4age stage camshafts Options

[20v_celica]

ok so i wanna buy camshafts for my 20v bt found some but heres wat i need to kno... ive been told if i go stage2 or higher i have to get new valve springs and everything else, but i have also been told the 4age blacktop was originally designed to be boosted like the 4agze, but due to japans economic situation at the time they upped the compression and left it a n/a... could nebody reassure me of the strength of the 4age head??? or do i really have to redo the whole valvetrain if i want stage2 cams??? anybody help!!!

[Kwanza26]

You heard wrong. "Stage 2" doesn't tell anything about a particular camshaft... since different manufactures use have different specs for different stages. As far as valve springs go... the reason some people say you should upgrade valve springs... is because of valve float, which can happen at high rpms. More aggressive cams work the valve train much harder, thus valve float can occur at a lower engine speeds... however cams that can do that typically aren't too good to use on the street anyway... which I imagine is your primary use. That said... don't get too aggressive of camshafts... The stock 20V head is good for about 8500 rpms fairly reliably, even on moderate cams. The next issue... you mention head strength... and that the 20V was designed to be boosted. This is incorrect... Why? ITBs. They are specifically designed for high revving top-end motors. Forced induction motors don't really *need* ITBs to a point, because most factory boosted motors are designed for mid-range power... so it's accurate to say, the 20V was designed, n/a all the way just because the cost-effectiveness of making a boosted ITB 4 banger for cars that run under 30 grand... not really. As far as strength goes... have you ever heard of engine heads failing on their own due to power? Yeah... not really. It's always other stuff that causes head failure... such as gaskets, oiling, valve springs... etc... so don't worry about that.

My advice... learn about cams and how they affect the valve train and make power... then choose a set you can run normally without affecting VVT or the factory valve train.