Parts changed in the rev-up VQ35DE:

LH Exhaust Camshaft
LH Intake Camshaft
RH Exhaust Camshaft
RH Intake Camshaft
Connecting Rod
Connecting Rod Bolt
Crankshaft: Uses the same connecting rod bearings and main bearings / thrust washers as other crank.
Crankshaft Assembly
Cylinder Head Assembly - LH
Cylinder Head Assembly - RH
Pistons - STD 1, 2, 3, & OS0.20
Pistion Ring Set STD
Piston Ring Set OS 0.20
Valve Spring
Track Valve Spring Retainer
VTC Pulley & Cover Kit LH (does not include gasket or bolts)
VTC Pulley & Cover Kit RH (does not include gasket or bolts)
VTC Cover Gasket LH
VTC Cover Gasket RH
VTC Cover Bolt

Not according to the tuner I've worked with and many a 350Z owner over on my350z.com. The stock rods in the VQ35DE are widely known to have problems under higher RPM loads and boost applications.

It was put in place for a number of reasons in the VQ35HR and the VQ37VHR engines, only one of which was to support higher RPM performance. The VQ37VHR is most likely the engine that will be boosted in the GT-R. Read the Engine section in this article for much more specific information and actual pics of the newer engine internals in the HR model engines:

http://www.nissanperformancemag.com/september06/vq35hr/

 

We've got a few members that rev quite freely to that RPM often enough to merit nismology's statement. They do have upgraded rod BOLTS, but are using the same stock rods.

[/QUOTE]This changes things significantly. But it has been stated time and time again that tuning in boosted Z33 applications plays a large role in engine life. And many of the 'pros' self destruct their engines due to poor tuning/lack of knowledge. If tuned correctly, very good power can be made safely under boost in a VQ35DE.

 

If it is "un-safe" to go past 7000rpm, then why did technosquare make the redline on all of their tuned ECU's to 7100rpm... I highly doubt that they just programmed some stuff and said, "here you go, now go and see what happens!"

 

I don't know why you felt the need to show me up and copy and paste this list from an old azz thread over on my350z when most of those items have nothing to do with the discussion at hand. Besides, these are all things i've already looked into. Nothing new here...

For n/a applications (which is what this thread is about right?) the stock rods are fine to 7500, at least. It's the rod bolts that fail. Simple fix...ARP.

Oh the ironing. This is precisely why that block design was put into place. It helps lower NVH as well. As for the high RPM thing, that's strictly an opinion. I am confident that there have been motors that rev to 7500 and beyond without the "deep skirt" design that the HR's block has.

Good read. But I also thought it was a good read the first time I read it months ago.

 

Yes, the rod bolts are a particularly weak point. The rod bolts aren't safe beyond 7200 RPM, the rods themselves can probably take more than that though IIRC they are only powdered rods so I wouldn't spin them much further than that.

Meh, only so much really. Quoted from NPM: The weak point of the VQ block is its open deck construction and freestanding bores. Nissan did this so the cylinder top end would be more evenly heated to reduce hydrocarbon emissions. Open decks also lend themselves to die casting better. The bad part about this is when the engine is loaded hard, the unsupported cylinders walk around compromising head seal and eventually cracking from the pressure. Thus a stock VQ block should not be boosted past 16 or so psi or have more than a 120 shot of Nitrous run through it or damage can result (without sleeving the block and so forth).

To reduce emissions the VQ has its compression rings near the top of the piston. This reduces crevice volume and the potential for hydrocarbons hiding in this area to contaminate the exhaust. The downside is that this weakens the piston and detonation can thus easily break the piston in the ring land area. Many a forced induction VQ in a Z has succumbed to this fate.

Most of the issues underlying the VQ35DE engine have been resolved in the newer VQ35HR redesign. I've not yet read a detailed technical breakdown of the VQ37VHR engine so I'm not sure what if any additional improvements Nissan has made with the newest engine that's shipping with the new G37 coupe. Can't wait to find out though!

 

This thread went way OT for no particularly good reason...

 

Don't they all.

 

HI, my name is Dan

 

still some good info though... 'course, I'm sure I won't use any of it anyway.

 

I have had the 7500rpm limiter for about two and a half years now, and although I still have no logical reason to rev that high I have done it hundreds of times. Mostly on the dyno. I don't recommend that for anyone because it now appears to me that the valves are starting to float past 7400 with the stock cams and springs.

You 6th gen owners really need to spend more time in the All Motor forum when you want to get serious about complex engine mods and higher than average naturally aspirated power levels. Your engine is nothing new and is pretty much the exact same VQ35 that you'll find in any 2002 Maxima or 2003 350Z, minus a few part number changes and external packaging.

So YES the aftermarket VQ35 cams will work and YES you can use the Ebay knockoff cams. You can buy JWT replicas and Nismo replicas. Both are a fraction of the price and just as good. And if you seriously want to do a cam swap I would also highly recommend that you use the VQ35HR valvesprings and retainers. This is another thing that has been extensively covered in the all motor forum which you can all readup on.

http://forums.maxima.org/showthread.php?t=519636

http://forums.maxima.org/showthread.php?t=497655

 

Cripes, Hopefully they will listen.