Ok so I have both motors (the y8 is currently in the car), my question is which motor is better to build for turbo? OR would it be better to build the z6 bottom with a y8 top or visa versa?

 

ok... here is how i understand it. the y8 had a better designed head and the z6's crank is better due to 2 oil ports per journal as to the y8's one. this is one of the reasons the y8 is more prone to spun bearings. Also, the y8 is OBDII and the z6 is OBDI, so if smog testing is an issue in your state, you may not want to change. And, to get a proper tune, you will want to have a chiped p28 ECU, which is the ECU for the z6.

 

there r tons of d16y8 vs d16z6 fourms i kno this cuz my boy has a z6 and i have a y8 if u want my imput i think the z6 is better just because of the it is better for top end power and i think it is easier to build of course many people will say different things but thats y its my imput and the y8 fails more often then the z6 and like i said i have the y8 so im putting my own build down

 

I have heard that the y8 has a better head but the z6 has the better block. If thats the case why not build the z6 block with a built y8 head?

 

z6 wayyy better i got a z6 swap in my 92 vx and it rips puttin 25 lbs of boost to it soon

 

Both motors are fairly similar. The compression is pretty close, obviously the displacement is. The difference in longevity is due to insufficient oil pressure. If you can bump the oil pressure up, then the single oil journal means nothing. You just have to maintain a constant coat of oil for the crank and rods to float on.

The reason the Y8 head is better is the head has two quench pads and a little different shape combustion chamber that holds the mix closer to the spark plug, so it would burn a little better. The intakes on the motors are different. The Z6 manifold is supposed to be better for mid range I think, and the Y8 is better for top end I believe. They're shaped different. The Z6 has a narrow chamber and longer runners, and the Y8 has a bigger chamber and shorter runners. That or I have it all backwards.

 

................. wheres your proof? i think that statement needs facts or its pretty much useless

 

From my understanding the Y8 has the better head and the Z6 has the better block. I'm wanting to rebuild the block (all stock parts) and only update the cam, IM, TB, and a small turbo (8-12lbs). Now when it comes to IM and TB, I was thinking of either going Skunk2 Pro Series or Edelbrock Performer X. My question is which IM is going to be better for this setup? Meaning Skunk2, Edelbrock or just running stock?

 

just bumping oil pressure up won't help much if you don't have the flow. You need to shim and port the oil pump to increase oil flow. That being said, I'm still picking a z6 to build over my y8 because of the horror stories

 

I keep "hearing" horror stories but have never seen evidence. Not saying that spun bearings do not happen more often in Y8's but I just keep seeing people repeating stories that they've heard as if somehow it will make it true.

If you're that paranoid get a Z6 crank and port and shim your Y8 pump. I'm running a ported/shimmed pump in my turbo Y8 for 2 years now with no issues.

 

my opinon if u plan on beating the hell of out ur motor get a z6 to be safe but if u r just a daily driver and maybe run it once in a while not meaning baby it but u know what i mean i dont see why a y8 would not be ok for u as long as u take care of ur engine like ur suppose to i think a y8 will be fine

 

y8 power!!!

 

z6 should be anyones 1st choice

 

hmm so a z6 block and a y8 head with the z6 ecu? what would you guys suggest regarding increasing performance without really loosing any mpgs, in that given setup?

 

Nothing.