-16 14:47:08
#11
Yeah, avoid rocker arm stoppers at all cost. If you get valve float you would rather throw the rocker than have it stay in place for the piston to come back up and hit the valve. Seen way too many motors destroyed because of rocker arm stoppers. Even without doing the twin grooved shim mod you can still rev your valvetrain to 8k with the s4s and stock springs and retainers. Even more safe with some BC springs and titanium retainers. I would do springs and retainers though. Its insurance and at 8k you wont be floating the valves at all.
2011-05-16 20:12:41
#12
Ok, cool guys. I really appreciate all the info. I wanted to do S&R at least. Which would be the best place to get them from? Any good deals out there now? I'd buy some used if anyone has a spare set. Also, would an N60 MAF and 3" CAI be of any real benefit over the DE MAF and 2.5" CAI I have now? This is just considering better flow possibly. I'm using the ebay SS (1 7/8-2"? don't know exactly?) header out to a 2.5" magnaflow glasspack with a side exit exhaust. I just thinking about doing these last few things before I get it tuned, because I won't be doing anything else to it in the near future. Mechanically anyway.
2011-05-16 23:35:26
#13
Originally Posted by Boostlee
Please do not listen to this advice (about buying RAS stoppers that is)

A dropped valve and damaged pistons are ALOT more expensive to fix that $100

And last I checked, DEs are still somewhat more than $100..........


opps, i ment to say the ras are less than $100,i know sr20's cost a lot more than 100. sorry if i pissed anyone off.
2011-05-17 00:26:34
#14
momma said rocker arm stoppers are the devill
2011-05-17 00:49:11
#15
Originally Posted by Barney'sB14
opps, i ment to say the ras are less than $100,i know sr20's cost a lot more than 100. sorry if i pissed anyone off.


He (and the rest of us) knew that you were referring to the RAS as being less than $100, but RAS are junk. It's much more beneficial to throw a rocker arm than to have a piston run into a valve because a motor costs more than repairing valvetrain.
2011-05-17 01:20:05
#16
Rocker arm stoppers are no good... and it's funny that under his username it said SR20 Prodigy
2011-05-17 05:38:14
#17
CN: No RAS means rockers pop out and act as a "fuse," usually only needing to be put back in place or small parts replacement (shims etc). RAS on stock valvetrain supposedly holds the rocker in, but this can then jam the valve open, thus coming into contact with the piston, bending the valve and possibly other damage. If the valvetrain is upgraded (springs & retainers) the spring will hold the valve closed and push the rocker out against the RAS, thus causing almost zero damage. (got this off another forum)
but why do you think i said "buy rocker arm stoppers along with your springs and retainers." (i mean aftermarket obviously) i knew what damage can be done with stock springs/retainers
2011-05-17 06:05:12
#18
The spring will not always push the rocker out onto the RAS. The RAS pushes down on the end of the rocker arm right at the lifter thus keeping it on the lifter. That isnt to say the rocker cant still pop out if something happens such as a mechanical overrev or whatever. If this happens and the rocker is being held onto the lifter the cam will come back around and still push the rocker onto the retainer or into the spring and cause the valve to drop or bend the valve. You name it, its happened. Its much safer to throw the rocker out of the way and maybe get broken against the head than to stay hovering over the retainer and spring. At worst case senerio when you throw a rocker with no RAS you might shatter the rocker and have to replace it. Better that than having to replace the motor or head.

Most knowledgeable people on this forum know RAS are no good. Period. Aftermarket valvetrain or not. The little drifter boys still swear by them and same with all the forumula d and japanese racers and so on. And they wonder why they blow the motor and drop valves when bouncing off the rev limiter and a rocker still pops off and then destroys the motor. But they swear by them so they must be good right? Wrong
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