murdocsgarage

I've noticed that the general consensus is to replace the intake retainers with AP2 and leave the exhaust untouched.

Is there a reason that the exhaust is left to AP1? Is there a problem with replacing them all to AP2?

I'm looking to replace my retainers and figured why not just replace them all since it'll be cracked open already. Is it okay to do AP2 on both sides? I feel weird asking that, but I've been seeing people note that they'll buy AP2 retainers for the intake and good ole AP1's for the exhaust. Just trying to figure out what the benefit of keeping the exhaust AP1.

Thanks.

s2klariat

Well, the method behind just changing the intake retainers is that the exhaust side isn't normally subject to cracking. HOWEVER, there have been multiple threads popping up lately where exhaust retainers in AP1's are cracking as well. Supposedly if you've never over revved you should be ok, but in all reality it's cheap insurance if you want to do the exhaust side as well. I'm going to be "refreshing" my valvetrain for when I go boost next year, but I'm going with Brian Crower dual springs with their steel retainers.

murdocsgarage

Thanks for the reply. But that is exactly why I want to just replace all of them. I've seen those cases too, and I'd rather just have all retainers on hand to replace then have half and see that an exhaust one is bad. I don't even know if any of mine are bad or not, just peace of mind I guess. Just trying to figure out if there is a reason some folks are buying AP1 retainers for the exhaust rather than Ap2's. Figure with the valve cover off, I'm half way there might as well replace. lol

But I don't really even drive my car too hard. I personally never mishifted, just have had it pegging the redline a couple times. I'm not the original owner so I don't know how the previous owners treated the car. I've been thinking about getting some aftermarket springs and retainers, but would probably be overkill since I intend to keep the car stock.

s2klariat

Gotcha. Word to the wise, be reallllly careful bolting the valvecover back on. Those little bolts will snap in a heartbeat. Search the correct tightening pattern and use an accurate torque wrench. I tightened all mine to 10ft lbs when I did my valve adjustment last summer but I think the manual calls for 8.7. This was using a crappy dial type torque wrench so I wasn't too confident in it's accuracy so I went a little over. DON'T GO ABOVE 10! It's a pain trying to fish that tiny little bolt out if it snaps.

05thumper

I'm getting mine done today actually. I elected to have all of them swapped to AP2 retainers for piece of mind.

s2000maniac

DONT!! replace the exhaust side with AP2 retainers because the AP1's are designed for a higher lift. If you replace the exhaust side with AP2 retainer, you are defeating the whole purpose. Replace the intake side with AP2 and exhaust side with brand new AP1's. By replacing the exhaust side with AP2 retainers you are bringing down the duration and lift limit of the AP1. So therefore even if you go to 9k you will crack them and drop a valve. But don't quote me on this, ask billman

05thumper

Are you certain about your claims?

It is my understanding that the AP2s sold in Europe (9k redline) have the upgraded AP2 retainers on both the intake and exhaust side. Also, I have clearly seen people with cracked AP1 retainers on the exhaust side on this very same forum. Finally, don't some people swap the ECU in AP2s (or tune them) to rev to 9k instead of 8k?

So let's hear what Billman has to say about it. The shop I went to does a lot of S2k work and recommended swapping the retainers on both sides as well.

s2000maniac

I'm just kind of quoting what billman mentioned in some other posts.

05thumper

Well, I'm just saying there seems to be a lot of mixed information out there. You have a link for where Billman stated what you wrote? I've read about valve float and issues with a miss-shift but never just running up to 9k rpm. Admittedly the AP2 retainers are 17.4% heavier than AP1 retainers but still it's only 2 grams.

I don't normally run past 8.5k rpm anyway but don't want to weaken the valve train. I think AP2 retainers on all valves is the best overall approach. A miss-shift will still cause damage as always.

SpitfireS

Yep.
A mild overrev, without piston-to-valve contact will still damage valve seats, as the valve slams shut.
The valve slamming shut can (and will if you do it long / often enough) crack 1:4 ratio (*) retainers = the AP1 retainer.
A severe overrev, with piston-to-valve contact will damage valves.
In both cases is doesn't matter what retainers you have.

So if you plan on overrevving on a regular basis you should:
#1 - learn how to drive.
#2 - ....

Well, lets face it, there IS no #2, is there.
And yes, I've produced a money shift as well and payed the money to fix it - swapped a head.

(*) - link to post about 1:4 and 1:5 angle ratio retainers.
https://www.s2ki.com/...iners-from-ap2/