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Guest Swifty Devil

vg30dett weight vs vh45dett weight

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Guest Swifty Devil

hey guys im weighing up the pros and cons of buying a vg30dett rebuilding it and turning over 300rwkw? thats about 400hp at the wheels.

however i feel the costs would be around the same to buy a 300 NA rolling shell and slam in a vh45 and make it vh45dett! without rebuilding the motor of course.

id be running moderate boost levels of 10-12psi.

all the fabrication would be done by a professional shop and same with the rebuild if i went down the vg30dett route.

 

im mainly wondering which engine would be heavier, i can handle if the vh45dett would be around the same weight, im just wondering how much it would affect handling and if it would be lighter to any degree.

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WOW! The VH45DE V-8 is 100 lbs lighter than the VG30DE V-6! hot.gif I’ll be honest with you, I’m having a hard time swallowing that one. Do you have any reference or any theory to support that claim? I for one would love nothing more than to find out that my ’96 VH45DE is lighter than my ’93 VG30DE! (I can’t say why that is, yet….)

 

Here is just my hypothetical guesstimate. I may be WAY off, I may be spot on, at any rate, I’d be willing to bet that the VH45DE long block weighs more than the VG30DE long block.

 

VH45DE, (Nissan built 4.5L V-8) vs VG30DE, (Nissan built 3.0L V-6), long block vs long block weight.

 

Ok, The VH45DE has two more cylinders so therefore the engine is longer. The V-8 block is aluminum, the V-6 is iron. Being as the V-8 is supporting two more iron sleeved cylinders, one more main web, lets call the blocks a wash.

 

The V-8 crank is heavier! It has one more throw on it that supports 2 rods, and it is longer, i.e. more forged steel. I say the V-8 crank weighs between 5 and 7 lbs more than the V-6.

 

Pistons and rods, each should weigh comparable. The V-6 has 6 of these, the V-8 has 8, by default, these components are heavier for the V-8. I say the 2 extra piston and rod assemblies add 10-15 lbs more weight total.

 

Cylinder heads. The heads are very similar by design, but the V-8 has 8 more valves, springs, cam lobes, valve seats, valve guides, etc. The had casting is longer etc. By default the V-8 heads are heavier. I say the V-8 heads combined add between 20-30 lbs.

 

 

Ok, by my conservative, purely hypothetical speculative guesstimation, the VH45DE long block weighs between 35 and 52 lbs more than the VG30DE long block.

 

If the VH45DE long block is lighter, than the VG30DE long block , well, I’ll … I’ll… I’ll do something publicly embarrassing. please.gif

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He also titled the thread vg30dett.With two turbos and all the goodies to go along with it that adds some weight.

 

The DETT is about 440lbs (N/A is 420) and the 5-speed is 120lbs.....carry the seven, divide by the width of my a**, add Thursday......I come up with 560lbs.

 

I should know for sure as im putting one of these engines in my car myself but this is what someone here told me.I have read elsewhere however several times that the vg30dett is 530 lbs and is heavier than vh

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Ok fellas. I’m still NOT buying that the VH45DE is lighter than theVG30DE! I am having a real hard time wrapping my feeble little mind around this and acknowledging that the VH is lighter than the VG, no matter what those other forum guys are saying… Just because I do own a ’96 Q-45, of which I am in the process of removing its VH45DE this weekend, and a ’93 Z-32, probably means nothing in regards to this thread, but I do look these engines over regularly and make somewhat of an effort to maintain them, and also as a professional engine builder, I have worked on the various parts, mostly the heads, of both VG30DE’s and VH45DE’s. I am not submitting actual proof or actual weights, (If I use my scales to weigh the VH45DE engine once I remove it, it wont matter any how wc.gif), but I am submitting to you my theory as to why I feel the VH couldn’t possibly by lighter than the VG. Though… I have been known to be WAY off target at times… iospalo.gif

 

 

To those who think the VH45DE is lighter than the VG30DE, please answer the following questions and offer explanations with at least some realistic theory, if not actual hard data to back up your claims if they differ from what I have presented for you to ponder…

 

1) The VH has 2 more pistons and rods. That is one third more pistons and rods than the VG engine. That would also mean that the total weight of the pistons and rods of the VH45DE should be 1/3 again heavier than the VG30DE pistons and rods. Do you agree or disagree with that? If not, please explain.

 

 

2) The heads of the VH45DE are 1/3 longer, (1/3 is not just a little, 1/3 is a substantial amount MORE mass), than the VG heads so in theory any how, the VH45DE heads should have approx 1/3 more mass, i.e. approx 1/3 heavier again, than the VG30DE heads, (which are NOT light heads by any stretch! Just pick up a fully assembled VG30DE head and you’ll know what I mean). So, again, the VH45 heads are guaranteed to be heavier. Do you agree or disagree with that? If not, please explain.

 

3) The VH45DE crank is longer than the VG30DE crank. It IS heavier! Do you agree or disagree with that? If not, please explain.

 

4) The Aluminum vs Iron block issue. In the domestic V-8 world, the aluminum vs iron block weight debate has been waged since the very first one was ever cast. No one disagrees with the fact that the aluminum blocks of a similar type engine are generally lighter, it is by “how much lighter”, that is usually in dispute as those aluminum blocks are also cast thicker to offset for its lack of tensile strength vs its iron counterpart. So, yes, a comparable VG30DE block, if it were cast in aluminum, would be little lighter than this iron counterpart. Now add 2 more cylinders to that aluminum block with iron sleeves, make that same aluminum block 1/3 again longer than the V6 version, which again, should mean that it is 1/3 again heavier than its comparable aluminum V-6 counterpart with all else being equal, that V-8 block will be heavier, by approx 1/3 again more weight. Now being as the VG30DE V-6 is actually iron not aluminum, that will offset SOME of the weight, but I feel that it wont offset all the difference that the material difference offers. My guess is that the VH45DE aluminum block is still heavier than the iron VG30DE, but I’ll give you guys the benefit of the doubt here and call it a wash, i.e. the blocks weigh approx. the same. Do you buy that? If not, please explain. (I’m sure someone will find lots of big holes in that theory so shoot away…)

 

5) The VH45DE utilizes 2 separate timing chains, not a single light weight timing belt. 2 timing chains are heavier then one timing belt. Do you agree with that? If not, please explain.

 

6) The VH45DE utilizes cast aluminum timing chain covers vs the plastic timing belt covers for the VG30DE. Do you agree or disagree that VH timing chain covers are indeed heavier? If not, please explain.

 

7) Intake manifolds, both are pretty big. I think the VH probably weighs more, but I’ll concede to them weighing similarly. Same goes for the exhaust manifolds, water pumps, and oil pumps.

 

That pretty much wraps up the majority of both the VH and VG entire engine assemblies. Now if I missed some gravity defying material or gravity defying part witch.gif that the VH45DE possesses that isn’t on the VG30DE, please let us in on it. We will make an effort to find away to get that unobtanium part adapted to not only the L-6, but also GM, Ford, and other power plants that people want to swap into their Z cars…

 

 

So if any one can submit actual side by side weighing of these two engines with similar components attached, (just the engine from intake to oil pan, exhaust manifold to exhaust manifold, i.e. no P/S pumps, no A/C compressors, etc), … my vote is the VH45DE is heavier than the VG30DE.caffeine.gif

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I've had both on an engine stand in my garage and that vh is a big beast. I'd think it was heavier . . . however I was ENTIRELY suprised how light some of the new Ford mudular v8 aluminum blocks are. It honestly felt half as heavy as an L block. Both the Vh and the ford blocks are 90 degree v8's, I'd think they might be in the same neighborhood in terms of weight.

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Guest sjohn280

Also while searching automotive forums for 300zx swaps the consensus is that the VH is about 100lbs lighter. If both engines were made equally the extra 2 cyls would make the V8 heavier but they are not made equally. At least thats how the guys that have swapped VHs into their z32s explained it to me

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It does make sence when you think a VG WITH TURBOs vs. a VH WITHOUT turbos. The 100 pounds the guy shaved from the car when he did the swap could have easily been caused by (assuming the motors wieghted fairly the same) 2 turbos are now missing, as is intercoolers, and the piping. Did he also use lightwieght headers-usually a few pounds lighter then a stock cast manifolds? Could he have possibly remove A/C and powersteering, I don't really want to search the entire site because I never have luck searching on other sites.

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Sorry guys, I’m still not buying it for a minute. Doesn’t anyone have any actual side by side empirical data to prove or disprove either way? chevvoi.gif All anyone has posted, including myself, is just theory and other threads which don’t support squat either way. I have been wanting to purchase a strain gauge just for weighing engines and the like. This thread has me so spun out that I just may end up doing this sooner than I had planned just to put this argument to rest once and for all, (if I’m wrong about which is heavier, I’ll eat my words gnam.gif). I am currently pulling a VH45DE out of my ’96 Q-45 and will be pulling the VG30DE out of my ’93 Z-32 some time later this year, and I also have access to a complete VG30DE and VG30DETT. You guys are killing me… beatin.gif

 

I would love nothing more than to find that the VH45DE is indeed lighter than the VG30DE and VG30DETT by ANY amount, but normal logic does not support that fantasy. zomp.gif

 

 

 

 

 

 

 

 

http://forums.nicoclub.com/zerothread/185771

 

The VH45DE weighs just at 500lbs with all accessories.

 

http://zdriver.com/forums/showthread.php?t=11335

 

The VG30DETT weighs a little over 600lbs.

 

Uh, you might go back and read that thread again. 478 lbs with NO accessories, no intake, no P/S, no Alternator, and only one exhaust manifold. Same poster then went on to say that the weight went over 500 lbs just by throwing the intake manifold on top, still NO ACCESSORIES! The other thread has NOTHING concrete to support that 100 lbs claim. There was mention of shipping weight, overall car weight, but NO mention of similar like engines with specific weights of each.

 

 

 

Also while searching automotive forums for 300zx swaps the consensus is that the VH is about 100lbs lighter. If both engines were made equally the extra 2 cyls would make the V8 heavier but they are not made equally. At least thats how the guys that have swapped VHs into their z32s explained it to me

 

Correct, they are not made equally, but they are the same in basic architecture, head design, etc and as such, any weight difference by “design” is going to be minimal at best, NOT 100 lbs worth. And if the weight difference were 100lbs, it would be that the VH is the heavier by 100lbs, which to me is believable. Not the other way around.

 

 

 

It does make sence when you think a VG WITH TURBOs vs. a VH WITHOUT turbos. The 100 pounds the guy shaved from the car when he did the swap could have easily been caused by (assuming the motors wieghted fairly the same) 2 turbos are now missing, as is intercoolers, and the piping. Did he also use lightwieght headers-usually a few pounds lighter then a stock cast manifolds? Could he have possibly remove A/C and powersteering, I don't really want to search the entire site because I never have luck searching on other sites.

 

I can’t believe that those two small turbos are that much heavier than the two extra pistons, 2 con rods, 8 valve’s, 8 valve springs, 8 rockers, that much more camshaft, another crank throw, extra cast aluminum material for the heads and block, etc.

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Paul, I've got a quick question: does a head with more valves in it weigh more or less than a similar head with less valves? I could see a case being made for less because of all the head material that isn't there any longer after you factor in the amount of material that is opened up for the ports. Is all that aluminum that is bored out for the port and the valve seat area more, or less material by weight than what would need to be added back in the form of a valve and springs/retainers/rockers or whatever?

 

Also, how much would a difference in con rod thickness and piston size factor into a weight comparison? I don't know the specs on these two engines off hand, that may not even be an issue in this case if they are the same...

 

The Z32TT had dual intercoolers, correct? Is the factory plumbing mostly metal, or rubber? I could see two cast iron manifolds, the turbos, and all the associated intercooler accessories weighing 50+ pounds. In the case of a swap, you would take out all the associated airbox plumbing, so would that factor in to the weight comparison, or no?

 

Besides that, the gigantic throttle body on the Q-45 probably weighs a good 5 or 6 pounds on it's own...(not really that much, I do have one of those handy!)

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Guest sjohn280

There is another post on which that same guy says that the VH with the other parts weighed in at 501, which is over 500. Great now I cant find the thread.

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Guest Swifty Devil

lol i assumed that the vh45de is ENTIRELY ALUMINIUM

except for pistons and rods the block is alloy.

does this not make sense that it would be far light and in terms of sheer size its not a hell of alot bigger than a vg30de.

 

i mean i started the thread so i may be a bit optimistic looking for confirmation of my guess.

 

vg30de has thicker walls too thicker CAST walls.

 

lets also factor in this from http://www.simetric.co.uk/si_metals.htm

according to this list of metals (when divided by 1000 to get g/cubic cm)

 

Aluminium based alloy is 2.8g/cubic cm

vs Cast iron which is 7.8g/cubic cm

 

obviously more aluminium is used in the building of said engine but lets not forget the plenum of the vg30de alone is quite heavy as are the heads.

 

it would seem more likely using simple science that the vh45 block is lighter however i would love someone to dig up their manuals

for a q45

and a 300zx so i can get ACCURATE manual specifications of engine weights.

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Paul, I've got a quick question: does a head with more valves in it weigh more or less than a similar head with less valves? I could see a case being made for less because of all the head material that isn't there any longer after you factor in the amount of material that is opened up for the ports. Is all that aluminum that is bored out for the port and the valve seat area more, or less material by weight than what would need to be added back in the form of a valve and springs/retainers/rockers or whatever? ….

 

Max,

My point in stating the individual parts was that the VH45DE head is 1/3 AGAIN longer than the VG30DE head and as such also has 1/3 again that many more parts which all have some weight. If they didn’t have any extra weight, than the VG30DE head wouldn’t weigh anything, but I digress.. The head port air thing would only hold water if the heads being compared were the same physical size, i.e. same length. They are not. Remember, the V-8 heads on the VH45DE are 1/3 again LONGER than the V-6 heads of the VG30DE. Do all the math about the open air ports etc, if the head is 1/3 again longer and also contains 1/3 again more parts than the other head, then there should be approx 1/3 again more weight, or at least close to that due to actual design differences.

 

 

Paul, I've got a quick question: ….

 

 

Also, how much would a difference in con rod thickness and piston size factor into a weight comparison? I don't know the specs on these two engines off hand, that may not even be an issue in this case if they are the same...

 

Individual con rods and pistons will be comparable to each other in weight and what little difference there is between them is going to be negligible at best, i.e. not 100 lbs or even 10 lbs worth. The VH45DE has a bore of, 93mm, (3.66”) the VG30DE bore is 87mm, (3.43”). that is alomst 1/4" MORE bore/piston area. Pistons for the VH45 will be slightly heavier each and the VH45DE has 2 more of those heavier pistons. The slight weight increase in piston size is really of no consequence, but the fact that there are 2 more of those parts is! Also 2 more con rods! Also, more block casting material that contains those 2 extra pistons, rods, and longer crankshaft, etc.

 

Paul, I've got a quick question: ….

 

 

The Z32TT had dual intercoolers, correct? Is the factory plumbing mostly metal, or rubber? I could see two cast iron manifolds, the turbos, and all the associated intercooler accessories weighing 50+ pounds. In the case of a swap, you would take out all the associated airbox plumbing, so would that factor in to the weight comparison, or no?

 

I would concede that those components could easily make up 50 lbs. No argument there.

 

Paul, I've got a quick question: ….

 

Besides that, the gigantic throttle body on the Q-45 probably weighs a good 5 or 6 pounds on it's own...(not really that much, I do have one of those handy!)

 

 

Too funny. The Q-45 TB is another thread altogether.. grin.gif

 

 

Also, the VH45DE has TWO timing CHAINS where as the VG30DE has one lightweight timing belt. Also, the VH45DE has cast timing chain covers vs the VG30DE plastic and stamped tin timing belt cover. Not too mention that the VH45DE is 1/3 again longer and contains 1/3 again more moving parts internally, (is there and echo in here?....) Now if that 1/3 MORE parts and material is LIGHTER, I’d be VERY surprised…

 

Here is an exploded view of the VH45DE timing chain and covers…

 

TimingVHMedium.jpg

 

 

 

lol i assumed that the vh45de is ENTIRELY ALUMINIUM except for pistons and rods the block is alloy.

does this not make sense that it would be far light and in terms of sheer size its not a hell of alot bigger than a vg30de.

 

i mean i started the thread so i may be a bit optimistic looking for confirmation of my guess. vg30de has thicker walls too thicker CAST walls.

lets also factor in this from http://www.simetric.co.uk/si_metals.htm

according to this list of metals (when divided by 1000 to get g/cubic cm)

Aluminium based alloy is 2.8g/cubic cm vs Cast iron which is 7.8g/cubic cm

obviously more aluminium is used in the building of said engine but lets not forget the plenum of the vg30de alone is quite heavy as are the heads.

it would seem more likely using simple science that the vh45 block is lighter however i would love someone to dig up their manuals for a q45 and a 300zx so i can get ACCURATE manual specifications of engine weights.

 

First off, the pistons are indeed aluminum, or at least an alloy of aluminum.

 

Secondly, both the VG30DE AND the VH45DE block are both CAST blocks. The VG30DE block is cast iron, the VH45DE is cast aluminum. Yes, aluminum is lighter for a given volume of material, BUT being as it is not as strong, when aluminum is used as an engine block, it is cast thicker to make up for its inherent lack of strength compared to a cast iron version.

Now back the VH45DE vs the VG30DE block (AGAIN!), being as the VH45DE block is 1/3 again longer, my argument is that 1/3 more mass will AT LEAST offset any and all weight savings that the aluminum block had by virtue of the material it was cast from. Now the VH45DE heads ARE heavier, period! They are longer and have more parts, material etc. There are two more pistons, rods, extra crankshaft length, TWO timing chains, cast timing covers vs the lightweight single timing belt of the VG30DE, and stamped tin, and 1/3 less moving internal components etc… The VH45DE isn't just a little bigger, it is physially 1/3 again longer than the VG30DE, Taller than the VG30DE and wider than the VG30DE, (45 degree included angle vs 60 degrees).

 

So the real question here then is… how and where did Nissan inject all that helium into the VH45DE to make it so much lighter than the VG30DE?

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Ill throw this into the mix.... regarding specific gravity and all. cast iron is roughly 3x as dense as cast aluminum. there aint NO WAY there is 3x as much material in a cast aluminum block vs a cast iron block of the same size.

 

I had a chance to pick up an NSX block at a shop that is working with me on my frankenstein head, and let me tell you it was a lot lighter than a VG block in similar condition. (i.e. the heads were off, no crank, no pistons, basically just a block.) I could pick it up with one arm.

 

I just dont see where its that hard to beleive that a VH could be lighter than a VG. I mean, look at a SBF with just aluminum heads, water pump and intake, its comes out lighter than an L series engine by a fair bit! and the L engine is already equipped with aluminum intake, head and timing cover.

 

IM not saying that he difference is that drastic in the VH VS VG, but I can definately see where a VH would be lighter than a VG, if only by a little bit.

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You are absolutely correct. The aluminum block will not be 3 times thicker to make up for lack of strength, (I don't think I eluded to that in my previous two posts?). What I was trying to say over and over and over and will say AGAIN, it will be least 1 ½ to 2 times thicker in most areas of the block. The weight savings of an aluminum block are real and not in question here and never have been in question. wall.gif

 

 

WHAT I have been saying is that weight savings is NOT as substantial as what the general public initially thinks when they think of aluminum blocks vs iron blocks! (How many more ways do I have to describe this?) Again, the iron block is a shorter V-6 block. The aluminum block is a LONGER V-8 block. By sheer volume of material in the V-8 block it should be heavier, but it is a lighter material, that should offset the weight difference, or if there is a difference in weight of the blocks alone, either way, do you guys really think that the there will be 100+ lbs or even 50+ lbs difference in the just the bare blocks alone? If so, you have to start sharing the drugs you are using because they are really good… sbonk.gif

 

 

 

Ok, IF just the bare aluminum VH block is lighter than the bare VG iron block, and for arguments sake, lets say the longer larger VH45DE block is 20 lbs lighter! (I strongly doubt it is even close to that), NONE of you guys have explained HOW or WHY adding two larger pistons, two more con rods, a longer crankshaft, longer and heavier heads with all the goodies that go into feeding those 2 extra cylinders, 2 separate timing chains, cast timing covers, could conceivably be lighter? Think about it guys. How can 8 pistons, 8 rods, 1/3 longer crankshaft, 1/3 longer/heavier heads, etc be lighter than 6 smaller pistons, 6 rods, a shorter crank, lighter heads, lighter single timing belt with stamped tin and plastic timing cover? Every one seems stuck on that aluminum block band wagon, but NO one has shown how all these extra parts that the VH45DE is packing around could possibly help keep that aluminum block weight savings from being canceled out or show how those EXTRA parts are helping make that bigger engine even lighter yet? C'mon guys, I'm giving you 20lbs that I truly don't believe are even there...

 

 

Sorry Mack, As for the SBF vs L-6, that is apples and oranges. Even the SBC with aluminum heads and other lightweight goodies can be lighter than the L-6. The inline 6 cylinder vs a V-engine is and apple to orange comparison as by design they are way different animals. This a multi valve 4 cam V-6 vs multi valve 4 cam V-8 comparison which are very similar in design and architecture.

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just thought i would ad my 2 cents to this convo.... although the number of pistons (and all associated gear) in the VH is 1/3 more than the VG, the actualy material in the block and head is not quite 1/3 more. one has to consider that there is material on either side of the first/last cylinders. so a more accurate figure would be 1/4 more or so. just thought i would stir up the stew a bit more :D

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just thought i would ad my 2 cents to this convo.... although the number of pistons (and all associated gear) in the VH is 1/3 more than the VG, the actualy material in the block and head is not quite 1/3 more. one has to consider that there is material on either side of the first/last cylinders. so a more accurate figure would be 1/4 more or so. just thought i would stir up the stew a bit more :D

 

 

 

 

lol.gif Okie Dokie. I'll give you guys 20'lbs for the block, and 1/4 more weight for the heads instead of the 1/3. iospalo.gif

 

I still say the VH45DE is heavier.. linguaccia.gif

 

….just thought i would stir up the stew a bit more :D

 

Good one...

laugh.gifass.gif

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