I got more valves than you....

x in the city

Guys, what difference (if any) does 16v have vs 24v, aside for 2 extra spark plugs..

noticed a 05 Civic has 16v and seems to have higher Bhp and Top Speed over a Similar Lexus (which has 24v).

anyone?

kdevitt

It has an extra two cylinders - the honda will be 4 cylinder with two inlet and two outlet valves, the lexus will be a straight 6 or V6 I presume with the same two inlet / outlets.

The 6 cylinder will have more torque, and a smoother power curve as opposed to the 4 cylinder.

colm_mcm

It's not quite that simple op

My current car has 89hp and 8 valves
My last car had 197hp and 24 valves
Both are 2.0 and the 89hp has a turbo...

Different engines are tuned to different outputs for different reasons.

Voodoomelon

Not to mention the Veyrons 64 valves. :O

Bumpstop

If you are talking about more cylinders, than the more the better. It's about inertia and balance, First off think of a large 4 litre engine. now imagine it just had one cylinder, and a massive heavy piston. The piston goes up and down, a huge heavy piston finds it hard to change direction, and would try to rip itself of its connecting rod, this engine would turn very slowly, and would not like changing speed.

The other problem with this engine is, in a four stroke situation, I.E. suck, squeeze, bang, blow. the engine only gets one power pulse every two revolutions so it would be very rough.

Now think about the same engine but with 4 cylinders, the pistons would weigh a lot less, and have less inertia, this engine would be able to rotate a lot faster, and change speed easily. it also would get 2 power impulse per revolution, so it would be much smoother.

And so it goes on. This is a massive simplification of a very complicated process, but it is a sort of outline.

That poor girl above looks like, she just knows, she lost a phillips head screw into the number 5 cylinder.

Bumpstop

Voodoomelon wrote: »

Not to mention the Veyrons 64 valves. :O

http://www.dogfathervito.com/vaeyron-review-fanny-pushing-engine.jpg

Caption competition.
I hope I can get this back in before he comes home.

colm_mcm

I may have to fold the superbs seats down to get this in...

I Was VB

colm_mcm wrote: »

I may have to fold the superbs seats down to get this in...

Pfft, the ya wouldnt have to fold down the seats in the Octavia!

Bumpstop

I Was VB wrote: »

Pfft, the ya wouldnt have to fold down the seats in the Octavia!

LOL:D

congo_90

I Was VB wrote: »

Pfft, the ya wouldnt have to fold down the seats in the Octavia!

shure the tdi will pull it on a trailer anyways

Plug

Jesus the starter motor is very small on the veyrons engine, unless there is another at the other side.

ShadowHearth

Voodoomelon wrote: »

Not to mention the Veyrons 64 valves. :O

http://www.dogfathervito.com/vaeyron-review-fanny-pushing-engine.jpg

And woman pushing it... Omg I loled.

Fair play for good find.

mike65

speaking of valves did Audi sticking an extra valve in make any difference? I have a 20v engine.

x in the city

x in the city wrote: »

Guys, what difference (if any) does 16v have vs 24v, aside for 2 extra spark plugs..

noticed a 05 Civic has 16v and seems to have higher Bhp and Top Speed over a Similar Lexus (which has 24v).

anyone?

What Lexus is similar to a Civic? Surely you are not comparing an IS200 to a Civic. Also the number of valves does not denote the number of sparkplus, there are plenty of 4 cylinders cars about with 8, 12, 16 and some have 20 valves.

alias no.9

mike65 wrote: »

speaking of valves did Audi sticking an extra valve in make any difference? I have a 20v engine.

Depends if it's a 1.8 20v 4 cylinder with 5 valves per cylinder or any of the 5 pot 20v with 4 valves per cylinder. The former probably doesn't make much diffference, the latter certainly does.

alias no.9

RoverJames wrote: »

What Lexus is similar to a Civic? Surely you are not comparing an IS200 to a Civic. Also the number of valves does not denote the number of sparkplus, there are plenty of 4 cylinders cars about with 8, 12, 16 and some have 20 valves.

Just to confuse things further, there are 4 cylinder cars with 8 spark plugs and 6 cylinder cars with none

YouTookMyName

Plug wrote: »

Jesus the starter motor is very small on the veyrons engine, unless there is another at the other side.

The starter is what you're looking at? :eek:

alias no.9

alias no.9 wrote: »

Just to confuse things further, there are 4 cylinder cars with 8 spark plugs and 6 cylinder cars with none

Yeah, I don't think we need to involve rotary engines in here

Tea 1000

OSI wrote: »

Just means you have a 5 cylinder engine. A lot of 2-2.5 litre petrol engines with 5 cylinders.

Not necessarily. There are 5 valve per cylinder 4-pot engines out there, Toyota and VW/Audi are two companies who make them.

RoverJames wrote: »

Yeah, I don't think we need to involve rotary engines in here

Rotary engines have sparkplugs, they have no cylinders though...

There are 8 cylinder cars with no sparkplugs also!

Tea 1000

OSI wrote: »

And 12 cylinder cars

http://www.autoblog.com/2008/01/13/detroit-2008-audi-unleashes-its-diesel-monster-the-r8-v12-tdi/

I was trying to think of one, that's not in production yet, but that engine is... in the Q7! Well remembered sir!
I'm sure there are 16 cylinder diesel engines in industrial use too!

OSI

OSI wrote: »

What rotary engine has 6 cylinders? I'm sure they're referring to Diesels.

skim read fail

CJhaughey

Multiple valves are used to reduce the inertial mass of the valve train.
More smaller valves are lighter and can take higher revolutions than larger valves.
Thats why diesel engine valves used in large slow revving diesels are huge compared to the small valves commonly used in smaller engines.
Think of holding a 100g weight in your hand and moving it rapidly up and down, now think of the same thing with a 1kg weight.
Thats what engine designers are trying to minimise in an engine. Decreasing valvetrain weight allows an engine to rev faster and harder.
Motorcycles were the first to use 5 valve heads in production engines then the technology trickled down to cars.
Honda made an 8 valve per cylinder head engine in the NR 750.

Zubeneschamali

CJhaughey wrote: »

Multiple valves are used to reduce the inertial mass of the valve train.

They also increase the total circumference of the valves, which increases gas flow as the valves open and close.

colm_mcm

I think some of the 1.2 polos are 6 valve

CJhaughey

colm_mcm wrote: »

I think some of the 1.2 polos are 6 valve

3 cyl x 2 valves per cyl?

colm_mcm

Yep.

mullingar

CJhaughey wrote: »

3 cyl x 2 valves per cyl?

I didn't believe it either, but according to here

There are 2x 1.2 3cyl versions:

6valve = 60hp
12 valve = 70hp

Matt Simis

mike65 wrote: »

speaking of valves did Audi sticking an extra valve in make any difference? I have a 20v engine.

1998 Audi S8 4.2 32v (4v per cylinder) engine: 340bhp
1999 Audi S8 4.2 40v (5v per cylinder) engine: 360bhp

I have the weener version!

Tea 1000

Matt Simis wrote: »

1998 Audi S8 4.2 32v (4v per cylinder) engine: 340bhp
1999 Audi S8 4.2 40v (5v per cylinder) engine: 360bhp

I have the weener version!

Just buy 8 more valves and a new drill!

x in the city

RoverJames wrote: »

What Lexus is similar to a Civic? Surely you are not comparing an IS200 to a Civic. Also the number of valves does not denote the number of sparkplus, there are plenty of 4 cylinders cars about with 8, 12, 16 and some have 20 valves.

A 2005 Civic Saloon and a 2005 Lexus IS200.

Both 2 litres, both well equipped and nice movers.

The lexus does seem a gas guzzler, and IMO a V6 with 'just' 150 odd Bhp is pretty crap, for less than 30mpg also.

A BMW M3 would prob do 25mpg....

shogunpower

x in the city wrote: »

A 2005 Civic Saloon and a 2005 Lexus IS200.

Both 2 litres, both well equipped and nice movers.

The lexus does seem a gas guzzler, and IMO a V6 with 'just' 150 odd Bhp is pretty crap, for less than 30mpg also.

A BMW M3 would prob do 25mpg....

the lexus is a stright 6 as far as i know and is a sow on petrol.

unkel

My last 3 cars have 80 valves between them (all V8 petrol). The car I currently drive most has only 24V

Dilbert75

16 valves, 8 spark plugs, 4 cylinders....

x in the city

shogunpower wrote: »

the lexus is a stright 6 as far as i know and is a sow on petrol.

ya, straight 6 i meant.

nice ride and well appointed but not impressed with Road Train mpg and just 150 horses.

A Honda Accord would be a better buy and easier to sell I think.

oops, Accord of course I meant.

Top Dog

colm_mcm wrote: »

My current car has 89hp and 8 valves
My last car had 197hp and 24 valves
Both are 2.0 and the 89hp has a turbo...

2.0, 8 valves and a turbo .... to only make 89bhp? Can I ask what you drive?

CJhaughey

Carina E turbo diesel?

colm_mcm

Carina E D-turbo only has 83 hp

The Avensis 2.0 TD is an animal in comparison, millions spent on liberating those extra 6 stallions :-)