vq40 swap

jnaut

yes i am searching... any positive or negative comfirmed info thanks. i am more interested in a block swap , keeping my original heads if possible. thanks for the help!!

__________________
Best 1/4 mile 12.24 Best mph 114.5_______

Xan

Why not get a stroker kit? I believe GTM has a 4.2 (un-sleeved) and 4.5 (sleeved) kit...

__________________

KingDavid

That sounds a lot cheaper...

1slow370

still waiting to see a vk56 swap now thats some displacement

__________________
ANSWER PRICE LIST
Answers - - - - - - - - - - - - - - - - $0.75
Answers (requiring thought) - - - - $1.25
Answers (correct) - - - - - - - - - - $12.50

CBRich

What kind of power are you really looking for? The twin turbo kits out there should give you all the power you ever need and by the time you're done going N/A with a stroker kit you've nearly spent the same amount.

FuszNissan

Are you looking for 800+ RWHP??
Hope you are ready to spend 40K

__________________
Mods: Too Many to list!
LouFuszNissan
ZDAYZ 2012

CrownR426

someone needs to get that M56 engine inside the z!
lol

__________________
Love + Hardwork + Passion
RIP SVTRacer

FuszNissan

Lead the way Crown!

__________________
Mods: Too Many to list!
LouFuszNissan
ZDAYZ 2012

jnaut

yes they do @ 6k... too much!!!. as you can get a vq40 for about 1.2k. our trans does bolt up to the vq40. i would just want the short block and put our heads on to the 4.0l. i do know that it is a taller deck , which will not let us use our lower plenum/ exhaust.

__________________
Best 1/4 mile 12.24 Best mph 114.5_______

jnaut

ok so i found this info...


VQ38/VQ40 strokers...

I thought I'd share this with the Z guys as well... I'm currently building a 3.8 liter stroker for a turbocharged 01 Maxima. We are using a VQ30DE block, however, if the 3.5 liter block was to be used, you'd have a 4 liter stroker, using the same crank/rods.. just slightly larger bore.. Here's the details..

The VQ40DE, used in the new Nissan Frontier, has a 92mm stroke! The deck height is much taller.. around 244mm, versus the VQ30/VQ35's 215mm deck height. So, it allows them to use a longer rod, and get a 1.8:1 rod/stroke ratio. By using the VQ40 crankshaft in the VQ30/VQ35 block, keeping the stock compression height.. would have to use a 138.9mm rod. That's 5.3mm shorter than the VQ35. This would yield a 1.51:1 rod/stroke ratio. Now.. if we were to use the stock 144.2mm rod, and move the wrist pin up 5.3mm in the piston.. we'd have a rod/stroke ratio of around 1.57:1. That's very acceptable.. For comparison, the SR20DET has a 1.59:1 R/S ratio.. we all know how capable that engine is.

So, say you want something better.. we use a smaller wrist pin, allowing us to move it up a little higher.. say, 2 more mm.. This would give us a 146.2mm rod, and yield a R/S ratio of 1.59:1.. same as a SR20. Since you are getting custom pistons made anyway.. you could get the pin where you want it, and whatever diameter you want. No big deal to go a tad smaller.. just use a thick tool steel pin (.140 wall) and you'd be fine.

Now, the cool part.. is what it would cost.. I did some research.. and found that the VQ40 crankshaft from Nissan is CHEAP! How cheap? Try 300.00 retail! It's forged, and very beefy.. The only downside, is that the main pins are 10mm larger in diameter. No big deal.. pay a good crank shop to grind it down to the VQ30/VQ35's 60mm diameter, and you're set. So, for around 500.00 you have a 92mm stroke! I went ahead and ordered a crank.. to modify, and check fitment.. I don't forsee and major block mods to get this to fit.. maybe some slight grinding for counterweight clearance.. Hell, you could knife-edge the counterweights, and not even have to clearance the block.

So, what's this cost?
VQ40 crank, cut down- 500.00ish..
Custom pistons- 750.00

That's around 1250.00 for a 4 liter stroker for the VQ35DE. If you stay N/A, the stock rods should be perfectly fine.. If you want big power... toss in some aftermarket forged pieces.. Hell, if you really wanted to go nuts.. do the 100mm bore, 92mm stroke... and you have yourself a 4.3 liter.

There's a lot of debate about rod/stroke ratio... Some would say that 1.75:1 is the "optimal" R/S ratio.. It just depends on what you want.. I think, that for a street driven car, around 1.6:1 is optimal.. It gives a good balance between top end, and low end/midrange TQ.

As for how high you could rev it.. the SR20 has a R/S ratio of 1.59:1.. people have taken them to 9K with solid lash adjusters.. I'd say that a 1.57:1 R/S ratio could easily rev to 8K safely.. I think with the right cams, a N/A monster could be had.. Of course, a turbo/super application would be the best, to take advantage of the increasein displacement. The TQ curve would be awesome.. You could use the 92mm crank, with stock rods, and move the pin up in the piston so that the rod would fit. That would be the best budget stroker kit.. and would be fine for up to 400whp or so.. You guys know what the VQ35 rods are good for..

__________________
Best 1/4 mile 12.24 Best mph 114.5_______

jnaut

ok, i will have to check about journal diameters between vq40 crank and vq37. i did not totally under stand about cutting 10mm( where?).i am not too worried about rod ratio as i build a honda running with piston speed of around 5500fps. so i am not afraid of taching out this longer rod setup. And yes the cranks are pretty cheap, not as cheap as he states but pretty close, but there is a lot of room since the stroker kits r 6k. just add it up the crank , rods, pistons, bearings, rings, balancing... 500 + 1000 + 1000+ 200+150+ 350 =3200 - 6000 = 2800 savings... me likey

__________________
Best 1/4 mile 12.24 Best mph 114.5_______

CBRich

Could you let us know who or where that info came from?