ok i just bought a 91 hatch has a bone stock d15b1 dual poin injection in it and had a blown headgasket. I have everything apart and i got to thinking... This car honeslty looks like no one ever changed the oil or the pcv valve has been plugged for a very long time.. The entire top end is gunked up like no other. So i looked over at my bench and relized i have a z6 head and a y7 head both are in way better shape then the d15b1. I am not trying to make this car fast so im leaving the z6 out of the question i will use that on another project later. But the y7 would be great if i could put it on. I know the intake manifold lines up no prob but would i have any problems with anything else?? I need to pass cali smog so im hoping this wont bump up my comression or throw my cam timming off or anything like that so has anyone done this before i do this??

Can i use the d15b1 cam gear and timing belt on the y7 without throwing off the cam timing?

Is this gonna bump my compression up?? I dont want to fail NOX emissions lol..

Do i need to remove that little oil jet in the d15b1 block??

I was gonna swap valve seals too are the d15b1 valve seals the same as the y7??

Thanks!!!

 

i BELIEVE you will need to use your D15 cam gear, since the y7 cam is indexed 4.5 degrees different than the D15 cam gear, but this is offset by the shorter deck height of the D15 compared to the D16 (5mm). so just use the d15 cam gear (same as a6/b2/b7/z6 etc).

this will bump your compression, but not TOO much.

yes, remove the oil jet from the block, the Y7 has one built into the head.

i believe valve seals are the same but u should be buying new ones.

 

awesome thanks for your help. BTW: lol i meant to say i was gonna swap the valve seals out for NEW ones. I would never reuse valve seals they fall apart when you try to take them off.

 

Ok here is the NEW problem!! I put it all together but now i have the problem of that 1 head bolt on the old head sits up higher then the rest and has a more shallow hole in the block. So now with the y7 head the bolt in the upper left hand side is bottomed out with about 1/2 inch left. Do u know what head bolt i could use to fix this?? thanks!

 

use one y series head bolt/stud

oh, ps, i was wrong its 4.75 degrees different.

 

o ok! Thanks!

So since there is a diffrence in cam timming. I can just swap a y7 or y8 cam gear on it to correct it right? I heard the y7 and y8s retarted the cam timming 4.5 degrees??

 

Yes, leave the y7 cam gear on it to correct the cam timing on the d15 block.
Your dissy will end up some where in the middle.