BigTwin

I'm thinking the way to go is a Z head mated to the 4.0 block. If the 4.0 is bored out you'd have to bore the Z block to match, which would be pointless if the Z head will match up.

r34 racer

iTrader: (1)

Is the problem that the pump cannot generate enough pressure, or that the injectors at 100% duty cycle cannot flow enough volume per time to sustain stochiometric conditions at high rpm? In either case, i'm sure a new fuel pump or bigger injectors could solve the problem.

articfury

I would imagine it would be a LOT cheaper to not buy a whole new engine. New being the key word, not a lot of cores going to be laying around soon.

You could get the engine re-sleeved with the proper spec sleeves.

I would think the least expensive way would be to do what Ares mentioned.

Or for slightly more money but built for upgradability:
VQ40 Crank
VQ40 spec Forged Connecting Rods
VQ40 diameter Forged Pistons in Compression suiting application
VQ40 diameter cylinder sleeves
Balance the entire rotating assembly
ARP bolts throughout
Sounds like a nice "kit" to me

With this route you could spec your Pistons for the best compression for your scenario: NA or FI.

Depending on costs so far and goals, getting the deck closed at the same time could be a good idea.

As for revs, with the second option and upgraded valve springs and retainers, 7000 revs shouldn't be a problem. Of course, the lightweight forged components help a lot in that department.

Unfortunately, that crank is probably not going to be cheap for a while.

How expensive is it to get crankshafts produced based on an original?

Sounds like the fuel pump/injectors would probably need to be looked at as well.

Then there is the question of what the ECU is going to think of all that extra displacement.

D

MY350Z.COM

iTrader: (2)

Preliminary Specs

4.0-liter DOHC V6
250-plus horsepower
270-plus lb-ft torque
(Final figures will be announced closer to production)

Note that the 250hp and 270lb. ft figures are low because the restrictions in the VQ40DE's intake and exhaust. Cams could be different as well.

What I'm mainly interested in here is the internals as articfury has mentioned.

BigTwin

And that's exactly what a stroker kit is. The point here is a stock short block (that would be cheaper than the massive rebuild suggested above) mated to a stock head, with much less required labor or custom fabrication.

milner

get an rb26dett. $3500.00 long block ,on line. dont ask me where i can not remember and have been looking for it since i found it a week ago. add about another 3500.00 to the motor and you will have 600 safe and reliable horse power. and Mike i am not sure of what kind of torque, so dont even ask.

AL350Z

A little off the subject but I've been wondering for awhile now if the Q45 345hp V8 would have a chance of fitting. Its an all aluminum V8 so the weight should not be THAT bad and lets face it, the possibilities are endless. Would there ever be enough width? The FX35/45 uses it but i'm sure there's plenty of room under the hood of it.

AL350Z

Milner, i've thought of this also. JGYCustoms.com sells RB series motors complete. No idea what THAT bad boy would cost but were talking big money now anyway. My question is the crossmember holding the motor and how much effort it would take to fabricate. God it would be awesome!

BigTwin

And then when you get rod knock what are you going to do? Or if you need a new oil pump, apex seal, alternator, etc etc? Spend 2 months trying to track one down and another 2-3 waiting on it to crawl across the Pacific on a cargo carrier? Despite any ricer pipedreams there are no parts bins full of RB parts just waiting to be plundered at the local Pep Boys, and even if there were they'd probably give you the wrong one.

spazpilot

iTrader: (2)

whats with the engine swap stuff. It would come out a lot cheaper to take out your factory motor send it to a shop and have it worked along with some sort of FI. swaping our vq35 for a 40 just to get an extra 20 rwhp is not worth it and I hate to say this but the rb26det is a dead engine and like BigTwin said you will be waiting on parts. Plus good luck on having this as a street legal car. Motor swaps don't pass emissions. the internals on a vq 40 are problaby not better then the vq35. Sounds like a waste of money if you ask me.

articfury

BigTwin,

I am well aware that what I outlined is essentially a stroker kit, save for the fact that it involves boring in a sense.

Do you truly believe that a whole VQ40 would cost less than a crank, pistons, and rods? Not the custom pieces in the second option, but the stock VQ40 pieces which Ares mentioned. Even the custom pieces may well be less expensive.

I very seriously doubt Nissan is going to sell an entire short block for less than a subset of its parts. Keep in mind a VQ35 from Nissan is in excess of $6k IIRC.

As for custom fabrication, spec'ed sleeves, pistons and con rods is not massive fabrication. Your statement of the ease of swapping the VQ40 and VQ35 blocks is based on a lot of assumptions that you don't know to be a fact.

miner/AL350Z,

Both the RB and VK45 motor swaps have been discussed several times on this site. Do a search for more details.

spaz,

Increasing displacement is almost always better.

A 4-liter vs. a 3.5-liter VQ with equal work to the heads, including cams, valves, springs and retainers, will make more power especially down low. A rule of thumb is for every percent increase in displacement there is roughly equal increase in torque and horsepower. Stock for stock with the same heads/plenum the 4-liter setup should make ~40hp more. YMMV

As is obvious from this and my previous posts, I don't think a swap is required to benefit from the VQ40 motor.

As for just going FI, well when we talk about turbo, 4 liters would help spool turbos at lower RPM, not to mention the potential power increase due to increase in displacement. The benefit for SC is more just the benefit of the increased displacement.

Why must every post about upgrade options be the best bang for the buck? I really don't understand why people feel that every post on this site must be beneficial to them for it to be worthy of the space. What happened to the innate interest in learning about all possible options to make more power. The 427cid swap for the C5 is not for everyone. But the discussion of what it takes to do it and the experiences of those that have done it, is still beneficial to the corvette community.

D

spazpilot

iTrader: (2)

articfury:

I understand what you are saying, but in my opinion bigger is not better. Unless you are planning on only racing straight line distance(1/4 mile at a time), an engine swap either way you go rb26 or vq40 will throw our cars out of balance. Power wise your right if the two were build identical it would be 40 more hp, but there not and I would not be willing to do a swap for 20hp at best. As for torque and modding the vq 40, I would rather mod my vq35. My car is my daily driver and am aiming for a 400rwhp mark with some form of FI. It will never see slicks, so increasing it much above this would turn it into a drag queen. 400 has already been done on our engine with stock internals. just think of all the pain and agony you will go through when doing simple maintaince alone. So I see no benifits if you ask me. I can make the same power with the vq35 as you could with a vq40 swap. Both would need better internals above 450rwhp.

mcduck

Basically what I was thinking since reading the first post on this tread. This will be easy if the only change is the stroke.

If the bore is changed, you may be able to change only the crank, keeping stock sized but upgraded pistons, but the end result will be something between 3.5 and 4.0L in displacement.

My question is this... if I were to go to Nissan now and say, "hey... I've blown a motor. I need to buy a crank, connecting rods, and pistons". What would those items cost for 3.5L VQ?

Yeah...yeah... better to buy aftermarket instead of stock replacements... I know. But what I'm trying to reason out is an approximation of what the 4.0L parts will run. Anyone know what stock internals cost? Or a replacement 3.5L?

BigTwin

BigTwin,

I am well aware that what I outlined is essentially a stroker kit, save for the fact that it involves boring in a sense.

Do you truly believe that a whole VQ40 would cost less than a crank, pistons, and rods? Not the custom pieces in the second option, but the stock VQ40 pieces which Ares mentioned. Even the custom pieces may well be less expensive.

I very seriously doubt Nissan is going to sell an entire short block for less than a subset of its parts. Keep in mind a VQ35 from Nissan is in excess of $6k IIRC.

You're using the term "short block" but you keep referring to the entire engine, i.e. the "long block", which is not what I'm talking about at all. I'm referring to taking the short block from the VQ40 and mating it to the head/valvetrain from the VQ35 (ala B20VTEC), not the entire engine. So owning a Z you already own a major part of the components required. The entire internals would only need to be swapped if the bore if different, as was mentioned above. And as for buying a new one give it six months and you'll be able to get a stock bottom end for half what Nissan charges for a new one. And yes, if its a part for a car you can buy the individual part.

Your statement of the ease of swapping the VQ40 and VQ35 blocks is based on a lot of assumptions that you don't know to be a fact.

Until someone actually does it its all conjecture. That's why I said "I think" and not "I know" in my first post where I suggested the idea.

FLY BY Z

All the existence of this motor signifies is that our motor can be stroked to 4 liters. Time has not told if this will improve performance or not. The decrease in RPM potential may outweigh the bigger displacement. No one knows yet if this will be a more potent combination than what we already have. I can argue that RPMs (not FI or NO2) can be an actual replacement for displacement. If anything can, it is RPMs. If I wanted 4 liters in my Z I would certainly not replace the motor. Only the crank and rods would be replaced (and pistons). If I was going to swap a different motor into the Z, it would have two more cylinders. That is an affective displacement change. You can make a small V8 rev just as high and have just as short a stroke as the VQ35 and it will make more power. It may not displace a whole lot more but it will certainly produce more at the same high RPM and sound badass.

JonsilvZ

Stop that! Your making the S2K guys feel really inadequate

ZedZed

CRANKSHAFT, 350Z - 3.5L 2003 $710.12

PISTON, 350Z, Grade 1 - 3.5L 2003 $57.30

CONNECTING ROD, 350Z - 3.5L 2003 $83.16

SHORT BLOCK, 350Z - 3.5L 2003 $3,541.43
Includes: Block, Piston, Connecting Rod & Crankshaft.

ENGINE, 350Z - 3.5L 2003 $6,525.67

MY350Z.COM

iTrader: (2)

not bad for crankshaft.

350zdanny

That would be one hell of a ticket price for a half a liter. These hybrid engine ideas work alot better for Hondas because the parts are dirt cheap. There are yards and yards of donor cars sitting all across the nation when you're making a B20 hybrid.

This is just not the case with the VQ. I think for the parts and labor being discussed, the average enthusiast would be better served by a turbo kit. Then if something goes wrong, maybe they could still return the car to stock and coax nissan into honoring a shattered warranty.

BigBadBuford

I think this idea would probably be best suited towards people who would be doing a full buildup and not just for people looking for a few more HP. If the motor was torn apart for a high performance rebuild it would be easy to at least use the new crank. Personally if I was going to build a motor I would use the stroker crank with good forged aftermarket rods and lower compression pistons (standard bore). You wouldn't get quite the amount of displacement, but if I was going to be using it in a turbo application I would feel better having the thicker cylinder walls. The 6250 redline is probably more a product of the camshaft they use than the mechanical limits of the motor, if this is being used in an SUV it wouldn't be making power past 6000 anyway. With stock 350Z cams and possibly a slightly upgraded valvetrain I don't see 7000 rpm being a problem.