What are the differences between the 1jz and 2jz heads as far as these are concerned:

Intake and exhaust port size?
Cams?
Valve size?
manifold bolt patterns?

I've heard that 2jz turbo kits will not bolt to the 1jz head, is that true? The 1jz exhaust manfold bolt & port patterns look almost identical to that of the 2jz...
Thanks,
-w

Here's the info I found:

quote:

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2JZ is 20mm higher in the block. Heads are the same thickness, that about where the likness ends.

2J and 1J have the same size valves.

2J has 3mm wider intake ports and 2 mm wider exhaust ports.TOTALLY different stud spacing for both manifolds.

2J has larger combustion chamber. They are the same depth in the chamber but the 1J has raised sections at the front and back of the cylinder.

Head gasket will swap but 2J's have a large relief around the combustion chamber. Unsure whether a 2j head gasket has a corresponding cut out piece.

2J and 1J share the same lift cams.(unsure of duration)

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I got this from the ToyMods forum:
http://www.toymods.org.au/forums/viewthread.php?FID=4&TID=6019

Norbie!
http://www.norbie.net

Good info. Thanks.

why the heck is it un upgrade for a 2jz ? aside from the fact that turbos would spool quicker, i dont see the logic?

Its normally the other way round isnt it?, with people swapping the 1J block for a 2J block..

adi
1992 JZA70 - Decat, hybrids.




http://www.hedgehogsandwich.com

its normally ppl swapping the 2jz head for the 1jz head but its not really a upgrade its just going backward imo cause they are going to some thing smaller the main diff is that the 1j head as stated above is .20 less so it boost comp levels up enough but ur going to smaller ports for intake and exhaust so u loose when u star to get in the higher hp range cause of that