Oh and there is also a stock VH45 twin turbo on LPG making 550hp on stock internals. So your answer is yes, i forgot about that car.

An LJ torana would be insanly tight !!!!!!

Sorry to bring this thread back from the dead.

I just joined the forum, and recently purchased a 1994 Q45t, silver on black, etc...and will be doing a few tweaks to it.

However, that isn't my reason for comment in this thread. I'm currently in the planning phases of a rather radical buildup. Requirements for the engine are dohc, displacement, preferrably narrow.

BACKGROUND:

I have looked a bit into the Lexus 1uz-fe, 3uz-fe and the Iron 2uz-fe...the northstar 4.6 liter, and it's little brother, the aurora 4.0 liter. The 4.6 liter and 5.4 liter ford motors (03+ cobra and trucks are iron block), and last but not least, the 5.6 liter nissan motor.

I'm in the early stages of planning here and haven't had time to get a ton of information, so bear with me.

Iron would be better for the strength of the engine itself I would suppose, but that only leaves the 2uz-fe, 4.6 liter ford and 5.4 liter ford. I can rule the 5.4 liter ford out because it has a 100ish mm stroke, which is far too much for the RPM I'd be trying to run. (I don't know the bore/stroke of the 5.6 liter nissan motor yet).

the 4.6 liter ford is a 4 bolt main (at least it is for the aluminum version), the 2uz-fe 4.7 liter toyota is a 2 bolt main. Toyota has a nice 94x84 bore*stroke, as opposed to ford's 90x90.

Then on the aluminum front, it comes down to the 1uz-fe/3uz-fe, VK and VH motors and the wildcard 5.6 liter nissan.

END BACKGROUND

Unless the nissan has a surprisingly large bore and short stroke, I'm thinking that for the RPM necessary, the piston speed will be too great. I have no information on how durable this engine is...webbing, mains, girdle, etc...if anyone here has some, I'm all ears.

The UZ motors are EXCELLENT engines. 6 bolt mains from the factory, the 1uz has a 87.5mm bore vs a rev happy 82.5mm stroke, the 3uz is simply a big bore (91.5) 1uz from what I have read.

The 1uz has already been used in the nitro drinking 2000hp 'groundfighter' running 50psi of boost.

the 'F' heads aren't quite as good as the G heads that my supras have, but if they can handle that type of horsepower, they can obviously be massaged quite well. Only other downfall of the Lexus motors is that I would prefer a bit larger displacement for the size turbos I will be running.

Via this thread I have found out that the VH motor also features the 6 bolt mains and seems to be very strong. (the goal of 1700bhp for the drag car in the other thread makes me more confident in the engine). I'm wondering if you all had any other information on this motor, or the VK motor (I don't really know anything about this engine) what are the bore/stroke on the two engines? I know the 41 has a short stroke, but it seems that there were a few comments pointing to this not being as strong of an engine as the 45??

And last but not least, I'd love some information on the 5.6 liter. I'm thinking the ford motor may be a bit too wide, and I would prefer a larger bore and shorter stroke for rpm purposes.

The dimensions I have so far are limited to the nissans

VK45DE-Dry Weight: 236.5 kgSize(mm)(L x W x H): 921 x 692 x 778

VH41DE-Dry Weight: 260 kgSize(mm)(L x W x H): 850 x 680 x 760

I know that the UZ motors are very narrow for a dohc v8. Once I can compile a list of dimensions, and pick a chassis (I already have one in mind), then my decision may come down to what I can fit in there

ANYWAYS! Sorry for the ridiculously long first post, just trying to put the bulk of my contribution out there so we can get some more conversation going on this topic. I appreciate any information.

I'm looking to make about 1600-1700hp at the engine...

i would only be looking to make 500 normal 750 max fwhp with two garrett gt turbos on 93 octane pump. with some 116, i could probably hit 900+ fwhp.

the only thing that turns me off about stock block boosting is the 10.2 compression.

i would like to drop the compression to around 8.5 with some high silicon forged pistons. if i have the motor open, i might as well do some beefier rods.

motec M800 running the show with dual wideband closed loop, and multi spark ignition.

vk56 has 6 bolt mains.

Does anyone have any information about the flow numbers on the VH or VK heads, or better yet, what can be achieved after porting?

considering the numbers the car makes stock, i would turbo the motor and leave the heads and manifold alone.

there was a story in which Q45Tech had the intake manifold extrude honed and it made little to no improvement.

considering its 4 valve/cylnder, i would only do some smoothing/polishing.

if your looking for NA gains, then a port job might be in order.

IvoryJ30t wrote:considering the numbers the car makes stock, i would turbo the motor and leave the heads and manifold alone.

there was a story in which Q45Tech had the intake manifold extrude honed and it made little to no improvement.

considering its 4 valve/cylnder, i would only do some smoothing/polishing.

if your looking for NA gains, then a port job might be in order.

I could port the heads on my supra motor, and N/A, I doubt I'd see much gains at all. But at 300whp/liter, you see huge gains. The efficency and power producing potential of an engine is all in the heads and manifolds. It would be getting a custom intake manifold no doubt. The runners are far too long for the RPM I would be looking to turn.

Same theory as to stock honda exhausts...get a mandrel bent unit with a larger interior diameter and you will gain nearly no power, possibly lose some at the bottom end, build the motor, throw on a large turbo and try to push 600+hp through it, and you'll definitely need to upgrade that exhaust.

for your power goals, then extensive head/intake work would be in order.

thats roughly double my power goals.

the motor would be living at 500 fwhp most of the time except for bursts at 700-750.

for a 3600 lb street car, i think thats more than sufficient.

also, with the motec controlling the intake cam timing, and the stock intake, the motor will have a very balanced powerband. since it will be a street car, i dont want to shift the power too high up the rev range.

with pistons and rods, ill probably set the limit around 7500 rpm.

for only 110hp/liter I'm sure you probably won't have to touch the top end of the motor. Like you said, it should have a nice broad powerband.

In my application I'm trying to figure out the capabilities of the head, and if there is any restriction as to cam dimensions I can put in there. The Lexus motors I was looking into have somewhat poorly designed ports on the heads (part of what makes them so narrow). They are angled very sharply torwards the combustion chamber which helps the width of the motor (it only has one cam gear IIRC), but hurts airflow in high horsepower applications. I figure I can do a decent bit of work to it and fix part of it...but if I can get an equally strong, larger displacement, and better flowing nissan motor, I'll go that route.

Are all years of VH and VK heads the same? How much different is the VK56 head from the VK45? Are the blocks completely different as well? I'm hoping that I can find some flow numbers on the heads, but I'm doubtful that they have been tested.

i have no idea about the newer vk motors.

some of the austrailian members have said that when they have the VH45 and 1UZ next to each other, that the block looks much beefier on the VH.

i would say that the VH block could take whatever the 1UZ block can and more.

i have examined the vh45, vh41, vk45, and vk56 and i doubt that the heads would be swappable on any of them. not 100% sure. the vk56 is kind of like two qr25 engines stuck together. by that i mean the architechture and stuff. if that is the case the heads prob flow very well as i know the qr25 head flows well. i will say the valve sizes on the vk56 are almost exactly the same as on the vk45 which is smaller but makes more power.

i was doing some research the other day, and i noticed that the VQ35DE connecting rod has very similar specs to the VH45DE rod.

the big end and small end [with bushing installed] are identical sizes. the rod is 2.8 mm shorter though, dropping the rod/stroke ratio from 1.777 to 1.743.

do you know the width of the big end and small end of the two motors rods?

that would save me some money. then i could use off the shelf carrillo rods, and custom pistons. since the vq35 rods are slightly shorter, i could move the rings down a little on the custom pistons.

unrelated to this thread...hey man, brian (easrchester) got his camaro out of the shop today. i am getting the 10 large around jan...spring the 240 should have all i want and more...

i wouldnt worry about the camaro. the stock RB at 12 psi will take him out.

/offtopic

what is the stroke on the vk56? that would be overkill if turboed. i wouldnt get the car to hook up for anything. slicks would just be snapping halfshafts. not to mention the low rpm tuning of the cams and intake.

IvoryJ30t wrote:i wouldnt worry about the camaro. the stock RB at 12 psi will take him out.

/offtopic

what is the stroke on the vk56? that would be overkill if turboed. i wouldnt get the car to hook up for anything. slicks would just be snapping halfshafts. not to mention the low rpm tuning of the cams and intake.

Haven't had time to research anything lately...to busy with work. Anyways...the entire point of (at least for me) going with a 'big' displacement V8 is so I can spool large turbos and generate obscene amounts of torque at (relatively) low boost pressures.

No such thing as overkill with the right package. I'm mating it to a powerglide rated at 2000-2100hp and nothing short of a 28 inch tire.

The only thing that will take the VK56 out of the running for me is if the stroke is too long...and only due to the fact that it won't be able to support the rpm I want (need) to run in this engine with this size of turbo(s).

If the stroke is indeed too long, it's back to deciding between one of the Nissan 4.5s...and I still want numbers on the lexus heads. Always have more research to do

BTW I very much doubt I would be running a variable cam/intake setup. I'd be designing and building a custom short-runner plenum and spec'ing my own camshafts.

(I know the thread doesn't concentrate on me ...I'm just trying to let you know where I'm coming from)

see, were at opposite ends of the spectrum.

i want a street car and your going all out.

i hate to say this, but you might be better off with the iron block toyota motor for that kind of power.

Once again, bringing the thread back from the dead.

Mark C. I'm in the same boat as you although i'll be building a top speed car instead of a drag car...I'm also quite interested in the VK56 for obvious reasons. One factor is the all aluminum construction as I'm shooting for the lightest possible set-up.

I'm sure people know this by now, but just incase:

-Bore is 98mm-Stoke is 92mm-6 bolt main-228kg (actually lighter than the VK45) Obviously there basically no aftermarket support as of yet, so custom rods/pistons are the only way to go.

I would like to wind out to at leat 8,000 rpm, perhaps a bit more if possible. I don't think this is too unreasonable.

Does anyone have any specs on the VK56 rods as of yet?It would be nice to use an already available rod similar in dimension if possible. The 1UZ have recently discovered that the 5.7" SBC rods are very close, and are developing ways to make them work

Also, anyone have any measurements on the vavle springs?

Anyone with ANY useful info on the VK56 would be greatly appreciated, not just by me either I'm sure.

We need to get our hands on one of these motors and work it over. But I guess like everthing new, it'll just take some time...

And just to get the creative juices flowing.....

http://www.zparts.com/showcase....html

Thought i would have a look at my old post i started way long ago, a work shop in Victoria is building a few vh45 and 41's

Check this out http://forums.nizpro.com.au/ph...?f=11

ARGAMEMENON wrote:-228kg

Where did this number come from, and does it include accessories?

Quote »Also, anyone have any measurements on the vavle springs?[/quote]For the stock VH45? 47.31mm free length, 535.5N at 26.8mm (477.6N limit)

For the VK56: 50.58mm free length, 165.8 - 187.0N at 37.0mm, 314.8 - 355.0N at 28.2mm

I knew it! The VH springs are way stiff!

Bart, do you need a password reset for your other login?

I found that figure in an actual Nissan engineering tech write up. I'll see if I can dig it up....

A few rod specs:

VH45/VK45;Rod Length (center dist): 147.0Rod Stroke Ratio: 1.778 (82.7mm stroke)Pin dia. w/bushing: 22.0Rod big end dia. : 55.0

VH41;Rod Length (center dist): 147.0Rod Stroke Ratio: 1.934 (76mm stroke)Pin dia. w/bushing: 22.0Rod big end dia. : 55.0

VK56;Rod Length (center dist): 154.5Rod Stroke Ratio: 1.679 (92mm stroke)Pin dia. w/bushing: 22.0Rod big end dia. : 57.0

Found at:http://forums.maxima.org/showthread.php?t=363610

Any other info on the 56 Daedalus?? Good work so far:-)

We need to find readily available parts, preferably cheap, to use in these motors....

I have whatever's in the Titan FSM. As far as the VH, I think that number is way under, unless maybe it doesn't include any accessories. Even then...not so sure.

That weight figure (228kg) was for the VK56. It comes out to about out 511 pounds, which sounds about right with accesories. I'm having a hard time finding the site, but it involved a 700+ hp VK56 in a test truck....A guy was able to get some info as they were testing at a local track... and it had a link to an actual Nissan engineering article describing the why's and how's of the 56, comparing it to the 45. I'll keep looking....

Can you copy off some more info from the FSM? I'm very interested.

VK56DE rod specs:

Length (center to center): 6.082"Crank journal diameter: 2.24"Pin diameter: .866"

Chevy big block 6.135" rod (I-Beam):

Length: 6.135"CJD: 2.2"PD: .990"

There 0.0523" longer, which isn't a huge deal. A slightly thicker HG takes care of that. You can machine 0.02" out of each piston, or to be on the safe side, machine it off the crank (2.2" is still plenty thick). While your at it, you could offset grind the crank 0.02" to reduce the 0.0523" down to 0.0323". Add a set of thicker bearings (0.062" each) and you're set.

The rods can be found from $300-500 a set on Ebay. Forged I-Beams good for 700-1,200 hp. Now, the cost of machining the crank, a set of bearings and perhaps new head gaskets add up as well, but still might be well under the price for custom rods. Just an idea....

I only posted the VK56 info up as that's the motor I'm interested in....I'll see what I can find for the 45 and so on.

Anyone with tech info, post it up!!!

How does the crank journal width compare?

SBC rods would certainly reduce the cost, and make it easier since there are hundreds of rod bearing types available.

Anyone know the amount of time needed to replace the rod bearings with the engine out and the oil pan off? Seem to be a weak spot on the VH engine.

The Chevy rods are .990" thick at the journal, haven't found any specs on the VK's journal...

.990"? That's thick! (Sounds like a root beer commercial.)

Q45denver why do you say the rod bearings are a weak spot?

I believe the rod bearing is fairly small in width???

The shop is in process of installing my 1990 Q45's fourth engine. The last three all had bad rod bearings. The first two engines were very clean with no evidence of neglect and reportedly low mileage. The last one had an oil pressure problem probably caused by bad bearings and a slight rod knock. I guess if the rod bearings were bad it would be wise to replace the main bearings also, which would probably mean an overhaul.