Hey folks. I have a burning question and I desperately need an answer. I've posed this question to some other online forums but haven't gotten a response just because this swap idea is probably unheard of, but here goes. Here's the story: I have a '71 Datsun 240z that I'm currently building up. Over the past couple of months of contemplating a myriad of engine swaps ranging from a Corvette LS1 to a Q45 to a Buick Grand National turbo motor. Just awhile ago, I stumbled on what, could very well, be the ultimate engine swap-- a RWD VQ30DE. I have posed this question in other forums but to no avail so I'm asking you: the devoted Maxima ppl.

Ok, it is a bit extreme but here's my reasoning behind this swap:

1) First of all, there are tons of Maxima's sitting in junk yards, JUST WAITING to donate its parts. I figure with Maxima motors going for dirt cheap and falling off trees, locating one in good condition for cheap will be easy.

2) I've always loved the VQ motor, smooth, linear power delivery, extremely lightweight (a good 200 pounds lighter than all of the other engines I considered). It's small size and featherweight will do wonders for the handling of the Z.

3) Bite level. I like blazing a new path and I know for certain, no one's done this kind of swap.

OK, here's how I plan to swap in the motor. We all know the maxima and new pathfinder engines are similar except that the maxima has a bore and stroke ratio of 93x73.3 while the late gen 300ZX twin turbo had an 87x84mm ratio. I plan on stroking the maxima engine to 84mm so a 300ZX's robust forged crank can be used. Using this crank , I'll be able to then mate the transformed Maxima engine (which will have a 3.4L displacement instead of 3.0) to the very strong 300zx 5-speed transmission. In order to mount the VQ longitudinally, I'll have to get the exhaust and intake manifold from a pathfinder so the motor and trans can be fitted.

I plan on boosting this motor @ 12#. Since I'm stroking and now boring the motor, I wouldn't have to worry about cylinder wall thickness anymore than anyone else whose turbocharged their Max's. So this brings me to my next question, how much boost can I safely run with the VQ? I'll be getting custom forged pistons, rods but I'm just uncertain about the aluminum block. Is 12# too much? Is the maxima engine smaller than a Datsun L6? If anyone here has any expertise about the motor and can answer my questions, it'll be greatly appreciated. This is an awesome site with knowledgeable people. No one's been able to answer my question so far, so you're my last resort. Please help!!

 

just slap it in

 

someone should be able to help you out. I'm glad you appear to know what you're talking about.

 

thanks. I just noticed I had a typo. I AM NOT boring the motor. There was a typo in the last paragraph.

 

Wouldn't it be easier using a 300ZX turbo VQ30DETT instead of the maxima VQ30DE. Then again..it is easier and cheaper to find a VQ30DE and the intake manifold/exhuast manifold off the pathfinder. Hmm...12psi of boost. Are you keeping the compression ratio the same? People have supercharged VQ30DE to about 10psi without problems. You said you are getting new forge pistons, so I guess you could change the compression ratio with different shape/type of pistons. Lower the compression and you can run 12psi without problems. Good luck. You are right..it is a crazy swap.

 

I say go for an RB26DET(or TT) if you can find one. It's an inline-6, just like the Datsun came with, so you know it will fit. Even though it might be a little harder to find an RB, you'll love the tuneability of the engine. It'll definitely handle more than 12psi. The trick is just finding one, but I've seen ads in Turbo magazine for a few places that import them.

The advantage of having a VQ, I guess, is having a great NA motor. You can see that it can be a little difficult to turbocharge the VQ, if you've been reading UncleMax and TurboMax95's posts. No one makes a kit as of yet, so any turbo work will have to be custom. If you could find a wrecked Pathfinder VQ, you'll already have 3.5L and won't need to worry about getting the VG30DE crank.

 

BlackVQ, I love you. You finally hit the nail on the head. The VQ is an excellent NA engine, but there are better choices if boost is your goal.

 

I remember SCC saying that engines like our VQ and the Sentra SE-R's QR would be better off with a light pressure turbo rather than even an SC, just because we have so much torque off the line. We don't need more power at the start, just more at the midrange and high end, when the car is already moving.
Oh yeah, more about the VQ. The SR20DE has made 300+hp in racing applications normally aspirated. They are primarily used in European touring car racing. Some NA SR20DE folks get their parts from Europe for big all-motor power. The VQ is used in racing as well(albeit not at much, I imagine), so there could be some NA parts available as well.

And here's where Medic will stop loving me.
It's not impossible to turbo the VQ, so don't get discouraged if you still want to do it. It's probably the specs(compression ratio, etc) on our USDM VQ that makes it hard. The JDM VQs come tt'd from the factory, running right up to the gov't imposed power limit of 280ps(276hp). In fact, the VQ30DETT is being discussed as a viable engine option for a range-topping 350Z...at least in Japan. If you can find out what the spec differences are on the JDM engine, you might be able to handle more boost. I'm sure they at least lowered the compression ratio.

 

Sopdadope...

What do you plan to do for cams if you go with the VQ30? Let me know if you plan on getting some grinded. I'd be interested because of my current project.

 

There's lots of problems with all the motors mentioned. The VG30DETT is extremely wide and heavy. It's a great motor but in order to work it in, extreme motor mounts have to be crafted as well as totally reworking the steering rod. It's too heavy for my preference, some of the V8 swaps are less complicated and lighter, not to mention, cheaper. The Pathfinder motor, although similar in design, has a totally different behavior than the max. Also VERY pricy. Factor in the marginal 5-speed transmission (not nearly as tough as the 300z's). Try finding one for anything less than 3K. The RB26DETT is a very cool swap and the only reason why I wouldn't do this swap is that it's just been done before. There are about a dozen Z's in the states that do have this motor. There's also an oil pump issue that seems to plague a lot of transplanted RB's. MOtor mounts would have to be bought from Japan. Parts availability would be a headache. The engine itself would cost an arm and a leg.

Which brings me back to the VQ. Sure, the VQ is torquey, a boosting it any would give a FWD car traction fits but I think it should be fine in the Datsun. I'm running sticky Yokohama AVS intermediates. Let's face it, aside from BMW's new straight six, this engine is the best 6-cylinder there is. I can go to the local yard right now and pick up a '98 engine for $400 and that's complete with ECU, harness and everything else electrical.

About the compression ratio. Correct me if I'm wrong, but the VQ30DE runs a 10.5:1 compression ratio, correct? Stroking the motor by 11mm would provide a 7:1 comp ratio, ideal for boosting. Doesn't JE makes forged pistons for the VQ? I think Arias produces them for $600 for a set of six. Thanks so far for the input on boosting levels I can safely run. I'm not planning to run extremely high boost, but in case I do, anyone think iron or titanium sleeving would allow me to push let's say 20#? I'll use the search function and see what I can find on Maxima turbo kits. I have a friend in a hot rod shop that will grind the cams for me. Since the VQ looks like it will narrow in the 240z engine bay, i'll be using a twin turbo setup using two Mitsu T04's that I've collected from some older gen eclipses along with the wastegates. The slugs will be piped to two Suzuki esteem intercoolers. As you can see, my parts list looks like cheapo depot, but they are more than adequate for the application. The only aftermarket items I'll use will be a Haltech engine management system and an HKS Super BOV. Thanks for everyone chiming in so far.

 

The VQ's compression is 10:1 and after stroking the motor, the new CR would be 7.5:1

 

a few of my inspirations for my own Z project car: here there's a Z with a T-78 turbocharged Q45 engine, a big boost Grand National Z, a Chevy smallblock V8 and a really outrageous turbo'd L31 Z

 

Corvette powered Z
[IMG] http://www.hybridz.org/rides/lone1_4.jpg [IMG]

Grand National Turbo Z

[IMG] http://www.hybridz.org/rides/ScottieGNZ1.jpg [IMG]

T-78 turbo Q45 Z

[IMG] http://v8zcar.topcities.com/s30z/q45z-04.jpg [IMG]

 

Doesn't anyone remeber the huge argument about putting the Z crank in the max engine? I thought the bearing journals do not line up. I also want do this kinda work to my engine but not until spring/summer, 2002....Then...I too may be doing some crazy ****....

 

Do a Supra TT swap.

 

The cost of being unique is very expensive. Can you afford to be unique? Does being unique also = transplanting a powerplant that is more powerfull than all the others? If not then I can't really see why you would want to be unique. Why be unique when the other more standard swaps would pull you?

I mean really, I could probably build a L28-T from a factory 280zx turbo and make 400-500hp. That's more than the LS1 swap right there.

 

Check out this:

Supercharged LT1 w/ 6-speed in a 240Z
http://taner.equinix.com/darius/Darius-240Z-full.mpg

More Movies
http://taner.equinix.com/darius/

Your idea sounds interesting, it's great to see people being original. Now go do it!

 

How 'bout a rotary swap? I bet a 26B quad-rotor would fit in there. Some of the rotary fanatic guys in PR use 'em and put out 700+hp easy.

Tell us what you plan on using the Z for once completed, too. That's an important factor to consider. For example, if you wanted to do some autoX, something lightweight such as a street ported 13B rotary(just under 300hp) or maybe even an SR20DET. If you just care about straight line speed, heck, try and stuff a Chevy 454 in it or something. Some good in-betweens are the VQ30 or VQ35, while the RB and VG tts are on the heavier side of well-balanced.

 

I've already helped a friend build up an L28. He used a T3/T4 hybrid slug. It's a great motor, but then again, not for me. Like I said, I've considered every type of motor swap possible, ranging from a mazda 20B to an SR20DE to a Cadillac Northstar.

I'm determined to use this engine and here's why:

1) I might do autocrossing. Many SCCA classes dictate that only a car powered by an engine of the same manufacturer can be run so that rules out everything except Nissan motors.

2) This engine is EXTREMELY light. A good 140 pounds lighter than the VG30DETT, RB26DETT and a good deal lighter than most other 6-cylinders for that matter. I'm trying to make the car as light as I can. Right now, I'm currently looking for a Corvette I.R.S. just because it's 90 pounds lighter than the datsun rear.

3) This swap will only cost manhours and not a lot of money because I have a friend who works in a hotrod shop and another in a machine shop who are willing to help me out at no cost. Here's a list of what I do have already and it's price respectively:

2 Mitsu T04's and wastegates= $450 for everything
2 suzuki esteem intercoolers= $100
300ZXTT 5spd = $800


I can get a complete VQ for $400 as I mentioned and I'd be looking to spend AT THE MOST about a grand and half for everything else (crank, haltech, pistons). I don't expect it to cost anything over 3 grand total. You can't even get a supra motor alone for that much. I'm very shrewd with my money and going this route would cost less than most of the swaps you already mentioned. I remember, my buddy spending $900 on forged 240sx pistons when he stroked his L28 to 3.1L. I mean really folks, I appreciate your advice but I have my mind set on this swap. I just wanted to see if anyone had any custom titanium or iron sleeves fabricated for their cars. Using these, I could run in excess of 20# but this is all in theory. I have a hard time believing a run-of-the-mill Chevy 350 or even 427 pulling a 3.4L V6 running at more than 12#. Traction in those cars are horrible. Going in a straight line is one thing, but imagine the 427 Z hitting a road course.

Screaminfast, you're telling me the Z crank journals don't line up? I'll look into this. Thanks everyone.

 

a SR20DE is not a bad choice too.

 

I'm going to head over to a shop tomorrow and ask the Nissan tech about the possibility of the Z crank fitting in a stroked VQ. After taking a look a the Z engine and the Max engine, I'm getting the uneasy feeling that it's not compatible and if I were to machine it to work, it'd cost much more time and other resources than I'd like to invest. Tons of machining work looks inevitable. I'll see what happens.

 

Good luck w/ whatever you do. You seem pretty good w/ stuff.

One thing though. You must be able to get stuff really cheap becuase the last time I looked at Haltech stuff, the retail for their stand-alones were over 1k.