does a VG30 crank and conrod fit into VQ30?

Post by **kahren** » Wed Apr 21, 2004 7:38 am

i was wondering if this was true, i remember reading somwhere a while back that if you take out the crank and rods from a 300zx VG30 and fit them into the VQ30 it will become a 3.4 liter. i was wondering if anyone of you could confirm this, or if u have the 2 cranks layign around and could measure this.

Post by **sil80drifter** » Wed Apr 21, 2004 7:38 am

this is very interesting, can someone confirm or oppose this? it sounds like something nissan may have done to make the "new" 3.5 liter VQ...

sil80

Post by **Q45tech** » Wed Apr 21, 2004 7:38 am

Everything in the 3.5 is new, totally different design.........light duty knifed crank and rods. Floating cylinder liners, low ring tension.......light pistons and wrist pins.

They attacked the HP poblem differently by reducing reciprocating weight and lowering residual friction [narrow bearings], bucket lifters.

Post by **sil80drifter** » Wed Apr 21, 2004 7:38 am

Ok, but what about the above rumor? It is common knowledge that there are quite a few parts across nissan engines that can be cross swapped, etc, what about these?

sil80

Website · Post by **s13sr20chris** » Wed Apr 21, 2004 7:38 am

not all vg30s are created equal. im not sure what size crank the z32 motors had but the sohc vg30s had a small crank in the older ones and a larger crank in the newer ones. this was to solve a prob with cranks snapping off after slappy at the lube and tune overtightened the belts.

Post by **PalmerWMD** » Wed Apr 21, 2004 7:38 am

So Dennis are you saying the VQ35 has "weaker" bearings than the VQ30?

Fred....

Post by **sil80drifter** » Wed Apr 21, 2004 7:38 am

let's not get off topic. this is kind of important. does anyone have sound data regarding the question?

sil80

Post by **Q45tech** » Wed Apr 21, 2004 7:38 am

Measure them! When you have a lighter crank [and lighter balance weights] because you have lighter rods and wrist pins you can use narrower bearings to reduce the friction.

Back in 80's and 90's many engines were over designed to extend the life............250,000-300,000 miles later engineers saw where they could reduce costs without affecting the requirements for at least 100,000 mile life..........many of these cost saving designs had the effect of increasing power and torque by reducing friction from oil whipping [knife edging balance weight portion].

Study section EM ---- pages 119-125 in your G35 FSM.

http://www.intermet.com/resour...5.pdfh ... Ne...19276

Post by **sil80drifter** » Wed Apr 21, 2004 7:38 am

I don't have either. But maybe someone else does.

sil80

does a VG30 crank and conrod fit into VQ30?

does a VG30 crank and conrod fit into VQ30?

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