how do i fit vh45 internals in vh41

[perana]

does 45 crank and rods fit in 41 block. if so, how does it work.Im trying to build a high comp n.a engine whith ,hot cams ,good port job and 150 hp nitrous. I have both 41,45 and found the 41 has better heads.I know chevy,ford v8s and can get over 400hp cheep,but want to keep my zx all nissan. The motor is allredy fitted but not running. The reason the projects on hold is the 300 or whot ever hp the 45 makes is not enough. THANKS.

[SuperHatch]

does 45 crank and rods fit in 41 block. if so, how does it work.Im trying to build a high comp n.a engine whith ,hot cams ,good port job and 150 hp nitrous. I have both 41,45 and found the 41 has better heads.I know chevy,ford v8s and can get over 400hp cheep,but want to keep my zx all nissan. The motor is allredy fitted but not running. The reason the projects on hold is the 300 or whot ever hp the 45 makes is not enough. THANKS.

You need a 45 Crank and 45 Pistons. The rods are the same in both motors, the wrist pin is moved up in the piston to accomodate the larger stroke.

[elwesso]

does 45 crank and rods fit in 41 block. if so, how does it work.Im trying to build a high comp n.a engine whith ,hot cams ,good port job and 150 hp nitrous. I have both 41,45 and found the 41 has better heads.I know chevy,ford v8s and can get over 400hp cheep,but want to keep my zx all nissan. The motor is allredy fitted but not running. The reason the projects on hold is the 300 or whot ever hp the 45 makes is not enough. THANKS.

how are the 41 heads better than the 45s?

[Mettler]

Elwesso, they flow slightly higher in stock trim... (we're talking like 10HP difference) but this is probably comparing the oval port 41 heads to the siamesed port 45 heads, and not the later oval port 45 heads which probably flow exactly the same as the 41 heads.

In summary, VH engine FTW!

[elwesso]

Elwesso, they flow slightly higher in stock trim... (we're talking like 10HP difference) but this is probably comparing the oval port 41 heads to the siamesed port 45 heads, and not the later oval port 45 heads which probably flow exactly the same as the 41 heads.

In summary, VH engine FTW!

that was more/less rhetorical... I wanted to see HIS answer...

[Q45tech]

The 41 has cams with much less duration than the 45 to match the 9% smaller displacement.

The oval ports were created to improve emissions under a specific condition and the fuel puddling that occured when throttle suddenly closed............not really an issue of power creation ability.

The distance from the transistion from dual to oval [near injector on 90-93 vs in head on 94 to present has to do with low speed tumble and low rpm reversion amount.............97 and later reduced valve diameter and in 96 duration to nearly compenstate.

[Mettler]

Tech you blow me away every time you post

It's interesting to see the reasons Nissan did something, as opposed to the result us aftermarket guys playing with the engines see.

[perana]

Elwesso, they flow slightly higher in stock trim... (we're talking like 10HP difference) but this is probably comparing the oval port 41 heads to the siamesed port 45 heads, and not the later oval port 45 heads which probably flow exactly the same as the 41 heads.

In summary, VH engine FTW!

Ok. So there are 45s whith oval ports. Do ihave the rite 41 and the wrong 45? I dont know much about nissan,I boutgh my first about a year ago. A 96 300zxtt m/t . The car blew a gasket after 1 week and kept giving me trouble even after the rebuild. The made good power whith the nitrous but eventualy died. I fitted the 45 and zx trans in july and done nothing ever since. I have been told to much diffrent things. Why are u using a 41 is it a space issue? THANKS.

[elwesso]

41s are easier to get in aussie land... Why most aussie guys go with 41s and most everywhere else go with 45s, since the 45s were easy in places where the Q was sold...

Is your alternator mounted on the bottom side (by the AC compressor) or up in the middle?

[perana]

I have a 45 in my zx and a 41 in the garage. Ill go and have alook to see what sits where. But would like to know what vh is going to give the most power.

[perana]

The 41 has alt in the middle,45 has it on the side.

[elwesso]

oh im sorry, i thought you were asking if you had a 41 or a 45... thats the easiest way to tell as theres not really any other easy differences (besides the 41 saying 4100 on the top)..

[Mettler]

Ok. So there are 45s whith oval ports. Do ihave the rite 41 and the wrong 45? I dont know much about nissan,I boutgh my first about a year ago. A 96 300zxtt m/t . The car blew a gasket after 1 week and kept giving me trouble even after the rebuild. The made good power whith the nitrous but eventualy died. I fitted the 45 and zx trans in july and done nothing ever since. I have been told to much diffrent things. Why are u using a 41 is it a space issue? THANKS.

I'm aware of three versions of the VH41DE, one of them is not as good as the others (the US released one). The one from US cars has this ugly manifold that doesn't have tuned length runners, and I've read various opinions from people that it has a reduced block, amongst other things. That's one I'd steer right away from.

The other two versions I'm aware of are early & late jap spec, and came with the spider style intake manifold. Mine's an early spec with the full bells & whistles... you can tell these because the intake manifold & other aluminium parts are a plain, cast grey colour... with the TCS motor being black.

The other one however, has an anodised bronze/goldy intake manifold & throttle body, and the TCS motor is also a goldy colour. I do not know anything else about this particular version, if it's a later model motor, or just released in a car other than the Cima. I don't know whether it's had any engineering changes either.

What I can tell you is that the JDM VH41DE is equal in strength to the VH45DE, sharing the same design of main bearing beam, internals etc. The main real differences are in how the VTC is activated... the VH41 has the solenoids up by the intake runners, whereas the VH45 has them on the front of the cams. Furthermore, the VH41DE runs a slightly improved timing chain setup (worded carefully so we don't hurt anyone's feelings here ).

The two motors are almost identical in size... there's no real space issue as such. The VH45 looks much bigger and bulkier, but this is due to the fatter casting of the front cover, visible in a pic of ultrapulse's stripped down VH45. The biggest real advantage to running the VH41 is that the alternator is mounted at the top/front of the motor, and on the VH45 it's at the side where it can potentially interfere with chassis rails when being transplanted into other cars.

Another couple of differences between VH41 & VH45... the VH45 runs a tin sump which can take a bump or two, the VH41 has a thick cast alloy sump which would probably crack if it took an impact.

The rocker covers on a VH45 look different, with a little panel as long as the outside face on each side. The VH41 doesn't have this. Not sure what it's for.

Both motors share the same deck height, and an identical valvetrain. If you want the 4.5 litres but are doing a conversion, I'd suggest transplanting the VH45 crank & pistons into your VH41, that way you get the best of all worlds.

I'm doing this same rebuild next year.

41s are easier to get in aussie land... Why most aussie guys go with 41s and most everywhere else go with 45s, since the 45s were easy in places where the Q was sold...

Is your alternator mounted on the bottom side (by the AC compressor) or up in the middle?

According to Ezekial, VH41s are not that common in aussie, it's VH45s which are. VH41s are far more common here in NZ (different country to aussie) because we got brand new JDM cars. Aussie has far different importing laws, and as such they got screwed when it came to getting cars like skylines etc.
Modified by Mettler at 12:21 PM 12/4/2006

[Mettler]

Oh, and just for Wes' benefit :

[elwesso]

Oh, and just for Wes' benefit :

Mettler, you are my new hero.. that was AMAZING, i definitely spit up on my computer!!!!!

I thought that the 45s were harder to get since the Q wasnt sold in Australia, same with the president, but I thought the cima was....

Either way.....

[mtcookson]

Furthermore, the VH41DE runs a slightly improved timing chain setup (worded carefully so we don't hurt anyone's feelings here ).

The only problem I see with that timing chain setup is I would think it would be noticably heavier than the single setup. Stronger, definitely... but weight reduction in the valvetrain area tends to make a pretty large difference.

[Ezekial]

Oh, and just for Wes' benefit :

look how much better australia looks

nice post about the differences too mettler

low km japanese imported VH45's are under $1000 AUD with waranty ... in australia

[SuperHatch]

It would be nice to find a place in the states that could get JDM VH41's... Space constraints limit me to the top mounted alternator setup. I don't care all too much about the spider intake vrs. the USDM "ugly" VH41 intake, but if the block really is weaker, that would give me pause.

According the the US FSM's, the US VH45 also has a girdle over the mains, whereas the US VH41 does not...

Maybe someone here knows an engine importer besides me?

[Mettler]

but if the block really is weaker, that would give me pause.

According the the US FSM's, the US VH45 also has a girdle over the mains, whereas the US VH41 does not...

I would guess that's probably where the main reduction in the US VH41 lies, removing the deep skirt and main bearing beam.

Another interesting thing I've noticed, is some VH41s and some VH45s have a throttle body with no TCS, it's just got the manual throttle, and then a nice machined surface for a hose clamp to go on... lucky for some! I had to chop up my throttle body, remove the TCS throttle, have the holes welded shut, and turn the throttle body down to accept a silicon joiner. >_<

[perana]

The reason i fitted the 45 is,i was told it by the guy i bought it from it off,the motor makes more power than a vg30dett and its cheeper and more reliable. I then read that it make 280,(my vg made 497hp with 150 shot nitrous.) This is what my plans are now: 1) make up 4 into 1 headers 2)fit all the plumbing. fuel, water,ac,p/s and 150hp nos. 3) new drive shaft. 4) smaller wheels. (i have 20x10r,20x8.5f) 5) zxtt diff. ( ihave n/a diff in car ) 6) loom. Thank alot to everyone for thier help u guys have encouraged me to go further.

[Mettler]

Hey mate no problem! You're dealing with a top motor here, and the guy who sold you it hasn't put you wrong.

In stock trim, the motor won't outperform a VG30DETT... but cmon, the VG weighs heaps more than the VH, so you already get a weight reduction by installing it... and look then, you have a motor that's 1.5 times the displacement with an assload more potential. You'd really want to throw a couple of turbos onto it to get it cranking out an instant 600HP+.

Also, in my car with its engine bay smaller than a 300ZX engine bay, I still find it reasonably easy to work around the VH engine, even to pull it out and drop it back in. The VG isn't quite so forgiving!

Since you're in NZ, I'm happy for you to contact me for any help or information that I may have which will serve to finish your project!

[perana]

Thanks again mate and thanks to nico. Yes i noticed the car is higher in front now,will have to turn the springs down some more.Are u using a nissan computer,if so what mods did u perform and can i use my nitrous on the stock motor and computer.

[Ezekial]

I would guess that's probably where the main reduction in the US VH41 lies, removing the deep skirt and main bearing beam.

Another interesting thing I've noticed, is some VH41s and some VH45s have a throttle body with no TCS, it's just got the manual throttle, and then a nice machined surface for a hose clamp to go on... lucky for some! I had to chop up my throttle body, remove the TCS throttle, have the holes welded shut, and turn the throttle body down to accept a silicon joiner. >_<

ahhhh yeh ... i have the non TCS throttle body

[SuperHatch]

I would guess that's probably where the main reduction in the US VH41 lies, removing the deep skirt and main bearing beam.

So the JDM VH41's have a main bearing beam still???

[Mettler]

Yeah mate they do, I covered that in one of my earlier posts JDM VH41 & US VH45 share the same bottom end & same valvetrain.

[SuperHatch]

Sorry, missed it... Still trying to absorb everything. There is a lot of info to cover.

So where can I get one of the JDM VH41's at in the states? Or where is somewhere in AU/NZ/Japan that is reputable to order one from? I've ordered an engine from AU before without any real problems, but that was years ago and the reseller isn't around anymore. Any suggestions?

Can a 90-95 JDM VH41 ECU be reprogrammed like a US Q45 ECU?

[Mettler]

Yeah they can. Any ECU that has a 28 pin eeprom can be remapped using the romulator gear (doesn't have to be just Nissan either). Mine does, haven't touched it yet though because I've been busy finishing the conversion... but in the next few weeks when I finish off the car, I'll be socketing & tuning my ECU too

No clue where you'd get one in the states sorry. It may be easiest for you to hook up with a car parts importer in the US, get them to bring a VH41 over for you (specifying that you want the one with black TCS motor etc).

Or even a contact in japan who exports.

That'd be the cheapest way, because then you'd basically be paying for the engine + the freight. If you got an engine from here, you'd be paying the already marked up price, as well as shipping... and freight to the US isn't cheap man, I export big crates to the US on a regular basis in my job, and the invoices aren't cheap.

VH engines usually sell for around NZ$1200+, I've seen some exorbitant prices right up to $2k for a halfcut here... I was lucky with mine and got it for $800.

[SuperHatch]

Why the Black TCS motor? What does that do for me?

I found a couple distributors that seem to know what they're dealing with. I asked them for a 90-95 Cima engine, VH41DE... they were going to get me quotes. Did I ask for the right thing? Or did the Cima have mutiple versions like the USDM VH45?

[Mettler]

You want the FGY32 Cima's VH41DE.

The black TCS motor (and other details which I posted above) are a means of identifying the desired engine.