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Location:
Perth
Registered:
October 2003
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1JZ Head Markings
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Wed, 15 December 2004 23:28
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I have 2 1JZ heads. On the back top of the head one has "JZ1" cast into it and the other has "JZ2". Does this mean anything? Both engines are rear sump JZZ - JZA types.
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I supported Toymods
Location:
Epping, Sydney
Registered:
May 2002
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Re: 1JZ Head Markings
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Wed, 15 December 2004 23:34
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only think I can think of is that "JZ2" is the designation after they fixed a couple of piping problems the initial 1jz design had, which effectively extended turbo life
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Location:
Gold Coast
Registered:
May 2002
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Re: 1JZ Head Markings
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Thu, 16 December 2004 00:11
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| draven wrote on Thu, 16 December 2004 10:34 |
only think I can think of is that "JZ2" is the designation after they fixed a couple of piping problems the initial 1jz design had, which effectively extended turbo life
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What? The Return cam cover vents that is extented alittle and a different one way valve on the intake side?? If your talking about this then extending the turbo life is a load of bullshit. There is no way this would have an effect on the turbos.
I'd be guessing if I knew why the different markings, nothing in the engine manual about it aswell.
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Location:
sunny coast, qld
Registered:
October 2002
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Re: 1JZ Head Markings
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Thu, 16 December 2004 00:14
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| draven wrote on Thu, 16 December 2004 10:34 |
only think I can think of is that "JZ2" is the designation after they fixed a couple of piping problems the initial 1jz design had, which effectively extended turbo life
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I think you mean "possibly". That is all hearsay I reckon.
Skip: how far do you have to pull stuff down to see this casting? Under the cams?
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I supported Toymods
Location:
Epping, Sydney
Registered:
May 2002
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Re: 1JZ Head Markings
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Thu, 16 December 2004 00:25
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possibly - yes.. still waking up
I'm just repeating rumours - apparently the changes meant the turbos could hadle 3psi extra boost. sounds like bollocks to me too, but there must have been some reason for making the change.
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Location:
Armidale
Registered:
January 2003
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Location:
Perth
Registered:
October 2003
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Re: 1JZ Head Markings
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Thu, 16 December 2004 01:46
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Chris if you put a mirror down the back of the head just under the ISCV cross over pipe you will see it.
Both engines have a different numbered sticker on the timing gear cover too.
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Location:
Perth
Registered:
October 2002
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Re: 1JZ Head Markings
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Thu, 16 December 2004 03:58
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FWLIW: My 1995 TCCS 1J has a JZ@ on it. My guess would be that it relates more to manufacturing location and process (maybe it came out of the 2nd Yamaha plant or production line?), rather than representing any real difference.
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Location:
Perth
Registered:
August 2004
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Re: 1JZ Head Markings
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Thu, 16 December 2004 08:36
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My head has JZ12 stamped on it...
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