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Discussion Starter · #1 ·
It sounds like the next IS will probably have a V6 rather than an in line six. That is bad news, and it looks like my next car will be a BMW.

OK, there are some V6 engines that work quite well, but the fact remains that V6's basically suck. In order to work tolerably well, they need two major band-aids, balance shafts and splayed crank pins. Straight six engines are inherently balanced and even firing, and will fit just fine in a front engine, rear drive car. V6's exist mainly because they package nicely in front-drive cars, so why use them in a car like the next IS?
 

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T Man said:
kokomokid said:
V6's exist mainly because they package nicely in front-drive cars, so why use them in a car like the next IS?
Maybe the next IS will be FWD. :lol: :eek:
In Japan the Sportcross comes in AWD models with the current I-6 SO that excuse just went up in smoke.

Face it, the V-6, when it happens, will be a cost-cutting, parts-consolidation move by Toyota. It'll put a smile on the face of every beancounter and stockholder. The V-6 is a nice piece though>
 

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It's a V6 so it fits in the IS and the ES/Camry. One engine is cheaper to design and build than two.
Hey, if it's got more power, is lighter and has much better gas mileage, that ain't so bad. The NSX has a V6 after all, and that one sounds pretty nice.
 

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kokomokid said:
OK, there are some V6 engines that work quite well, but the fact remains that V6's basically suck. In order to work tolerably well, they need two major band-aids, balance shafts and splayed crank pins.
While I too would prefer that Lexus stick with the L6 what you say about V6 engines isn't universally true. The points about the balance shafts and offset crank journals are true for 90 degree V6's. Many of these engines were derived from existing V8 engines. For a V8 a V4 or even a V2 (like Ducati motorcycles), 90 degrees between the banks provides ideal balance but it's not idea for a V6. Manufacturers only did this to avoid the expense of re-tooling when gas prices started to go up in the 70s and engine sizes had to go down. They just crudely lopped 2 cylinders off the end of their favorite V8 engine.

A 60 degree V6 is well balanced and has no need for balance shafts or offset crank journals. Most manufactures, if designing the engine from scratch, follow the 60 degree configuration. Another advantage is that a 60 degree engine will be even more compact than a 90 degree one.
 

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Discussion Starter · #10 ·
wjbertrand said:
kokomokid said:
OK, there are some V6 engines that work quite well, but the fact remains that V6's basically suck. In order to work tolerably well, they need two major band-aids, balance shafts and splayed crank pins.
While I too would prefer that Lexus stick with the L6 what you say about V6 engines isn't universally true. The points about the balance shafts and offset crank journals are true for 90 degree V6's. Many of these engines were derived from existing V8 engines. For a V8 a V4 or even a V2 (like Ducati motorcycles), 90 degrees between the banks provides ideal balance but it's not idea for a V6. Manufacturers only did this to avoid the expense of re-tooling when gas prices started to go up in the 70s and engine sizes had to go down. They just crudely lopped 2 cylinders off the end of their favorite V8 engine.

A 60 degree V6 is well balanced and has no need for balance shafts or offset crank journals. Most manufactures, if designing the engine from scratch, follow the 60 degree configuration. Another advantage is that a 60 degree engine will be even more compact than a 90 degree one.
Maybe I need to think about this a little more, but doesn't even a 60 degree V6 need offset crank pins to fire evenly?
 

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kokomokid said:
Maybe I need to think about this a little more, but doesn't even a 60 degree V6 need offset crank pins to fire evenly?
Nope, the reason that 90 degree V6s were given offset crankpins was in fact to make them fire more evenly, like a 60 degree engine.
 

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CRB said:
T Man said:
kokomokid said:
V6's exist mainly because they package nicely in front-drive cars, so why use them in a car like the next IS?
Maybe the next IS will be FWD. :lol: :eek:
In Japan the Sportcross comes in AWD models with the current I-6 SO that excuse just went up in smoke.

Face it, the V-6, when it happens, will be a cost-cutting, parts-consolidation move by Toyota. It'll put a smile on the face of every beancounter and stockholder. The V-6 is a nice piece though>
Not entirely. AWD cars come in two flavors, front drive with a transfer shaft to feed rear wheels; engine is mounted laterally. And rear drive with a transfer shaft to feed the front wheels; engine mounted front to back. The SportX is part of the second family. Subaru's, Volvos, and most other AWD cars are inhearantly front drive with the rears added in to "help". BMW and Lexus use the rear drive platform and add in the front wheels to help. I'm not sure what type of system the RX uses.

Although, the Volvo S80 uses an inline 6 mounted laterally, first in the world. SO the V6 wasn't souly desinged for front drive cars, it just happens to be much easier to work with.
 

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csdstudio said:
CRB said:
T Man said:
kokomokid said:
V6's exist mainly because they package nicely in front-drive cars, so why use them in a car like the next IS?
Maybe the next IS will be FWD. :lol: :eek:
In Japan the Sportcross comes in AWD models with the current I-6 SO that excuse just went up in smoke.

Face it, the V-6, when it happens, will be a cost-cutting, parts-consolidation move by Toyota. It'll put a smile on the face of every beancounter and stockholder. The V-6 is a nice piece though>
Not entirely. AWD cars come in two flavors, front drive with a transfer shaft to feed rear wheels; engine is mounted laterally. And rear drive with a transfer shaft to feed the front wheels; engine mounted front to back. The SportX is part of the second family. Subaru's, Volvos, and most other AWD cars are inhearantly front drive with the rears added in to "help". BMW and Lexus use the rear drive platform and add in the front wheels to help. I'm not sure what type of system the RX uses.

Although, the Volvo S80 uses an inline 6 mounted laterally, first in the world. SO the V6 wasn't souly desinged for front drive cars, it just happens to be much easier to work with.
RX is front platform
 

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I'll point out more...

The I-6 as you already know fires every 120 degrees (perfectly balanced)and the V6 in 60 and 90 degrees configurations. The 90 degree version comes directly from the V8 production line minus the 2 extra cyls and run at 150/90 degrees. That means that 1 extra cylinder fires at 150 degrees of crank rotation then the next 90 degrees, repeated twice. In a nutshell it suffers from 1st and 2nd order harmonics. The 60 degree V6 fires every 120 degrees which gives power similar to I6's but has 1st and 2nd order moments greater than the 90 degree versions. In terms of production cost, although V6 has 3 fewer main bearings, it has more valve gears - which is getting more and more costly these days, with the introduction of twin-cam, hydraulic tappets / finger follower and variable valve timing. Inline-6 in the long run will be cheaper than an equivalent V6.

Doesn't sound good for a V6 isn't it? While I like the I6, a 60deg V6 would not be as bad. It capable of producing power similar to the I6 (less overall torque though) and has better fuel economy(e.g. VQ35 from Nissan). After next year, only BMW, Volvo and Porsche (Flat 6 is equivalent to the I6, perfectly balanced) will continue to use the I6.
 

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ckolsen said:
It's a V6 so it fits in the IS and the ES/Camry. One engine is cheaper to design and build than two.
Hey, if it's got more power, is lighter and has much better gas mileage, that ain't so bad. The NSX has a V6 after all, and that one sounds pretty nice.

but those cars are FWD so they have a FWD motor; which may not be used on a RWD car. and im 99.9999999999999999999999% sure new IS is not going to be FWD
 

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It's really got nothing to do with inline vs V6 costs, it's all about engine sharing with the Camry/ES. They already have the V6, so they can put it in the new IS with minimal development cost - which is what it's all about for Toyota. There is zero chance of a new inline motor.

CharlieD06 said:
ckolsen said:
It's a V6 so it fits in the IS and the ES/Camry. One engine is cheaper to design and build than two.
Hey, if it's got more power, is lighter and has much better gas mileage, that ain't so bad. The NSX has a V6 after all, and that one sounds pretty nice.

but those cars are FWD so they have a FWD motor; which may not be used on a RWD car. and im 99.9999999999999999999999% sure new IS is not going to be FWD
 

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CharlieD06 said:
ckolsen said:
It's a V6 so it fits in the IS and the ES/Camry. One engine is cheaper to design and build than two.
Hey, if it's got more power, is lighter and has much better gas mileage, that ain't so bad. The NSX has a V6 after all, and that one sounds pretty nice.

but those cars are FWD so they have a FWD motor; which may not be used on a RWD car. and im 99.9999999999999999999999% sure new IS is not going to be FWD
They can be used on FWD and RWD cars. The Maxima (FWD) and 350Z (RWD) share the same motor. In fact, the original VQ was being developed for racing purposes but Nissan was running out of money so they decided not to race. Instead, they stuck it in the Maxima and the rest is history... :D
 

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The Aluminum head and block V-6's are quite used very WIDELY in toyota/lexus. If you havent noticed or known. (RX, Camry, Solara, ES, Sienna,Avalon,.....) Almost all the same 1MZ-FE.

But anyone know the angle that those V-6's are created? Plus the way its mounted is pretty ridiculous. The rear bank of 3 cylinders, the motor is angled far back that you cant get to the plugs from the top at all. Just imagine a V but about 45 degrees back. Compared to the more evenly mounted Honda/Acura V-6's, whats with Toyota/Lexus design with this? It helps a tad bit in bringing the weight toward the middle, but its more negligible more than anything. Hope they don't use the FE head. Crap personally. Plus the strengthening of the block needs ALOT of work. Very little "structual strengthening ribs" compared to Honda/Acura V-6's.... Toyotas got to revamp their V-6s to put out ALOT more power with its current displacement.

Has anyone else noticed that the ENTIRE Auto industry has been gradually stepping up in displacement these past 5 years? I thought they were trying to work with decreasing fuel consumption, but everyone still continues to increase in displacement; with given more power, but whatever happened to EPA's idea with working with the automobile industry and creating alot more fuel efficient cars? I think the Auto industry should be cranking out more power in current displacement motors rather than just increasing the displacement.
 
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