Stick to your stock cams.

I already gave you all the info you need.

 

I read what you wrote but it doesn't make sense. You stated the retainer would bottom out, how would an aftermarket retainer be any different, are they that much thinner? So if that is the question then why not just get some skinny retainers if that is the part in question.

 

Because valve float.

You can get springs that will support them for around $300.

Just spend the money if you need those cams.

 

The real question is why are you trying to run camshafts that are meant for 10k RPM with a 64mm or larger turbo going all in for big power numbers in a "stockish setup at 20psi".


The stock retainer bottoms out because it is thicker.

 

What I wrote makes perfect sense, and that's exactly how it is. Aftermarket retainers are much thinner. There's no aftermarket retainers for stock springs because they're very narrow beehives and it'd be stupid to do that anyway because the retainers would cost just as much as getting proper springs for the cams.

Based on the fact alone that you're going to run a stock turbo and factory redline means you have zero need for a larger cam. If you're wanting to do this because you want your car to sound wIcKed cOOlz yO at idle and gain all the scene points at the local car show then bump your idle down to 400rpm on stock cams.

 

S3's don't even really lope. Just get S2's if that's all you're after.

 

I am not trying to run anything, this is theory only, of course running those cams on stock setup would be pointless, but let's say you were stranded in the desert with a broken cam shaft and the only thing available was the S3, could you successfully run it without creating damage to the engine, performance be damned.

 

So, now we've come to a hypothetical that will never happen. Great.

 

Ok I got confirmation here and from GSC that coil bind would occur because of what was said above, thank you all for your time, I appreciate your input and the info. Wasn't this easier just asking then trying something dumb?? This is why I still read the forums, great info as always.

Thank you.

I got some follow up info that didn't make sense to me from EVOAustin, I got it figured out now.

This was from GSC "Replacing the springs alone is an issue as the OEM retainer bottom will contact the valve stem seal and cause oil to enter the cylinder over time."

I am not saying that that cam lift spec you gave is wrong, this is addition too, you just can't replace the springs only but I always thought retainers came with spring sets.

So it needs to be a fully matched springs, retainers, cam set to work properly.

 

Wonders never cease to amaze. Neither do people haha