jarvis199

ok guys i did a leakdown the other day and it read like this
40% 20% 35% 30%

i performed it several times to make sure i didnt just screw it up, and its legit...

so im figuring its gonna cost me at least 100 dollars for a valve job on this head... and im worried ill get it apart and the guides or seats will be toast, and i dont relaly have the cash at this point to buy new head parts (kid on the way)...

so... i have a low mileage y8 head lying in my garage, and im thikning of slapping it on, anyone have any good reason not to? im hoping to make 350whp on the next dyno trip, is this head going to hinder me any?

and also, im kind of worried about the timing on it, not sure how to setup the cam, cam gear, etc.

so can i do this...

-run my z6 headstuds and use extra washers on the 2 studs that are too long???
-run my 59300 camshaft with the D16Z6 camgear and just timing it to tdc normally???
-shoot the timing to 16btdc and it not explode???

at this point i cant afford a new set of headstuds, nor an adjustable gear, but in my mind, using the z6 gear on the 59300 z6 cam should be ok right???

and maybe even go ahead and shoot the timing to 12*btdc so its happy...

but hten im stumped on what timing map to use, and how mcuh timing the engine will handle...

HiProfile

Well you'll have moderately higher CR with the y8 head, as thats ~2.5cc less room in the chaimbers. The y8 flows slightly less, but if people can make nearly 350whp with a stock z6 head, I can't see 350whp being an issue with a y8 running the right turbo & boost pressure. I'd make sure the cam & dizzy end up being the same spots as the as it was on the z6 head. Its a bit late to wrap my mind around it, but I think 16* would make the most sense, assuming the dizzy can be moved to the right spot.

I'd say use the y8, set it up to mimic the z6, then recondition/build the z6 head.

jarvis199

thanks man, i thought it might work...

maddog20

If your using a Y8 head you should use 12 degrees base timing and p2p base map and tune from there. The Z6 timing maps are to aggressive and you'll be replacing HG's every oil change.

I am not a tuner by any means, but I speak from experiance. I am the wipe who had replace all the HG's

go to xenocron.com and look in the Crome bin directory and you'll see the difference

jarvis199

ive checked out the difference, i was just not sure how mcuh the camshaft had to do with it???

anyway, im going to be sticking with the z6 head and just replacing my valve stem seals since it burns a hair of oil on starts...

maddog20

Good idea

the keyway on a Y8 is 4.75* advanced