I have a 2007 m35x 3.5L v6 awd. could I put a fx50s 5.0L v8 engine in it ?

Not easily or cheaply, but it has been done.

You will need to buy a new bell housing for your trans to mount up to the engine, the engine itself with all extra parts like fuel rails and such, the full wring harness for the engine, intake tube or aftermarket intake, apparently also need a new throttle body because it seems the VK45 has a 75mm TB and the VQ35 has a 70mm?, and should get the thicker sway bars to support the heavier load, and a full custom UpRev tune to remove some of the error stuff and NATS and get the ECU set to run the new engine. Oh and I suppose you will also need to make changes to your exhaust to connect it to the new engine as the engine location and sizing is different.

To be honest it is probably simpler for a shop and around the same cost in the end to simply have a shop bolt on the cheapest turbo or supercharger setup they can do to your VQ35 and you will be at or more than the HP of a VK45 already. Stock VQ35 can handle 400whp maximum before the rods give out, Id shoot for about 350whp and it should be plenty reliable if you go that route.

thank you for answering.
I mean if its around the same amount I would like to just do the engine swap , I honestly think its a cool idea .
what do you think a job like that would cost, minus the cost of the fx50s engine

Just a note, FX50 engine is a VK50ve, not a VK45.

DenisMcG wrote: ↑

Wed Mar 09, 2022 5:10 am

Just a note, FX50 engine is a VK50ve, not a VK45.

Oh yes, sorry. lol. I am too used to thinking the next model up always had the 45's and forgot those special couple of years for the FX. Sorry about that. And nice to see you with an actual FX50 that we are talking about here


Three other things then that you will have to deal with. First is the transmission, it wont be as easy as I thought just buying the bell housing and swapping it onto your current trans. The FX50 had the 7 speed transmission, and so I dont think the bolt pattern of the bells matches up. Either you would have to buy a 7 speed trans, TCU, and valvebody and get them communicating with the rest of the car, which may mean a dashboard upgrade as well but not positive on that. Second is you wont simply be able to just reflash and tune your current ECU, you will need an ECU made for the new engine. I highly doubt the old ECUs have functionality for variable valve lift the new engine uses. And third, if you have a new 7 speed trans that means you most likely need a new driveshaft that is a different length and/or different input flange.

It is a major project, basically just using your frame and the misc things a car has that makes it roll, and swapping out an entirely different car into your frame. You would effectively be changing every major component of the vehicle. Just a super rough estimate, but for the cost of all the parts Id estimate getting everything in decent, used condition would cost around $5k alone, and then probably somewhere between $7-10k for labor at a shop that can actually do it, which is not just a basic mechanic shop.
@EdBwoy could also probably provide a guess on a rough estimate as he has a LOT of experience replacing engines and other major car parts and swaps. But those are the numbers I would estimate. If you have the expertise to do it yourself then you can save a big chunk of change, but you will need to be handy with a multimeter and understand all the electric diagrams and know what every parts does that you are messing with. It can be learned, but not many people outside of those who do it for a job actually have the knowledge


A turbo setup when all is said and done would cost somewhere around $7-10k and there are way more shops that are capable of that. So if you are laying down this kind of money, saving a couple thousand may not really be that much of a difference anymore, and the V8 swap would actually give you more feeling of power and off the line performance IMO since the turbo setup only makes its big power once spooled up, where the V8 has nice low end torque. At 2000RPM the VK50 is already making 300 lb-ft




Not to hijack the thread here or anything, but a swap I am actually looking at doing in a year or two if just swapping the transmission. Nissan now has a 2022 Pathfinder I believe it is with the VQ35DE engine we already have, and they have it running with the newest 9 speed trans from Jatco that is based on the Mercedes 9G-Tronic It should be a somewhat easy swap since the trans mates right up to the engine, just have to get all the electronics talking and the dah to know what all the extra gears are. lol. But getting that 9 speed would bring both some better performance and some seriously better MPG to my car. I am hoping to go back to a turbo setup similar to what I had before to get the HP up, though I will probably keep things very "conservative" this time compared to last for some reliability. ANyway, just my own idea I have on part swaps for the car.

I think enigma summed it up best. It's possible, but I don't think it would be easy. How "cheap" it is, is a matter of personal opinion, but I feel like for the cost of getting all the components to make a VK50 engine run in a Y50 body, I might just as well just buy an FX50 and drive it.

1. Engine
2. Transmission
3. ECU
4. Security modules/reprogramming/tuning
5. Wiring harnesses
6. Gauge cluster maybe
7. Exhaust
8. Custom driveshaft
9. Rear differential perhaps (and axles)
10. Are you going to run it AWD? (Need front axles)
11. Appropriately sized starting/charging circuit and fuseboxes
12. Labor to remove M35 drivetrain
13. Labor to install FX50 drivetrain*
14. If it's not a bolt-on fit in the engine bay, then there will need to be some fabrication done

If you have decided that you absolutely want this engine in your car, the simplest way to get it done is to buy an FX50 and start swapping things over. Inside the cabin, at minimum you'll need the engine wiring harness since you are at a disadvantage by not having wiring and logic to support 8 cylinders.
#2 is that even if you were starting with an M45, the FX50 engine has a little more tech that needs to be accounted for.

EniGmA1987 wrote: ↑

Wed Mar 09, 2022 9:04 am

...
Not to hijack the thread here or anything, but a swap I am actually looking at doing in a year or two if just swapping the transmission...

Any concerns in running a FWD transmission in a RWD application?
I know face-to-face the bell housing *should* mate with the block, but since the FWD transmission sends power to an integrated differential then outwards to the front axles, while the the RWD sends it rearwards, do you foresee any fitment or power degradation issues? Or are you going to just send power to one axle - which in this case will be your RWD driveshaft?