what one is better y8 or z6? cylinder head

 

y8 for me

 

Y8 has better designed combustion chambers...squared off. Means better quench, they also flow better than the z6's. Supposedly might also have a slightly larger cam, but i've never taken the calipers to a z6 cam and a y8 cam to find out, so it's just speculation.

 

the one you can score cheaper, I think the y8 works better with a obd0 dizzy but I have only used a z6 so I am not 100%

 

y8 ^^^^they said it all

 

i was just woundering cuz my car came with the z6 swap all ready in it

 

ive read up on this topic a bit, and heres my conclusion.........
both heads have their strong and weak points. ironically, the pros and cons of each head mirror each other. the y8 head has a pent roof combustion chamber design. the large,flat quench pads ensure combustion happens in the center of the chamber for a quicker, more controlled burn.
the downside to the y8 head is that the right side of the splitter is in the intake ports. the air makes a steep right turn in the head, which is intended to promote the "swirl effect". it works well-in stock motor @ 3,000 rpm. in a motor modified for performance, it just gets in the way of flow. there isnt much you can do without "hogging out" the port, which is also counter productive.
fortunately the z6 head didnt have the swirl port design. unfortunately, it didnt have the quench pad combustion chamber, either.
the 2 heads in stock form make nearly identical power. but the z6 head will outflow the y8 due to the y8 swirl splitter design.

 

somepeople here pull ---- out of their ***, the z6 is better, goto sohchonda.org, the owner there is a very good friend of mine and have many comparisons clearly stating the z6 is better. but drunkinmaster1, got it right, everyone else was pulling opinions out of their ***

 

this is good stuff since i've been chasing a d series vtec head to mini-me this thing, mad 3rd gear vtec scream down I-5

 

SOHC VTEC is over rated. A6/ZC head outflows Z6/Y8 with boost.