So I spent a few days researching wether or not it was possible to put a y7 head onto a z1 block. All I really found was people saying you need to change the to a1 pistons for it to run.... the compression ratio would be to low to run NA.. or the deep dish pistons make it only good for a turbo... I couldn't actualy find anything saying someone did it. I have had the z1 in my car for over a year now... I have been enjoying the fuel savings.. but I have been craving some power.. any power at all. my research came up with absolutely nothing anywhere on the net. So recently having aquired y7 head with 80xxx kms on it in amazing shape clean as a whistle I decided after a few beers for breakfast to just git er done and give it a try.

It worked.. it's done... and I'm pleasantly impressed with the results.

Here I am to put the information out there for others who may want to try the same thing.

In my obd2b ek hatch I have a z1 block with an s20 transmission. I took off the z1 head and put on a new head gasket, then installed the y7 head using the head bolts from the z1. The first problem I had was the 2 outer head bolts on the rear were way too long. The head bolts are all the same length. I went to my bucket of bolts and grabbed 2 shorter ones (not sure if they were from a y7 or a y8 but that's the only bolts I would of had in the bucket). That solved that and I carried on. I used the stock y7 intake manifold the y7 obd2b distributor, a y7 harness and a p2e ecu. As well I used the z1 timing belt. Now when it came to the timing no matter what I did I was half a tooth off in either direction. It ran acceptable being half a tooth off in either direction... but when I installed my aem tru time gear it ran way better... you cannot get the timing right with the y7 cam gear. you require an adjustable d series cam gear to get it perfect.

I am very happy with the results... with the s20 transmission I can get a decent couple second chirp out of 3rd gear where as before I could barely get a half second chirp out of second.

I do have one final thought though.. maybe someone with some experience can chime in here... I know when putting a vtec head on a non vtec block you need to remove the oil control jet... In reverse should one of been put back into the block? I didn't put one in... should I have done so? what can possibly happen without one???

I think that's it. Hope this helps someone.

 

Nice work on your thorough investigation and making it work. I doubt it would hurt your build but do monitor oil pressure to see if its low.

 

Any easy way to check pressure?

 

Gauge

 

If it is low anything I can do other than tear it apar t again... my dummie light isn't on at idle.... or any other time... but we all know that light is essentially usless.