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are they better than ours? anyone (hardcore???) got an idea.

if so, will it be cheaper to buy some from a Z and stick em on or will it be cheaper to port and polish mine? or am ibeing stupid, forgetting about the extra cost for a simultaneous valve job?

I say this assuming the heads are the same and our intake manifold/valve covers will bolt onto either

help me out y'all.

i am trying to find reasonable ways to make this car faster NOW! and am just conducting a brainstorming sessionl
 

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3.5SE Auto said:
assuming the heads are the same and our intake manifold/valve covers will bolt onto either
This is the problem I see getting in the way. Another Maxima.org search.
 

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I would think that it would be cheaper to have your current heads worked on then to buy a new set. Granted the 350z heads might offer a little more flow, most of the hp gain is from the ECU, intake and exhaust. Does anyone remember the thread from a long time ago where the guy took a new 3.5 from his dad's lot and had the heads worked on and gained 40+hp at the wheels?
 

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Slurppie said:
Does anyone remember the thread from a long time ago where the guy took a new 3.5 from his dad's lot and had the heads worked on and gained 40+hp at the wheels?
where was that?
 

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it was in a thread on A.net that linked to some other site. Ok I found it,
heads, compression, MORE power
Well, I had a chance today to look at the valvetrain of a VQ35DE from a 2002 Altima. My friend brought his car up to my grandfathers racing shop and we spent about 3 hours taking both heads off.

Let me tell you, if the heads on the Z are anything like the Altima's, then there will be a LOT to gain with headwork, a valve job, and MAYBE a compression increase.

Today, we finished our exhaust side polish and got halfway done porting the stock exhaust manifolds on the engine. Eventually, we will have a complete 3 angle valve job with valve seat corrections matched with custom made valve springs, a full polish job on the exhaust side, and an intake side that isn't completely polished to retain some agitation in the intake.

We ordered a custom made head gasket which should reduce head/block clearance on both sides by .015. This bump in compression should yield about .4 or .5 of a point increase, we're not sure yet how the ECU will react, but are confident of the small compression increase.

Now, to stray from the facts and venture into my personal opinions:

This car looks to have MUCHO potential. I have already learned a lot from just messing with the RESTRICTIVE as hell heads. The exhaust ports are relatively large and did not need much porting, but we did manage to bowl out the chamber to improve exhaust flow.

As for the intake side, let's just say, UGHHH! A good extrude honing will take care of the restrictiveness, maybe at a loss of some bottom end.

So, I might take some pics, I might not, depends on how much time I have and if anyone really WANTS pics. Anyway, when I get my Z, I will already have some heads up for running a N/A setup if somebody is interested.

Also, I'm sure JWT will prevail again and yield some great improvements as well.
Here are the links and you have to sign in :(
http://www.my350z.com/forum/showthread.php?s=&threadid=509&s=1e00ebf606f20dc3f62e4bb9e0db31a7
http://www.my350z.com/forum/showthread.php?s=&threadid=138
 

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Slurppie said:
If you still want to guy some heads, I'm sure Hardcore can get you a nice price. Just out of curiosity, I wonder how much they would go for.
The answer to this is interesting, I've never checked it out before. The 2002 Altima and the 350z have the same heads part#11040-8J100 for the right part#11090-8J100 for the left. The book list price is $611.33 each. However the 2003 Altima has different heads part# 11040-9J000 for the right part#11090-9J000 for the left, for a book list price of $854.80 each. Obviously a major design change here. I have never done the research on this. I would have to check into it further.:rolleyes:
 

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Still working on this cyl head thing, Right now can't figure out why the 2003 Altima head is a different part# and price. The 2002 Alty & the 2003 Alty have the same intake manifolds and exhaust manifolds and cam shafts. At first I thought the 2003 might be ported different, and that was where Nissan got that magic 5hp on the 2003. But the manifolds are all the same so that's not the case. It could be that there just different castings so ones more money than the other. But I'll let everyone know if I come up with anything. :confused:
 
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Hardcore said:
The 2002 Altima and the 350z have the same heads part#11040-8J100 for the right part#11090-8J100 for the left.
Hardcore, this is interesting. I remember a post on Maxima.org some time ago reporting the short block part numbers for the '02 Altima and Maxima VQs were the same. If true, that's not too surprising. But the fact that the '02 Altima and '03 350Z share identical cylinder heads is not something I would have expected.
 

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Yes, I thought the 350z had different heads, when I ask my techs thats what they seem to think. But after looking them up in the parts catalog there all the same. So on the 350z horse power comes from other sources. Intake exhaust and tuning.
 

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Discussion Starter #18
whoo hoo

maybe we can bolt on the extra 5 hp for 800.00 that sounds lieka a good investment:rolleyes:

but maybe something to do with the materials? which may be an easy way to upgrade for a turbo
 

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Re: whoo hoo

3.5SE Auto said:
maybe we can bolt on the extra 5 hp for 800.00 that sounds lieka a good investment:rolleyes:
Seems like an even worse idea when the project Altima dyno'd better than the Track Edition 350z...
 

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Re: whoo hoo

3.5SE Auto said:
maybe we can bolt on the extra 5 hp for 800.00 that sounds lieka a good investment:rolleyes:

but maybe something to do with the materials? which may be an easy way to upgrade for a turbo
Very true, I'm sure if you actually had upgraded heads you would get more than 5hp. I still think that 5hp thing on the 2003 ALTIMA is BS.
 
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