Rocker Arm Stoppers: Good or Bad?

[the555car]

Hi All

I came across some information on the a SR20DE forum, debating the effectiveness of using rocker arm stoppers (RAS) on an SR20DE (FWD) with stock valvetrain.

The verdict (not agreed by all, but seems to be the general consensus) was:
- NO RAS on stock valvetrain as it causes more damage than it prevents
- YES RAS on built valvetrain (springs + retainers mainly)

Please read the following links for the debate and more information:
Read me (http://www.sr20forum.com/all-motor/153679-rocker-stop-not.html)
Read me (http://www.sr20forum.com/general-sr20/211834-rocker-stoppers-good-bad-wtf-where-you-thinking.html)
Definitely read me (http://www.sr20forum.com/turbo/119852-threw-rocker-arm-even-though-rocker-stopper.html)
Yes read this too (http://www.sr20forum.com/turbo/118462-best-valve-springs-s4s-cam-gear-questions.html)
Last one (http://www.sr20forum.com/all-motor/124447-what-check-when-putting-new-cams.html)

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.

Does this pertain to the RWD SR20DET that is commonly swapped into a 240SX? I am assuming so as they valvetrain is set up very similar and the RAS fits either engine. If they are completely separate and this issue does not concern RWD SR20DET engines, please close this thread

Anyone experienced rockers popping out or engine damage to RAS? Please include whether or not your valvetrain was stock, the damage that occured, and what (you think) caused the damage.

I realize that the general way of thought is that RAS are good insurance, this was my perception as well, until reading those threads. I was under the impression that the RAS would stop the rockers from flying out, and they would just sit there nicely and all would be well. I am looking for more information related to RWD SR20DETs, as for obvious reasons, there isn't much on the SR20DE forum.

Please do not post without backing up your comments with some sort of reasoning and proof (photos, data, anything) if you have it.

cheers
-Evan

NB: All claims/information/data are from what I have read, I have no direct experience with this, nor to I agree or disagree with either school of thought at the moment.

[HYPNOTIK]

I've never heard of problems caused by RAS. Don't over rev and you won't have a problem. I've been using RAS for the last year with no issues. Revved to 8200 on a few occasions.

[Boostin 240]

I have the circuit sport rocker stoppers never had any problems

[fliprayzin240sx]

Personally, its always better to have it than none at all. For stock, definitely nice to have it just in case you miss-shift or pinging off the redline.

[the555car]

Personally, its always better to have it than none at all. For stock, definitely nice to have it just in case you miss-shift or pinging off the redline.

Right, this is what I thought as well, because you can throw a rocker at high rpm and it will bounce around in the valve cover. But in the links above, it is discussed that this causes less damage than having the RAS on stock valvetrain, which caused bent valves and other cam/head damage in some cases (also discussed and show in the threads above).

Keep posting up guys,

cheers
-Evan

[volcomprodigy02]

7200rpm rev limit stock valvetrain with ras, the ras stopped my rocker from flying off alright, my rocker just snapped in half and dropped a valve. I think its more of a luck of the draw situation.

[codyace]

There really isn't any 'right' answer to this

No RAS:
Pro-There are instances where people can scatter rockers, and not ruin anything.
Con-There are others where it becomes rocker arm salad i the valvetrain, ruining anything

With RAS:
Pro-There are guys who have overshifted without issue.
Con- There are people who have had rockers come up and bind, bending valves. Also have seen (would hafta search again for it) guys still kick rockers sideways/spit shims with the RAS too.


As pointed out above, the only true 'fix' is to not mis shift, or over-rev. Sounds simple, but we all have done it. Those of us on track probably more than those on street, but it exists.

I personally have had a set of RAS in my car since day one. I dont' have good luck, so if I kicked a rocker i'd have metal soup uptop and ruin the head anyway. I figured the RAS may give me *some* safety. I would install them again.

[the555car]

Good info, thanks guys.

Upon further musing on the worst case scenarios for each option, if for example a single rocker were to bind, 2 valves would be bent and would need replacing plus whatever little things break, whereas if a single rocker arm flies around and could potentially wreck everything in the head, instead of just the two valves from the one binding rocker.

I have a set that I was debating whether or not to install and I think I may take your advice codyace, mainly because you have the Bandit as your avatar...

cheers
-Evan

[uperformance]

my current sr is fully stock, only got ras on the top end. ive banged 8500 for 4-8 seconds on the rev limit and several times each race. i also run 21 psi. on a 3071. i put 1200 track km on it last year and i ran it hard with no problems.

honestly, my last sr setup didnt last a day of daily driving abuse without 3 rocker arms breaking and valve chunks chewed up my cams. stock valvetrain or not, every sr i run will have ras installed.

[deathrace2000]

I can't say that I know much about RAS and their application in an SR. However, some tool from my are destroyed his new engine because of the supposed lack of rocker arm stoppers.