That's some major internal differences to be the same block. The 350 and 305 are a lot closer than that, and at least share the same stroke. I'm willing to bet money the VG20 is it's own block. They probably look similar because Nissan had a specific formula they used for V6 component layouts at the time.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
That's some major internal differences to be the same block. The 350 and 305 are a lot closer than that, and at least share the same stroke. I'm willing to bet money the VG20 is it's own block. They probably look similar because Nissan had a specific formula they used for V6 component layouts at the time.
Ummm.... 91.5mm bore with 83mm stroke = 3.3L. i.e VG33
VG30 was 87mm bore and 83mm stroke.
And to reduce stroke, you don't have to reduce deck height. You can make the rods longer or the pistons taller or both.
As far as why, there could be any number of reasons. It could have been for emissions, it could have been for power reasons, it could have been for governmental control restrictions. Fuel economy, etc.
Looking around z31club.com, it appears the VG20 and VG30 engines are externally the same size.
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Ok bore is 87 mm and stroke is 83 mm on the VG30. First site I went to didn't differentiate between the 2.
You can add thicker pistons to reduce stroke, but that also substantially increases reciprocating weight. Might mean the VG20 was slower to rev and had a lower redline than the VG30.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
Ok bore is 87 mm and stroke is 83 mm on the VG30. First site I went to didn't differentiate between the 2.
You can add thicker pistons to reduce stroke, but that also substantially increases reciprocating weight. Might mean the VG20 was slower to rev and had a lower redline than the VG30.
Not necessarily. Piston acceleration plays a huge factor into this. The less the piston has to move, the more it can weigh and not affect redline. I haven't found a spec sheet for the VG20ET redline yet. Point is, there are a bunch of factors that weigh into everything. What you said with no supporting evidence means it's all theory. Which also means that what I say about them is also all theory. But which theory makes more sense?
i.e. would you make a smaller displacement engine with less stroke have a lower redline?
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Obviously Nissan had it figured out, but since the VG20ET isn't made anymore there may have been some problems with the design. I can only guess as to what those problems may or may not have been, but one factor is that a 2.0 liter V6 using the same size block as a 3.0 liter, is a lot of wasted space and weight...... 2.0 liters is nothing a 4 cylinder engine couldn't do and maybe do better.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
Obviously Nissan had it figured out, but since the VG20ET isn't made anymore there may have been some problems with the design.
The VG30ET isn't made any more either. Must be problems with it's design as well. /sarcasm.
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A 2.0 liter V6 just doesn't make a lot of sense. That is strange that externally they are the same size...does anyone have pics to prove that?
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=1985 Nissan 300ZX - My Z (being rebuilt)
=1990 Chevy Cavalier - My winter beater
"Racing in a honda is like the special olympics, even if you win, you're still retarded."
A 2.0 liter V6 just doesn't make a lot of sense. That is strange that externally they are the same size...does anyone have pics to prove that?
They also made the RB20, which is a 2.0 liter I-6. Theoretically, that doesn't make a lot of sense either. But at least the RB wasn't based off some other engines block.
If you want more pics, try Googling VG20ET pics. There are surely some around somewhere. I read somewhere that it was in the '89 Maxima. Probably just the JDM version, never heard of it in the U.S.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
The VG30ET isn't made any more either. Must be problems with it's design as well. /sarcasm.
Not the ET, but the E block lives on in the current truck lineup, right? Kinda like the SBC, which is like in it's 10th generation now...... Doesn't look much like it did when it started.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
The Japanese are taxed on liter displacement in their cars, so a 3 liter is alot more expensive to own than a 2 liter. For this reason you see many cars with a 2 liter 6. Dimensionally the VG20 is a smaller more compact block than the larger VG sisters as well. To change stroke you lengthen or shorten the rods and you can also change the piston pin to skirt height so that the pin is closer or farther away from the oil control ring. The piston weight doesn't change much if at all only the pin placement.
Also remember the ZR1 is powered by an RB20...
Troy
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SHIFT_Happiness
1992 S13 240SX SE Fastback KA24DE 5 spd - Type X Aero & Seibon Carbon Hood & Hatch -soon GT28RS
1993 U13 Altima SE KA24DET 5 spd w/ Nismo LSD - A high hp FWD can be fun (GT30R Turbo inside)
1990 Z32 300ZX VG30DETT 5 spd - 600HP & Very Civilized (working on twin GT28RS turbos)
Still trying to import a 1988 R31 Skyline GTS-R w/ RB20DET-R - only 800 produced (legal under show/display regs)
Not the ET, but the E block lives on in the current truck lineup, right? Kinda like the SBC, which is like in it's 10th generation now...... Doesn't look much like it did when it started.
VG30 hasn't been around since the VG33 was introduced in 1995. And the VG33 is not being retired in favor of the VQ motors.
Just because something isn't made any more doesn't mean it was a failure.
Quote:
Originally Posted by KA24Tech
Dimensionally the VG20 is a smaller more compact block than the larger VG sisters as well.
I'd like to know where you read/found this. Everything I've read says the VG20 is the same size block externally. Just like the VG30 and VG33 are the same size externally.
This picture makes them look like all the external parts would swap around with no problems.
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I'd like to know where you read/found this. Everything I've read says the VG20 is the same size block externally. Just like the VG30 and VG33 are the same size externally.
This picture makes them look like all the external parts would swap around with no problems.
I lived over there for three years and have seen them in person, they are definitely smaller when you look at them.
There may not be a big difference in size but there was one.
Troy
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SHIFT_Happiness
1992 S13 240SX SE Fastback KA24DE 5 spd - Type X Aero & Seibon Carbon Hood & Hatch -soon GT28RS
1993 U13 Altima SE KA24DET 5 spd w/ Nismo LSD - A high hp FWD can be fun (GT30R Turbo inside)
1990 Z32 300ZX VG30DETT 5 spd - 600HP & Very Civilized (working on twin GT28RS turbos)
Still trying to import a 1988 R31 Skyline GTS-R w/ RB20DET-R - only 800 produced (legal under show/display regs)
/sarcasm.
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