6G Celicas Forums

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!!!

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.

the stage 2 i speak of has 272/272 duration compared to the 255/258 stock duration... and .321/.321 gross lift compared to the .340/.346 stock gross lift... thats all i kno about them... as far as the boost goes well i was told the motor was designed to handle boost like its predicessor 4agze but they upped the compression and added the ITBs but like i said idk i heard this from a lexus mechanic... neways those numbers on the stage 2's and the stock cams are the only things i got and i have no idea wat they mean... there is also a 7.8mm stock something and i can choose from 8mm or a bunch of other sizes... any idea wat these numbers mean in respect to valve float??? to be honest i have no idea wat that means either haha

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Which camshafts are you getting? The only ones I can even think of are toda Camshafts. There was a few sets that didn't require you to get valve spring sets but there was 1-2 of them that did, but those were high durations. I don't think you want to make your motor such high duration unless your going for some seriouse Horsepower and high revving. I think if there too high your rpms stick around 2-3000 rpms, and you prob don't want that unless in a daily driver. By the way there so expensive, last time i checked they were around $600-1000 for 1 camshaft.

haha yea i kno well crower makes some and toda makes some... yes they are very expensive a set of two is like $1200 at the least... i kno stage 3's and up will set ur idle at about 3grand... my idle is already at 1100 so i figure some stage 2's will not be so bad, gain horse power without bein too annoyed at the idle and still save a lil bit of gas haha... but if u dont kno about the stages can u at least give me some help on which ones dont need valve springs or how hard it is to install valve springs... i heard it has to go to a machine shope to be remachined if u even wanna adjust them so changing them out must be expensive

so you're looking for 15+ hp with the 7a ?

yay.

no...he has a 4A-GE...you Joker. here's the original post in case you missed it at the top of the screen

hahahahahaha 7a thats a good one haha ha ha... ur funny.

This post has been edited by 20v_celica: Jan 14, 2009 - 10:06 AM