maxcosity

Probably a stupid question but what is the difference between the two engines? Other than "one comes in the Z and the other in the Maxima." And other than "one is stronger than the other"..

Is the bore/stroke different? Is the timing advanced? Does it have a better exhaust manifold (header) and exhaust? Does it have a better cat or something? WHAT?

Quicksilver

iTrader: (1)

If the bore and stroke were different, I don't think they'd call it a 350Z It's probably pistons, heads, cams, ECU...etc

bigdo26

iTrader: (3)

someone mentioned a difference between the intake manifolds of the two cars. otherwise, the exhaust is different, as seen by the dual outlets and a different exhaust note. also i believe the 350Z makes its peak hp/torque at slgihtly higher RPMs than the Max

Greek to the Max

iTrader: (2)

i can only imagine it breathes better and farts better. Plus, the computer is designed to do so as well.

chi02max

as greek max said above, it breathes a lot better than the max. better intake manifold and better exhaust system. maybe tweaked the ECU(im not sure), but i heard the cam lift is higher for the 350z.

SteVTEC

- Intake manifold is different.
- Exhaust system is different.
- Cams are more aggressive (pretty sure of this)
- Variable timing on both intake and exhaust cams (pretty sure of this)
- Pistons are probably different (11.2:1 CR vs 10.3:1 on the Maxima)
- ECU (duh )

Y2K2Driver

iTrader: (1)

I thought some time ago DaveB had cross-referenced part numbers between the 350Z and Maxima and saw that all internals were the same. I believe it was emax who was curious about the specific differences as he was trying to use 350Z parts on his Maxima. I believe the conclusion at that time was that the only difference was intake, exhaust, and ecu. He even tried to use a 350Z intake manifold, but couldn't get it to work w/o a hood modification plus whatever else. I think a lot of the misinformation out there about the 2 is from speculation prior to 350Z launch which has since carried over. Once search becomes active again, we can look that info up.

vqman

actually an engine can still displace 3500cc's and have a different bore and stroke...

but the 350z and the Maxima engine have the same bore and stroke.

but here's a scenario...

The BMW M3 has a displacement of 3245cc

the Mercedes C320 has a displacement of 3199cc

very close in engine size, but the bore x stoke is WAY different.

BMW's is 87.0mm x 91.0mm

Mercedes is 89.9mm X 84.0mm



with 6 cylinders both come very close to 3.2L (they call the M3 3.3L, but it's only 3245cc...it's more like a 3.25) they use different ways to get there power/displacement.

if you have a certain size engine...lets say 3.0, you can increase displacement 2 ways...you can increase the bore size, or you can decrease the stroke length....with a larger bore, and a shorter stroke, the engine doesn't have to work as hard for 1 revolution, making it easier to get high rpms out of an engine. but there is a limit to how HUGE you can make the bore, and how short you can make the stroke..

The vq30de revs quicker than the vq35de for this reason...as the 3.0 motor has a larger bore when compared with it's stroke...now it's not larger than the 3.5L's bore, but proportionatly, it allows for better revving..

can anyone explain the "over square" vs. "square" engine thing? I don't know how to explain it.

here's another scenario of bore and stroke being different, and the displacement being the same...probably a better analogy that the first, because the engines displacement are almost identical.

Honda S2000 (should be called the Honda S1997 because it has 1997cc of displacement) has a bore and stroke of 87.0 x 84.0mm

the sr20de engine (found in the G20 and SE-R) has a 1998cc displacement and it's bore and stroke is 86.0 X 86.0mm

here's some 3.4/3.5L comparisons

Taurus SHO 3.4L V8 ....... 82.4 x 79.5 mm
using the V8 really show's how different the bore/stroke can be with similar displacement
Tundra 3.4L V6 ........... 93.5 X 82.0 mm
see how much bigger the cylinders are in the 3.4L V6's when compared to the SHO V8? cool huh?
GM Lumina DOHC 3.4L V6 ... 92.0 x 84.0 mm
the pistons in the 3.4L V6's are WAY bigger than the pistons in the 3.4L V8!
GM Grand Am OHV 3.4L V6 .. 92.0 x 84.0 mm
notice how the OHV and DOHC GM engines probably used the same friggin block...GO GM! great engineering!


Diamante 3.5L V6 ...... 93.0 x 85.8 mm

300M 3.5L V6 .......... 96.0 x 81.0 mm

350Z 3.5L V6 .......... 95.5 x 81.4 mm

Maxima 3.5L V6 ........ 95.5 x 81.4 mm

3.5RL 3.5L V6 ........ 89.0 x 86.0 mm

Intrigue 3.5L V6 ...... 89.5 x 92.0 mm


-vq


just wanted to clarify...

limsandy

iTrader: (1)

The engine man comes to rescue!


~limsandy

NizanDrivn

02MaximizedVQ

[QUOTE]Originally posted by VQMAN
if you have a certain size engine...lets say 3.0, you can increase displacement 2 ways...you can increase the bore size, or you can decrease the stroke length....with a larger bore, and a shorter stroke, the engine doesn't have to work as hard for 1 revolution, making it easier to get high rpms out of an engine.

And this, folks, is why a 383 Stroker motor is so popular in domestic hot rods. I believe you take a 400 crank and place it in a 350 block. The new crank has rod journals that are futher away from the centerline of the crank than a regular 350, which gives the motor more leverage (torque). Then you bore the motor out and put bigger pistons in. Finally, you insert shorter connecting rods. So you end up with a motor that has as shorter stroke than a 400 (higher RPM capability) but is larger in displacement than a 350...its a real beast.


can anyone explain the "over square" vs. "square" engine thing? I don't know how to explain it.

I think the term "undersquare" means a motor has a larger bore than stroke. I believe the BMW 330Ci is an example.

Jesse

SteVTEC

If the intake manifold, exhaust system, and ECU are the only changes, then how do you explain the 11.2:1 compression ratio?

SteVTEC

That's backwards actually.

Oversquare means larger bore than stroke.
Undersquare means larger stroke than bore.


The 3.0 VQ is actually one of the most oversquare production engines I've ever seen. 3.66in bore x 2.89in stroke. One of the few production engines to have such a hugely oversquare design, yet it remains so torquey. And thanks in part to the very low pistons speeds due to the short stroke, the engine can maintain high revs and be very smooth like it's nothing.

In comparison, the J30A1 engine in my 2001 Accord V6 was 3.39 x 3.39 and completely torqueless, but that was due to the cams, not the internal geometry of the engine.

Y2K2Driver

iTrader: (1)

Easily, it doesn't. Here is a link to NPM specs on the 350Z. I agree that it may not mean much b/c you could equally find sites which show 11.3:1 as well, though they usually lack alot of other info indicating that it was compiled before Nissan released the car, thus speculation. The only way to be sure is to find someone with a 350Z shop manual.

http://www.nissanperformancemag.com/...2/zspecstable/

SteVTEC

My source which is usually very reliable (www.autosite.com) could very well be wrong in this case, as Nissan's official spec table also shows 10.3:1

http://www.nissannews.com/nissan/200...0z/specs.shtml

But then again, I've seen some error's on even Nissan's site as well.


So where the hell is this 11.2/11.3 coming from? Yup, I guess we need a shop manual then.

SR20DEN

iTrader: (7)

Alll of this information has been looked up by DAVE B and myself.

Pistons: Same part #
Cams: Same part#
Intake: Obviously different
Exhaust: Different
Injectors: Different part#

There are no internal differences between these engines. They have the same 95.5mm bore and the same 81.4mm stroke. They use the same pistons, rods, cams, block and im pretty sure the exact same heads too. The CR's are the same @ 10.3 from all the data I have read (from car mags, and various tech info) If indeed it is different then dozens of sources have posted it incorrectly.
The 350Z engine simply doesn't make enough power to prove otherwise. Emax and some other have proven that with simple bolt ons we can get the exact same 230+ whp that the 350Z has. It shoudl be obvious enough from knowing that you cna take a stock 2002 Maxima and put 200 - 205 hp on the ground and add 10hp to that from simply removing the oem filter cartridge.

The only difference is that we (Maxima drivers) have the asphyxiated
version of the engine.

SR20DEN

iTrader: (7)

True..true..

Then there is the Ford 289 from the earlier Mustangs. 4.00" x 2.87" (101.6mm x 72.9mm)

SteVTEC

But the 350Z still has VTC on both the intake and exhaust cams, correct? The Alty/Max/Path I think only have it on the intake came side.

SR20DEN

iTrader: (7)

Yes and no.

The engines all have the save type of chain setup. The variable device is only located on the intake cam but the exhaust cam is slaved off the intake cam via a separate chain. Therefore the Maxima and Altima have the same intake and exhaust cam variable timing as the 350Z. The lob separation angles are always going to be the same no mater what the timing is.

vqman

the REAL engine man comes to the rescue!

this guy doesn't have to use Google...I do...

-vq

SteVTEC

Now something sounds screwy here.

The whole point of having phase variable intake and exhaust cam setups is so that you can vary the amount of overlap independently for either emissions/economy, or performance. You're saying that the lobe separation angles (between intake and exhaust lobes?) are always the same, or did I just not understand you correctly?

SteVTEC

thanks, but I am not a "REAL" engine man. There are plenty here that know a ton more about engine internals and modification than I do. lol

SR20DEN

iTrader: (7)

Yeah thats what I was saying. Find the cutout pic of the 350Z engine and it becomes pretty clear. The VQ35 in that form still only has the variable unit on the intake cam only. Just like the previous 300ZX and the current Maxima and Altima.
Also, if it were able to adjust the I/E lob separation angles then wouldn't it have to have cam timing sensors on the exhaust cams too? Im certain it only has the sensors on the intake cams.

vqman

thanks, but you're not my type...even though you drive a Maxima...

-vq

vqman

did anyone even notice this part of my post?

this GM geek at work a few years ago was talking about what a marvel of engineering the 3.4L DOHC V6 was...jeez....what a waste...

-vq

SteVTEC

That blows!!!

SteVTEC

All those 2.8/3.1/3.4 engines are all based on the same block I think, and they all suck. The 3800 is much better.

Sam03

Do you happen to know the cc's of the Maxima,(3.5) and the cc's of the Z's injectors?

SR20DEN

iTrader: (7)

Yeah and they're just barely 3.4 liters anywho. I had one of those 3.4 Liter 24 valve motors once in a '91 Gutlass. What a POS. They call it the X motor (from the VIN). It's another one of their bastard children that they want to quietly dissapear.

SR20DEN

iTrader: (7)

Im in the process of trying to get that information. Im going to arrange to have a Maxima injector sent to RC engineering to get flowed.

SR20DEN

iTrader: (7)

That depends on who you ask. The 3800 (L67) is a crustly old boat anchor that needs to die and GM agrees. All of the new 'Global' engines will be based on the 60º design which is much more modern. There will be a 3.5 Liter 2 valve version and a 3.6 Liter 4 valve version. The bore spacing on this engine is so much that there will one day be a 3.9 liter version and will weigh less than and make tons more power than the L67. The ONLY reason the 3800 is popular is because GM added forced induction to them on several occasions.

vqman

yeah, that 2.8 and 3.1 used to be in the Cavalier Z24...before the 2.4L DOHC....they were real dogs.

hasn't the 3800 been around since the late 60's?

-vq

vqman

that's not the ONLY reason...another reason it was popular, is because almost EVERYONE that drives has owned a car with one...they've been around since the dawn of time...

-vq

Sam03

Thank you, thats very much appreciated

SR20DEN

iTrader: (7)

And thats probably why you can count a dozen of them in any repair shop at any time.

GPXSS

The "3800" has only been around since 88'. The series2 3800 thats in all the cars now is quite different than the old 3.8 your thinking of. The 3800 is the chain smoker of the GM line.. its only worth a damn if its helped with its breathing. Gm is gonna ****can it in the next few years cause its such an underperforming boat anchor.

3.1 is a dog eh?
My 3.1 managed to push my 3500lb fatass down the quarter at 15.51@87.. you only managed a 14.99 in your lighter car.. talk about the pot calling the kettle black..

Sam03

He ran his times at altitude, are you familiar with what that can do to times?

SR20DEN

iTrader: (7)

GPXSS and I ran our times at about 500 feet altitude.
The point he was making is that no matter what, 14.99 is not a good representation of a 3200 pound car with 200 fwhp 225 lb. ft. tq.

rocktboy

can anyone explain the "over square" vs. "square" engine thing? I don't know how to explain it.

I think the term "undersquare" means a motor has a larger bore than stroke. I believe the BMW 330Ci is an example.

Jesse [/B][/QUOTE]

no.......Larger bore than stroke is OVERSQUARE. Most super high performance engines (high HP/Liter) have that configuration. (F1, motorcycle...etc)
I can't remember the reason behind it. But someone mentioned high rpm capability and that is definitely one of the reasons.

Sam03

Gotcha, but from what I read VQ Man is a n00b at the track and that was his fist run ever.