PoWeRtRiP

10.3:1 stock

Z1 Performance

iTrader: (564)

a VQ40 is just a bored out VQ35.....there is more than enough room to bore the VQ35 to a 4.0 liter.

DrVolkl

Looks like Nissan is going to be using the VQ4.0 in most of their vehicles...

I bet we see a 400Z soon...

jreiter

iTrader: (6)

Really? If that's the case, then I'm guessing the VQ40 engine doesn't weigh more than the VQ35, nor would it be any bigger. (?) So assuming all that is true, then mounting a VQ40 in a Z shouldn't be hard. Tuning it would be another thing, though.

S12 driver

If the VQ40 block is a bored out version of the VQ35, then the VQ35 head should bolt on to it. The VQ40 is only rated at 250hp, so the VQ35 head will probably flow better. This will be just like LS/Vtec build ups.

Loco350Z

damn im getting confused! will a maxima head fit? just bolt right on and add HP are would you have to do some adjusting and tuning. Also do you think that adding nismo cams will void any warranty?

jreiter

iTrader: (6)

I'm guessing the VQ40 discussed above is probably tuned for low-rpm torque rather than max hp (since it's apparently destined for a truck), and thus the low 250 hp number. I'm sure it could be re-tuned for high-rpm power via numerous changes, such as what you mentioned.

sausage5000

yeah but any of this would cost somewhere well over $8000, any way you look at it.

if you "bored out" the 3.5 to 4.0... what would happen with the pistons and heads? ...guess you would have to work some new 4.0 pistons, correct?

wouldn't a new 4.0 engine cost maybe just a few dollars?

bottom line is: boost is much more cost effective than any other route. just a turbo kit tuned correctly can give you more HP than any other plan mentioned, for $4500. i know it's easy to get like 320-330 WHP, and if you tune it right... a good bit more.

a nissan 8 doesn't quite make that much stock.

...how much HP would you think a 4.0 would make over the 3.5, just for being .5 litre bigger? in reality, it's all about how you work and tune what displacement you have.

to nearly match the monies for the mentioned projects, you could work the existing internals to low compression, and then boost up to 16 or so PSI. the result would be 500+ WHP. it would crush any N/A project. $4500 for boost, and at least that much more to do the internals the right way. it would be a solid plan though, $$$ for proven known result. ...the only way some dude that spent just as much to swap in or bore out to 4.0 could touch it, is if he went and spent another $4500 to boost.

the only alternative that makes sense is my suggestion, the maxima heads. if done correctly... it could cost well under $3000 to get a high compression N/A engine, start to finish. that is cheaper than any other known method of getting considerable extra HP. ...but then add JWT cams too, it would be pretty sick. still costs much much less than some fantasy for "boring out" the 3.5 engine.

Z1 Performance

iTrader: (564)

to get to a 4.0 liter you would need at a minimim to replace pistons....it would be silly to do and not replace rods with good forged units as well. This can be done for around $3500 give or take, depending what components you use and who does the work.

I have no idea on the weight of the VQ40

None of this means a VQ40 from nissan will just bolt in - remember, there are many versions of the VQ35 depending if it uses a FWD, RWD or AWD platform - motor mounts certainly differ between these drivetrains and not all are swappable into a 350Z. Not to mention who knows what is different on the heads between a VQ40 and VQ35 - I would not be so quick to assume the heads of a 350Z just bolt onto a VQ40, nor do I have a clue as to what CR that combo would yield. Who knows what a bone stock VQ40 is safe to rev to. For all these reasons and more, if it were me the only option would be building a proper bottom end with good aftermarket hardware. Doing it any other way, IMHO, is half assed.

Yes the VQ30 heads fit - this is essentially what the NISMO high compression heads are- however you lose the variable valve timing, which for me, for a street car, is too much of a trade off in terms of overall driveability.

Adam

sausage5000

just to clarify... that would mean $3500 for the pistons, on top of the monies it would cost "bore out" the 3.5 to 4.0. ...so, at least double that figure for the entire project, correct?

turbo-maxima

Newbie listen to him. He said $3500 for both pistons and connecting rods. And no you don't need new connecting rods if you are just keeping N/A. boring out the block cost anywhere from $300-$600. You would completely have to strip the block it would be bes to have a spare one. It will have to be bored and honed. Boring the blocktakes material away from the sleeves and the honing puts scratches in the sleeves to help keep oil below the piston rings.

Z1 Performance

iTrader: (564)

you don't "need" new rods no, but if you are going through the time and expense of fitting a good forged piston to increase the displacement, you would be well served to fit forged rods and good hardware throughout the bottom end as well.

All told, I know our engine builder would charge roughly $3500f or a complete shortblock assembled as this (forged rods, pistons, boring, hardware and assembly). This can vary up or down a bit depending on the exact components used (ie piston prices can vary, as can rod prices, depending on what brand you choose as well as other options thrown into the mix as well)

Adam

sausage5000

*this post edited to be more anally correct.

noob or not, i don't think you can work an engine with all the parts and labor included for 3500... and still make any money off it.

stu46

Dude, the internet is a wonderful thing. You should learn to use it. Let me help you get started.

www.google.com
www.howstuffworks.com

There's many more but this should be fine for now.

sausage5000

someone should definitely jump all over it and have this done ASAP. the very best thing would be a group deal. say put it in writing that you can fully work 3 vehicles for $3500 each total cost.

remember, i'm the noob here.

PoWeRtRiP

do you think our stock ecu could handle an increase in displ to 4.0? probably would need new injectors as well. theres more to it obviously than just modding the shortblock but it would make for a nice project

sausage5000

you should go over to this thread and set these poor guys straight. they are fixing to get ripped off bigtime, you can be their all-knowing savior.

https://my350z.com/forum/showthread....0&pagenumber=1