i was talking to this guy that works at nissan and my car came up.

i told him i planned on putting in nismo r cams, valve spring retainers, rod bolts and some other stuff. then he told me that i should get head studs if im doing this build. my question is do you guys think that its gonna be an issue?

i plan on revving to 7500rpm at the most. ive never read on this board about people having problems with the factory head studs so this is why im asking. i don't mind a safe build, but i don't want to spend money on unnecessary equipment when oe can handle the job.

 

That's because they don't have them, they have bolts, and suprisingly they are not the tourqe-to-yield bolts that must not be re-used, allthough the fsm does give some detailed measurements that must be done on the bolts before re-using them. But regardless, the headgasket in the 3.5 is a known weak point and hks gaskets with arp studs is THE MOVE. Considering the heads are coming off, and you might even need to purchase new bolts anyways, I think you would be silly to not get them, that's my opinion on the subject. Headgaskets blow more than 3.5 rod bolts break no?

 

The clamping force that the OEM head bolts can provide are enough for ANY naturally aspirated motor. The general consensus over on my350z is that the stock head bolts actually clamp HARDER than the standard ARP head studs. To do any better you have to get the L19 studs which are complete overkill and impossible to justify the purchase of because they cost so much more than OEM ($449.00 vs. ~$80 for OEM).

As for the head gaskets, the reason FWD 3.5 head gaskets tend to fail is because they only have 2 layers. The 350Z head gasket (3-layer) is a good upgrade and like the OEM head bolts will be more than enough for this motor.

I'd also recommend cleaning the head bolt holes with a thread cleaning chaser (NOT A TAP) to make sure the preliminary torque steps are accurate. Got a torque angle meter?

 

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stop stealing my lines...

 

i see. so i guess its quite clear that the head bolt does not need to be changed. as for the 350z gasket, any idea how much that'll run me?

and i have a torque wrench.... but thats probably way off.

EDIT: i did some searching and i didn't find any 3.5 motors with blown headgaskets... wee there many? AFAIK there are very very few people going cammed w/ the FWD 3.5 motor.

 

That's good to know, and also the fact that the stock headbolts are only $80/16= $5 a peice I think for the peice of mind and ease of not having to measure them........

on the price of the 350z gaskets?

Also, Andy, he is talking about a tourqe angle meter, it's a little different than a tourqe wrench, but imho.....blah.....it's pretty easy to accuratly eyeball 90*, I did it for a 700hp boosted modular engine and slept pretty good that night.

 

I wouldn't reuse the ones that came with the motor.

MSRP is $40.83 each.

It's not a particularly common occurance but it's happened.

Well you don't have to remove the heads to install cams although the labor overlaps.

 

Who's blown a FWD 3.5 HG?

 

95blkmax did. But I saw a couple when I used to work at a nissan dealer. Seems to be more common than 3.0 HG failures.

 

I was at the dealer last week and they were doing one on an alty

 

You might like to know that the 2005 OEM 350Z head gaskets, P/N 26240PT and 26239PT, Federal Mogul parts, from Rock Auto is two layers, not three layers.

Would you like to buy two brand-new ones? Before I return them?


Note: a pair of these HKS gaskets from Swift Motorsport is $240.00 + shipping etc.
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And HopUp Racing has a pair or HKS askets for $319.00...
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I've handled and inspected OEM 350Z head gaskets personally, and believe me they have 3 layers. They were from Nissan though. Rock Auto might have mixed some part numbers up.

 

Nuttinn' personal here - yeah, Rock might be substituting, but I did cross-check their ordering numbers out of their catalog vs. what I got, and the numbers match 2005 350Z head gaskets. Bummer.

Are all years of 350Z head gaskets 3-layers? Or any particular years of 350Zs ?

Maybe I should check a Nissan dealer or two ??
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EDIT: Import Parts Pro has a pair of Cometics for $180.00.
http://www.importpartspro.com/comehegani35.html
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edit again: Courtesy Nissan has 2002-2004 350Z head gaskets for about the price you mentioned:
http://www.courtesyparts.com/Merchan...engine-gaskets
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edit again: Just ordered a pair - we shall see.
Sigh.