DISASSEMBLING THE NISSAN VH45DE V8

[Sabre_Logos]

Hey guys. I thought you would find this topic interesting. I disassembled my spare VH45DE engine and took a bunch of pics. I know that we've talked about the strengths and weaknesses of the VH on this forum before.

Here's the link for the full write-up with photos: http://turbo-infiniti.org/viewtopic.php?p=2462#2462

 

[Sabre_Logos]

 

[Sabre_Logos]

 

[Lextreme II]

Nice work... why are you dissamblying the engine? Did you have a blown headgaskets?

 

[jibbby]

For a time I was very fond of this Q45 engine...As I read and researched it I found that the bottom end of the engine is very weak.. Much weaker then the 1uz-fe's bottom end so boosting for big power would not be wise on this stock motor as it will most likely fail.......Sabre, have you read anything to that effect?...

For that reason alone I never considered this engine again...

 

[Lextreme II]

Personally I think that is one GREAT engine. Its too bad not too many performance parts for it. Timing chain and intergrated 6 bolt main itself is something to talk about for years to come.

 

[Sabre_Logos]

Nice work... why are you dissamblying the engine? Did you have a blown headgaskets?

This was a spare engine that I bought a while back. There really wasn't anything wrong with it other than the fact the oil wasn't changed like it should have been. I didn't have a place to store it anymore so I decided to just disassemble it.

 

[cribbj]

I was just thinking the same thing David. The bottom end looks h*ll for stout with that mains girdle. I'm surprised I can see the pics, but our IT Gestapo must be blocking only photos hotlinked from pic hosting sites.

I'm guessing with that timing chain it's an interference motor?

Those hydraulic tappets with the roller cam followers look like they'd be troublesome, but Toyota have gone that way now too, haven't they?

Are these $500 on eBay like the 1UZ's?

 

[Sabre_Logos]

For a time I was very fond of this Q45 engine...As I read and researched it I found that the bottom end of the engine is very weak.. Much weaker then the 1uz-fe's bottom end so boosting for big power would not be wise on this stock motor as it will most likely fail.......Sabre, have you read anything to that effect?...

For that reason alone I never considered this engine again...

I found some posts on the internet where someone says the VH45 has a weak bottom end but I can't see why they would think so. The engine has 6 bolt mains, plus a ladder frame that ties in all the bearing caps. The crank is a non-twist forged unit with plenty of overlap and the rods are also forged. If the VH has a weak bottom end, then I want to see what a decent bottom end looks like.

Here are some more pics:

THE VH45DE HAS 6 BOLT MAINS. YOU CAN SEE 4 BOLTS PER MAIN FROM THIS ANGLE. THERE ARE AN ADDITIONAL 2 BOLTS THAT SCREW INTO THE MAIN CAPS FROM THE SIDE OF THE ENGINE.

HERE YOU CAN SEE THE ADDITIONAL BOLT FOR THE BEARING CAP.

THE MAIN BEARING CAP BOLTS HAVE BEEN REMOVED ALONG WITH THE LADDER FRAME. YOU CAN NOW SEE THE MAIN BEARING CAPS WHICH ARE MADE FROM STEEL.

THE CONNECTING RODS ARE MADE FROM FORGED STEEL.

 

[jibbby]

In reference to Lex's timing chain comment....

I wonder what performance guru's prefer better, timing "chains" driven motor like shown above or a timing "belts" driven motor like our Xuz-fe's? I suppose the chains would wear out less frequently, can handle more stress, and there would be little or less flex to throw off timing when comparing that to the rubber timing belts...Hmmmm??? One must wonder?


In regards to the pro-claimed weak bottom ends....I was reading on the Infinity forums last year that the motors can fail around 350-400whp when boosted...Two reads came up to that effect... I would love that to be wrong... They seemed like reliable reads too... I'll try and find that post if I can... That bottom end does infact look stout...Hmmmm?

 

[Lextreme II]

Structurally this one awesome machine! Personally I prefer timing chain. You dont have to change is at all unless the tensioner is bad. Secondlly, most timing chain engines have their waterpump away or outside, so wont have to deal with the chain when water is change.

 

[Sabre_Logos]

I'm guessing with that timing chain it's an interference motor?

Yes, it's an interference fit head but I've never heard of a timing chain failing on these engines. The 90-93 Q45s had problems with the plastic backed chain tensioners falling apart and that cause the chain to skip teeth. The later 94-96 engines came with metal backed tensioners and they last for a long time. My 94 Q has over 230k miles on the engine.

Those hydraulic tappets with the roller cam followers look like they'd be troublesome, but Toyota have gone that way now too, haven't they?

Yes, the valvetrain is more complicated but there are no know issues with it. The engine revs to 6900 rpm in stock form.

Are these $500 on eBay like the 1UZ's?

You can get a low mileage JDM takeout for between $500 - $1000.

...................

 

[Sabre_Logos]

In regards to the pro-claimed weak bottom ends....I was reading on the Infinity forums last year that the motors can fail around 350-400whp when boosted...Two reads came up to that effect... I would love that to be wrong... They seemed like reliable reads too... I'll try and find that post if I can... That bottom end does infact look stout...Hmmmm?

I'm running 6 psi on my engine without any problems. It's putting out somewhere around 420 hp. One of the guys on my site is running 8 psi on his Q45 and again no problems. The only reason for failure of the VH45DE at 350-400 whp would be bad tuning or a defect in the engine.

 

[jibbby]

I forgot what exactly is the liter size of these motors and what horse power does this motor come rated in stock form? It's been a while and I forgot.. I believe they come rated higher in power then the same year 1uz's...

If the bottom ends are infact decently stout on these motors then they should be a great motor to swap, buy, toy with, etc.. Every bit equal to the 1uz-fe's for price and reliability which is hard to find...

Just to note, I have driven a few older Q45's with these motors and they always had more pep then any stock Sc400 Lexus I have ever owned or driven in stock form...

 

[Sabre_Logos]

I forgot what exactly is the liter size of these motors and what horse power does this motor come rated in stock form? It's been a while and I forgot.. I believe they come rated higher in power then the same year 1uz's.....

The VH45 is rated at 278 by Nissan but the actual output is more. Most estimates are somewhere closer to 300. The reason for Nissan claiming a lower hp was the "Gentleman's Agreement" between the Japanese auto manufacturers and the Japanese government which placed a 280 hp limit on engines.

 

[sideshow]

i wired one of these engines in an old wb ute ages ago

not sure f they make a bellhousing for a good manual box as these are all auto form faotry like a 1uz

enignes like revs the cams feel like vtec at around 5500 rpm

but they are a big engine

very wide at the bottom and a pain in the butt at the top where radiator cap or hoses go

they are bit more fiddly to fit than a 1uz and it was bloody tight in this wb

ive seen one in a 300zx was tight aswell

i dont think they would be as easy conversiona s the 1uz

these engines are not as popular so if u find one at an importers maybe haggle with them on price

as they dont get sold much cause i tdont htink they would fit itno many every day street cars

 

[Lextreme II]

I think that is one of the major draw back on this engine. It is physically huge....... and hard to swap. That is why the 1uz is so popular on swaps.

 

[jibbby]

I am sure it weighs more then a 1uz-fe then, if that is the case... It looks like an aluminum block so that will help cut down the weight much like the 1uz-fe's....

 

[Sabre_Logos]

The VH is definitely bigger than the 1UZ which makes it kinda hard to use for a lot of swaps. As far as weight, it is over 500 lbs with all accessories. The block is aluminum but all the cross bracing makes it heavy. I think it is a perfect candidate for boost applications. Change out the rods and pistons for a killer high-boost DOHC V8.

 

[Sabre_Logos]

Some more pics:

THE VH45DE HAS PISTON OIL SPRAYERS BUILT INTO THE CONNECTING RODS. YOU CAN SEE THE OIL SPRAYER HOLE IN THIS PIC.