I found the picture (I could not see any laser etching or dimples on mine):

 

So the cotters are a different size for the ap2 retainers?! Im going to order enough for the intake and exhaust sides. What part number is the ap2 cotters or where did you buy it from?

 

Yes - they are different (as above). Plug the details of a 2004 S2000 into Majestic Honda's parts website - that's where I ordered mine.

I've never heard of anybody with cracked exhaust retainers - only intake. I only changed my intake side.

 

Interesting, not to go off topic but I bet all the aftermarket aluminum and titanium retainers are made to 1:4 angle ratio spec since they were developed during AP1 release.

 

in the picture above, it shows the dimples on the retainer lined up with the space between the cotters.. is it important to line them up as shown?
im currently replacing mine and i didn't even notice these dimples..!

also, has anyone managed to lift the rocker assembly? i removed the cams but i can't get the rocker assembly to move.. and space is very limited!!

thanks

 

Not threadjacking, but i have an ap1 and i am at 89k miles and i think mine might be shot... would it hurt to change both intake and exhaust sides?

 

If you are going to spend the time and money to change retainers.. just upgrade the springs and retainers to some aftermarket stuff.

the stock springs wear out and have a hard time controlling valve motion anyway.

Its alot of labor to not really make anything better.

 

I planned to replace both intake and exhaust, because the parts arent expensive really so might as well do it while you're there.
The general consensus is that its best to leave the exhaust ones to AP1, and the intake to AP2.
So I ordered AP1 exhaust (retainers only) and AP2 intakes (retainers and cotters).

However, I didnt manage to remove the rocker assembly and found it impossible to remove the exhaust ones ... the spring compressor tool wouldnt even fit.
So I ended up just replacing the intake ones ... I didnt find a single cracked one, so I'm not really worried about the exhaust ones. From the top they also look perfect.

 

i bought the retainers and cotters but never got around installing it. so im selling the ap2 retainers and cotters. pm me if anyone is interested. for cheap too

 

your PM box is full, did you have just the intake cotters/retainers for sale or both exhaust/intake?