Nissan 350Z Forum : 350Z / 370Z Tech Forums - View Single Post - Engine Upgrade to 4.1 liter
View Single Post
Old 10-30-2005, 07:21 PM   #8 (permalink)
etraxx
Grand Touring Member
 
etraxx's Avatar
 
Join Date: Oct 2006
Location: Lugoff, SC
Posts: 3,850
Send a message via MSN to etraxx Send a message via Yahoo to etraxx
Default

The question raised was .. could we simply slip the Nissan VQ40DE into our 350Z (specifically, into Toykilla's Z. If the theory proves out (meaning that the majority of those present declaim it so) then I'm proposing that Toykilla use the VQ40DE as a 350z-tech.com project car. That being said .. what then IS the VQ40DE? (some of the following I freely admit I posted earlier .. just more together here).

Freshalloy.com (Nisan Infiniti Enthusasts) has an Nissan Engine Catalog. Here you find Nissan Engine Series including VK, VH, VQ, RB, VG, VE, QR, QG, SR, KA and GA.

Focusing in on the VQ series we find that they are a V-6, DOHC, 4-valves per cylinder. The VQ35DE has Variable valve timing and that the VQ30DE-K has Variable intake manifold. They are all aluminum, Direct Ignition with Microfinished crankshafts and camshafts and moly coated pistons. New for the VQ35De : Fifty percent of internal components were redesigned.

Examples:

- Reworked camshaft,

- Variable induction system,

- Composite plastic intake runners and

- VCariable capacity muffler (whatever THAT means).

They have been produced in 2.0L, 2.5L, 3.0L, 3.5L and 4.0L versions. Engines have been VQ30DET (Gloria/Cedric - Japan), VQ35DD - Japan), VQ30DE (Maxima 1995-1999), VQ30DE-K (Maxima 2000-2001), VQ35DE (Maxima 2002+, Pathfinder 2001+, 350Z), VQ40DE (Frontier, Pathfinder/Xterra 2005+).

Note: The VQ35DE was in the Pathfinder. That's a truck (ok .. like a truck!)

From a post on Acurazine

Don't forget so was the VQ35DE in the Pathfinder for several years. It can have a different cam and a few changes to make it into a G35 over 300 hp.

Note: Freshalloy also has a Nissan Engine Designations page. Here we find :

VQ = Series (we knew that)

40 = Displacement in liters (we knew that too)

D = Valve train

E = Fuel delivery

That's all well and good you may say .. so what about the VQ40DE? Specifically?

Nissan Infiniti News Bureau

The new Frontier powerplant is derived from the Nissan's award-winning VQ engine series utilized in the 350Z, Maxima, Altima, Murano and Quest. The 3.5-liter V6 VQ has been named to Ward's Communications' "Ten Best Engines" list for each of the last 10 years.

The new Frontier engine features a longer stroke than the 3.5-liter version (92.0 mm versus 81.4 mm) and has been specifically tuned for truck applications.

In addition to the taller engine block, the engine has been modified to include additional block reinforcements and increased main journal diameter for improved NVH (noise, vibration and harshness control).

Like other engines in the VQ series, the new 4.0-liter version includes such advanced design features as Continuous Valve Timing Control (intake only), Nissan variable Induction Control System (NICS), Nissan Direct Ignition System (NDIS), silent timing chain, microfinished camshaft and crankshaft surfaces, molybdenum-coated pistons, resin intake manifold, digital knock control system, high capacity muffler, lightweight aluminum block and platinum-tipped spark plugs.

The new Frontier powerplant will be produced at Nissan's engine assembly plant in Decherd, Tenn. The facility produces 950,000 engines and 300,000 transaxles annually and recently announced a $47.3 million expansion program. In addition to the Frontier's new 4.0-liter V6, the Decherd plant builds all the engines for the complete line of Nissan and Infiniti vehicles manufactured in the United States, including a 2.5-liter 4-cylinder, 3.5-liter V6 and a 5.6-liter V8.

From some posts on V6Performance.net

The current VQ35DE is already approaching the limit on bore (96 mm bore with a 108 mm bore spacing on the block = 12 mm cylinder wall). They could probably go a tad more, but in 3.5L configuration the engine still only has an 81.3 mm stroke. A big stroke would be something more around 95-100 mm, like on a Honda K24, or a Nissan QR25DE (Sentra, Altima). So there is tons of room to stroke. Since trucks need lots of torque and don't care about high revs much, I suspect the VQ40DE will be a stroker engine and that bore won't be changed much from the VQ35.

Also, it'll be interesting to see what anybody might venture to try as far as parts swapping in the VQ35DE or other cars now that there will be parts available in the US for bigger things ala the 3.2TL guys swapping in longer stroke MDX parts for 3.5 setups. So anybody with a VQ35 would be able to up the displacement very easily now I bet.

(and later)

As predicted, it's a stroker motor. The 4.0L has the same 95.5 mm bore size as the 3.5L engine, but stroke goes from 81.4 mm on the 3.5L up to 92.0mm on the 4.0L. IIRC, a Nissan press release somewhere stated that the VQ40 had "minor block modifications". I believe SR20DEN from Maxima.org measured and predicted that they would have needed to extend the deck height of the VQ short block to accommodate the additional stroke, as the existing one for 2.0-3.5L displacements might have come up a bit short. (can't have pistons impacting with the head).

From a post on Max-World Forums

It appears that one of my predictions were right. They didn't increase the bore size at all which I anticipated they would. But in order to use a 92mm stroke they would need to increase the height of the block and that is what they did.

Specs thus far on the VQ40DE for the Frontier

265hp

284tq

95.5mm bore

92mm stroke

3954cc

So. The blocks are the same .. right?

From a post on NissanClub.com

Has anyone looked into swapping a VQ40DE from the new Nissan trucks into a 350z or G35 yet? I wonder if they (VQ35DE and VQ40DE) use the same bellhousing pattern or location of engine mounts. It could be an interesting combination. I know that there is already a 4.3L stroker kit for the VQ35DE, but this new engine could be a more viable alternative, as that kit costs a good bit if I remember correctly. (After a little research, one price was found to be $7800, which should be quite a bit more than a "new" VQ40DE, if one could be found or ordered.) But, back to my question. Has anyone looked into how related these two engines are, or is naming the new truck motors as VQ engines just a marketing ploy?

It's likely that the 4.0L motor from the new truck shares a lot with the VQ35, since the 6-speed in the Frontier is probably very similar to the 6-speed from the Z/G35. I doubt that Nissan built a completely different transmission for a new application - one strong enough to handle the power potential of the Z should be able to handle the truck application. Even if they are different, you could always throw the 4.0 transmission in with the motor. But why?

So. The blocks are the same .. right?

From a post on Fresh Alloy

Q: Hi, is the VQ40DE using the same block as the VQ35DE?

A: Absolutely not the same.

Rear of block that accepts transmission bellhousing has a totally different shape.

That would be the major obvious difference I noticed; there are most certainly others.

From a post on Maxima.org

No specs have been released on the VQ40 engine, the heads are totally different from the current 3.5L. Nissan has its R&D department around my work and I talked to Yiko the guy who does alot of testing for Nissan at one stop light. I got to check out the new Pathfinder in person a month ago. The intake manifold is different and resembles more of a VK56DE than the 350Z one. I'm gonna use my rebuild-15K miles ago 5spd tranny with 100K miles on it. 6spd tranny sucks up too much WHP compared to the 5spd in the 3.5L Altima- ever notice how Altimas put out way more power than Maximas with bolt ons ?

From Autodurocher

With a new VQ40DE, 4.0L, 24-valve, DOHC V6 engine under the hood, it produces 265-horsepower at 5,600 rpm and 284 lb-ft of torque at 4,000 rpm, an increase of 85-horsepower and 82 lb-ft of torque, making it the most powerful V6 not only in its class, but on the light truck market today. The new engine is based on the award-winning VQ engine series that powers everything from the Altima sedan to Infiniti's M35 sport sedan, although it was specifically modified to meet the demands of truck use with a longer stroke, reinforced block and revised camshaft profile for notable torque response.

So .. what about the tranny?

From 2006 Nissan Xterra

6-speed close-ratio manual transmission

5-speed automatic transmission

from <a href="http://fourwheeler.com/roadtests/129_0409_path/" target="_blank">

Four Wheeler
</a>

Thankfully, Nissan didn't neglect the engine on the new model, featuring an all-new tall-block version of the VQ-series V-6. With a nearly 10mm increase in stroke over the VQ35, the still-oversquare VQ40DE cranks out a V-8-like 270 horsepower at 5,600 rpm, and 291 lbs./ft. of torque at 4,000 rpm. The only transmission available with the Pathfinder is a version of the Titan and Armada's 5-speed automatic.

A final thought from FreshAlloy

And finally Nissan has now decided it was time for the VQ (all-aluminum, DOHC, and 24 valves) to go into the new Frontier. For the V-6 models, Nissan bumped the already large 3.5 liter displacement to 4 liters! This larger V-6 features the usual VQ formula for success: Continuous Valve Timing Control (C-VTC), Nissan variable Induction Control System (NICS), silent and long-life timing chain, microfinished camshaft and crankshaft surfaces, moly-coated pistons, resin intake manifold, cross flow engine coolant pattern, high capacity muffler, and platinum-tipped spark plugs.

Nissan, in their usual mind game with other manufacturers, won't announce final horsepower figures until the vehicle is close to release. They're giving out an estimate of over 250 bhp and 270 lb-ft of torque. Uh-huh. If the VQ35DE in the 350Z makes 287 bhp, we'd bet a few dollars the new VQ40DE would (or could easily) crank out over 290 horsepower and a lot more torque. One reason behind the secrecy may be the Frontier's arch- enemy, the Toyota Tacoma, which will be offered with a factory supercharger option good for over 300 bhp. (Editor's note: If you look in Toyota's press release, they actually say their new truck is faster than the 350Z.) The other hesitation might be that Nissan didn't want the VQ stepping on the Titan's 305 bhp figure. Nissan will offer both a 5-speed automatic or 6 speed manual ("sportstruck" anyone?). According to Nissan, the new Frontier will be able to tow over 5,500 lbs. (up 500 lbs. from the previous Frontier)

Ok. There you have a start. Should be plenty of 'beef' there to start a discussion.



__________________
Socrates: "I drank .. wat?"
my Blog: etraxx.coml

- a Klansman is a Nazi in sheets clothing -
etraxx is offline   Reply With Quote