your opinion on the vq40 hybrid.

[Guest Johnnys240z]

What do you guys think of the vq40 truck crank in the vq35 block? The only thing I know the vq4o motor itself has a half inch taller deck height. I was thinking of trying to get the block to see if it is meatier all around. But the motor itself is expensive, plus needs extensive head work to flow 'well'. Lots of parts have same bolt patterns like the heads of course. The Nissan vq40 crank I can get brand new for dirt cheap. Pauter Rods and ?pistons are custom of course. Im in the process of ordering one for experimentaion with the extra vq35 blocks we have. We currently (I call it the limit for reliabilty sake, some people dont) produced 470rwhp out of the factory vq35de(tt), which has seen many abused daily driven miles. We currently have (550+rwhp)built vq35s for forced induction and have used a few in our customers cars. Sleeves are too iffy, time consuming and expensive. I want something different, but doesnt need exotic machining(we can do, too much time involved) or expensive customs. The other stroker kits out there are the 4.3l, but I think thats pushing it, maybe not. I dont know, you guys think its worth dicking with? It just seems so easy cause the 4.0 crank is available.

[ZROSSA]

The first thing that comes to mind is how much will the engine weigh and what do you want to put it in?

 

Douglas

[Guest Johnnys240z]

Well the motor will weigh as much as a complete vq35de out of the 350z or g35.

I know our equal length exhaust manifolds are lighter than the stock cast pieces. The whole exhaust sytem from cat to back is about 20lbs less than factory. Plus the intercoolers, wastegates, ic pipng and turbos, maybe an xtra 75 lbs give or take. The motors are currently for 350zs and g35s. I however have a 72 240z, which *might*(i have 2 complete 2jzgt and 7mgte motors) get the 4.0l vq tt motor. Most of the motors are going into road going 350 and g35's. However, a friend of mine builds sand rails and he wants to try a 4.0l vq twin turbo. I want to experiment with a high compression n/a motor, and a f.i. vq40, to offer to the offroad world in 2 packages. I thought about it and I will go ahead and try to build this 4.0 liter. I might make(cnc) mounts for the 240z to mate with the vq motor+6spd, just in case some people here want a 350z motor.

[260DET]

Seems like you know more about them than most of us would Those big power VQ's, what durability mods do they require. I've heard that the stock cylinder liners are a problem have have to be replaced with a 'one piece per side' arrangement.

 

As for demand, I guess if there is a demand for that sort of engine and the product is good and competitively priced.......... Maybe the V8 forums here would be the place to ask that question.

[JMortensen]

This is PURE speculation, but generally when the automaker increases the deck height it's to allow a longer stroke AND a longer rod. If they did that with the VQ40 it's probably because the rod ratio would have been bad with the lower deck height. That makes me think that you want to use the whole shortblock from the VQ40, and maybe use the VQ35 heads if that would bump compression. If not it might be a better idea just to use the whole VQ40 engine.

[Guest Johnnys240z]

This is PURE speculation, but generally when the automaker increases the deck height it's to allow a longer stroke AND a longer rod. If they did that with the VQ40 it's probably because the rod ratio would have been bad with the lower deck height. That makes me think that you want to use the whole shortblock from the VQ40, and maybe use the VQ35 heads if that would bump compression. If not it might be a better idea just to use the whole VQ40 engine.

 

Thats true about the deck height and rod ratios... But many people have taken the vq35 block and increase the bore and stroke to produce 4.3 liters with aftermarket cranks(some with and without sleeves). All they did was get some custom pistons and rods, along with the custom crank and bearings. I would think, but I dont know yet, that the vq40 truck crank is millimeters smaller(or pretty close to eachother) than the aftermarket stroker cranks, and can be remedied by custom pistons/pin height, and rods. Im gonna go and check the bore size, and stroke height of the 4.3 l strokers for the vq35, then I'll check the factory vq40's stroke and bore size. We were gonna just use the bottom ends of the vq40, but we have so many vq35 blocks/heads to spare. Plus if this works out, it will be cheaper than the stroker kits out there, less machining=less down time, 350z and g35 owners can use there existing blocks, uses factory nissan crankshaft(doesnt matter though),and 1 more mod that people have an option to do to wring out every ounce of power.