[turbophil]

Eibach springs are fine on the stock valves. Not enough controlled test data to make a judgement as to whether the heavier springs are good, bad, or indifferent to the stock valves breaking. Most of the stock valves break at the keeper groove. Most likely due to float. So, the eibachs should help prevent this. Again, the data is somewhat circumstantial...

Known fact is the Supertech valves and springs are junk for the 2ZZ. No flame suit needed for that statement, as the evidence is there.

Ferrea springs are not needed on motors with sub ~8500 operating ranges... Ferrea valves are the only replacement valves to install...

Ti Retainers are not needed, but they sound cool.

Bottomline, should be fine to upgrade the springs on the stock valves. The Eibachs will support the Stage 3 cams. No idea if the stock valves will mind the extra lift/duration, but don't see why they would.


-Phil

 

[<@¿@>]

I'm not sure, but I think the OEM valves have only one, deep groove for the spring keeper and the aftermarket ones have two smaller ones. The one deep groove is a stress concentration point that the OEM valves can't hold up. Now if you install stronger springs, you've just made the problem worse.

 

[bri3d]

Perfect, thank you! Exactly the info I was looking for. Makes sense that stock valves are probably happier if they're not getting slapped by the piston.

It would make sense from a labor standpoint to go Stage 2 or 3 while I have the cams out, but I don't want to spend a lot on tuning now if I'm going to go supercharged down the road. As always, more to think about!

 

[turbophil]

I'm not sure, but I think the OEM valves have only one, deep groove for the spring keeper and the aftermarket ones have two smaller ones. The one deep groove is a stress concentration point that the OEM valves can't hold up. Now if you install stronger springs, you've just made the problem worse.

As Ricky Bobby would say, "Now with all due respect, and I do mean, with all due respect"
Dammit man, will you stop that stuff! :thwack: You cannot go off willy-nilly making these statements when they're totally off. It confuses the heck out of threads:thwack:


Now to put the toothpaste back in the tube

There's a single groove in the stock and aftermarket valves. The stock springs are single groove just like all the aftermarket ones.

OE and aftermarket springs are SINGLE spring per valve EXCEPT Ferrea springs. Ferrea is dual spring and they're good for about 11-12,000RPMs. The ferrea springs uses a special stepped seat and retainer to locate the dual springs... not much different than a small-block chevy...

-Phil